DOCSLIB.ORG

High Energy Processes in Active Galaxies

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

High Energy Processes in Active Galaxies Núria Torres i Albà ADVERTIMENT. La consulta d’aquesta tesi queda condicionada a l’acceptació de les següents condicions d'ús: La difusió d’aquesta tesi per mitjà del servei TDX (www.tdx.cat) i a través del Dipòsit Digital de la UB (diposit.ub.edu) ha estat autoritzada pels titulars dels drets de propietat intelꞏlectual únicament per a usos privats emmarcats en activitats d’investigació i docència. No s’autoritza la seva reproducció amb finalitats de lucre ni la seva difusió i posada a disposició des d’un lloc aliè al servei TDX ni al Dipòsit Digital de la UB. No s’autoritza la presentació del seu contingut en una finestra o marc aliè a TDX o al Dipòsit Digital de la UB (framing). Aquesta reserva de drets afecta tant al resum de presentació de la tesi com als seus continguts. En la utilització o cita de parts de la tesi és obligat indicar el nom de la persona autora. ADVERTENCIA. La consulta de esta tesis queda condicionada a la aceptación de las siguientes condiciones de uso: La difusión de esta tesis por medio del servicio TDR (www.tdx.cat) y a través del Repositorio Digital de la UB (diposit.ub.edu) ha sido autorizada por los titulares de los derechos de propiedad intelectual únicamente para usos privados enmarcados en actividades de investigación y docencia. No se autoriza su reproducción con finalidades de lucro ni su difusión y puesta a disposición desde un sitio ajeno al servicio TDR o al Repositorio Digital de la UB. No se autoriza la presentación de su contenido en una ventana o marco ajeno a TDR o al Repositorio Digital de la UB (framing). Esta reserva de derechos afecta tanto al resumen de presentación de la tesis como a sus contenidos. En la utilización o cita de partes de la tesis es obligado indicar el nombre de la persona autora. WARNING. On having consulted this thesis you’re accepting the following use conditions: Spreading this thesis by the TDX (www.tdx.cat) service and by the UB Digital Repository (diposit.ub.edu) has been authorized by the titular of the intellectual property rights only for private uses placed in investigation and teaching activities. Reproduction with lucrative aims is not authorized nor its spreading and availability from a site foreign to the TDX service or to the UB Digital Repository. Introducing its content in a window or frame foreign to the TDX service or to the UB Digital Repository is not authorized (framing). Those rights affect to the presentation summary of the thesis as well as to its contents. In the using or citation of parts of the thesis it’s obliged to indicate the name of the author. HIGHENERGYPROCESSESIN ACTIVEGALAXIES núria torres i albà directors: Dr Valentí Bosch Ramon Dr Kazushi Iwasawa Departament de Física Quàntica i Astrofísica Facultat de Física Universitat de Barcelona Núria Torres i Albà , High Energy Processes in Active Galaxies, PhD Thesis Barcelona , June 2019 Cover Image: - universitat de barcelona departament de física quàntica i astrofísica Programa de doctorat en física Línia de recerca en astronomia i astrofísica High Energy Processes in Active Galaxies Memòria presentada per Núria Torres i Albà per optar al grau de Doctor en física per la Universitat de Barcelona Directors de la tesi: Dr Valentí Bosch Ramon Dr Kazushi Iwasawa Tutor de la tesi: Dr Alberto Manrique Oliva Barcelona , June 2019 DECLARATION This thesis is presented following the regulations of the University of Barcelona (Aprovada pel CdG en sessió del 16 de març de 2012 i modificada pel CdG de data 9 de maig i 19 de juliol de 2012, 29 de maig i 3 d’octubre de 2013, 17 de juliol de 2014, 16 de juliol de 2015, 15 de juny i 21 de novembre de 2016, 5 de desembre de 2017 i 4 de maig de 2018). The listed regulations allow for the presentation of a PhD thesis as a "compendia of published articles". According to the regulations, the thesis must contain a minimum of four published or accepted articles. This thesis contains the published version of four ar- ticles, which is sufficient to allow its presentation. It also contains two additional articles, not yet accepted for publication at the moment of thesis presentation. Barcelona , June 2019 Núria Torres i Albà ABSTRACT This thesis has as an objective the study of very energetic phenomena in the central regions of active galaxies. Intense star formation is trig- gered by mergers of galaxies, and the funneling of large quantities of gas toward the inner regions is thought to also cause accretion onto the central black hole. Whether the two processes necessarily take place together as a step of galaxy evolution is still debated. Regardless of the origin of their connection, star formation