Astrochemistry: From nanometers to megaparsecs – A symposium in honour of John H. Black This symposium is organised jointly by the divisions Astronomy and Plasma Physics and Onsala Space Observatory at the department of Space, Earth and Environment, Chalmers.

This event has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 730562 [RadioNet].

The symposium has also received funding from the Swedish Research Council (Vetenskapsrådet), dnr. 2018-06786. BE GREEN KEEP IT ON THE SCREEN The scientific organising committee (SOC)

Susanne Aalto Chalmers University of Technology Maryvonne Gerin LERMA-LRA Eric Herbst University of Virginia Gunnar Nyman Gothenburg University Amiel Sternberg Tel Aviv University Ewine van Dishoeck Leiden Observatory Naoki Watanabe Hokkaido University Eva Wirström (Chair) Chalmers University of Technology

The local organising committee (LOC)

Susanne Aalto Per Bjerkeli Sabine König Boy Lankhaar Gunnar Nyman Sandra P. Treviño-Morales Eva Wirström (Chair) Robin Garnham

Onsala Space Observatory. Credit: S. Treviño-Morales Participants

Thomas Ayres University of Colorado Paul Barklem Uppsala University Shmuel Bialy Harvard Center for Astrophysics John Black Chalmers University of Technology Per Bjerkeli Chalmers University of Technology Laure Bouscasse Max-Planck-Institut für Radioastronomie Andrew Burkhardt Harvard & Smithsonian Hannah Calcutt Chalmers University of Technology Nuria Calvet Paola Caselli Max-Planck-Institut für extraterrestrische Physik Steven Charnley NASA Goddard Space Flight Center Igor Chernykh Institute of Computational Mathematics and Mathematical Geophysics Ilse Cleeves University of Virginia Laura Colzi Università degli Studi di Firenze Carla Maria Coppola Università degli Studi "Aldo Moro" di Bari Taïssa Danilovich KU Leuven Elvire De Beck Chalmers University of Technology David Dubois NASA Ames Research Center /BAER Institute Juan Enrique Romero Universitat Autònoma de Barcelona Edith Falgarone Ecole Normale Supérieure Malcolm Fridlund Leiden Maryvonne Gerin LERMA, CNRS and Observatoire de Paris Caroline Gieser Max Planck Institute for Astronomy Barbara Michela Giuliano Max-Planck-Institut für extraterrestrische Physik Javier Goicoechea CSIC Isabelle Grenier Université de Paris and CEA Saclay Nanase Harada ASIAA Lee Hartmann University of Michigan Aarto Heikkilä Chalmers University of Technolog Eric Herbst University of Virginia Åke Hjalmarson Chalmers University of Technology Cathy Horellou Chalmers University of Technology Liv Hornekar Aarhus University Martin Houde University of Western Ontario Chia-Jung Hsu Chalmers University of Technology Maria S. Kirsanova Russian Academy of Sciences Sabine König Chalmers University of Technology Maciej Koprowski University of Nicolaus Copernicus Sergiy Krasnokutskiy MPI for Astronomy & Jena University Lars E. Kristensen Niels Bohr Institute Copenhagen University Charles Lada Harvard & Smithsonian Boy Lankhaar Chalmers University of Technology Sofie Liljegren Stockholm University Brett McGuire NRAO Brendan McLaughlin Queen’s University of Belfast Chiara Mininni University of Florence - INAF Ayane Miyazaki Hokkaido University Sebastien Muller Chalmers University of Technology Zsofia Nagy Max-Planck-Institute for Extraterrestrial Physics David Neufeld Johns Hopkins University Gunnar Nyman Gothenburg University Hans Olofsson Chalmers University of Technology Henrik Ottosson Uppsala University Marco Padovani INAF-Osservatorio Astrofisico di Arcetri - Italy Carina Persson Chalmers university of technology Fereshteh Rajabi University of Waterloo Elena Redaelli Max Planck Institute for Extraterrestrial Physics Evelyne Roueff LERMA, Observatoire de Paris Maryam Saberi Chalmers University of Technology Hilda Sandström Chalmers University of Technology Stephan Schlemmer Universitaet zu Koeln Christopher Shingledecker Max-Planck-Institut für extraterrestrische Physik Sigurd Sigersen Jensen Centre for Star and Planet Formation and Niels Bohr Institute Olli Sipilä Max-Planck-Institut für Extraterrestrische Physik Amiel Sternberg Tel Aviv University CCA Flatiron Institute Benoît Tabone Leiden University Linda Tacconi Max-Planck-Institut für Extraterrestrische Physik Kotomi Taniguchi University of Virginia Julia Tjus Ruhr-University Bochum, Germany Sandra P. Treviño-Morales Chalmers University of Technology Floris van der Tak SRON / U Groningen, NL Charl van der Walt Niels Bohr Institute Copenhagen University Ewine van Dishoeck Leiden Observatory / MPE Luis Velilla Prieto Chalmers University of Technology Geronimo Villanueva NASA Goddard Space Flight Center Wouter Vlemmings Chalmers University of Technology Naoki Watanabe Hokkaido University Raphael Wicker Eva Wirström Chalmers University of Technology Mark Wolfire University of Maryland Hans Zinnecker Universidad Autonoma de Chile Programme

Monday, June 24

9:00 Registration & Coffee

10:30 Eva Wirström Welcome and logistics 10:40 John H. Black Opening talk

Photon-dominated processes

11:10 Linda Tacconi Cold molecular extragalactic medium 11:50 Amiel Sternberg The atomic to molecular (HI- to-H2) transition in Galaxy star-forming regions

12:10 Lunch & registration

14:00 Nanase Harada Models of extragalactic astrochemistry

14:40 Evelyne Roueff Photon-driven chemistry + 15:20 Maria S. Kirsanova Merged H/H2 and C /C/CO transitions in the Orion Bar PDR

15:40 Coffee/Tea

16:10 Sandra Treviño-Morales Probing the HI/H2 layer around the ultracompact HII region MonR2 16:30 Ewine van Dishoeck Isotope selective photodissociation 17:10 Laura Colzi Enhanced nitrogen fractionation at core scales: the high-mass star-forming region IRAS 05358+3543

17:30 Welcome to the City of Gothenburg

17:40 City of Gothenburg reception Tuesday, June 25

Simple molecules

9:00 David Neufeld Small molecules observed at high spectral resolution with SOFIA: recent results from EXES and GREAT observations of two molecules, H2 and HeH+

9:40 Floris van der Tak Water in star formation 10:20 Olli Sipilä Modeling deuterium chemistry in dense cores: full scrambling versus proton hop

10:40 Coffee

11:00 Liv Hornekar Polycyclic Aromatic Hydrocarbons as catalysts for H2 formation 11:40 Brendan McLaughlin Formation of dicarbon in collisions of two carbon atoms 12:00 Steve Charnley Formation of Complex Organic Molecules in Dark Clouds 12:20 Taissa Danilovich The circumstellar sulphur chemistry of AGB stars

12:20 Lunch

14:00 Carla Coppola State-to-state and non-equilibrium phenomena in the chemistry of the early Universe 14:40 Paul S. Barklem A final-state resolved merged-beam experiment of mutual neutralization of Li+ and D− at stellar photospheric temperatures with DESIREE 15:20 Sebastien Müller Molecules towards QSOs

15:40 1-minute poster flash presentations

16:00 Poster session and refreshments Wednesday, June 26

Spectroscopy and Radiative transfer

8:20 Stephan Schlemmer Lab spectroscopy for astrochemistry 9:00 Brett McGuire Detecting Complex (Polycyclic?) Aromatic Molecules in the ISM 9:40 Geronimo Villanueva The delivery and evolution of water within the solar system studied via the D/H

10:20 Coffee

10:40 Elvire de Beck Spectroscopy of evolved stars 11:20 Hans Olofsson Heavy element recombination lines towards an evolved star: In the footsteps of John Black 11:40 Fereshteh Rajabi Dicke’s Superradiance and Maser Flares 12:20 Martin Houde Non-Zeeman Circular Polarization of Rotational Molecular Spectral Lines

12:40 Takeaway lunch for pick-up

13:00 Bus departs for Excursion to Marstrand

Marstrand archipelago. Credit: Philippe Salgarolo Thursday, June 27

Cosmic rays and Energetic interactions

8:20 Eric Herbst Cosmic-ray driven chemistry 9:00 Marco Padovani Cosmic rays: the ubiquitous probe for the interstellar medium 9:20 Shmuel Bialy The Multiphased HI Gas – from Solar to Low Metallicities

9:40 Poster session + Coffee

10:40 Isabelle Grenier Cosmic rays and the dark neutral medium 11:20 Julia Becker Tjus Ionization signatures and gamma-rays from supernova remnants 11:40 Christopher N. Simulating Ion-Irradiation Experiments using Shingledecker Astrochemical Models

Transient and non-equilibrium processes

12:00 Edith Falgarone Cold molecular gas around high-z starbursts

12:40 Lunch

13:40 Paola Caselli Isotopic Fractionation in Star-Forming Regions 14:20 Andrew Burkhardt Using Shocked Outflows to Probe Interstellar Ice Chemistry 14:40 Javier Goicoechea Reactive molecular ions as tracers of harsh interstellar environments

15:20 Coffee

15:50 Ilse Cleeves Transient chemistry in disks 16:30 David Dubois Laboratory, modeling and observational study of benzene condensation on Titan’s stratospheric aerosols 16:50 Thomas Ayres Carbon Monoxide in the Solar Atmosphere: from Photosphere to COmosphere 17:10 Lee Hartmann Special talk

18:30 Celebratory Dinner at Universeum, including guided tours Friday, June 28

Gas/Solid interactions

9:00 Naoki Watanabe The ortho-to-para ratio of hydrogen and water molecules desorbed from ice dust: experimental approach 9:40 Ayane Miyazaki Detection of OH radicals on amorphous solid water 10:00 Juan Enrique Romero Reactivity of HCO with CH3 and NH2 on Water Ice Surfaces. A Comprehensive Accurate Quantum Chemistry Study

10:20 Coffee

11:00 Serge Krasnokutski Experimental Characterization of Low- temperature Surface Reactions 11:20 Barbara Giuliano Direct measurements of the optical properties of CO ice in the THz range and opacity calculation 11:40 TBD Closing remarks

12:30 End of meeting Astrochemistry: from nanometers to megaparsecs - List of posters

# Name Poster title 1 Laure Bouscasse Chemical diversity in early massive protostellar objects 2 Daria Burdakova Radiative association of small molecules 3 Hannah Calcutt The stacking revolution: searching for the seeds of life 4 Igor Chernykh Supercomputer simulation of astrochemical problems 5 David Dubois The Fundamental Vibrational Frequencies and Spectroscopic Constants of the Dicyanoamine Anion: Quantum Chemical Anal- ysis of a Likely Planetary Anion, NCNCN (C2N3) 6 Maryvonne Gerin Large scale mapping of the Orion B molecular cloud 7 Caroline Gieser Physical and chemical complexity in high-mass star-formingre- gions + 8 Ake˚ Hjalmarson Odin and Herschel observations of H2O, CH and CH in the barred spiral galaxy NGC 1365 - bar induced activity in the cir- cumnuclear torus region 9 Chia-Jung Hsu Mixing of the First Supernovae Metals 10 Chia-Jung Hsu Simulating deuterium fractionation in massive pre-stellarcores 11 Maciej Koprowski Determining star formation rates in high-redshift galaxiesfrom IRX-β relation 12 Maciej Koprowski IRX-β relation at high redshifts 13 Serge Krasnokutski Fullerene oligomers and polymers as carriers of unidentifiedIR emission bands 14 Charles Lada CO Depletion and the X-Factor on Subparsec Scales Across the California Molecular Cloud 15 Boy Lankhaar The polarization and molecular Zeeman effect of masers 16 Chiara Mininni GUAPOS: G31.41+0.31 Unbiased ALMA sPectral Observational Survey 17 Zsofia Nagy The chemical structure of the starless core L1521E + + 18 Elena Redaelli Deuteration of N2H and HCO in the prestellar core L1544 and + first evidence of N2D depletion 19 Hilda Sandstrom¨ Quantum Chemical Evaluation of Polarity-Inverted Membranes and Polymers on the Surface of Titan 20 Benoˆıt Tabone Molecule formation in dust-free irradiated jets 21 Kotomi Taniguchi Cyanopolyyne Chemistry around Massive Young Stellar Objects 22 Charl van der Walt Nature vs. Nurture: What sets the chemical complexity in star- forming regions? 23 Luis Velilla Prieto Molecular complexity in the envelopes of evolved stars Oral contributions Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Carbon Monoxide in the Solar Atmosphere: from Photosphere to COmosphere Presenting author: Thomas Ayres Contact: [email protected] Institute: University of Colorado, Center for Astrophysics & Space Astronomy

Carbon monoxide is Nature’s most durable molecule; able to survive the harsh conditions of the Sun’s photosphere; even into the low chromosphere, which, paradoxically, should be too hot to support molecules. The unexpected high- altitude CO – revealed by anomalous limb-darkening and off-limb emissions of the strong 5µm bands – has been dubbed the “COmosphere.” It could be caused by a “molecular cooling catastrophe,” driven by CO itself. Or, it might represent pockets of cold gas in overshooting convective plumes. Beyond the curious pres- ence of CO in the low chromosphere, the photospheric isotopologues are key tracers of isotopic ratios in the solar mixture, which carry hints concerning the formation of the Sun from the pre-solar nebula. Pilot analyses, based on classi- cal 1D solar reference models, suggested that the Sun was isotopically “heavier” than the Earth, quite at odds with the volatile fractionation processes thought to operate during the condensation of the rocky planets. More recently, that conclusion has been challenged by 3D convection models. The large point-to- point thermal fluctuations in such simulations apparently have disproportionate influence on the CO formation. Based on 3D CO spectral synthesis, the Sun now has been found to be lighter than the Earth, isotopically speaking. Further, the CO-derived O abundance is trending upward toward the helioseismic-favored value, thus averting, perhaps, what has come to be called the “solar oxygen crisis.” Looking forward, soon-to-be- commissioned 4-m Daniel K. Inouye Solar Telescope on Haleakala, Maui, finally will achieve the high spatial resolution in the thermal-IR needed to resolve the solar – and broader astrophysical – issues raised by CO.

Figure 1: Right– 3D “Baseline” model: light= upflows; dark= downflows; red arrows= horizontal velocities (gray scale saturates at 2 km s 1). Left– Blue dashed curve is 3D average T profile; red dot-dashed is FALC 1D ± semi-empirical solar reference model, slightly warmer in upper layers. Gray shading is power-density map of temperature variations. Green dot marks white-light continuum surface. Hatched curves are relative CO concentrations: blue– Baseline 3D model; black– 3D + T in outer layers to match 1D profile; red– 1D FALC. 1D and 3D + T have same < T >, but latter produces more CO, thanks to thermal fluctuations. Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Afinal-stateresolvedmerged-beamexperimentofmutualneutralization of Li+ and D− at stellar photospheric temperatures with DESIREE Presenting author: Paul S. Barklem Contact: [email protected] Institute: Department of Physics and Astronomy, Uppsala University, Sweden Co-author: Jon Grumer, Gustav Eklund, Stefan Rosen,´ Najeeb Punnakayathil, Henrik Ced- erquist, Henning Zettergren, Henning Schmidt

Measurement of Li abundances in stars is an important probleminastrophysics. For example, as primordial Li was produced in the Big Bang, therelationship between the amount of Li observed in old, metal-poor stars andtheprimordial abundance is important to understand. Accurate stellar Li abundances tell us about the Big Bang, stellar evolution, and physical processes in stars. These measured abundances are, however, sensitive to modelling ofLi+Hcollisionsand these collisions have been an uncertainty in the modelling oftheLiresonance line, early work being based on a classical atomic collision model known as the “Drawin formula” (Steenbock & Holweger 1984). It has since been demonstrated that quantum models differ from these by orders of magnitude,andthatmutual neutralization (MN) of Li+ and H− is the most important process, which cannot be described by the classical model (Barklem et al. 2003). We report on a merged beam experiment on the MN of Li+/D−,equivalenttoLi+/H−,atlowenergies(0 − 0.6 eV), performed at the new double electrostatic storage ring national facility DESIREE in Sweden (Thomas et al. 2011). The only previous measurements of this process (Peart & Hayton 1994), though providing absolute measurements, were performed for collision energies higherthanwhatisofinterestincoolstellaratmospheres, and the final states were not resolved. The experimental resolution at DESIREE is sufficient to resolve the 3s from the 3p+3d states, which is shown in Figure 1. Calculations have predicted that the cross section for the 3s final state is approximately a factor of 3 larger than for 3p,andafactorof10largerthanfor3d(Belyaev &Barklem2003).Theexperimentalresultsindicatethatthebranching ratio between the 3s and the 3p+3d channels are more equal than predicted by calculations. A precise quantitative conclusion on the branching ratio awaits further detailed analysis.

Figure 1: Histogram of the distances between the MN products at the time of arrival on the detector for collisions at centre-of-mass energies close to 0 eV. The 3s final state, corresponding to the right peak, and the 3p+3d final state, corresponding to the left peak, are clearly distinguishable.

Our eventual goal is to map the absolute, final-state resolved, MN cross sections from meV energies to a few eV. This would provide strong constraints on both the theoretical modelling of electron transfer in atomic collisions, as well as the astrophysical modelling and ultimately on the Li abundance in old stars.

References: • Barklem P S, Belyaev A K, and Asplund M (2003) A&A 409 L1 • Belyaev A K and Barklem P S (2003) Phys. Rev. A 68(6) 062703 • Peart B and Hayton D A (1994) J. Phys. B 27 2551 • Steenbock W and Holweger H (1984) A&A 130 319 • Thomas R D et al. (2011). Rev. Sci. Inst., 82(6),065112 Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: The Multiphased HIGas – from Solar to Low Metallicities Presenting author: Shmuel Bialy Contact: [email protected] Institute: Harvard-Smithsonian Center for Astrophysics Co-author: Amiel Sternberg

The neutral atomic ISM is found to be multiphased, composed of the cold neu- tral medium (CNM, T 100 K) and the warm neutral medium (WNM, T 104 ⇠ ⇠ K), which coexist at approximately the same thermal pressure, P/kB 3000 3 ⇠ cm K. Such a multiphase structure is predicted by models of heating-cooling [1 2] thermal balance , where heating is dominated by photoelectric heating from dust-grains (and/or cosmic-ray heating), and cooling by Ly↵ line emission (for the WNN, T 104 K) and [C II] and [O I] line-emission (for the CNM, T 100 K). Inter- ⇠ ⇠ mediate temperatures are thermally unstable. The multiphase phenomena and the thermal instability zone, may play a key role in regulating the star-formation properties in galaxies. I will present recent results[3] discussing the thermal properties of HIgas, as functions of the UV intensity, the cosmic-ray ionization rate, and gas metallicity, from solar to primordial metallicities. I will discuss the importance of the residual H2 in controlling the thermal structure of the predominantly HI gas. Despite its low equilibrium abundance (H /HI 10 6), we find that H cooling and heating 2 ⇠ 2 mechanisms (dominated by H2 ro-vibrational cooling, UV pumping heating, and H2 formation heating) strongly affect (or totally dominate) the phase structure at low metallicities and/or when the UV intensity to cosmic-ray ionization rate ratio is low.