and strong AGN activity often coexist in the nuclei of galaxies. Even after star formation is no longer ongoing, the nuclear starburst in a merger results in the formation of galactic bulges. Therefore, stellar densities in the inner kiloparsecs of a galaxy are typically high. As stars, or star forming regions, are close to the AGN, interaction between the two is expected to be frequent, and it can result in a multitude of phenomena worthy of study. In particular, the goal of the thesis is to study the emission pro- duced by these phenomena, in the range of X-rays to gamma-rays, whether to disentangle their individual contributions or to detect emission resulting from their interaction. The thesis intends to pro- vide data to continue the study of the starburst-AGN connection, and new models to explain the production of gamma rays in other galax- ies. The first part focuses on the X-ray analysis of a local sample of lu- minous infrared galaxies (LIRGs). In this part we analyze data for 84 sources which span a wide range of activity types and merger stages. We provide X-ray images, fluxes, luminosities and radial profiles, as well as comparison with IR data and information on the AGN pres- ence within their nuclei. The central part of the thesis focuses on the interaction of AGN jets with stellar populations. We consider the interaction caused by stars being within the jet, penetrating it, or exploding as supenovae within it. We study whether their dynamical evolution and impact on the jet, and estimate if their gamma-ray emission is detectable. The last part estimates the possible contribution of AGN jets to the reionization of the Universe, given how their interaction with cosmic microwave background radiation can result in the production of ion- izing photons. vii ACKNOWLEDGMENTS In the first place, I would like to thank my supervisors Dr. Valentí Bosch i Ramon and Dr. Kazushi Iwasawa for their teachings and their guidance along these past four years. This thesis would not have been possible without their knowledge and willingness to share it. I would also like to thank Dr. Josep M. Paredes, who introduced me to the group and helped me throughout the first stages of my scientific ca- reer. Part of the research presented in this thesis has been carried out in other institutions. I thank Dr. Andrea Comastri and Dr. Christian Vig- nali for their warm reception in Osservatorio Astronomico di Bologna, where I learnt both X-ray astronomy and properties of AGN at all wavelengths. I thank Dr. Manel Perucho, who kindly welcomed me to Valencia, and taught me about hydrodynamical simulations. I also thank Dr. Gustavo Romero, Dr. Daniela Pérez and Dr. Santiago del Palacio for welcoming me to Instituto Argentino de Radioastronomía in La Plata. In particular, I want to thank Dr. Florencia Vieyro, who has taught me all she knows about relativistic jets and who has be- come a very dear friend. I would also like to thank the GOALS people; in particular Dr. Tanio Díaz Santos, Dr. Claudio Ricci and Dr. Vassilis Charmandaris, who helped improve the C-GOALS paper and gave me valuable ad- vice. Tanio taught me all I know about infrared astronomy, and with- out him my understanding of U/LIRGs would be much poorer. I would like to thank Benito, Xavi, Victor and Dani, my first office mates, who were always present when I struggled and never refused to help me when I asked. Their knowledge of programming and ob- servational astronomy has been invaluable. Likewise, I want to thank Edgar, with whom I’ve shared MAGIC shifts, stays abroad and teach- ing duties, and who has always been reliable. I also need to thank Nico and Jose, who have been there with me from the very beginning, and were always willing to lend me a hand. Special thanks to Laia, who was the friend I needed most and who is missed dearly. I thank also Roger, Lluis, Ignasi, Alfred, Pau, Samuel, Ali, Juan, David, Dani and everyone else who shares our everyday lives and helps make the PhD a truly enjoyable experience. And of course, I thank JR, Rosa, Jordi and all the personnel in secretaries and informatics, who help us make science possible. ix RESUMENCATALÀ Aquesta tesi té com a objectiu l’estudi dels fenòmens altament en- ergètics a les regions centrals de les galàxies actives. Les galàxies ac- tives són aquelles que tenen una emissió molt intensa a les regions més centrals, i que és clarament diferent de l’emissió de la majoria de galàxies. Tant un episodi de formació estel·lar especialment intens (galàxia "starburst", de l’anglès per a "explosió estel·lar") com acre- ció de material sobre el forat negre supermassiu central (AGN, de l’anglès per a "nucli actiu de galàxia") poden donar lloc a aquesta activitat.
Recommended publications
  • Naming the Extrasolar Planets

    Naming the Extrasolar Planets

    Naming the extrasolar planets W. Lyra Max Planck Institute for Astronomy, K¨onigstuhl 17, 69177, Heidelberg, Germany [email protected] Abstract and OGLE-TR-182 b, which does not help educators convey the message that these planets are quite similar to Jupiter. Extrasolar planets are not named and are referred to only In stark contrast, the sentence“planet Apollo is a gas giant by their assigned scientific designation. The reason given like Jupiter” is heavily - yet invisibly - coated with Coper- by the IAU to not name the planets is that it is consid- nicanism. ered impractical as planets are expected to be common. I One reason given by the IAU for not considering naming advance some reasons as to why this logic is flawed, and sug- the extrasolar planets is that it is a task deemed impractical. gest names for the 403 extrasolar planet candidates known One source is quoted as having said “if planets are found to as of Oct 2009. The names follow a scheme of association occur very frequently in the Universe, a system of individual with the constellation that the host star pertains to, and names for planets might well rapidly be found equally im- therefore are mostly drawn from Roman-Greek mythology. practicable as it is for stars, as planet discoveries progress.” Other mythologies may also be used given that a suitable 1. This leads to a second argument. It is indeed impractical association is established. to name all stars. But some stars are named nonetheless. In fact, all other classes of astronomical bodies are named.
  • IAU Division C Working Group on Star Names 2019 Annual Report

    IAU Division C Working Group on Star Names 2019 Annual Report

    IAU Division C Working Group on Star Names 2019 Annual Report Eric Mamajek (chair, USA) WG Members: Juan Antonio Belmote Avilés (Spain), Sze-leung Cheung (Thailand), Beatriz García (Argentina), Steven Gullberg (USA), Duane Hamacher (Australia), Susanne M. Hoffmann (Germany), Alejandro López (Argentina), Javier Mejuto (Honduras), Thierry Montmerle (France), Jay Pasachoff (USA), Ian Ridpath (UK), Clive Ruggles (UK), B.S. Shylaja (India), Robert van Gent (Netherlands), Hitoshi Yamaoka (Japan) WG Associates: Danielle Adams (USA), Yunli Shi (China), Doris Vickers (Austria) WGSN Website: https://www.iau.org/science/scientific_bodies/working_groups/280/ ​ WGSN Email: [email protected] ​ The Working Group on Star Names (WGSN) consists of an international group of astronomers with expertise in stellar astronomy, astronomical history, and cultural astronomy who research and catalog proper names for stars for use by the international astronomical community, and also to aid the recognition and preservation of intangible astronomical heritage. The Terms of Reference and membership for WG Star Names (WGSN) are provided at the IAU website: https://www.iau.org/science/scientific_bodies/working_groups/280/. ​ ​ ​ WGSN was re-proposed to Division C and was approved in April 2019 as a functional WG whose scope extends beyond the normal 3-year cycle of IAU working groups. The WGSN was specifically called out on p. 22 of IAU Strategic Plan 2020-2030: “The IAU serves as the ​ internationally recognised authority for assigning designations to celestial bodies and their surface features. To do so, the IAU has a number of Working Groups on various topics, most notably on the nomenclature of small bodies in the Solar System and planetary systems under Division F and on Star Names under Division C.” WGSN continues its long term activity of researching cultural astronomy literature for star names, and researching etymologies with the goal of adding this information to the WGSN’s online materials.
  • Cyclic-Permutation Invariant Networks for Modeling Periodic Sequential Data: Application to Variable Star Classification

    Cyclic-Permutation Invariant Networks for Modeling Periodic Sequential Data: Application to Variable Star Classification