Figure 1: Figure adopted from Bialy & Sternberg (in prep.). The thermal pressure as a function of gas den- sity for various metallicities. The solid (dashed) curves are for models that include (exclude) the H2 heating and cooling processes. As the metallicity decreases, the WNM-to-CNM transition moves to higher densities and pressures, as metal line cooling becomes less efficient. The H2 cooling and heating processes start to dominate and smooth out the multiphase structure.

References: [1] Field, Goldsmith & Habing, 1969, ApJ. 155 L14 [2] Wolfire, McKee, Hollenbach & Tielens, 2003, ApJ. 587 278 [3] Bialy & Sternberg, in prep. Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Using Shocked Outflows to Probe Interstellar Ice Chemistry Presenting author: Andrew Burkhardt Contact: [email protected] Institute: Center for Astrophysics Harvard & Smithsonian | Co-author: Christopher N. Shingledecker, Romane Le Gal, Brett A. McGuire, Anthony J. Remi- jan, Eric Herbst

It is believed that many of the most complex, and potentially prebiotic, molecules known in the interstellar medium are formed within the ice mantles on dust grains [Herbst & van Dishoeck 2009]. While infrared absorption of vibrational features has allowed us to detect the solid-phase population for a limited num- ber of molecules, the majority of ice chemistry remains observationally uncon- strained (Boogert et al. 2015). However, low-velocity astrophysical shocks may prove to be crucial probes of this phase of astrochemistry. Due to non- thermal desorption in these regions, the chemically-rich ices can be temporar- ily lifted into the gas phase, where they can be detected with rotational spec- troscopy, before redepositing onto the dust grains (Arce et al. 2007). Here, we discuss recent interferometric observational and modeling efforts to study the chemical evolution within shocked regions within protostellar outflows. In par- ticular, we find certain gas-phase molecules are solely enhanced by this non- thermal desorption, while others undo significant post-shock gas-phase chem- istry.

Through recent observations with the Atacama Compact Array and the Submillimeter Array, weperformed a series chemical surveys for a handful of known chemically-rich molecular outflows to study the radial de- pendence of shock chemistry, as well as how this regime of chemistry varies over astrophysical environments. The derived abundances and morphologies are then compared to gas-grain chemical models which have been adapted to simulate shock chemistry, which is able to predict which species either are useful probes for un- derlying ice chemistry or undergo significant post-shock gas-phase chemistry [4]. Both of these classes are species are found to be useful to disentangle the complex physico-chemical processes in these sources.

References: Herbst, & van Dishoeck 2009, ARA&A, 47, 427 Boogert et al. 2015, ARA&A, 53, 541 Arce • • • et al. 2007, Protostars and Planets V, 245 Burkhardt et al. 2019, ApJ, in Review • Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Isotopic Fractionation in Star-Forming Regions Presenting author: Paola Caselli Contact: [email protected] Institute: Center for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics

Deuterium and 15-Nitrogen fractionation of interstellar molecules is known to oc- cur in star forming regions spanning a large range of evolutionary stages, from starless cloud cores to low- and high-mass protostellar environments, to proto- planetary disks. Primitive material in our Solar System as well as our Earth’s oceans and atmosphere show evidence of isotopic fractionation, possible relic of the chemical processes happening in the proto-Solar Nebula. In this talk, I shall review isotopic fraction measurements and our currentunderstandingof the processes behind them. Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Formation of Complex Organic Molecules in Dark Clouds Presenting author: Steven Charnley Contact: Steven.B.Charnley@nasa.gov Institute: NASA Goddard Space Flight Center Co-author: Eva Wirstrom,¨ Vianney Taquet

Understanding interstellar organic chemistry can yield important insights into the chemical conditions prevalent at the birth of the Solar System (see Ehrenfre- und & Charnley 2000). Interstellar complex organic molecules (COMs: CH3OH, CH2CO, CH3CHO, C2H5OH, HNCO, NH2CHO, HCOOH, CH3OCH3,HCOOCH3) have plausible formation pathways on grain surfaces and havebeenfoundpri- marily in protostellar environments - hot cores and hot corinos - where ice man- tles have been evaporated from dust grains (e.g. Herbst & van Dishoeck 2009). However, gas phase ion-molecule chemistry, triggered by thesublimationofthe main ice components at Tdust > 100 K, is likely to be a significant contributor to the formation of many COMs in hot cores/corinos (Taquet et al.2016). Recent observations of cold molecular clouds (e.g. L1698B, Bacmann et al. 2012; Cernicaro et al. 2012; L1544, Vastel et al 2014; Taquet et al. 2017) demonstrate that, although the actual desorption mechanismisunclear,grainmantlesindarkcloudsalready contain many large COMs. The inventory of these ’cold’ COMs isverysimilartothatofhotcoresandtheir molecular abundances are comparable amongst the sources: ∼ few×10−10,about100timeslowerthanthatof methanol. These observations raise serious problems for theories of COM formation, particularly for CH3OCH3 and HCOOCH3.ForTdust ∼ 10 Krecombinationofphoto-generatedradicalsinducedbygrain heating is inef- fective and thermal desorption cannot occur; for Tgas ∼ 10 Kandatthelowabundancesofinjectedmantle material ion-molecule reactions are inefficient (Garrod et al. 2008; Vasyunin & Herbst 2013). In this presentation we describe a new gas-grain model for COMformationincoldgas.

References: • Bacmann, A., Taquet, V., Faure, A., Kahane, C., & Ceccarelli,C.,2012,A&A,541,L12• Cernicharo, J., Marcelino, N., Roueff, E. et al. 2012, ApJ, 759, L43 • Ehrenfreund P, Charnley S.B. 2000. Annu. Rev. Astron. Astrophys., 38, 427 • Garrod, R. et al. 2008, ApJ, 682, 283 • Herbst, E. & van Dishoeck. E.F. 2009, Ann. Rev. Astron. Astrophys., 47, 427 • Taquet, V., Wirstrom,¨ E. S., Charnley, S. B. 2016, ApJ, 821, 46 • Taquet, V., Wirstrom,¨ E. S., Charnley, S. B., et al. 2017, A&A, 607, A20 • Vastel, C. et al. 2014, ApJL 795, L2 • Vasyunin, A., Herbst, E. 2013, ApJ, 769, 34 Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Transient chemistry in disks Presenting author: Ilse Cleeves Contact: [email protected] Institute: University of Virginia Co-author: Abygail Waggoner (University of Virginia), Edwin Bergin (University of Michigan), Karin Oberg¨ (CfA), Sean Andrews (CfA), David Wilner (CfA), Ryan Loomis (NRAO), Chunhua Qi (CfA), Bradford Snios (CfA), Edward McClain (CfA)

The chemistry of protoplanetary disks sets the initial composition of newly formed planets and may regulate the efficiency by which planets form.Diskchemical abundances typically evolve over timescales spanning thousands if not millions of years. Consequently, it was a surprise when ALMA observations taken over the course of a single year showed significantly variable emission in H13CO+ relative to the otherwise constant thermal dust emission in the IM Lup protoplanetary disk. HCO+ is a known X-ray sensitive molecule, and one possible explanation is that stellar activity is perturbing the chemical ”steady state” of the disk [1]. If confirmed, simultaneous observations may provide a new tool to measure (and potentially map) fundamental disk parameters, such as electron density, as the light from X-ray flares propagates across the disk. Simulations suggest that flares can impact the abundances of many commonly observed molecules, both over short time periods (days to weeks) and extending over much longer times when taking into account the aggregate effect of flares over time [2]. These findings suggest disks, and possibly other astrophysical regions with variable irradiation, are far more chemically dynamic than previously assumed.

References: • [1] Cleeves et al. 2017, ApJL, 843, 3. • [2] Waggoner & Cleeves, 2019, ApJ, Submitted. Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Enhanced nitrogen fractionation at core scales: the high-mass star-forming region IRAS 05358+3543 Presenting author: Laura Colzi Contact: [email protected] Institute: Universita` degli Studi di Firenze Co-author: F. Fontani, P. Caselli, S. Leurini, L. Bizzocchi, G. Quaia

It is well known that the 14N/15N isotopic ratio found for the proto-Solar nebula (PSN), 440 (Marty et al. 2010), is significantly higher than that measured in pris- tine Solar System materials, like comets ( 140, Hily-Blant et al. 2017 and ref- ⇠ erences therein). This suggests a local chemical enrichment of 15N during the Sun formation process. However, the cause of this enrichment and its relation with the natal clump are still uncertain. Since there is growing evidence point- ing out that our Sun was born in a rich cluster containing massive stars (e.g. Lichtenberg et al. 2019), we have studied the 14N/15N ratio in a large sample of high-mass star forming regions. In this talk I will first show the overall behaviour of the 14N/15N ratio across the Galaxy (Colzi et al., 2018a, Colzi et al., 2018b). We have confirmed, based on a solid statistics for the first time, that the 14N/15N ratio increases with the Galactocentric distance as a consequence of the Galactic chemical evolution. Moreover, we have estimated that the 14N/15N ratio in the lo- cal interstellar medium is about 400, i.e. very close to the PSN value. Then, I will zoom-in into the massive star-forming protocluster IRAS 05358+3543, where we have obtained the first interferometric maps of N-fractionation combining single- 15 + dish and high-resolution interferometric observations of the N isotopologues of N2H (Colzi et al. 2019). The analysis yields 14N/15N ratios of 100-200 in the cores, and higher values of 200 in the diffuse clump gas. This result, which strongly suggests a local chemical enrichment of 15N at core-scales, helps us to understand how the chemical inventory evolves from the parental molecular reservoir to smaller-scale objects, in which star-formation occurs. It suggests also that the 15N-enrichment measured in the pristine Solar System material could occur locally, in the environment in which the Sun was born, during the protocluster evolution.

+ Figure 1: Left panel: Averaged map of N2H (1–0) at 93.1734 GHz. The contour levels are 4, 7, 10, 13, 16 and 18 times the 1 rms of the map, equal to 6 mJy/beam. Right panel: Averaged map of 15NNH+(1–0) at ⇠ 90.26 GHz. The black contour levels are 3, 5 and 7 times the 1 rms of the map, equal to 0.5 mJy/beam. In ⇠ both panels, the blue contours correspond to the 5 level of the averaged maps, from which we have defined the ”core-scales” and derived the 14N/15N ratios. In both panels, the black squares indicate the position of the continuum sources. The dashed circle represents the NOEMA field of view and the synthesized beam is the ellipse indicated in the lower left corner. References: Colzi, L., et al., 2018a, A&A 609, A129 Colzi, L., et al., 2018b, MNRAS, 478, 3, p.3693-3720 • • Colzi, L., et al., 2019, arXiv:1903.06567 Hily-Blant, P., et al., 2017, A&A 603, L6 Lichtenberg et al., 2019, • • • arXiv:1902.0402 Marty B. et al., 2010, Geoch Cosmoch. Acta, 74, 340 • Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: State-to-state and non-equilibrium phenomena in the chemistry of the early Universe Presenting author: Carla Maria Coppola Contact: [email protected] Institute: Dipartimento di Chimica - UniversitadegliStudi“AldoMoro”diBari-Italy`

The chemistry of the early Universe is usually considered as relatively simple and easy to implement, due to the presence of few chemical ingredients. Most of the adopted models lie on the hypothesis of local thermal equilibrium and the time evolution of atomic and molecular species is eventually dependent only on the initial conditions and the cosmological framework, together with few key reaction rates. In this contribution, an overview on a state-to-stateapproachtotheearly Universe chemistry is presented, together with the inclusion of non-equilibrium features in the description of the interaction between matter and the cosmic mi- crowave background (CMB). In particular, the case of molecular internal states for the hydrogen molecule, its cation and its deuterated variant is described and the effects of such a resolution is commented, based on the results on the evo- lution of the fractional abundances of atomic and molecular species. The effects on the thermal balance of the gas is also described and an extension to the simulations of early star formation is provided. As a result,theneedforstate-to- state data and the urge for a proper description of the chemistry of the internal molecular levels are described.

Figure 1: Typical chemical network for the early Universe chemistry (from Coppola & Galli 2019)

References: • Galli, D., Palla, F., Astron.Astrophys., 1998, 335, 403-420 • Lepp, S. et al., J. Phys. B: At. Mol. Opt. Phys., 2002, 35, R57 • Coppola, C. M. et al., ApJSS, 2011, 193, 7 • Walker, Kyle M. et al., 2018, ApJ, 867, 152 • Coppola, C. M. & Galli, D., 2019, in “Gas-Phase Chemistry in Space”, IOP Publishing, 2514-3433, 1-26 Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: The circumstellar sulphur chemistry of AGB stars Presenting author: Ta¨ıssa Danilovich Contact: [email protected] Institute: KU Leuven

Sulphur is the tenth most abundant element in the universe and its behaviour in terms of what molecules it forms in circumstellar envelopes has been seen to vary for different types of AGB stars. There are clear differences across chemi- cal types, with CS forming more readily in the circumstellar envelopes of carbon stars, while SO and SO2 have only been detected in oxygen-rich stars. How- ever, we have also discovered differences in sulphur chemistry based on the density of the circumstellar envelope (Danilovich et al., 2016, Danilovich et al., 2017, Danilovich et al., 2019). For example, the radial distribution of SO is drasti- cally different between AGB stars with lower and higher density circumstellar en- velopes. H2S can be found in high abundances towards higher density oxygen- rich stars, whereas SiS accounts for a significant portion of the circumstellar sulphur for higher density carbon stars and is present in higher abundances for higher density oxygen-rich stars. I will discuss these differences across AGB stars and what this implies for the chemical evolution of the circumstellar enve- lope. Studies of post-AGB stars show us that sulphur is not significantly depleted onto dust during the AGB phase (Waelkens et al. 1991, Reyniers & van Winckel 2007), making it a good tracer of changing circumstellar chemistry.

Figure 1: R Dor SO and SO2 channel maps for the central three velocity channels, showing the co-location of these two molecules in the circumstellar envelope. The background colours show the SO (8 7 ) transition, 8 ! 7 with the beam for those observations indicated in white in the lower left corners of each channel plot. The black contour plots show flux levels at 3, 5, 10, and 20 times the rms noise for the SO (20 19 ) transition, 2 1,19 ! 2,18 with the beam for those observations shown in black in the bottom left hand corner of each channel plot.

References: Danilovich T., et al., 2016, A&A, 588, A119 Danilovich T., et al., 2017, A&A, 606, A124 • • • Danilovich T., et al., 2019, MNRAS, 484, 494 Waelkens C., et al., 1991, A&A, 251, 495 Reyniers M., van • • Winckel H., 2007, A&A, 463, L1 Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Spectroscopy of evolved stars Presenting author: Elvire De Beck Contact: [email protected] Institute: Department of Space, Earth and Environment, Chalmers University of Technology Co-author: –

Evolved stars can feed more than half of their mass into the interstellar medium through steady outflows carrying gas and dust. As such, they enrich their host galaxies with newly formed elements and dust grains, affecting the for- mation of new generations of stars and planets. The chemical composition of the star and its outflow influences the efficiency of the mass loss and this, in turn, dramatically affects the stellar evolution itself. Molecular emission from such an outflow was first traced by Solomon et al. (1971) who observed the CO (J = 1 0) transition towards the carbon-rich star CW Leo, a.k.a. IRC +10 216, the brightest source at 5 µm outside the Solar System. To date, we have detected emission from around 80 different molecules towards similar stars, including water, carbon chains, phosphorus- bearing molecules, and polycyclic aromatic hydrocarbons (PAHs). The outflows present an enormous range of densities (102 1012 cm 3) and temperatures (5 3000 K) and, given their relatively simple, nearly spherical structures, these outflows are excellent astrochemical test beds. The location of matter in the outflow can be translated into an age since ejection, allowing us to investigate the temporal evolution of the chemical processes in the gas and dust. To probe the span of physical and chemical conditions from the onset of the outflows out to the interaction region with the interstellar medium, we observe a large variety of molecular species and excitation conditions. We use them to image the motions of the stellar surface of giants, to derive mass-loss rates, to understand dust formation, and to trace high-speed jets piercing the surrounding medium. An unbiased inventory of molecules in the outflows of a representative variety of galactic evolved stars, based on sample surveys and spectral scans, provides strong empirical constraints to chemical models that describe the processes governing gas, dust, and gas-dust chemistry. I will present the chemical richness in outflows from red giants, supergiants, and planetary nebulae and discuss some of the open questions in the field.

Figure 1: Left: CO(J = 1 0) emission measured by Solomon et al. (1971) towards CW Leo at 115 GHz; right: spectral scan towards AGB star R Dor from De Beck & Olofsson (2018) at 159 – 368 GHz.

References: Solomon, P., Jefferts, K. B., Penzias, A. A., Wilson, R. W. 1971, ApJ, 163, L53 De Beck, E. • • & Olofsson, H. 2018, A&A, 615, A8 Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Laboratory, modeling and observational study of benzene condensation on Titan’s stratospheric aerosols Presenting author: David Dubois Contact: [email protected] Institute: NASA Ames Research Center/Bay Area Environmental Research Institute Co-author: E. Sciamma-O’Brien, L. T. Iraci, E. L. Barth, F. Salama, S. Vinatier

Aerosol particles in Titan’s atmosphere impact its thermal structure and can act as condensation nuclei for the formation of clouds. Follow- ing the northern spring equinox in August 2009, Titan’s global atmo- spheric circulation reversed within two years. This event also increased the mixing ratios of benzene (C6H6) and other species at the South pole. Simultaneously, a strong cooling with temperatures dropping be- low 120 K favored the condensation of organic molecules at unusually high altitudes (>250 km). C6H6 ices have been detected during the Cassini mission by the Composite Infrared Spectrometer (CIRS), in the South polar cloud system, but the existing laboratory data is insufficient to allow models to reproduce the formation of the observed cloud sys- tem.

Here, we present the first results of combined laboratory, modeling and observational studies to investigate the equilibrium vapor pressure and ice nucleation of C6H6 on Titan’s aerosols as an important component of the cloud system that appeared during the autumn at 300 km above Titan’s South pole. We have performed experimental measurements of vapor pressure of C6H6 at Titan-relevant temperatures using the Ames Atmo- spheric Chemistry Laboratory (Iraci et al., 2010) and are studying the conditions required for condensation of benzene on laboratory-produced Titan aerosol analogs using the Titan Haze Simulation experiment developed on the NASA Ames COSmIC facility (Sciamma-O’Brien et al., 2017 & Salama et al., 2017). The experimental data has been used to constrain nucleation and condensation in microphysical models (Barth 2017). This is performed in order to determine expected cloud altitudes and particle sizes, in synergy with observations from CIRS in the 9-17 µm spectral region (Vinatier et al., 2018) and to better understand the molecular composition of this cloud system.

References: Iraci, L. T. et al., Icarus 210(2), 985-991, 2010. Sciamma-OBrien, E. et al., Icarus 289, 214- • • 226, 2017. Salama, F. et al., Proceedings IAU No. 332, 2017. Barth E. L., Planet. Space Sci. 127, 20-31, • • 2017. Vinatier, S. et al., Icarus 310, 89-104, 2018. • Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Reactivity of HCO with CH3 and NH2 on Water Ice Surfaces. A Comprehensive Ac- curate Quantum Chemistry Study Presenting author: Juan ENRIQUE ROMERO Contact: [email protected] Institute: Institut de Planetologie´ et d’Astrophysique de Grenoble (IPAG) Co-author: Cecilia CECCARELLI, Albert RIMOLA

Interstellar complex organic molecules (iCOMs) [Herbst & van Dishoeck 2009; Ceccarelli et al. 2018] have a great importance for the astronomical community for several reasons, including that they can contain an important fraction of car- bon in a molecular form easy to be used to synthesise more complex, even biotic molecules. Moreover, they have gained a lot of attention since the discovery of iCOMs in solar-type protostars [Cazaux et al. 2003; Bottinelli et al. 2004]. Indeed, iCOMs formed in the protostellar phase could have been inherited from the small bodies of the Solar System, e.g. carbonaceous chondrites and comets, and played a role in the origin of life on Earth [e.g. Caselli & Ceccarelli 2012]. Thus, understanding how iCOMs are formed and destroyed is of high im- portance to predict the ultimate organic complexity reached in the interstellar medium (ISM). Two paradigms are invoked in the literature. Both argue that simple molecules and atoms are hydrogenated on the interstellar grain surfaces during the cold prestellar phase. Following this first step, one paradigm assumes that iCOMs appear as a result of gas-phase chemical processes, whereas the other predicts that radical-radical reactivity on the grain sur- faces is the major responsible for the observed chemical complexity. The latter is nowadays the most popular among astrochemical models, even though some basic assumptions of the paradigm are still a topic of debate. Among them, the assumed radical-radical reactivity on grains is extremely difficult to simulate and prove experi- mentally. Here we propose a complementary and, possibly, alternative method: theoretical quantum chemistry calculations, which can provide a precious atomistic perspective from which to study such processes [e.g. Enrique-Romero et al. 2016; Rimola et al. 2018]. In this contribution, we present our recent quantum chemical study on the surface reactivity of two radical couples: CH3 + HCO and NH2 + HCO. According to observational evidences, the icy mantles that cover interstellar dust grains are dominated by water [Boogert et al. 2015]. We, therefore, use two cluster-like models made of 18 and 33 water molecules, respectively, to simulate the grain surface where the radical-radical reaction occurs. We then study the reactivity of the two biradical systems by means of static quantum chemical calculations to verify the formation of acetaldehyde (CH3CHO) and formamide NH3CHO), respectively. Besides the formation of the two iCOM, we also observe competitive processes leading back to simpler species, for example to CH4 and CO in the first system. The occurrence of one process or the other could entirely depend on the relative orientation of the radicals upon encounter, namely on the water ice structure and interaction with the two radicals. These results indicate that the fraction of iCOMs generated in the current astrochemical models is certainly overestimated since the competitive reactions are not included.

References: Herbst, E. & Van Dishoeck, E. F. 2009, Annual Review of Astronomy and Astrophysics, 47, • 427-480. Ceccarelli, C., Viti, S., Balucani, N. et al. 2018, Monthly Notices of the Royal Astronomical Society, • 476(1), 1371-1383. Cazaux, S., Tielens, A. G. G. M., Ceccarelli, C. et al. 2003, The Astrophysical Journal, • 593(1), 51-55. Bottinelli, S., Ceccarelli, C., Lefloch, B. et al. 2004, The Astrophysical Journal, 615(1), 354- • 358. Caselli, P.& Ceccarelli, C. 2012, The Astronomy and Astrophysics Review, 20(1), 56. Enrique-Romero, • • J., Rimola, A., Ceccarelli, C. et al. 2016, Monthly Notices of the Royal Astronomical Society: Letters, 459(1), 6-10. Rimola, A., Skouteris, D., Balucani, N. et al. 2018, ACS Earth and Space Chemistry, 2(7), 720-734. • Boogert, A. A., Gerakines, P. A., & Whittet, D. C. 2015, Annual Review of Astronomy and Astrophysics, 53, • 541-581. Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Cold molecular gas around high-z starburst galaxies Presenting author: Edith Falgarone Contact: [email protected] Institute: Ecole Normale Superieure,´ Paris Co-authors: M.A. Zwaan, B. Godard, A. Vidal-Garcia, C. Herrera, E. Bergin, R. J. Ivison, A. Omont, F. Walter, P. M. Andreani, F. Bournaud, D. Elbaz, and I.Oteo

Starburst galaxies at redshifts z ∼ 2 -4areamongthemostintenselystar-forming galaxies in the universe. The way they accrete their gas to form stars at such high rates is still a controversial issue. ALMA has detected the CH+(1-0) line in emis- sion and/or absorption in all the gravitationally lensed starburst galaxies targeted so far at 1.6 < z < 4.2 with star-formation rates in the range 300 to 1400 M⊙ yr−1.Theuniqueconjunctionofitsspectroscopicandchemicalproperties allows CH+(1-0) to highlight the sites of most intense dissipation of mechanical energy. The absorption lines reveal highly turbulent reservoirs of low-density molecular gas, extending far out of the galaxies. The emission lines, ofwidthsupto1400 km s−1,muchbroaderthanthoseofCO,ariseinmyriadmolecularshocks pow- ered by star formation and possibly active galactic nuclei. The CH+(1-0) lines therefore probe the fate of prodigious energy releases, primarily stored in tur- bulence before being radiated away. The turbulent reservoirs act as sustained mass and energy buffers over timescales up to a few hundreds ofMyr.Their mass supply involves gas inflows from galaxy mergers and/or cold stream ac- cretion, as supported by Keck/KCWI Lyα observations of one of these starburst galaxies.

Figure 1: Subset of ALMA continuum-subtracted CH+(1-0) spectra. Green curves show fits to the spectra obtained with one Gaussian for the emission and one (or two) Gaussian(s) for the absorption (dashed curves). The velocity scale is in the galaxy restframe obtained through accurate redshift measurements. The redshift and the lens magnification of each galaxy are given in the bottom left corners.

References: • Falgarone, Zwaan, Godard, et al. 2017, Nature 548 430 • Godard, Pineau des Forets,ˆ Lesaffre, et al. 2019, A&A 622, A100 • Li, Cai, Prochaska, et al. 2019, ApJ 875 130 Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Direct measurements of the optical properties of CO ice in the THz range and opacity calculation Presenting author: Barbara M. Giuliano Contact: [email protected] Institute: Max Planck Institute for Extraterrestrial Physics Co-author: A. A. Gavdush, B. Muller,¨ K. I. Zaytsev, T. Grassi, A. V. Ivlev, M. E. Palumbo, G. A. Baratta, C. Scire,` G. A. Komandin, S. O. Yurchenko, P. Caselli

Reliable, directly measured optical properties of astrophysical ice analogs in the far infrared and terahertz range are missing. These parameters are of great importance to model the dust continuum radiative transfer in dense and cold regions, where thick ice mantles are present, and are necessary for the inter- pretation of future observations planned in the far-IR region. Coherent THz ra- diation allows direct measurement of the complex dielectric function (refractive index) of astrophysically relevant ice species in the THz range. The time-domain waveforms and the frequency-domain spectra of reference samples of CO ice at different thicknesses, have been recorded. A new algorithm is developed to reconstruct the real and imaginary parts of the refractive index from the time- domain THz data. The developed algorithm enables, for the first time, the direct determination of optical properties of astrophysical ice analogs. The obtained data provide a benchmark to interpret the observational data from current ground based facilities as well as future space telescope missions, and allow to calculate the opacities of the dust grains more accurately.

Figure 1: Optical properties of CO ice. (a) Real part of the refractive index, (b) power absorption coefficient, (c) real and (d) imaginary parts of the dielectric permittivity for the different deposition intervals of tdep = 4, 5 and 6 min. Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Reactive molecular ions as tracers of harsh interstellar environments Presenting author: Javier R. Goicoechea Contact: [email protected] Institute: Instituto de Fisica Fundamental, CSIC, Madrid, Spain.

Reactive ions are transient species for which the timescale of reactive collisions (leading to a chemical reaction) with H2, H, or e is comparable to, or shorter than, that of inelastic collisions (Black et al. 1998). The formation of reactive ions such as CH+ and SH+ depends on the availability of C+ and S+ (i.e., of UV pho- tons, thus high ionization fractions xe = n(e) / nH) and on the presence of excited H2 (either UV-pumped or hot and thermally excited). This allows overcoming the high endothermicity (and sometimes barrier) of their formation (Sternberg & Dalgargo 1995; Agundez´ et al. 2010). The reaction C+ +H(v) CH+ +H(1), 2 ! for example, is endothermic by E/k 4300 K if v=0, but exothermic and fast for ' v 1 (Hierl et al. 1997). The reaction S+ +H(v) SH+ + H (endothermic by 2 ! E/k 9860 K when v=0) becomes exothermic when v 2 (Zanchet et al. 2019). ' CH+ was one of the first molecules detected in the 1930s. Due to the high endothermicity of reaction (1), explaining the presence of CH+ absorption lines in diffuse clouds has been a long standing problem in astrochemistry (e.g. Godard, Falgarone et al. 2012). Herschel and now ALMA, have allowed us to image the emission from CH+ and SH+ rotational lines toward interstellar and circumstellar sources irradiated by strong stellar UV fields (see Gerin et al. 2016 for a review). 5 3 + In dense gas, nH & 10 cm , the lifetime of CH is so short, a few hours, that the molecule may form and be de- stroyed without experiencing non-reactive collisions with other species. Contrary to most interstellar molecules, this implies that CH+ does not have time to thermalize, by elastic collisions, its translational motions to a ve- + locity distribution at Tk. Hence, CH rotational lines are expected to show broad line shapes related to the energy excess upon formation (thousands of K) and not to the actual Tk nor to an enhanced gas turbulence. Hence, CH+ can be excited by radiation many times during its its mean-free-time for non-reactive collisions, so that it remains kinetically hot (large velocity dispersion) and rotationally warm (high Trot) while it emits. Reac- tive ions can thus “retain some memory of the energetics of the formation process”. This “formation pumping” was anticipated by John Black in his eloquent Faraday Discussion’s paper (1998) and explicitly modelled af- ter Herschel’s detections (Nagy et al. 2013; Godard & Cernicharo 2013). Today, CH+ (J = 1–0) emission has mapped at parsec scales along Orion star-forming region (Goicoechea et al. 2019) and SH+ emission has been 2 spatially resolved at the edge of the Orion Bar PDR with ALMA at . 10 pc resolution (Goicoechea et al. 2017). Research on reactive ions is active and offers a common ground to study fundamental processes by as- tronomers and chemists (both in the lab and by ab initio quantum calculations).

References: Agundez,´ M., Goicoechea, J. R., Cernicharo, J., Faure, • A., & Black, J. H. 1998, Faraday Discussions, 109, 257 Gerin, M., • • Neufeld, D. A., & Goicoechea, J. R. 2016, ARAA, 54, 181 Godard, B., • et al. 2012, A&A 540, A87 Godard, B., & Cernicharo, J. 2013, A&A, • 550, A8 Goicoechea, J. R., et al. 2017, A&A, 601, L9 Goicoechea, • • J. R., et al. 2019, A&A, 622, A91 Hierl, P. M., Morris, R. A., & Viggiano, • A. A. 1997, JCP, 106, 10145 Nagy, Z., et al. 2013, A&A, 550, A96 • • Sternberg, A., & Dalgarno, A. 1995, ApJS, 99, 565 Roueff, E. 2010, ApJ, 713, 662 Zanchet, A., et al. 2019, A&A, in press. •

Figure 1: IR image of Orion and CH+ (J = 1–0) emission in contours. Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Cosmic rays and the dark neutral medium Presenting author: Isabelle Grenier Contact: [email protected] Institute: AIM, Universite´ de Paris & CEA Saclay

GeV to TeV cosmic rays rather uniformly pervade the local interstellar medium. They penetrate deeply into clouds and produce gamma rays from hadronic in- teractions with the gas nuclei along their path, thereby revealing the total gas column densities independently of its state or chemistry. They serve to gauge the molecular mass in the CO-bright regions (to scale the N(H2)/W(CO) con- version factor) and they reveal large quantities of ”dark” gas at the translucent H-H2 interface [1,2]. Preliminary constraints on the dark-gas composition point + to a large abundance of diffuse H2 and other molecules (HCO ,C2H) with only little CO at the onset of CO formation [3], as predicted by Ewine van Dishoeck and John Black in 1988 [4]. An interesting relation between the H2-dark and CO-bright mass needs confirmation [2]. These results pave the way to search for means to observe this elusive phase in and beyond the solar neighbourhood and to study the conditions that lead to this dark phase.

References: [1] Planck Collaboration, Fermi Collaboration et al., 2015, A&A, • 582, A31 [2] Remy Q., Grenier I. A., Marshall D. J., Casandjian J. M., 2018, A&A, 611, A51 [3] Liszt H., • • Gerin M., Grenier I., 2019, arXiv e-prints, arXiv:1905.05369 [4] van Dishoeck E. F., Black J. H., 1988, ApJ, • 334, 771 Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Models of extragalactic astrochemistry Presenting author: Nanas Harada Contact: [email protected] Institute: ASIAA

Some galactic centers host energetic activities such as starburst or active galac- tic nuclei, which can alter their chemical composition from what is known in the spiral arm clouds in the Galaxy. Possible driving forces of the chemistry include UV-radiation, cosmic rays, X-rays, shocks, as well as the high density. To identify diagnostic molecular abundances or ratios of each mechanism, several types of models have been constructed. I will review previous modeling work and discuss future challenges. Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: An appreciation of the career of JJ Charfman Presenting author: Lee Hartmann Contact: [email protected] Institute: University of Michigan

JJ Charfman was one of John Black’s closest, not to say intimate, collabora- tors. He first shot to fame due to the spectacular detection of interstellar Boron Sulphide in astronomical associations. Even though he has long been retired, residing at the Bora-Bora Radio Observatory, there have beenoccasionalcontri- butions from new collaborators centered at the Steward Observatory. Charfman even has a Twitter feed, though posting is quite sporadic. I shall review some of Charfman’s old achievements, with special emphasis on my ownpersonalobser- vations of Charfman’s effort in the early 1980s to become Director of A Center for Astrophysics.

References: • Detection of Interstellar BS in the Cirrus Dark Cloud of the Num- bum Association - Part One - an Intuitive Model and its Subsequent Observation, JJ Charfman, 1980, IAU Symposium 87, p. 645. • On the Utter Irrelevance of LPL Graduate Students: An Unbiased Survey by Steward Observatory Graduate Stu- dents, JJ Charfman et al. Somewhere on the web. • The Effects of Moore’s Law and Slacking on Large Computations, Gotbrath et al., https://arxiv.org/abs/astro- ph/9912202 • The Super Huge Interferometric Telescope: A New Paradigm In Optical Interferometry. Rudnick, Charfman et al., http://adsabs.harvard.edu/abs/1999AAS...195.8713R • https://twitter.com/jjcharfman Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Cosmic Ray Driven Chemistry Presenting author: Eric Herbst Contact: [email protected] Institute: University of Virginia Co-author: Christopher N. Shingledecker

Cosmic rays play a very important role in the chemistry of the interstellar medium. They are energetic enough to ionize molecular hydrogen in dense interstellar + clouds, leading to the production of the simplest polyatomicmoleculeH3 ,and helping to start a chain of ion-molecule reactions leading eventually to carbon- chain molecules and deuterated species among other species.Moreover,they are the major source of visible and ultra-violet radiation inregionsofhighex- tinction into which external photons cannot penetrate. The well-known mecha- nism for the production of radiation is the excitation of H2 followed by emission of Lyman and Werner photons with the radiation important for photodissociation processes in both the gas and on dust particle mantles. In addition to photodisso- ciation, cosmic rays sputter material from grain mantles into the gas and heat the grains to temperatures high enough to enhance the rate of thermal desorption considerably. In addition to these processes, cosmic rays are energetic enough to ionize and excite components of interstellar ice mantles,whichleadtoachainofnon-thermalreactionsthat eventually can produce organic molecules known as COMs. Although this sequence of solid phase reactions, known as irradiation, produces COMs in laboratory experiments of energetic protons and electrons bombard- ing ices with some source of carbon, it has not been studied until recently in theoretical detail, especially in the interstellar medium, where the production of COMs at low temperature can enhance the abundances achieved by current chemical simulations not enhanced by other exoticprocesses. In a recent series of papers, Shingledecker et al. developed an approach to the chemistry occurring in irradiation by high energy protons. The theory they developed can be utilized by itself, or can be guided by experimental determination of needed parameters such as Gvalues(moleculesproducedordestroyed per 100 eV of incoming radiation) and determination of so-callled “stopping” cross sections of elastic and inelastic processes, which help to relax the system and lead to a number of highly excited neutral radicals known as “suprathermal” molecules. These molecules have sufficient electronic-vibrational energy to react with neutral species no matter how high the activation energyfortheprocessesis.Thisnon-thermalchemistry distinguishes irradiation from other non-thermal processes including photolysis, which occurs at much lower and better defined energies. The processes involved in irradiation can be treated by a detailed Monte Carlo approach for simple systems, such as the bombardment of oxygen ice to produce a steady-state abundance of ozone. Inclusion of a large number of processes into current chemical simulation networks requires a more approximate rate equation approach. A parallel attempt to reproduce experiments involving the bombardment of water ice has also been undertaken.

In a preliminary approach to using irradiation in con- junction with other chemical processes to study the chemistry of cold prestellar cores, it was found that en- hanced abundances of the gas-phase COM methyl for- mate do occur, leading to better agreement with obser- vations. A model with a more complete set of reac- tions that synthesize COMs involving the production of suprathermal neutrals and their subsequent reactions is underway. References: • Shingledecker, C.N., & Herbst, E. 2018, PCCP, 20, 5359 • Shingledecker, C. N., Tennis, J., Le Gal, R., & Herbst, E. 2018, ApJ, 861:20

Figure 1: A high-energy proton producing tracks of high-energy electrons, which can undergo reactions to produce ions and excited neutrals. Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Polycyclic Aromatic Hydrocarbons as catalysts for H2 formation Presenting author: Liv Hornekaer Contact: [email protected] Institute: Dept. Physics and Astronomy, Aarhus University Co-author: The names of the Co-authors

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the interstellar medium, however, their impact on interstellar chemistry is still not thoroughly in- vestigated. Theoretical calculations and experimental measurements show that PAHs react readily with atomic hydrogen to form superhydrogenated species -e.g.PAHmoleculeslikepentaceneandcoronenecanbefullysuperhydro- genated with one excess H atom pr. carbon atom in the molecule via H atom ad- dition. Once super-hydrogenated, PAH molecules have been shown to catalyze molecular hydrogen formation and may also catalyze further reactions. These findings may explain observations of increased molecular hydrogen formation rates in photodissociation regions with high PAH abundances. Here we present results on stable superhydrogenation configurations and cross-sections for the initial H and D addition reactions for coronene and pentaceneanddiscussreac- tions towards more complex species via hydrogenation of pentacene-quinone.