    Cyclic-Permutation Invariant Networks for Modeling Periodic Sequential Data: Application to Variable Star Classification Keming Zhang∗ Joshua S. Bloom Department of Astronomy Department of Astronomy University of California at Berkeley University of California at Berkeley Berkeley, CA 94720 Berkeley, CA 94720 [email protected] [email protected] Abstract Current recurrent and convolutional neural network (RNN; CNN) architectures are sub-optimal for modeling periodic sequences because of their acyclic topology. Here, we present cyclic-permutation invariant networks, a new type of CNN for which the invariance to cyclic-permutations, or phase shifts, is guaranteed by representing data in phase-space and performing convolutions in polar coordinates, which we implement by means of “Symmetry Padding.” Across three different datasets of periodic variable star light-curves (time-series of brightness) [1, 2, 3], we show that two particular implementations of the cyclic-permutation invariant network: the iTCN and the iResNet, consistently outperform both non-invariant versions of the same network, as well as previous state-of-the-art approaches including Random Forests. This methodology is first presented in [4] and is applicable to a wide range of science domains where periodic data abounds due to physical symmetries. 1 Introduction Strictly periodic data is common in the physical sciences where periodicity occurs both spatially and temporally. Neural networks for which invariances arising from periodicity are explicitly considered either in the input features or the loss function, have been previously applied to particle physics [5] and atomic physics/chemistry [6]. In this study, we focus on periodic time series arising from variable stars, which is important to many sub-fields of astronomy, including the study of the cosmic distance ladder, galactic archaeology, and stellar evolution.
  • Astronomy Magazine 2011 Index Subject Index

    Astronomy Magazine 2011 Index Subject Index

    Astronomy Magazine 2011 Index Subject Index A AAVSO (American Association of Variable Star Observers), 6:18, 44–47, 7:58, 10:11 Abell 35 (Sharpless 2-313) (planetary nebula), 10:70 Abell 85 (supernova remnant), 8:70 Abell 1656 (Coma galaxy cluster), 11:56 Abell 1689 (galaxy cluster), 3:23 Abell 2218 (galaxy cluster), 11:68 Abell 2744 (Pandora's Cluster) (galaxy cluster), 10:20 Abell catalog planetary nebulae, 6:50–53 Acheron Fossae (feature on Mars), 11:36 Adirondack Astronomy Retreat, 5:16 Adobe Photoshop software, 6:64 AKATSUKI orbiter, 4:19 AL (Astronomical League), 7:17, 8:50–51 albedo, 8:12 Alexhelios (moon of 216 Kleopatra), 6:18 Altair (star), 9:15 amateur astronomy change in construction of portable telescopes, 1:70–73 discovery of asteroids, 12:56–60 ten tips for, 1:68–69 American Association of Variable Star Observers (AAVSO), 6:18, 44–47, 7:58, 10:11 American Astronomical Society decadal survey recommendations, 7:16 Lancelot M. Berkeley-New York Community Trust Prize for Meritorious Work in Astronomy, 3:19 Andromeda Galaxy (M31) image of, 11:26 stellar disks, 6:19 Antarctica, astronomical research in, 10:44–48 Antennae galaxies (NGC 4038 and NGC 4039), 11:32, 56 antimatter, 8:24–29 Antu Telescope, 11:37 APM 08279+5255 (quasar), 11:18 arcminutes, 10:51 arcseconds, 10:51 Arp 147 (galaxy pair), 6:19 Arp 188 (Tadpole Galaxy), 11:30 Arp 273 (galaxy pair), 11:65 Arp 299 (NGC 3690) (galaxy pair), 10:55–57 ARTEMIS spacecraft, 11:17 asteroid belt, origin of, 8:55 asteroids See also names of specific asteroids amateur discovery of, 12:62–63
  • The Detectability of Nightside City Lights on Exoplanets