Figure 1: Scanning Tunneling Microscopy Image of Superhydrogenated Coronene on Graphite

References: • E. Rauls and L. Hornekr. Astrophys. J. 679, 531 (2008) • J. D. Thrower et al. Astrophysical Journal 750, 1, (2012) • V. Menella, L. Hornekr, J. Thrower and M. Accolla. Astrophys.J.Lett.745,L2(2012)• J. D. Thrower, E. E. Friis, A. L. Skov, B. Jrgensen and L. Hornekr. Phys. Chem. Chem. Phys. 16, 3381 (2014) • S. Cazaux et. al. Sci. Rep. 6, 19835 (2016) • P. Jensen et al. MNRAS (2018); doi.org/10.1093/mnras/stz1 202 • E. Habart et al. Astron. Astrophys. 397, 623 (2003) • E. Habart et al. Astron. Astrophys. 414, 531 (2004) Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Non-Zeeman Circular Polarization of Rotational Molecular Spectral Lines Presenting author: Martin Houde Contact: [email protected] Institute: The University of Western Ontario Co-author: M. Chamma, T. Hezareh, F. Rajabi, S. Jones, J.-M. Girart, R. Rao

In this presentation I will discuss the recent discovery of circular polarization signals in the rotational line profiles of molecules that are negligibly sensi- tive to the Zeeman effect. Our initial findings obtained for CO in the Orion KL star-forming region with the Caltech Submillimeter Observatory [1] were followed with similar detections for two transitions of CO in an exhaustive study of the supernova remnant IC 443 (G), obtained with the IRAM 30m [2]. These new results have clearly established that circular polarization arises, as predicted, from the conversion of linear polarization signals in- cident on the molecules responsible for the detected radiation. I will show how the anisotropic resonant scattering model developed to explain these observations and others directly involves the ambient magnetic field [3]. These results, and new ones using SMA archival data [4], suggest the pos- sibility of starting a whole new subfield of more incisive studies of magnetic fields in the interstellar medium.

Figure 1: Circular polarization spectrum of the 12CO (J = 2 1) observations made at the peak ! position of Orion KL at the Caltech Submillime- ter Observatory with the Four-Stokes-Parameter Spectral Line Polarimeter (FSPPol). Top: Stokes I spectrum, uncorrected for telescope efficiency, and circular polarization levels (symbols with un- certainty, using the scale on the right). Bottom: the Stokes V spectrum, also uncorrected for tele- scope efficiency. The frequency resolution of the 1 Stokes I spectrum is 61 kHz (0.08 km s ), while the Stokes V spectrum was smoothed by a factor of 20. Taken from [1].

References: [1] Houde et al. 2013, ApJ, 764, 24 [2] Hezareh et al. 2013, A&A, 558, A45 [3] Houde, M. • • • 2014, ApJ, 795, 27 [4] Chamma et al. 2018, MNRAS, 480, 3123 • Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

+ Title: Merged H/H2 and C /C/CO transitions in the Orion Bar PDR Presenting author: Maria S. Kirsanova Contact: [email protected] Institute: Institute of Astronomy, Russian Academy of Sciences Co-author: Dmitri S. Wiebe

High-resolution ALMA images towards the Orion Bar show no discernible off- set between the peak of H2 emission in the photodissociation region (PDR) and the 13CO(3–2) and HCO+(4–3) emission in the molecular region (Goicoechea et al., 2016). This implies that positions of H2 and CO dissociation fronts are indistinguishable in the limit of ALMA resolution (1 arcsec). We use the chemo- dynamical model MARION (Kirsanova et al., 2009; Akimkin et al., 2015) to show that the ALMA view of the Orion Bar, namely, no appreciable offset between 13 + the CO(3–2) and HCO (4–3) peaks, merged H2 and CO dissociation fronts, and high intensity of HCO+(4–3) emission, can only be explained by the ongoing propagation of the dissociation fronts through the molecular cloud, coupled to the dust motion driven by the stellar radiation pressure, and are not reproduced in the model where the dissociation fronts are assumed to be stationary. Modelling line intensities, we demonstrate that after the fronts have merged, the angular separation of the 13CO(3–2) and HCO+(4–3) peaks is indeed unresolvable with the ALMA observations. Our model predictions are consistent with the results of the ALMA observations about the relation of the bright HCO+(4–3) emission to the compressed gas at the border of the PDR in the sense that the theoretical HCO+(4–3) peak does corre- spond to the gas density enhancement, which naturally appears in the dynamical simulation, and is located near the H2 dissociation front at the illuminated side of the CO dissociation front.

104 200 90 + Tgas HCO (4-3) 80 n CO(3-2) gas 6 W 10 150 70 HCO+

3 n

10 gas 60 , (cm 5 50 (K km s (K) (K) 10 100 gas CO 40 -3 T T 2 )

10 30 -1 4 10 50 20 ) 10 101 103 0 0 20 22 24 26 28 30 32 34 20 22 24 26 28 30 32 34 r (arcsec) r (arcsec)

Figure 1: Results of the time-dependent calculations for the Orion Bar. The horizontal axis shows the distance r from the origin of the computational domain. The source of UV photons is supposed to be located to the left of the computational domain. Left: theoretical spatial distributions of gas temperature (Tgas) and density 13 + (ngas). Right: peak intensity of the CO(3–2) emission line and integrated intensity of the HCO (4–3) emission line. Red and green dashed lines show theoretical locations of the CO and H2 dissociation fronts, respectively. Hatched rectangles of both panels indicate observational values of the abundances, Tgas and ngas with the error bars obtained by Goicoechea et al., 2016.

References: Akimkin V. V. et al., MNRAS, 449, 440, 2015 Goicoechea J. R. et al., Nature, 537, 207, 2016 • • Kirsanova M. S. et al., ARep, 53, 611, 2009 • Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Experimental Characterization of Low-temperature Surface Reactions Presenting author: Serge Krasnokutski Contact: [email protected] Institute: Laboratory Astrophysics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University Jena Co-author: Thomas Henning

Low-temperature reactions on the surface of cosmic solid particles (dust) are thought to be responsible for the formation of complex organic molecules ob- served inside dark molecular clouds and planet-forming disks. These molecules could later be delivered to planets and facilitate the formation of biopolymers. However, there is a lack of quantitative experimental data on the relevant sur- face reactions. We describe an experimental technique, which can be used to measure the energy released in reactions of a single pair of reactants. These data can be directly compared with the results of quantum chemical computa- tions leading to unequivocal conclusions regarding the reaction pathways, the presence of energy barriers, and the final reaction products. Schematic rep- resentation of the experimental technique is given in Figure 1. In the experi- ment superfluid He nanodroplets are used as a nanocalorimeter and as a third body. Therefore, reactions investigated inside superfluid He nanodroplets are analogues to those occurring on chemically inert surfaces, for example, water ice surfaces. The new method was applied to study the reactions of C atoms with H2, CO2, NH3 and C2H2 molecules. The formation of HCH, C2O2, CNH3, and triplet cyclic-C3H2 products has been revealed. The method has applications beyond laboratory astro- physics in studying surface reactions.

R1

Hen

R2

Figure 1: Schematic representation of the chemical reactions occurring inside He droplets. R1 and R2 are the two different reactants. Reactants are incorporated sequentially into He droplets. In less than 1 µs they meet inside the droplets. Exothermic reactions with zero energy barriers in the entrance channel proceed spontaneously on encounters. The reaction energy is transferred to the droplets leading to a size reduction. 1 Each evaporated He atom removes about 5 cm of energy. By measuring the size of He droplets before and after the evaporation, we can calculate the amount of energy released in the reaction.

References: T. Henning and S. A. Krasnokutski, to appear in Nature Astronomy, 2019. http://dx.doi.org/10.1038/s41550- • 019-0729-8 Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Detecting Complex (Polycyclic?) Aromatic Molecules in the ISM Presenting author: Brett A. McGuire Contact: [email protected] Institute: National Radio Astronomy Observatory and Center for Astrophysics Har- | vard & Smithsonian Co-author: Andrew M. Burkhardt, Ryan A. Loomis, Kin Long Kelvin Lee, Christopher N. Shin- gledecker, Ci Xue, Eric R. Willis, Steven B. Charnley, Martin A. Cordiner, Eric Herbst, Sergei Kalenskii, Anthony J. Remijan, and Michael C. McCarthy

Despite the widespread acceptance of the existence of a large reservoir of aro- matic carbon in the ISM for many decades, likely polycyclic aromatic hydrocar- bons (PAHs), no individual PAHs have been detected to date (McGuire 2018), and detailed observational studies of aromatic chemistry in general have been lacking. Motivated by our discovery of benzonitrile (cyanobenzene; C6H5CN) in the dark cloud TMC-1 (McGuire et al. 2018), we have undertaken two large ob- servational follow-ups with the GBT: GOTHAM and ARKHAM. Here, I will present the first science results of both projects. GOTHAM aims to explore the extent of aromatic chemistry in TMC-1, where we detected C6H5CN, using a deep spectral line survey. Our detections of six new interstellar molecules from this work, in- cluding the first individually detected PAH molecules in the ISM, will be described. ARKHAM seeks to understand how widespread detectable aromatic chemistry is at the earliest stages of star formation. From ARKHAM, we will present our detections of benzonitrile in sources outside TMC-1, including those in which collapse toward protostellar formation, and a protostellar source itself, are included.

References: McGuire 2018 ApJS 239, 17 McGuire et al. 2018 Science 359, 202 • • Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Formation of dicarbon in collisions of two carbon atoms Presenting author: Brendan M McLaughlin Contact: [email protected] Institute: School of Mathematics and Physics, Queen’s University of Belfast (QUB) Co-authors: Ryan T Smyth (QUB) and James F Babb (Center for Astrophysics, Harvard & Smith- sonian)

Radiative association cross sections and rates are computed, using a quantum approach, for the formation of C2 molecules (dicarbon) during the collision of 3 1 two ground state C( P) atoms. We find that transitions originating in the C ⇧g, 3 5 d ⇧g, and 1 ⇧u states are the main contributors to the process (Babb et al. 2019). The results are compared and contrasted with previous results obtained from a semi-classical approximation. New ab initio potential curves and transi- tion dipole moment functions have been obtained for the present work using the multi-reference configuration interaction approach with the Davidson correction (MRCI+Q) and aug-cc-pCV5Z basis sets. Applications of the current computa- tions to various astrophysical environments and laboratory studies are briefly discussed focusing on these rates. We also discuss recent calculations on collisions of a carbon atom and a carbon ion.

-16 10

Semiclassical (Andreazza & Singh, 1997) Sum (present) C C-A ) 2 -1 d-a

s 5 5 3 1 ∏g-1 ∏u

-17 10 rate coefficient (cm

-18 10 100 1000 10000 temperature T (Kelvin)

Figure 1: Maxwellian averaged radiative association rates (cm3/s) as a function of temperature (Kelvin) for the C2 molecule. Results are shown for the dominant singlet, triplet, and quintet transitions with their appropriate statistical factor included. The total quantal rate (brown line) is seen to lie above the previous total semiclassical rate (dashed black line: Andrezza and Singh 1997) at all but the highest temperatures.

References: Andreazza, C. M., & Singh, P. D. 1997, MNRAS, 287, 287 • Babb, J. F., Smyth, R. T, & McLaughlin, B. M., 2019, Astrophys. J, in press • Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Detection of OH radicals on amorphous solid water Presenting author: Ayane Miyazaki Contact: [email protected] Institute: Institute of Low Temperature Science, Hokkaido University Co-author: N. Watanabe, WMC Sameera, T. Hama, H.Hidaka, A. Kouchi

Surface reactions on interstellar grains play an important role in molecular for- mation in dense clouds. Surface reactions proceed via elementary processes: adsorption, diffusion, and collision with another adsorbate. Therefore, diffusion process on dust grain surface is crucial to surface reactions and should be clari- fied experimentally. Recently, Watanabe et al. developed a method for detecting H atoms on amorphous solid water (ASW), using the combination of photostimu- lated desorption and resonance-enhanced multiphoton ionization (PSD-REMPI) [1-3]. They reported the surface diffusion mechanism and activation energy of H-atom diffusion on ASW. In the present study, we focus on the detection of OH radicals on ASW, because surface reactions of OH radicals would contribute to the formation of complex molecules or those precursors. However, there is no experiment for the direct detection of OH radical on water ice because of intrinsic technical difficulty. In an infrared absorption spectroscopy, an OH radical spec- trum can be hardly separated from H2O band in ice. Temperature-programmed desorption little provides the information about behavior of OH radical on water ice surface. Using the PSD-REMPI method, we have first succeeded in monitoring OH radicals on the ice surface, which were produced by UV photolysis of ASW. I present the experimental details on detection and behavior of OH radicals on ASW

References: [1] N. Watanabe et al. ApJL 714, L233 (2010). [2] T. Hama et al. ApJ 757, 185 (2012). [3] • • • Kuwahata et al. Phys. Rev. Lett. 115, 133201 (2015). Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Molecular absorbers against background quasars: the cosmicmicroscopes Presenting author: Sebastien Muller Contact: [email protected] Institute: Chalmers University of Technology

More than thirty orders of magnitude separate nanometers andmegaparcsecs. The former traditionally requires powerful microscopes, the latter powerful tele- scopes. I will show that studying molecular absorption against background quasars is equivalent to use a cosmic microscope. This simplebutpowerful technique allows us to scrutinize the interstellar medium and reveal the chemical setup of distant galaxies, without the distance dilution affecting studies in emis- sion. In turn, the molecules at high redshifts are privilegedcosmologicalprobes, giving us information on how is the Universe evolving. Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Small molecules observed at high spectral resolution with SOFIA: recent results from + EXES and GREAT observations of two molecules, H2 and HeH Presenting author: David Neufeld Contact: [email protected] Institute: Johns Hopkins University

Small molecules provide a valuable probe of fundamental processes in the inter- stellar medium. and provide unique information about the environment in which they are observed. In this talk, I will discuss recent observational studies of two + molecules, H2 and HeH ,whichhavebeenobservedathighspectralresolution using the EXES and GREAT instruments on the SOFIA airborne observatory. These studies show the value of high spectral resolution spectroscopy in the mid- and far-infrared spectral regions conducted from altitudeswheretheatmosphere is largely transparent. The H2 observations (Neufeld et al. 2019), performed with the EXES mid-IR spectrometer at a resolving power λ/∆λ ∼ 105,targeted the S(4) - S(7) pure rotational lines of H2.ObservationsofwarmgasinHH7, aclassicbowshock,revealedsmallvelocityshifts∼ 3kms−1 between the ob- served emission lines of ortho-H2 [S(5) and S(7)] and those of para-H2 [S(4) and S(6)]. These velocity shifts bear witness to the conversion of para-H2 to ortho-H2 within the shock front, and provide compelling evidence for “C”-type shocks in which the flow velocity varies continuously. The HeH+ observations (G¨usten et al. 2019), performed with the GREAT spectrometer, have led to the first astrophysical detection of the helium hydride cation. Here, the R(0) transition at 2.01 THz (149µm) was detected toward the young planetary nebula NGC 7027. Thanks to the unprecedented spectral resolving power of GREAT at this frequency, the HeH+ line could be distinguished for the first time from a nearby CH transition. The detection of HeH+ provides a beautiful demonstration of Nature’s tendency to form molecules; despite the unpromising ingredients (hydrogen and the noblegaselementhelium),andtheharshconditions (strong UV irradiation and temperatures of several thousandKelvin),HeH+ forms within a thin shell near the Stromgren¨ radius where He+ and H coexist. More than four decades ago, with his 1978 paper on the sub- ject, John Black played a central role in the recognition thatHeH+ was a potentially-detectable astrophysical molecule: it has now been found at last, precisely where he suggested looking.

Figure 1: Left panel: spectra of H2 rotational transitions obtained by EXES toward HH7 (Neufeldetal.2019). Right panel: spectra of HeH+ J = 1 − 0 obtained by GREAT toward NGC 7027 (G¨usten et al. 2019).

References: • Black, J. H. 1978, ApJ,222,125• Neufeld, D. A., DeWitt, C., Lesaffre, P., et al. 2019, ApJ, in press • G¨usten,R.,Wiesemeyer,H.,Neufeld,D.,etal.2019, Nature,568,357 Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Heavy element recombination lines towards an evolved star: In the footsteps of John Black Presenting author: Hans Olofsson Contact: [email protected] Institute: Space, Earth and Environment, Chalmers Co-author: J. Black, E. Humphreys, M. Lindqvist, M. Maercker, L.-A. Nyman, S. Ramstedt, D. Tafoya, W. Vlemmings

The 26α and 30α recombination lines of a heavy element have been detected using ALMA towards an evolved low-mass star in a binary system, HD101584 [1]. The star is classified as a post-RGB object, but post-AGB remains a possibility. The most likely carrier of the lines is Mg, but there may also becontributions from Na, Al, Si, K, and Fe. The modest temperature of the star, about 8500 K, means that the corresponding lines from H, He, and C are not detectable. A simple model for the immediate surroundings of the star has been developed to estimate the properties of the gas, including its elemental abundances. Optical spectra have provided additional constraints. This is a potentially new method of observing cool stars, such as AGB stars and the more massivecounterparts, red supergiants and yellow hypergiants.

References: • Olofsson et al. A&A 623, A153, 2019 Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Cosmic rays: the ubiquitous probe for the interstellar medium Presenting author: Marco Padovani Contact: [email protected] Institute: INAF-Osservatorio Astrofisico di Arcetri - Italy Co-author: (in alphabetical order) P. Caselli, A. Ferrara, K. Ferriere,` D. Galli, P. Hennebelle, A. Ivlev, A. Marcowith

Galactic cosmic rays are an omnipresent source of ionisation and dissociation of the interstellar gas, competing with UV and X-ray photons as well as natu- ral radioactivity in determining the fractional abundance of electrons, ions, and charged dust grains in molecular clouds and circumstellar discs. Cosmic rays activate the rich chemistry that is observed in molecular clouds and also regu- late the cloud collapse timescale, determining the efficiency of star and planet formation. However, they cannot penetrate up to the densest part of a molec- ular cloud, where the formation of stars takes place, because of energy loss processes and magnetic field deflections. Cosmic rays can also be produced in protostellar shocks, and this local source can explain energetic phenomena such as the synchrotron emission observed in jets, and the associated unusually high ionisation rates. In this talk I will present recent results on cosmic-ray physics and chemistry in star-forming regions obtained by analytical and numerical mod- els, supplemented by dedicated observations together with predictions on the capability of future instruments such as SKA in detecting synchrotron emission in molecular clouds.

References: Cosmic-ray acceleration in young protostars - Padovani et al. 2015, A&A, 582, L13 • Protostars: Forges of cosmic rays? - Padovani et al. 2016, A&A, 590, A8 • The plasma physics of cosmic rays in star-forming regions - Padovani et al 2017, PPCF, 59, 014002 • Cosmic-ray ionisation in circumstellar discs - Padovani et al. 2018a, A&A, 614, A111 • Production of atomic hydrogen by cosmic rays in dark clouds - Padovani et al. 2018b, A&A, 619, A144 • Synchrotron emission in molecular cloud cores: the SKA view - Padovani et al. 2018c, A&A, 620, L4 • Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Dicke’s Superradiance and Maser Flares Presenting author: Fereshteh Rajabi Contact: [email protected] Institute: Perimeter Institute for Theoretical Physics and the Institute for Quantum Computing Co-author: Martin Houde (University of Western Ontario)

Burst phenomena covering a wide range of timescales are ubiquitous in astrophysics (e.g., from less than a millisecond for Fast Radio Bursts to several years for some maser flares). Understanding their origin and un- derlying physical processes is an important goal of contemporary astro- physics.To this end, we have recently applied Dicke’s superradiance, a co- herent quantum mechanical radiation mechanism, to the physics of the in- terstellar medium (ISM) to explain some of these burst phenomena. In this presentation I will focus on so-called maser flares and show how un- der certain conditions a region initially hosting a maser can transition to a superradiance regime. When superradiance sets in, individual molecules (or atoms) become entangled and do not emit independently but do so as a group. One important consequence is that a superradiance system will radiate through powerful bursts with a peak intensity proportional to the square of the number of molecules contained in the radiating gas. Although it was first discussed by R. H. Dicke in 1954 and has been studied in the laboratory for several decades, superradiance remained unnoticed by as- tronomers until recently. I will thus present observational evidence for superradiance in the ISM and describe our models developed to explain corresponding radiation flares seen in the 6.7-GHz methanol, 1612-MHz OH, and 22-GHz water spectral lines.

Figure 1: Superradiance model for the S255IR-NIRS3 flare. Top: The black dots are for the data and the solid cyan curve for the superradiance model fit as a func- tion of retarded time. Bottom: The solid black and cyan curves, respectively, show the temporal evolution of the inverted population density and the pumping rate. The fit is produced using a single super- radiance sample of length L = 140 au composed of N 6 1019 inverted and SR ' ⇥ entangled methanol molecules. The in- version level prior to the appearance of the pump pulse corresponds to approxi- 3 mately 0.1 cm for a molecular population 1 spanning a velocity range of 1 km s . The column density of the inverted population is (nL) = 6.4 103 cm 2 and the SR flux SR ⇥ density is scaled to the data. Taken from [4].

References: [1] Rajabi & Houde 2016a, ApJ, 826, 216 [2] Rajabi & Houde 2016b, ApJ, 828, 57 [3] Rajabi • • • & Houde 2017, Science Advances, 3, e1601858 [4] Rajabi et al. 2019, MNRAS, 484, 1590 • Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Photon-driven chemistry Presenting author: Evelyne Roueff Contact: [email protected] Institute: LERMA, Observatoire de Paris Co-authors: E. Bron, J. Le Bourlot, F. Le Petit

John Black and Alex Dalgarno [1] emphasized more than 40 years ago the po- tential diagnostics of the infrared response of molecular Hydrogen to ultravio- let radiation. These predictions have been beautifully confirmed a few months later by Gautier et al. [2] thanks to a Fourier transform spectrometer installed at the Steward Observatory telescope towards the Kleinmann-Low nebula in Orion. The infrared spectrum of molecular hydrogen has been subsequently detected in various UV illuminated regions by ISO, Spitzer in space but also on the ground by CFHT, Lowell Observatory, VLT, McDonald, .... Photon dominated regions (PDRs) are recognized as key areas for under- standing the interface between molecular gas, where stars form, and the sur- rounding galactic environment [3]. The Herschel Space Observatory has recently opened the possibility to detect warm molecular gas present in galactic and ex- tragalactic sources by covering CO excitation lines from J = 4 to J 20 [4]. up up ⇠ The derived CO spectral line energy distributions (SLEDs) including high-J levels allow to highlight energetic processes occurring in these star-forming regions. Constant density models fail to reproduce the corresponding emissivities; however isobaric models allow + to successfully account for excited CO as well as other tracers including H2, HD, CH , .... found at the edge of PDRs. Indeed, a thin but extended layer of molecular emission emerging from the FUV-irradiated gas is found with the one arc second resolved observations provided by ALMA [5]. A strong correlation between the gas pressure and the impinging radiation field is derived both from galactic [4] and extragalactic [6] observations. My talk will outline how these new results reveal the multiple physical and chemical processes at work, from the formation/photo-destruction of molecular Hydrogen and occurence of an endothermic chemistry triggered by vibrationally excited H2 (following UV pumping and pointing to a state-to-state chemistry) to the radiative feedback-induced gas dynamics. A bright future is foreseen for PDR modelling where new physical contraints such as surface chemistry combined to possible photodesorption as well as time-dependent thermo-chemical evolution [7] deserve consideration.

References: [1] J.H.Black & A. Dalgarno 1976, ApJ 203, 123, [2] T.N. Gautier et al. 1976 ApJ 207, L129 • • • [3] D.J. Hollenbach & A.G.G.M. Tielens 1999, Rev. Mod. Phys. 71, 173 [4] C. Joblin et al. 2018, A&A 615, • A129, Parikka et al. 2018, A&A 617, A77, S. Cuadrado et al. 2019, Astron. Astrophys. 625, L3, Wu et al. 2018, A&A 618, A53, A B. Mookerjea et al. 2019, arXiv:1905.03161 [5] J. Goicoechea et al. 2016, Nature • 537, 207, J. Goicoechea et al. 2017, Astron. Astrophys. 601, L9 [6] M.Y.-Lee et al. 2016, &A 596, A85 [7] • • E. Bron et al. 2018, arXiv:1801.01547, Kirsanova and Wiebe 2019, MNRAS 486, 2525 Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Lab spectroscopy for astrochemistry Presenting author: Stephan Schlemmer Contact: [email protected] Institute: Universitaet zu Koeln Co-author: Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Simulating Ion-Irradiation Experiments using Astrochemical Models Presenting author: Christopher N. Shingledecker Contact: [email protected] Institute: Max-Planck-Institut fr extraterrestrische Physik Co-author: Anton Vasyunin, Eric Herbst, Paola Caselli

The upcoming launch of JWST promises to usher in an astrochemical ”ice age” by allowing for the collection of an unprecedented amount of data regarding species frozen onto interstellar dust grains. Astrochemical models will surely figure prominently in both interpreting these data, as well asininformingfuture observing proposals. However, this great opportunity callsformodelswhichare equal to the task and, unfortunately, there remain significant uncertainties re- garding the chemistry of dust grains and dust grain ice-mantles - a situation that has given it the dubious reputation of ”the last refuge of the scoundrel.” These ices are exposed to a constant ionizing radiation flux, typically in the form of cos- mic rays, stellar winds, and radionuclide emission. There isnowalargebody of experimental work showing that these kinds of radiation can trigger significant physico-chemical changes in ices, including the dissociation of species (radioly- sis), sputtering of surface species, and ice heating (HudsonandMoore,2001). Even so, modeling the chemical effects that result from interactions between ionizing radiation and interstellar dust-grain ice mantles has proven challenging due to the complexity and variety of the underlying physical processes. Here, we review recent effort by us on this topic (Shingledecker et al., 2019), as well as some surprising insights regarding the mechanisms underlying bulk chemistry that can by gained through the use of such models.

References: • Hudson, R. L., Moore, M. 2001, J. Geophys. Res. 106 33,275 • Shingledecker, C. N., et al. 2019, Ap.J. submitted Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Modeling deuterium chemistry in dense cores: full scrambling versus proton hop Presenting author: Olli Sipila¨ Contact: [email protected] Institute: Max-Planck-Institute for Extraterrestrial Physics (MPE) Co-author: Paola Caselli, Jorma Harju

Deuterated molecules are excellent probes of the dense and cold centers of molecular cloud cores. This is because they appear in conditions where other- wise abundant tracer molecules such as CO are frozen onto dust grains. Deu- terium is transferred from the main molecular reservoir, HD, to other species via the H+ + HD H D+ + H reaction followed by a variety of efficient deuteron- 3 ! 2 2 donation reactions such as H D+ +N N D+ +H . The efficiency of deuteration 2 2 ! 2 2 is also very strongly influenced by spin-state chemistry, because certain forma- tion/destruction channels are forbidden by selection rules. An open question in numerical models of deuterium chemistry at low temperature is the nature of the + reaction mechanism when protons/deuterons are exchanged. For the H3 + H2 system, there is evidence that the proton transfer proceeds through full scram- bling, in which several atom interchanges can take place in a relatively long-lived reaction complex (e.g., Suleimanov et al. 2018). On the other hand, Le Gal et al. + (2017) demonstrated that the formation of H2Cl is governed by direct proton ab- + straction in HCl + H2. Here we present new models for deuterium and spin-state chemistry (Sipila¨ et al. 2019, in prep.) where all proton-donation reactions of the form XH+ + Y YH+ + X (and deuterated analogs), with the exception of the H+ + H system, are treated as ! 3 2 either full scrambling or proton/deuteron hop reactions. We apply our model to the starless core H-MM1 where we recently found (Harju et al. 2017) that the observed D/H and spin-state abundance ratios of deuterated ammonia do not match the non-statistical ratios predicted by our previous chemical model (Sipila¨ et al. 2015). We find that the hop model reproduces the observed D/H ratios better than the full scrambling model does. The spin-state ratios predicted by the two models are very similar because they are heavily dependent on the + H3 +H2 system which we do not modify, and indeed we find that the back-effect of the various proton/deuteron- + transfer reactions on H3 and its isotopologs is very small. Figure 1 shows some example results at constant density and temperature, highlighting the difference between the full scrambling and hop models.

+ Figure 1: D/H abundance ratios of ammonia (left), H3 (middle), and water (right) at constant density (n(H2) = 6 3 10 cm ) and temperature (Tdust = Tgas = 10 K). Solid lines represent the full scrambling model, and dashed lines represent the proton/deuteron hop model.

References: Harju, J., Daniel, F., Sipila,¨ O. et al. 2017, A&A, 600, A61 Le Gal, R., Xie, C., Herbst, E. et al. • • 2017, A&A, 608, A96 Sipila,¨ O., Harju, J., Caselli, P., and Schlemmer, S. 2015, A&A, 581, A122 Sipila,¨ O., • • Caselli, P., and Harju, J. 2019, in prep. Suleimanov, Y., Aguado, A., Gomez-Carrasco,´ S., and Roncero, O. • 2018, J. Phys. Chem. Lett., 9, 2133 Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: The atomic to molecular (HI-to-H2)transitioninGalaxystar-formingregions Presenting author: Amiel Sternberg Contact: asternberg@flatironinstitute.org Institute: Flatiron Institute Co-author:

As was emphasized in John Black’s famous PhD thesis, the atomic to molecu- lar hydrogen (HI-to-H2)phasetransitionisoffundamentalimportanceforstar- formation and the emergence of chemical complexity in the interstellar medium of galaxies. I will present an overview, and discuss recent theoretical studies, numerical and analytic, of the HI-to-H2 transition in irradiated systems, with ap- plications to the multi-scale behavior observed in star-forming galaxy disks from low- to high-redshift. Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Cold molecular extragalactic medium Presenting author: Linda Tacconi Contact: [email protected] Institute: Max-Planck-Inst. fuer extraterrestrische Physik Co-author: Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Ionization signatures and gamma-rays from supernova remnants Presenting author: Julia Becker Tjus Contact: [email protected] Institute: Ruhr-University Bochum, Bochum, Germany

The origin of cosmic rays is still one of the central open questions in physics and astrophysics. Still, scientists have come closer to the answer in the past decades - three supernova remnants (SNRs) have been identified as cosmic ray emitters via the identification of the so-called pion bumpintheirgamma- ray spectrum, which must be hadron-induced. While uncontontroversial in the result, these detections do not grant that the entire spectrum of cosmic rays as observed at Earth is produced by SNRs: The three SNRs in question are strong emitters at GeV energies, however, they barely produce any signal in the TeV - PeV range, which is necessary in order to explain the entire cosmic ray spectrum. The search for solid proof is therefore ongoing with high insistence. In particular, finding methods to identify more cases of cosmic-ray emittingSNRsisnecessary to prove the case. This talk will address the method that I worked on together with John - we in- vestigated if cosmic-ray induced ionization can help to solve the question by look- ing for correlated signatures in molecular lines and gamma-rays. This talk sum- marizes the state-of-the-art on the topic of cosmic-ray ionization and gamma-ray emitting SNRs. Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Probing the HI/H2 layer around the ultracompact HII region MonR2 Presenting author: Sandra P. Trevino-Morales˜ Contact: [email protected] Institute: Onsala Space Observatory/Chalmers University of Technology Co-author: A. Fuente, A.´ Sanchez-Monge,´ P. Pilleri, J. Goicoechea, V. Ossenkopf-Okada et al.

One of the first signposts of high-mass star formation is the presence of com- pact HII regions, surrounded by layers of photon-dominated regions (PDRs). The study of the properties of these objects is of special interest because they pro- vide information on the dynamical and chemical evolution of forming high-mass stars. Reactive ions are thought to be excellent PDR tracers.Inparticular,high + fractional abundances of CO are expected in the HI/H2 transition layer of dense PDRs. Our team has performed a study of the spatial distribution of the CO+ rotational emission toward the MonR2 star-forming region, where there exists a + series of PDRs surrounding an expanding UC HII region. The CO emission presents a clumpy ring-like morphology that surrounds the HII region (Figure 1). We compared the CO+ distribution with other species present in PDRs, such as [CII], H2 S(3), polycyclic aromatic hydrocarbons (PAHs), and molecular gas tracers (Trevino-Morales˜ et al. 2014, 2016). We find that the CO+ emission is + spatially coincident with the PAHs and [CII]emission,confirmingthattheCO only survives in a narrow dense + layer of the HI/H2 interface. We determine the CO fractional abundance relative to [CII]towardthreepositions associated with different PDRs. The abundances range from 0.1 to 1.9×10−10,andareingoodagreement + with chemical model predictions for the physical conditionsprevailinginthisUCHII region. Moreover, the CO linewidth is larger than those found in molecular gas tracers, and their central velocity are blue-shifted with re- spect to the molecular gas velocity. We interpret this as a hint that the CO+ is probing photo-evaporating clump surfaces. Overall, the spatial distribution and the kinematics of the studied species suggest the presence of photo-evaporating clumps in the dense frontier between the HII region and the molecular cloud. This scenario supports the idea of a fragmented ionization and photo-dissociated fronts that was previously suggested by Young et al. (2000) and Goicoechea et al. (2016).

Figure 1: MonR2 star-forming region as seen with CO+ (in color). Black contours correspond to the PAH 11.3 µmemission(PanelA);theH2 9.7 µmemissiontracingthelayerbetweentheHII region and the molecular gas (Panel B); and the [CII]emission(PanelC,Pillerietal.2014).Theredcontours(Panel B) show the NeII emission tracing the HII region (Berneetal.2009).Thebluesquareindicatestheionizationfron´ tposition.

References: • Berne,´ O., et al. 2009, ApJ, 706, L160 • Goicoechea, J., et al. 2016, Nature, 537, 207 • Pilleri, P. et al. 2014, A&A, 561, A69 • Trevino-Morales,˜ S. P., et al. 2014, A&A, 569, A19 • Trevino-Morales,˜ S. P., et al. 2016, A&A, 593, L12 • Young et al. 2000, ApJ, 540, 886 Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Water in Star Formation Presenting author: Floris van der Tak Contact: [email protected] Institute: SRON / University of Groningen

Water plays the double role of agent and tracer in the origin ofstars,planets, and habitability. This talk reviews the role of water as a tracer of the star for- mation process, in particular the formation of high-mass stars. After discussing observational advances from the ground (APEX, ALMA) and fromair/space(Her- schel, SOFIA), I will emphasize the importance of radiative transfer calculations (RADEX, RATRAN) and molecular input data (LAMDA, Basecol) for interpreting observational data. The talk concludes with an outlook into future opportunities, with instruments such as JWST/MIRI, ELT/METIS, and SPICA/SAFARI. Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Isotope selective photodissociation Presenting author: Ewine F. van Dishoeck Contact: [email protected] Institute: Leiden Observatory, Leiden University Co-authors:

Studying isotope selective photodissociation in space requires a detailed under- standing of microscopic processes at the molecular level. John’s most cited pa- pers are exactly on this topic, linking in-depth knowledge ofphotodissociation processes with astronomical applications. An overview willbepresentedofour current understanding of isotope selective photodissociation for the H2, CO and N2 isotopologs. Applications will range from individual diffuse and translucent clouds, to large scale collections of clouds, AGB stars, protoplanetary disks, comets and meteorites. Details do matter, but once they are well constrained they open up precision astrochemistry! Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: The delivery and evolution of water within the solar system studied via the D/H Presenting author: Geronimo L. Villanueva Contact: [email protected] Institute: NASA - Goddard Space Flight Center, Greenbelt, MD 20771, USA

The majority of our planet is covered with water (71%), while an ancient ocean covered at least 19% of the Martian surface and held more waterthanEarths Arctic Ocean, as recently revealed from water isotopic measurements. The in- ner planets in our solar system were thought to be formed within the frost-line, and should be in principal mostly devoid of water. Where does this water come from? Small bodies rich in water (e.g., comets, asteroids) have been proposed as vehicles for this delivery, yet alternative findings suggest that this water may have been primordially endowed to Earth and Mars.

The D/H is a powerful metric in order to address these questions. Not only it permits to understand about the origin and delivery of water to the inner solar system, but it also permits to characterize the evolution of the habitability on these planets. For instance, ground-based observations of D/H on Mars revealed that atmospheric water in the near-polar region was enrichedbyafactorofseven relative to Earths ocean water, implying that water in Mars permanent ice caps is enriched by 8-fold. Mars must have lost a volume of water 6.5 times larger than the present polar caps to provide such large enrichment, implying the existence of an ancient ocean on Mars.

Specifically, instruments and missions to characterize water and its isotopes across the solar system have reached an unprecedented level of sophistication and maturity, opening new windows in the astrobiological ex- ploration of our solar system. High-resolution infrared spectrometers with broad spectral coverage at ground- based observatories (e.g., Keck, IRTF, VLT) and arrays of radio telescopes with state-of-the-art receivers (e.g., ALMA) now permit the investigation of the kinematics, composition and thermal structure of a broad range of these bodies with unprecedented precision. These, combined with the advent of comprehensive spectro- scopic databases containing billions of lines, accurate radiative transfer models, and unprecedented available computational power, are transforming the way we investigate water in the solar system.

In this talk, I will present a review of our current understanding of water in the solar system, and how new capabilities will provide unprecedented opportunities forstudyingtheorigin,deliveryandevolutionofwater. Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: The ortho-to-para ratio of hydrogen and water molecules desorbed from ice dust: experimental approach Presenting author: Naoki Watanabe Contact: [email protected] Institute: Institute of Low Temperature Science, Hokkaido University Co-author: T. Hama, H. Ueta, A. Kouchi

Hydrogen (H2) and water (H2O) molecules have two nuclear isomers, ortho and para states for the total spin of 1 and 0, respectively. At thermal equilibrium, the ortho/para nuclear spin ratios (OPRs) of H2 and H2O are the functions of temper- ature, which is so-called nuclear spin temperature. Because the ortho and para spin isomers take rotational states with odd and even quantum numbers, respec- tively, observing the population of rotational states of those molecules gives the OPR, in other words, the nuclear spin temperature. Radiative transition between ortho and para states is forbidden. Furthermore, ortho-para conversion in gas + phase by spin exchange reactions with proton and ionic species like H3 occur very slowly [1], the OPR has been often used as a tool to investigate physical and chemical condition of the birth place of molecules. For H2, the OPR strongly affects not only chemistry like deuterium fractionation [2] in the gas phase but also gas dynamics of core formation [3] because the energy difference between the ortho and para states is significant. For H2O, it has been often proposed that the spin temperature closely correlates to the temperature either at birthplace of H2O molecule, i.e. the cosmic dust surface, or the inner cometary nucleus [4]. Recent years, laboratory experiments have shaded light on the behaviors of the OPR of H2 and H2O molecules on ice. For H2, it was found that the OPR of nascent H2 produced by H-H recombination is 3 and gradually decreases if H2 stays on the ice surface [5]. The ortho-para conversion rate is accelerated when O2 molecules coexist on the ice surface because of magnetic dipole interaction [6]. The combination of the Stark effect and Fermi contact was first proposed as a conversion mechanism [7]. The conversion rate on ice strongly depends on the ice temperature, which can be explained by energy dissipation by phonon process [8]. Very recently, the theoretical explanation for the conversion has been updated [9]. For H2O, the ortho-para conversion was observed in solid argon matrix[10]. However, the OPRs of water both thermally desorbed [11] and photodesorbed from ice at 10 K [12] indicate nearly 3 regardless of water formation processes. Last year, we further demonstrated that the OPR is also 3 for H2O photodesobed from ice which is produced from only para-H2O at around 11 K [13]. These findings clearly show the different behavior of the OPR between H2 and H2O on ice. In my presentation, I will make a brief review for experimental approach to the OPR of H2 and H2O from ice and discuss what controls the OPRs of these molecules on ice.

References: [1] D. Wilgenbus, S. Cabrit, G. Pineau des Forets,˝ D. Flower, In Molecular Hydrogen in Space, • p.123, ed. F. Combes & G. Pineau des Forets,˝ Cambridge: Cambridge Univ. Press, 2000. [2] L. Pagani, • E. Roueff, and P. Lesaffre, ApJL. 739, L35 (2011). [3] N. Vaytet et al. A&A 563, A85 (2014). [4] W. M. • • Irvine, F. P. Schloerb, J. Crovisier, B. Jr. Fegley, M. J. Mumma, In Protostars and Planets IV, p.1159, ed. V. Mannings, A. P. Boss, & S. S. Russell, Tucson, AZ: Arizona Univ. Press, 2000. [5] N. Watanabe et al. ApJL • 714, L233 (2010). [6] M. Chehrouri et al. Phys. Chem. Chem. Phys. 13, 2172 (2011). [7] T. Sugimoto and • • K. Fukutani, Nat. Phys. 7, 307 (2011). [8] H. Ueta et al. Phys. Rev. Lett. 116, 253201 (2016). [9] E. Ilisca • • Chem. Phys. Lett. 713, 289 (2018). [10] L. Abouaf-Marguin et al. Chem. Phys. Lett. 447, 232 (2007). [11] • • T. Hama, K. Kuwahata, N. Watanabe, et al. ApJ, 757, 185 (2012). [12] T. Hama, A. Kouchi, N. Watanabe, • Science, 351, 65 (2016). [13] T. Hama, A. Kouchi, N. Watanabe, ApJL 857, L13 (2018) • Posters Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Chemical diversity in early massive protostellar objects Presenting author: Laure Bouscasse Contact: [email protected] Institute: Max-Planck-Institut fur¨ Radiostronomie Co-author: Timea Csengeri, Karl M. Menten, Friedrich Wyrowski, Arnaud Belloche, Sylvain Bon- temps, Rolf Gusten¨

The physical conditions in massive dense cores (MDCs) leading to high-mass star formation are poorly constrained. Observations are lacking to confront the- ory. From the 870 micron ATLASGAL survey of the inner Galaxy, in the frame of the SPARKS project (Survey for high-mass Protostars with ALMA Revealed up to Kpc Scales, PI: Csengeri), we performed an ALMA follow-up on the most massive mid-infrared quiet clumps within 5 kpc. We found 6 sources that stay single from 0.3 pc to 2000 au scales. This makes them relatively easy targets for single-dish observations to study the early warm-up phase chemistry leading to the appearance of classical hot-cores. In addition to the 8 GHz instantaneous bandwidth at 345 GHz obtained with SPARKS, we obtained a complete spec- tral survey covering the 2 mm, 1 mm and 0.8 mm atmospheric window with the APEX telescope towards a handful of sources. We will present here the chemical composition of the protostellar envelopes. We aim to pin down where different molecules are located within the envelope with a particular focus on the distribu- tion and diversity of complex organic molecules. Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: The stacking revolution: searching for the seeds of life Presenting author: Hannah Calcutt Contact: [email protected] Institute: Chalmers University of Technology Co-author: J. B. Jolly

Complex organic molecules (COMs) are readily detected in theinnerregions of the gaseous envelopes of forming protostars. Their detection is crucial to understanding the chemical evolution of the Universe. Particularly, to explore the link between the early stages of star formation and the formation of solar system bodies, where complex organic molecules have been found in abun- dance.

In recent years, the astrochemical community has made significant progress in terms of surveying the chemical content of star forming regions. Several of the brightest and most well known regions have had whole band surveys per- formed (e.g. IRAS 16293–2422, Jørgensen et al. 2016, and Sgr B2, Belloche et al. 2016), providing us with an array of new molecular detections, particularly of the weakest molecules. Despite this, detections of some ofthemostcom- plex molecules, such as amino acids, have remained elusive. Studying these molecules is important to link the chemical content of star forming regions to the pathway to life formation. Their low abundance in star-forming regions makes their detection a particular challenge, even with the unprecedented sensitivity provided by ALMA observations.

Fundamentally, to detect the weakest molecules, we need to improve the signal-to-noise of our observa- tions. This is a problem that has also been encountered in high-redshift galaxy studies, but can be mitigated by using line stacking techniques, to overcome the intrinsic limitations in spectral observations (Jolly et al. in prep., Stanley et al. 2019). In this talk, I present work which applies these techniques to the local universe. We take an average of a large sample of Galactic hot cores, with the aimofdramaticallyimprovingthesignal-to-noise and detecting several biologically significant molecules for the first time in the ISM.

References: • Belloche, A., M¨uller, H. S. P., Garrod, R. T., & Menten, K. M. 2016, A&A, 587, A91 • Jørgensen, J. K., van der Wiel, M. H. D., Coutens, A., et al. 2016, A&A, 595,A117• Stanley, F., Jolly, J. B., Konig,¨ Knudsen, K. K., 2019, A&A Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Supercomputer simulation of astrochemical problems Presenting author: Igor Chernykh Contact: [email protected] Institute: Institute of Computational Mathematics and Mathematical Geophysics SB RAS, Novosibirsk, Russia Co-author: Igor Kulikov, Victor Protasov

Numerical simulation plays a key role in modern astrophysical researches be- cause the characteristic time scale for the most of the processes begins from split seconds for some chemical processes and goes up to hundreds of mil- lions of years for galaxies collision processes. In our presentation we provide anewapproachforthenumericalsimulationofastrophysicalandastrochemical processes. This approach is based on combining of both distributed and paral- lel computing techniques with advanced code vectorization for modern proces- sors architectures such as Skylake-SP/Cascade Lake-SP. Ournumericalcode is based on the hydrodynamics approach with using of Godunov’s scheme as a base of the solver. Astrochemical solver is based on chemicalkineticsapproach. In our presentation, we will show the result of the numerical simulation of some termolecular chemical processes for the high gas temperatures and densities. This research was supported by the RSCF grant 18-11-00044.

References: • Kulikov I., Chernykh I., Tutukov A. A New Hydrodynamic Model for Numerical Simulation of Interacting Galaxies on Intel Xeon Phi Supercomputers. Journal of Physics: Conference Series,Vol.719,ArticleNumber012006,2016.• Kulikov I.M., Chernykh I.G., Glinskiy B.M., Protasov V.A. An Efficient Optimization of HLLMethodfortheSecondGenerationofIntelXeon Phi Processor. Lobachevskii Journal of Mathematics,Vol.39,pp.543–550,2018. • Kulikov I.M., Chernykh I.G., Snytnikov A.V., Glinskiy B.M., Tutukov A.V. AstroPhi:Acodeforcomplexsimulationofthedynamics of astrophysical objects using hybrid supercomputers, Computer Physics Communications,Vol.186,pp.71– 80, 2015. • Chernykh et al. Advanced vectorization of ppml method for Intel⃝R Xeon⃝R scalable processors. Communications in Computer and Information Science,Vol.965,pp.465–471,2019. Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: The Fundamental Vibrational Frequencies and Spectroscopic Constants of the Dicyanoamine Anion: Quantum Chemical Analysis of a Likely Planetary Anion, NCNCN (C2N3) Presenting author: David Dubois Contact: [email protected] Institute: NASA Ames Research Center/BAER Institute Co-author: Ella Sciamma-O’Brien, Ryan Fortenberry

Since the first identification of anions in dense molecular clouds and cir- cumstellar envelopes (CSE) in 2006 (McCarthy et al., 2006), their detec- tion has remained difficult. The well-studied IRC +10216 CSE (e.g. Remi- jan et al., 2007) has nonetheless revealed the presence of CnH carbon- chain as well as cyano molecular anions (e.g. Thaddeus et al., 2008) such as Cn 1N (n = 2 6). Among these, C8H (Brunken et al., 2007) represents the largest carbon-chain anion detected in the interstellar medium (ISM). In addition, Saturn’s moon Titan also unveiled the presence of large anions with masses up to 13,800 u/q which require further identifica- tions.

The effort in the detection of anions has relied on a strong collaboration be- tween theoretical and laboratory analyses to measure rotational spectra and spectroscopic constants to high accuracy. The advent of improved quantum chemical tools operating at higher accuracy and reduced computational cost is a crucial solution for the fundamental characterization of astrophysically-relevant anions and their detection in the interstellar medium. In this context, we have turned towards the quantum chemical analysis of the dicyanamide anion NCNCN (C2N3), a structurally bent and polar compound. We have performed computations of C2N3 using a CcCR (for Complete basis set limit, core Correlation and Relativity) quartic force field (QFF) method, which satisfy both computational cost and 1 accuracy approaches (Fortenberry 2017). This ion displays a bright ⌫2 (2130.9 cm ) and a lesser ⌫1 (2190.7 1 cm ) fundamental vibrational frequency, making for strong markers for upcoming infrared observations with the James Webb Space Telescope. Such an ion could potentially be detected in nitrogen-rich environments of the ISM or in the atmosphere of Titan, where advanced N-based reactions may lead to its formation.

References: McCarthy M. C., Gottlieb C. A., Gupta H., and Thaddeus P., 2006, The Astrophysical Journal, • 652:L141-144 Thaddeus P., Gottlieb C. A., Gupta H., et al., 2008, The Astrophysical Journal, 677:1132-1139 • Fortenberry R. C., 2017, International Journal of Quantum Chemistry, 117, 81-91 • Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Large scale mapping of the Orion B molecular cloud Presenting author: Maryvonne Gerin Contact: [email protected] Institute: LERMA, Observatoire de Paris Co-author: J. Pety, S. Bardeau, V. de Souza Magalhaes, E. Bron, J.R. Goicoechea, P. Gratier, V. Guzman, Hughes, A., Languignon D., F. Le Petit, F. Levrier, H. Liszt, K. Oberg,¨ J.H.Orkisz, N. Peretto, E. Roueff, A. Sievers , P. Tremblin

Located at about 400 pc from the Sun, the Orion Giant Molecular clouds (GMCs) are the closest regions of massive stars formation. At large spatial scales, GMCs are known to exhibit a complex structure, shaped by turbulence, gravity and mag- netic fields. To better understand the impact of the environment onto the stellar formation efficiency, sensitive, wide-field, spectroscopic mapping of the molecu- lar gas is required. The ORION-B project (Outstanding Radio-Imaging of OrioN B) currently uses the IRAM-30m/EMIR 3mm receiver to image a field of 5 square degrees, located near the southern edge of the Orion B molecular cloud. A total frequency bandwidth of 40 GHz is being observed with a spectral resolution of 195 kHz (0.6 km/s), a typical spatial resolution of 27” (i.e., 50 mpc or 104 AU at 400 pc, the distance of Orion B), and a typical sensitivity of 0.1 K (Pety et al. 2017). Using the 12CO and 13CO(1-0) lines, we characterized the ratio of com- pressive vs. solenoidal motions in the turbulent flow, and we related this to the star formation efficiency in various regions of Orion B (Orkisz et al. 2017). The C18O(1-0) line allows us to finely characterize the dynamics of the filamentary network in the Orion B (Orkisz et al. 2019). Compared to previous studies, the filament population is dominated by low-density, thermally sub-critical structures, suggesting that most of the identified filaments are not collapsing to form stars. In fact, only 1% of the Orion B cloud mass covered by our observations can be found in super-critical, star-forming filaments, consistent with the low star formation efficiency of the region. We have performed statistical analyses of the multi line information acquired in the survey to use the diversity of information carried by the various molecular species. These first analyses performed on a subset of the whole map (Gratier et al. 2017, Bron et al. 2018) show that accurate information on the gas column density, density and UV illumination can be extracted from the molecular line intensities, and that difference in chemical pattern can be related to differences in physical con- ditions. We are now working on a wider field of view and on more detailed analyses including comparison with predictions from chemical models.

Image of the CO isotopologue emission in the Orion-B molecular cloud, 12CO is shown in blue, 13CO in green and C18O in red (Pety et al. 2017).

References: Bron et al. 2018 A&A 610, A12. doi:10.1051/0004-6361/201731833 Gratier et al. 2017, • • A&A 599,A100. doi:10.1051/0004-6361/201629847 Orkisz et al. 2017 A&A 599,A99. doi:10.1051/0004- • 6361/201629220 Orkisz et al. 2019 , A&A in press, arxiv 1902.02077 Pety et al. 2017 A&A 599, A98. • • doi:10.1051/0004-6361/201629862 Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Physical and chemical complexity in high-mass star-forming regions Presenting author: Caroline Gieser Contact: [email protected] Institute: Max Planck Institute for Astronomy Heidelberg Co-author: Henrik Beuther, Dmitry Semenov, Aida Ahmadi, Sumeyye¨ Suri and the CORE team

The birthplaces of massive stars are ideal laboratories to study the formation and destruction of molecules in the interstellar medium. Here, we present a detailed observational analysis of the physical and chemical properties of 18 luminous high-mass star-forming regions. This study is part of the NOrthern Extended Millimeter Array (NOEMA) large program CORE (Beuther et al. 2018). The observations were carried out with NOEMA at 1.4 mm with an angular resolution of 0.4 and to include large-scale emission observations using the IRAM 30 m ⇡ 00 telescope were complemented. The 1.4 mm continuum of the sample shows a large diversity of fragmenta- tion properties (Beuther et al. 2018). In addition, the spectral line data (covering emission lines from simple and complex organic molecules) reveal large differ- ences between the regions as well as nearby dense cores (Feng et al. 2016, Gieser et al. in prep.). In this study, we quantify the chemical content with re- spect to the physical properties and investigate the spatial extent of the molecular emission.

Figure 1: Each panel shows the integrated intensity map of the H CO 3 2 transition. The white contour 2 0,3 0,2 marks the 5 level of the integrated intensity. The green contour is the 5 level of the 1.4 mm continuum emission. The beam size of the spectral line data is shown in the lower left corner. The tick spacing is set to 500.

References: Beuther, H., Mottram, J. C., Ahmadi, A., et al. 2018, A&A, 617, A100 Feng, S., Beuther, H., • • Semenov, D., et al. 2016, A&A, 593, A46 Gieser et al. in prep. • Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

+ Title: Odin and Herschel observations of H2O, CH and CH in the barred spiral galaxy NGC 1365 - bar induced activity in the circumnuclear torus region Presenting author: Åke Hjalmarson Contact: [email protected] Institute: Dept of Space, Earth and Environment, Chalmers University ofTechnology,Onsala Space Observatory, SE-439 92 Onsala, Sweden Co-author: Aage Sandqvist, Bengt Larsson, Per Olof Lindblad, Urban Frisk, Stefan Lundin and Gustaf Rydbeck

NGC 1365 is a prominent barred spiral galaxy in Fornax clusteratadistanceof 18.6 Mpc (where 1′′ corresponds to 90 pc). The galaxy displays a wide range of activity phenomena, including a Seyfert 1.5 type nucleus,anejectionjetof hot gas from the nucleus (black hole), and a circumnuclear torus containing a number of bright hot super star clusters and their associatedmassivemolecular cloud complexes. The Odin satellite is now in its nineteenth year of operation,muchsurpassing its design life-time of two years. We have recently used Odin to search for water vapor in NGC 1365 and have obtained a tentative detection of the 557 GHz ground state o-H2Olineinthecentralregionofthegalaxy.HerschelSpace Observatory has mapped the inner region of NGC 365 with the SPIRE and PACS instruments and we have analyzed these mostly unpublished results, which are available in the Herschel Science Archive. A number of water lines were detected by SPIRE and the SPIRE results at 557 GHz are supporting the Odin results. ′′ The H2Oemissionislocalizedtoa15 size region near the north-eastern peak of the central molecular torus of NGC 1365 -a region displaying various signs of shocks and strong star formation triggered by the bar- driven inflow. We study the ongoing physical processes by means of the aforementioned multi-transition H2O(andCO)obser- vations, and here make additional use of new Statistical Image Deconvolution applied to SEST observations of the CO (3–2) line, yielding an effective resolution of 5′′.Theatomicgasinthegalaxycenterisalsostudied using unpublished VLA HI observations. Astudyoftheongoingchemicalprocessesinthecircumnuclear torus region is also performed-aiming + at evaluating the most relevant excitation and formation scenarios for H2O, CH and CH (and also other molecules) in this region of cloud-cloud collisions, increased turbulence, shocks, and extensive star formation (leading to outflows/shocks and PDRs). Here an increased ionization level caused by cosmic ray focussing (in the observed, aligned magnetic field), and also by X-rays, mayplayanadditionalrole. Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Simulating deuterium fractionation in massive pre-stellar cores Presenting author: Chia-Jung Hsu Contact: [email protected] Institute: Chalmers University of Technology Co-author: Jonathan Tan

The degree of deuterium fractionation is thought to be an important indica- tor of the chemical ages of pre-stellar cores. The physical properties and the timescale required to reach a high deuterium fraction of N2H+ are under de- bate. Here we utilize KROME to couple a sophisticated chemical network into a three-dimensional magnetohydrodynamical simulation run by ENZO. The chemi- cal network involves general three-atom species as well as H3O+ and its deuter- ated form, which could influence the timescale and the fraction at steady state. The improved model enables us to analyze the time evolution of N2D+ and H2D+ more accurately and assess their role in observational studies of pre-stellar cores.

References: S. Kong, P. Caselli, J. C. Tan, V. Wakelam, and O. Sipila. The Deuterium • Fractionation Timescale in DenseCloud Cores: A Parameter Space Explo- ration.Astrophysical Journal, 804:98, May 2015. M. D. Goodson, S. Kong, J. C. Tan, F. Heitsch, and P. Caselli. Structure, Dy- • namics, and DeuteriumFractionation of Massive Pre-stellar Cores.Astrophysical Journal, 833:274, Dec 2016 Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Mixing of the First Supernovae Metals Presenting author: Chia-Jung Hsu Contact: [email protected] Institute: Chalmers University of Technology Co-author: Ke-Jung Chen, Daniel J. Whalen, Jonathan Tan

Metal enrichment by the first generation (PopIII) supernovae changes the abun- dance pattern in the early universe, and influences the next generation of star formation. The chemical enrichment highly depends on the mixing and fallback processes behind supernovae explosions. We utilize two popular codes, FLASH and ZEUS, to simulate the explosion process of the first supernovae in miniha- los. Besides, we are interested in the influence of cooling processes and in- volve the physics by KROME. We investigate the mixing process triggered by a core-collapse supernova whose progenitor is a 15 M metal-free star in a photo- evaporated minihalo. Our results provide an abundance pattern to discuss the astrochemistry and the formation of metal-poor stars in the early universe.

References: Daniel Whalen, Bob van Veelen, Brian W. O’Shea, Michael L. Norman. The • Destruction of Cosmological Minihalos by Primordial Supernovae.Astrophysical Journal, Jul 2008. Ke-Jung Chen, Daniel J. Whalen, Katharina M. J. Wollenberg, Simon C. O. • Glover, Ralf S. Klessen. How the First Stars Regulated Star Formation. II. En- richment by Nearby Supernovae, Aug 2017 Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Determining star formation rates in high-redshift galaxies from IRX-beta relation Presenting author: Maciej Koprowski Contact: mkoprowski@fizyka.umk.pl Institute: University of Nicolaus Copernicus Co-author: Kristen Coppin, James Dunlop, Jim Geach, Michał Michałowski, et al.

Precise determination of star formation rates for many galaxies at high redshifts is very difficult, as they often lack IR observations, sensitive to the starlight re- processed by dust. In order to account for this, one has to, therefore, utilize alternative methods, most popular of which involves estimating the energy re- emitted in the IR based on the amount of reddening in the rest-frame UV via the so-called IRX- relationship (Meurer et al. 1999). Many works, however, seem to indicate that this local relation may not necessarily hold at high redshifts (eg. Capak et al. 2015). In this talk I will present the stacking analysis of a large sam- ple of optically-selected Lyman-break galaxies (LBGs) in the JCMT SCUBA2 and Herschel SPIRE bands that was done in order to re-calibrate the IRX- relation- ship at redshifts 3 5. I will show that at high redshifts, the average galaxy suffers from the dust attenuation law which is characteristic of local sources (Calzetti et al. 2000). I will also explain how different methods of estimating the UV slope, , can cause the resulting rela- tion appear flatter and therefore often consistent with the SMC-like attenuation law (eg. Reddy et al. 2018). In addition, I will show how the individual values of the IRX and were calculated for a sample of 41 z 3 LBGs, ⇠ detected in the recently-finished ALMA follow-up survey of the UDS SCUBA2 sources (Stach et al. 2018). I will explain how the apparent scatter in the IRX- plane is driven by the relative distribution of the stars and dust, as encoded in the shapes of the attenuation curves, as well as show how the shapes of the assumed attenuation curves affect the resulting stellar masses, as estimated via SED fitting. The results presented in this talk indicate that while, on average, star formation rates for high-redshift galaxies can be estimated from UV data alone, the values for the individual sources cannot be trusted in the absence of the IR data.

Figure 1: IRX- relation for z 3 LBGs (black circles) compared with some of the recent literature results. The black solid and dashed ⇠ lines represent the Calzetti- and SMC-like dust curves. It is clear, while ours and McLure et al. (2018) data are consistent with the Calzetti-like dust, others seem to be lying between two dust curves.

References: Calzetti D., Armus L., Bohlin R. C., Kinney A. L., Koornneef J., Storchi-Bergmann T., 2000, ApJ, • 533, 682 Capak P. L. et al., 2015, Nature, 522, 455 McLure R. J. et al., 2018, MNRAS, 476, 3991 Meurer • • • G. R., Heckman T. M., Calzetti D., 1999, ApJ, 521, 64 Reddy N. A. et al., 2018, ApJ, 853, 56 Stach S. M. et • • al., 2018, preprint (arXiv:1903.02602) Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Fullerene oligomers and polymers as carriers of unidentified IR emission bands Presenting author: Serge Krasnokutski Contact: [email protected] Institute: Laboratory Astrophysics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University Jena Co-author: M. Gruenewald, C. Jager,¨ F. Otto, R. Forker, T. Fritz, Th. Henning

Several unidentified IR emission bands (UIBs) have been assigned to neutral C60 molecules present in circumstellar and interstellar environments. However, due to the similarity of IR spectra of C60 in the solid state and in the gas phase, there is as yet no consensus on the aggregation state of C60. We will show that even strong covalent chemical bonding might have very little influence on the IR spectrum of C60, and that therefore such chemically bonded C60 could be the carrier of the same UIBs. It would best explain observations like the missing emission from C60 ions and a large variation of relative band intensities between different sources. In our previous work, we demonstrated that C additions at low temperature enhance the chemical activity of the surface of C60 by carbene formation. The lat- ter may pave the way toward a generation of a new class of fullerene derivatives. Reactive C60 carbene species may also be formed in interstellar and circumstel- lar environments containing C and C60, where they could add other molecules, to form variety of fullerene derivatives and even fullerene polymers C60(C=C60)n. In our recent study, we demonstrated that such a chemically bonded C60 poly- mer can be produced by co-condensation of C atoms together with C60 molecules on the surface of refractory dust particles. The experiments were performed in UHV chamber focusing molecular beams of C60 molecules and C atoms on SiO2 substrate. This leaded to the formation of a three-dimensional C60 polymer film. Such polymerized C60 molecules cannot easily desorb, while their spectral properties in the VIS and IR are almost undisturbed by polymerization. As can be seen in Figure 1, the IR spectrum of C60 polymer film demonstrate only few new weak absorption bands, while the positions of the main absorption bands of C60 are not altered.

Figure 1: IR (a) and UV-VIS (b) absorption spectra of the film produced by deposition of C60 alone and together with C atoms. Arrows point to the new IR bands appearing after the polymerization of C60 molecules. Panel (b) demonstrates that the electronic properties of C60 remain almost unaltered upon polymerization.

References: S. A. Krasnokutski, M. Kuhn, A. Kaiser, A. Mauracher, M. Renzler, D. K. Bohme, and P. Scheier, • JPCL 7 (2016) 1440. S. A. Krasnokutski, M. Gruenewald, C. Jager,¨ F. Otto, R. Forker, T. Fritz, Th. Henning, • to appear in ApJ, 2019. Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: CO Depletion and the X-Factor on Subparsec Scales Across the California Molecular Cloud. Presenting author: Charles J. Lada Contact: [email protected] Institute: Harvard-Smithsonian Center for Astrophysics Co-author: John Lewis, John Bieging

We report the results of an extensive investigation into the relation between dust and gas-phase CO column densities across the California Molecular Cloud (CMC), perhaps the largest and most massive GMC in the solar neighbor- hood. We compare dust emission maps derived from Herschel observations with 12CO(2-1), 13CO (2-1) and C18O(2-1) emission obtained with the Steward Observatory’s SMT to make deep (2 A 60 mags) and direct comparisons  V  of CO and dust column density measurements at matched sub-parsec resolu- tion across this GMC. We find that on these scales there is no single value of the X-factor that characterizes the gas in the cloud, confirming results from an earlier study (Kong et al. 2015). Indeed, measured X-factors range between 0.5-25 with XCO approximately 13 ⇡ proportional to AV for cold ( TD < 17 K) gas. We compare CO (LTE) column densities with dust column den- sities for each map pixel to derive and map the 13CO depletion factor across the CMC. We find this depletion factor to range between 1 in the warmer (T > 17 K) and lower extinction regions of the cloud to >20 in the ⇡ D colder (TD < 17 K), higher extinction regions of the cloud, consistent with expectations of chemical desorption of gas-phase CO onto cold grains. We use our depletion factor maps to define the boundaries of dense cores and construct a corresponding catalog of ”depletion” cores. We derive the core masses from the dust column densities and depletion measured sizes and compare the results to similar measurements based solely on extinction measurements. We use the 13CO and C18O observations to measure the virial parameters of the cores. We find a well behaved relation between the virial parameter and mass of a core that is consistent with a pressure confined sequence, similar to other clouds (e.g., Lada et al. 2008; Kirk et al. 2017). Only about half the cores appear to be bound solely by gravity.

50 120

100 40

80 (K)

30 dust

60 T

40 Depletion 20

20 (b) Latitude Galactic

W[12CO (J=2-1)] (K km/s) (J=2-1)] W[12CO 0 10 20 30 40 50 60 Galactic Longitude (l) Visual extinction (mag)

Figure 1: Left panel shows the relation between W(12CO) and extinction for the CMC, clearly demonstrating the lack of a unique X-factor for the cloud. The right panel is a map of the 13CO depletion factor in one region of the CMC. Depletion contours are plotted on top of a gray scale map of the Herschel derived dust column density. At any point the measured depletion factor is a line-of-sight average and thus a lower limit to the true value in the depleted inner regions. The peak of depletion in this map corresponds to a depletion factor >>12.

References: Kong et al. 2015, ApJ, 805, 58. Lada et al., 2008, ApJ, 672, 410. Kirk et al. 2017, ApJ, 846, • • • 144. Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: The polarization and molecular Zeeman effect of masers Presenting author: Boy Lankhaar Contact: [email protected] Institute: Chalmers University of Technology Co-author: Wouter Vlemmings

Understanding the magnetic field strength and morphology of (high-mass) star forming regions and proto-planetary disks is of great importance in understand- ing their dynamics. A tracer for the magnetic field in the densest parts of star forming regions are molecular masers. Molecular masers are often found to be (highly) polarized, both linearly and circularly, and can therefore reveal in- formation on both magnetic field strength and morphology of the regions they occur in. In this talk, I will present recent work on the molecular Zeeman pa- rameters of methanol, a maser specie which occurs in (high-mass) star forming- regions. Computing methanols Zeeman parameters using quantum-chemical methods allowed us to perform the proper (re-)analysis of 10 years of methanol maser observations, which was not possible before due to the missing Zeeman parameters. I will also present the resuls of a new radiative transfer code that is concerned with maser polarization. We find that the most strongly polarized maser emission must come from alternative polarization mechanisms such as anisotropy in the pumping. Alternative polarization mechanisms could be revealing for the dynamics surround- ing the maser region. We will also discuss the influence of higher order matter-radiation interactions, such as anisotropic resonant scattering, on the maser polarization radiative transfer.

References: B. Lankhaar, W.H.T. Vlemmings, G. Surcis et al., Characterization of methanol as a magnetic • field tracer in star-forming regions, NatAs 2 (2018) B. Lankhaar, G.C. Groenenboom, A. van der Avoird • Hyperfine interactions and internal rotation in methanol, J Chem Phys 145 (2016) Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: GUAPOS: G31.41+0.31 Unbiased ALMA sPectral Observational Survey Presenting author: Chiara Mininni Contact: [email protected] Institute: University of Florence Co-author: M. T. Beltran,´ A.´ Sanchez-Monge,´ V. M. Rivilla, R. Cesaroni, P. Schilke, F. Fontani, S. Viti, I. Jimenez-Serra,´ L. Testi, T. Moller¨ and L. Colzi

Some of the best sources to study the richness and complexity of chem- istry in the interstellar medium, are Hot Molecular Cores (HMCs), the birth- places of high mass stars. Spectra of these sources show a very high den- sity of molecular lines, including emission from hydrogenated species, O-bearing species, N-bearing species, deuterated molecules and interstellar Complex Or- ganic Molecules (iCOMs) (e.g. Belloche et al. 2013). This richness is due to their 7 3 typical mass (M > 100M ), density (n 10 cm ) and temperature (T > 100K), ⇠ that allow the release in gas-phase, by thermal evaporation or due to shocks associated with the high mass star formation process, of the products of the chemical reactions occurring on the surface of grain mantles. Moreover, the high temperatures allow to activate the neutral-neutral reactions that cannot occur in colder material. Spectral surveys in HMCs have been carried out mostly towards Sgr B2 (Sanchez-Monge´ et al. 2017; Belloche et al. 2013), but this source can not be considered as a template for typical HMCs in the Galaxy, since its proximity to the Galactic Center leads to peculiar environmental condi- tions, that could indeed have an impact on the chemistry. Here we present the project GUAPOS (G31.41+0.31 Unbiased ALMA sPectral Observational Survey), a full ALMA Band 3 spectral survey with a resolution of 1.2” towards G31.41+0.31 (G31), one of the most well-known and chemically-rich HMC in the Galaxy (Cesaroni et al. 2010; Beltran´ et al. 2018). G31 is located at 3.7 kpc, with a luminosity 104L (Beltran´ et al. 2005) and has no UC HII region embedded on it (Cesaroni et al. 2010). The first detection of glycolaldehyde outside the Galactic Center has been obtained towards G31 (Beltran´ et al. 2009), and heavy complex molecules such as methyl formate or ethylene glycol have also been prevoiusly observed in this source (Rivilla et al. 2017). The spectrum of the GUAPOS project, covering the spectral interval 84 - 116 GHz with a spectral resolution of ⇠ 500 KHz, will allow us to identify the large number of molecules present in this source (including iCOMS such ⇠ as C2H5CN, CH3CHO, CH3OCHO, CH3OCH3 and CH3COCH3 - see Fig.1) and to unveil its chemistry.

Figure 1: In black: G31 spectrum from the GUAPOS project, between 98 and 101 GHz; in red: preliminary synthetic spectrum obtained with XCLASS (Moller¨ et al. 2017)

References: Belloche et al. 2013, A&A 559, A47 Sanchez-Monge´ et al. 2017, A&A 604, A6 Beltran´ et • • • al. 2018, A&A 615, A141 Beltran´ et al. 2005, A&A 435, 901 Cesaroni et al. 2010, A&A 509, A50 Beltran´ • • • et al. 2009, ApJ 690, L93 Rivilla et al. 2017, A&A 598, A59 Moller¨ et al. 2017, A&A 598, A7 • • Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: The chemical structure of the starless core L1521E Presenting author: Zsofia Nagy Contact: [email protected] Institute: Max-Planck-Institute for Extraterrestrial Physics Co-author: Silvia Spezzano, Paola Caselli, Anton Vasyunin, Mario Tafalla, Luca Bizzocchi, Domenico Prudenzano, and Elena Redaelli

L1521E is a dense starless core in Taurus which was found to have relatively low molecular depletion (e.g. Tafalla & Santiago, 2004). We haveobtained∼2.5×2.5 17 arcminute maps in transitions of key molecular species, including C O, CH3OH, c-C3H2,CN,SO,H2CS, and CH3CCH, using the IRAM-30m telescope, to study the chemical structure of L1521E. We compared the results to those obtained toward the more evolved and better characterized L1544 pre-stellar core (Spez- zano et al. 2017 and references therein). Based on the IRAM-30m C17Omap and N(H2)derivedfromHerschel/SPIRE data, CO depletion toward L1521E is more significant than suggested by earlier studies, with a lower limit of 4.9±1.8 on the CO depletion factor toward the dust peak. The abundances of most sulfur- + 34 33 bearing molecules such as C2S, HCS ,C S, C S, SO, and OCS are higher toward L1521E than toward L1544 by factors of ∼2-20, which suggests that sig- nificant sulfur depletion is taking place during the dynamical evolution of dense cores, from the starless to pre-stellar stage. This is also confirmed by chemical models.

L1521E L1544 102

101 OH) 3

100 N(X)/N(A-CH 10-1

10-2

OH + + 2 C 3 N H 13 CCH CN 18 O CN CS S 33 S 34 S CS 3 3 H 3 3 13 SO 13 OCS C 2 C C HCS H 2 HC c-C C 4 HN E-CH CH CH HC H HCO HCN

Figure 1: Comparison of the abundances of species observed toward the dust peak of both L1521E and L1544.

References: • Tafalla M. & Santiago J., 2004, A&A, 414, L53 • Spezzano, S.; Caselli, P.; Bizzocchi, L. et al. 2017, A&A 606, 82 Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Radiative association of small molecules Presenting author: Daria Burdakova Contact: [email protected] Institute: Chemistry and molecular biology Co-author: Gunnar Nyman, Magnus Gustafsson, Thierry Stoecklin

When new stars are born, matter is contracting towards their center of mass during a so called gravitational collapse. The gravitational energy is then trans- formed into kinetic energy, similar to a falling object. For the star formation to continue efficiently, some of the kinetic energy must be removed, which can oc- cur by emitting electromagnetic radiation [1]. Emission of electromagnetic radi- ation can be efficiently done by molecules. Therefore knowing which molecules are present in the interstellar media, how they are created and destroyed is of importance when considering star formation. This work focused on radiative association (RA) reactions to form the CH + and Na +H2 molecules. RA is the process where a molecule is formed, from two atoms or smaller molecules, while emitting a photon. The CH molecule was chosen for this study because of its occurrence in several chemical reactions in the interstellar medium, the sun, and comets [2]. Since metal ions have been observed in the envelope of IRC+10216 [3], studying molecules containing metal + ions has been of interest. This motivates this choice of the Na H2 molecule. The focus of the study was to calculate the reaction cross sections and reaction rates. The reaction cross section is a measure of how frequently the atoms will collide and form a molecule. The cross section is then used to obtain the reaction rate constant, thereby giving an understanding of the formation process of the molecule. Since RA is a very slow process it is hard or impossible to study experimentally and here we have studied it numerically. Two different programs have been used to obtain the reaction rates. The CH molecule was treated using a locally written program that calculates the reaction rates for the formation of diatomic molecules through RA. That program uses a semiclassical (SCl) method the results of which are compared to the results obtained using a method based on perturbation theory (PT). The advantage of the SCl method is that it is computationally cheaper than the PT method. A program written by Thierry Stoecklin that calculates RA + reaction rates to form triatomic molecules was used to obtain the rate coefficients for Na H2 formation from + Na +H2. The program is using a method [4] developed using the photodissociation theory by Band et al. [5] and Balint-Kurti et al. [6] together with the driven equations method by Heather et al. [7]. Since photodissociation is the reverse process of RA some changes were made.

References: Reference 1 D. Prialnik (2000). An Introduction to the Theory of Stellar Structure and Evolution. • Cambridge University Press. pp.198199. Reference 2 B. D. Abdallah, et al (2008). Ab initio potential • energy surfaces for the study of rotationally inelastic CH(X2) + H(2S) Collisions, Chem.Phys. Lett. 456, 7- 12. Reference 3 S. Petrie, R. C. Dunbar (2000), Radiative association reactions of Na+, Mg+, and Al+ • with abundant interstellar molecules. variational transition state theory calculations, J. Chem. Phys. 104, 44804488. Reference 4 T. Stoecklin, F. Lique, M. Hochlaf (2013), A new theoretical method for calculating • the radiative association cross section of a triatomic molecule: application to N2-H, Phys. Chem. Chem. Phys. 15, 13818-3825. Reference 5 Y. B. Band, K. F. Freed, D. J. Kouri (1981), Half-collision description of nal state • distributions of the photodissociation of polyatomic molecules, Journal of Chemical Physics 74, 43804394. • Reference 6 G. G. Balint-Kurti, M. Shapiro (1981), Photofragmentation of triatomic molecules.295 theory of angular and state distribution of product fragments, Chem. Phys. 61, 137155. Reference 7 R. W. Heather, • J. C. Light (1983), Photodissociation of triatomic molecules: Rotational scattering eects, J. Chem. Phys. 78, 55135530. Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

+ + Title: Deuteration of N2H and HCO in the prestellar core L1544 and first evidence of + N2D depletion Presenting author: Elena Redaelli Contact: [email protected] Institute: Max Planck Institute for Extraterrestrial Physics Co-author: P. Caselli, L. Bizzocchi, O. Sipila,¨ et al.

5 The elemental abundance of deuterium is D/H = 1.5 10 (Linsky 2003), but in the cold phase of the interstellar medium (ISM), molecules exhibit enhancements up to four orders of magnitude with respect to this value (Ceccarelli et al. 2014). + In fact, in cold and dense environments the production of H2D , the progenitor of all deuterated species, is greatly favored (Dalgarno & Lepp 1984). The deutera- tion fraction is thus considered a good diagnostic indicator of the star formation process, and it is linked to other important quantities such as the electron fraction (Caselli et al. 1998). L1544 is one of the most studied prestellar cores, which represent the initial stages of low-mass star formation. In this work, we present new, high sensitivity and high spectral resolution maps of several molecular ions: + + 18 + + N2H (1-0) and (3-2), N2D (1-0), (2-1) and (3-2), HC O (1-0), and DCO (1-0), (2-1) and (3-2). Combining the physical model of the source (Keto et al. 2015) with the abundance profiles derived with a gas-grain chemical model (Sipila¨ et al. in prep), we are able to perform a full non-LTE radiative transfer analysis at the core’s dust peak, using the code MOLLIE (Keto 1990) This approach allows us to derive the excitation conditions of each molecule and to use this information to compute reliable values for the molecular column densities and thus of the D/H ratios, shown in Figure 1. Our study confirms that the LTE assumption does not hold for the analyzed transitions. We compute peak values for the deuterium fraction of D/H + = (0.19 0.02) and D/H + = (0.027 0.003), respectively, in good N2H ± HCO ± agreement with previous work. We are able to investigate the D/H ratio up to 4500 ( 6000 AU), where D/H + + ⇡ ⇡ values drop to 1% for HCO and 7% for N2H . The chemical code used to model the observations predict ⇡ ⇡ + the partial depletion at the core’s center for all the molecules, including N2D . This is to our knowledge the first + time that the freeze-out of N2D onto dust grains, often predicted by models, finds observational confirmations.

+ + Figure 1: D/H ratios derived in L1544 for N2H (left panel) and HCO (right panel). The black cross represents the position of the mm dust peak (Ward-Thompson et al., 1999). The beam sizes are shown with red circles.

References: Caselli, P., et al. 1998, ApJ, 499, 234 Ceccarelli, et al. 2014, in Protostars and Planets VI, ed. • • H. Beuther, R. S. Klessen, C. P. Dullemond, & T. Henning, 859 Dalgarno, A. & Lepp, S. 1984, ApJ, 287, L47 • Keto, E. R. 1990, ApJ, 355, 190 Keto, E., Caselli, P., & Rawlings, J. 2015, MNRAS, 446, 3731 Linsky, J. • • • L. 2003, Space Sci. Rev., 106, 49 Ward-Thompson, D., Motte, F., & Andre, P. 1999, MNRAS, 305, 143 • Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Quantum Chemical Evaluation of Polarity-Inverted Membranes and Polymers on the Surface of Titan Presenting author: Hilda Sandstrom¨ Contact: [email protected] Institute: Chalmers University of Technology Co-author: Martin Rahm

Saturn’s moon Titan is the only other body in our solar system, except Earth, that hosts a dynamic liquid cycle that supports lakes, rivers and rainfall on its surface (Tokano et al., 2006). The lakes on Titan are predominately made out of liquid methane and ethane (Stofan et al., 2007), and photochemistry in the atmo- sphere produces a rich a variety of organic compounds (Niemann et al., 2005). Titan has been proposed as a strict test case for the limits of life, and the possibil- ity for ”methanogenic” life has received much attention (Lunine, 2010). In 2015, Stevenson et al. (Stevenson et al., 2015) suggested the possible self-assembly of cell membranes made from acrylonitrile under Titan’s cryogenic conditions, based on theoretical calculations. The membranes were referred to as azoto- somes and were proposed to form due to an enthalpy driven self-assembly through the dipole-dipole interaction of the nitrogen containing groups. Azotosomes were found to be kinetically stable and of comparable flexibility to lipid bilayer membranes on Earth. In 2017, acrylonitrile was detected in Titan’s atmosphere by the ALMA radio telescope (Palmer et al., 2017), further fuelling speculation of the molecule’s importance. To evaluate these claims, we have performed quantum mechanical calculations to estimate the thermodynamic stability of the proposed azotosome membrane relative to the molecular crystal structure of acrylonitrile. Our calculations strongly suggest that azotosome self-assembly is unlikely. This contribution will include a brief update on our current research into cryogenic polymerization of hydrogen cyanide within the context of Titan.

References: Tokano, T.; McKay, C. P.; Neubauer, F. M.; Atreya, S. K.; Ferri, F.; Fulchignoni, M.; Niemann, • H. B. Nature 2006, 442, 432-435. Stofan, E. R. et al. Nature 2007, 445, 61-64. Niemann, H. B. et al. • • Nature 2005, 438, 779-784. Lunine, J. I. Faraday Discuss 2010, 147, 405-18; discussion 527. Stevenson, • • J.; Clancy, P.; Lunine, J. Sci Adv 2015, 1, e1400067. Palmer, M. Y.; Cordiner, M. A.; Nixon, C. A.; Charnley, • S. B.; Mumma, M. J.; Teanby, N. A.; Kisiel, Z.; Irwin, P. G. J. Sci Adv 2017, 3, e1700022. Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Molecule formation in dust-free irradiated jets Presenting author: Benoˆıt Tabone Contact: [email protected] Institute: Leiden Observatory, Leiden University Co-author: G. Pineau des Forets,ˆ B. Godard, S. Cabrit, E. van Dishoeck

Jets and outflows are ubiquitous in accreting young stars of all ages, with similar col- limation and dynamics indicating a universal connection (probably of magnetic origin) between accretion and ejection. However, jets appear to have a very different chem- istry evolving from molecular in the youngest protostars (Class 0) to purely atomic in late stages of disk accretion (Class 2, a few Myr). Such a chemical richness in the youngest jets is intriguing for a flow heated by ambipolar diffusion and irradiated by a strong FUV and X-ray field from the accreting protostar. The unique combination of high angular and spectral resolution provided by ALMA allows us to reveal for the first time the complex chemical and kinematic structure of molecular protostellar jets close to their launching region. ALMA observations of the typical Class 0 HH212 jet have revealed a SO/SO2 rotating flow emanating from the disk, and well reproduced by a slow dusty MHD disk-wind model launched from 0.2 to 40 au (Tabone et al. 2017, Tabone et al. submitted). These findings are consistent with Panoglou et al. 2012 who have shown that molecules can survive and be formed through warm formation routes in a Class 0 disk-wind launched beyond the dust sublimation radius ( 0.2au). ALMA has also unveiled a rotating SiO jet ⇠ attributed to the inner dust-free streamlines of the same extended disk-wind, or to a dust-free X-wind (Lee et al. 2017, see Fig. 1-a, Tabone et al. 2017). This discovery, based on the flow kinematics is challenging astro- chemical models of these unusual environments (e.g. Glassgold et al. 1991 or Cabrit et al 2012) and invites us to design new complementary tests based on the chemical content of the jets to pinpoint their launching point. In this contribution, we would like to review our recent ALMA study on the origin of molecular outflows and present our current modeling work on the formation of molecules in dust-free irradiated jets. We will show that in absence of dust, molecules such as CO, SiO, H O can be formed in short time scales ( few yr) through 2 ⇠ endothermic reactions from a small fraction of H2 formed by electronic catalysis (through H). Our jet model indicates that the FUV field can be efficiently attenuated by C close to the source ( 10 au) and by S, Si and ⇠ other atomic species further out (see Fig. 1-b). Preliminary shock models will also be presented and the influence of a small fraction of surviving dust will be emphasized. These results will be compared to available data and future JWST observations, that will probe the H2 and atomic content of jets, will be discussed.

N3 a) SiO b) H 50 N2

H2 N1 - e CO

(au) 0 Disk Δδ S1 Si S2 C Relative abundances SiO –50 + 0 C H 2O Cont S3 Si O Distance from the source (cm)

Figure 1: a) ALMA view of the HH212 rotating SiO jet at 8 au (0.0400) resolution (from Lee et al. 2017). b) Model of a dust-free advective PDR illustrating the influence of the attenuation of the FUV field by the gas along the jet (Tabone et al. in prep). Shocks will enhance molecular abundances by increasing density and temperature.

References: Glassgold et al., ApJ, 373, 254 Cabrit et al., 2012, A&A, 548, L2 Panoglou et al., 2012, • • • A&A, 538, A2 Lee et al., 2017, NatAs, 1, 0152 Tabone et al. 2017, A&A, 607, L6 Tabone et al., submitted • • • Astrochemistry: From nanometers to megaparsecs - A symposium in honour of John H. Black Gothenburg, Sweden, June 24-28, 2019

Title: Cyanopolyyne Chemistry around Massive Young Stellar Objects Presenting author: Kotomi Taniguchi Contact: [email protected] Institute: University of Virginia Co-author: Eric Herbst, Paola Caselli, Alec Paulive, Dominique M. Maffucci, & Masao Saito

Recent observations reveal chemical complexity in both low- and high-mass star- forming regions. Unsaturated carbon-chain molecules, such as C2nH, CCS, and cyanopolyynes (HC2n+1N), had been thought to be abundant in young starless cores and decrease in abundance in later stages of low-mass star formation[1]. On the other hand, saturated complex organic molecules (COMs) are abun- dant around star-forming cores, so-called hot cores and hot corinos in high- and low-mass star-forming regions, respectively[2]. In contrast to the above classi- cal picture, some low-mass protostellar cores rich in carbon-chain species have been found. In these sources, methane (CH4) sublimates from dust grains at a temperature of 25 K and reacts with ionic carbon (C+) in the gas phase ∼ leading carbon-chain formation, which was named warm carbon chain chemistry (WCCC)[3]. However, it is unclear whether carbon-chain molecules are formed around massive young stellar objects (MYSOs) and what factors bring chemical diversity around star-forming cores. We found that HC5N is abundant around some MYSOs, using the Green Bank 100-m and Nobeyama 45-m radio telescopes[4]. Moreover, chemical diversity around MYSOs is suggested; organic-poor MYSOs are surrounded by a cyanopolyyne-rich lukewarm envelope, while organic-rich MYSOs, namely hot cores, are [5] surrounded by a CH3OH-rich lukewarm envelope . We conducted chemical simulations of hot-core models with a warm-up period using the astrochemical code Nautilus[6] in order to investigate cyanopolyyne [K] Temperature chemistry around MYSOs, motivated by the partic- H ularly high abundance of HC5N in the G28.28–0.36 N)/n MYSO[4]. The cyanopolyynes are produced by a com- 5 bination of neutral-neutral and ion-neutral gas-phase n(HC reactions during the warm-up period (T > 25 K) and accumulate on and in the dust mantles before the The lower limit of HC5N temperature reaches their sublimation temperatures. abundance in G28.28-0.36 The sublimation of first CN and secondly the C2nH2 5x105 1x106 2x106 (n = 1, 2, 3) species enhances key reactions to form the time [yr] cyanopolyynes, which partly accrete onto dust mantles. Figure 1: The gas-phase HC5N abundance with As the temperature rises, the pattern of enhancements the three-phase model during the warm-up period. in the production of the gaseous cyanopolyynes fol- The different colors of lines indicate different heating lowed by partial accretion onto grains leads to a charac- timescales; red, green, and blue indicate Fast (5 104 × teristic spectral-type pattern (Figure 1). The lower limit yr), Medium (2 105 yr), and Slow (1 106 yr), respec- × × of the HC5N abundance observed in G28.28–0.36 can tively. The dashed lines indicate the temperature and be reproduced only after HC5N sublimates from dust their colors correspond to the heating timescales. grains with temperatures above 100 K. Future JWST observations will enable us to confirm such a relationship between gas-phase cyanopolyyne chemistry and dust-surface chemistry. Furthermore, we propose the different heating timescales as a possible origin of chemical diversity around MYSOs. This timescale depends not only on stellar masses but also on the rela- tionship between the size of the warming region and the infall velocity. The size of the warming region and the infall velocity relate to the various physical conditions in star-forming regions, and hence the chemical diversity around MYSOs may reflect a variety of massive star formation processes.

References: [1] Suzuki, H. et al. 1992, ApJ, 392, 551, [2] Herbst, E. & van Dishoeck, E. F. 2009, ARA&A, • • 47, 427 [3] Sakai, N. & Yamamoto, S. 2013, Chemical Reviews, 113, 8981 [4] Taniguchi, K. et al. 2017, • • ApJ, 844, 68 [5] Taniguchi, K. et al. 2018b, ApJ, 866, 150 [6] Ruaud, M. et al. 2016, MNRAS, 459, 3756 • • Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Nature vs. Nurture: What sets the chemical complexity in star-forming regions? Presenting author: Charl van der Walt Contact: [email protected] Institute: Niels Bohr Institute, Copenhagen University Co-author: Lars E. Kristensen, Jes K. Jørgensen, Hannah Calcutt, the PILS-Cygnus team

Understanding the origin of the rich chemistry observed in newly formed pro- tostars is one of the key questions facing astrochemistry. One of the unknown aspects is the role the external environment plays on this chemical complex- ity. To this end, we performed a systematic line survey of 10 intermediate-mass 2 5 (10 L⊙ < Lbol < 10 L⊙)hotcoresintheCygnusXstar-formingregion(ThePro- tostellar Interferometric Line Survey: Cygnus X, or PILS-Cygnus). This survey is unique in that it covers such a large frequency bandwidth toward so many sources. This is an important frequency range, since many complex organic molecular line transitions fall in this range. The PILS-Cygnus sources are all lo- cated in the same cloud at the same distance, around 1.7 kpc, and were selected for their location with respect to massive O-type stars. Thiswilldeterminewhat role the UV-radiation of the physical environment in which the sources are located plays on the chemistry of newly formed stars. By comparing thespectraofthe10sources,andconsidering this external radiative environment, we will address the question of nature vs. nurture. We here present preliminary results from the survey, including a detailed study of the source Cygnus X-N30 (N30). It is the brightest of the 10 sources from the PILS-Cygnus program, and is a system consisting of 4 hot cores, including a binary component with a separation of about 1700 AU, and two cores at larger distances from the central binary. The spectra of the binary components, N30-MM1a and MM1b, have revealed ∼ 400 different line transitions from 28 different molecular species (van der Walt et al., in prep.). The spectra of the two components look strikingly similar, suggesting that theinitialconditions,ornature,thatsetsthechemical evolution, plays a bigger role than the external environment, or nurture.

Figure 1: Herschel 3-colour image of part of the Cygnus X star-forming region, showing 8 of the 10 sources of the PILS-Cygnus survey. The cut-out image centre-top is the SMA continuum image of Cygnus X-N30, with the 4 cores marked. The spectrum of N30-MM1a is shown on the right, with the brightest lines marked. Astrochemistry: From nanometers to megaparsecs -AsymposiuminhonourofJohnH.Black Gothenburg, Sweden, June 24-28, 2019

Title: Molecular complexity in the envelopes of evolved stars Presenting author: Luis Velilla-Prieto Contact: [email protected] Institute: Chalmers University of Technology Co-author: C. Sanchez´ Contreras, J. Cernicharo, M. Agundez,´ J. Alcolea, V. Bujarrabal, and G. Quintana-Lacaci

The death of a Sun-like star is a complex process that plays a key role in the chemical evolution of the Universe, particularly, in the formation of dust grains. At the end of their lives, low-to-intermediate mass stars undergo an intense mass-loss process that creates a surrounding circumstellar envelope composed of molecules and dust. Most of this material is ejected by the star during the asymptotic giant branch (AGB) stage. Eventually, all this material enriches the interstellar medium, the base component for later cloud, stellar, planetary, and, maybe, life formation. After decades of research and observations, the physical conditions in these objects, which span the properties of a variety of different astrophysical environments, are relatively well-known. They thus present one of the best astronomical laboratories to investigate the formation and destruction of molecules and dust and the growth of molecular complexity. The latest advances in the field of instrumentation are allowing us to observe the molecular content of the circumstellar envelopes of evolved stars in the mil- limeter wavelength range with an unprecedented sensitivity, spatial, and spectral resolution. In particular, spectral line surveys are consolidated as excellent techniques to characterise the molecular inventory and the physico-chemical properties ofcircumstellarenvelopes.Thankstoourrecent work, it has been shown that the chemistry of oxygen-rich objects is not as poor as it was previously thought, with the detection of species such as HNCO, HNCS, or SO+ among others. The analysis of the spectral line surveys we have presented in Sanchez´ Contreras et al. 2015, Velilla-Prieto et al. 2015, andVelilla-Prietoetal. 2017 support the idea that the chemistry of AGB envelopes can be substantially altered by high-speed shocks, probably caused by the interaction between the slow AGB wind and the fast (few 100 km s−1)highlycollimated bipolar winds that some more evolved objects (post-AGB) display. The impact that binarity or magnetic fields have on this evolution has to be understood yet, although, from the chemical point of view, it is clear that non-equilibrium processes increase the complexity of the molecular material in these circumstellar envelopes.

Figure 1: Spectral line surveys in the 2 mm-wavelength range of the O-rich circumstellar envelopes OH231.8+4.2 (top) and IK Tau (bottom) observed with the IRAM 30m telescope.

References: • Sanchez´ Contreras, C., Velilla Prieto, L., Agundez,´ M., et al. 2015, A&A, 577, A52 • Velilla Prieto, L., Sanchez´ Contreras, C., Cernicharo, J., et al. 2015, A&A, 575, A84 • Velilla Prieto, L., Sanchez´ Contreras, C., Cernicharo, J., et al. 2017, A&A, 597, A25