    The Detectability of Nightside City Lights on Exoplanets

    Draft version September 6, 2021 Typeset using LATEX twocolumn style in AASTeX63 The Detectability of Nightside City Lights on Exoplanets Thomas G. Beatty1 1Department of Astronomy and Steward Observatory, University of Arizona, Tucson, AZ 85721; [email protected] ABSTRACT Next-generation missions designed to detect biosignatures on exoplanets will also be capable of plac- ing constraints on the presence of technosignatures (evidence for technological life) on these same worlds. Here, I estimate the detectability of nightside city lights on habitable, Earth-like, exoplan- ets around nearby stars using direct-imaging observations from the proposed LUVOIR and HabEx observatories. I use data from the Soumi National Polar-orbiting Partnership satellite to determine the surface flux from city lights at the top of Earth's atmosphere, and the spectra of commercially available high-power lamps to model the spectral energy distribution of the city lights. I consider how the detectability scales with urbanization fraction: from Earth's value of 0.05%, up to the limiting case of an ecumenopolis { or planet-wide city. I then calculate the minimum detectable urbanization fraction using 300 hours of observing time for generic Earth-analogs around stars within 8 pc of the Sun, and for nearby known potentially habitable planets. Though Earth itself would not be detectable by LUVOIR or HabEx, planets around M-dwarfs close to the Sun would show detectable signals from city lights for urbanization levels of 0.4% to 3%, while city lights on planets around nearby Sun-like stars would be detectable at urbanization levels of & 10%. The known planet Proxima b is a particu- larly compelling target for LUVOIR A observations, which would be able to detect city lights twelve times that of Earth in 300 hours, an urbanization level that is expected to occur on Earth around the mid-22nd-century.
  • Stellar Atmospheres of Nearby Young Solar Analogs

    Stellar Atmospheres of Nearby Young Solar Analogs

    Stellar Atmospheres of Nearby Young Solar Analogs Eric J. Gaidos12 Division of Geological & Planetary Sciences California Institute of Technology, Pasadena, CA 91125 [email protected] and Guillermo Gonzalez3 Astronomy Department, University of Washington, Seattle, WA 98195-1580 [email protected] ABSTRACT High-resolution (R ≈ 90, 000) spectra of 34 nearby, young Sun-like stars were analyzed using stellar atmosphere models to estimate effective photosphere temperatures, surface gravities, and the abundance of certain heavy elements (C, Na, Mg, Si, S, Ca, Ti, Fe, and Ni). The effective temperatures derived from spectroscopy were compared with temperatures estimated using opti- cal and near-infrared photometry. In many cases the spectroscopic temperatures are significantly higher than the photometric estimates, possibly as a result of spottedness or chromospheric ac- tivity on these active stars. Values of effective temperature, surface gravity, and luminosity were compared to theoretical stellar evolution tracks and the evolutionary status of these objects was evaluated. The correlation between heavy element abundance patterns and kinematics (space motion) was also examined. Two nearby stars that were tentatively assigned to the Hyades clus- ter based on kinematics have Fe abundances that are also consistent with membership in that cluster. Members of the Ursa Major kinematic group exhibit a range of [Fe/H] values but have monotonic [Si/Fe]. These two observations suggest that heterogeneous incorporation of the heavy elements into protostars is creating the variation in metallicity. Local Association members have a distinctly different Si/Fe that probably reflects their distinct origin and chemical inheritance. arXiv:astro-ph/0203518v1 29 Mar 2002 Subject headings: stars: abundances, fundamental parameters, kinematics, planetary systems; PACS 97.10.Ex, 97.10.Jb, 97.10.Tk, 97.10.Zr 1.
  • A Green Line Around the Box Means a Habitable Planet Exists in the Starsystem

    A Green Line Around the Box Means a Habitable Planet Exists in the Starsystem

    Hussey 575 BD+30 2494 BD+24 2733 1.5 BD+14 2774 2.5 1.5 1.5 Ross 512 1.5 WO 9502 1.5 BD+17 2785 2 BD+15 3108 G136-101 Sigma Bootis BD+30 2512 1 Struve 1785 1.5 1 2.5 via LP441.33 1.5 BD+24 2786 1.5 1.5 1.5 1.5 1.5 45 Bootis L1344-37 GJ 3966 Ross 863 1.5 Lambda Serpentis Wolf 497 BD+25 2874 1.5 3 via V645 Herc Gliese 625 1 1.5 3.5 via GJ 3910 3 via V645 Herc 1.5 BD-9 3413 GJ-1179 Zeta Herculis 1.5 Eta Bootes 1 Rho Coronae Borealis 1.5 1.5 2.5 via Giclas 258.33 Luyten 758-105 BD+54 1716 1 BD+25 3173 Giclas 179-43 1.5 1.5 1.5 1 3 via Ross 948 3 via WO 9564 3 via GJ 3796 3 via Ross 948 Eta Coronae Borealis Chi Draconis 3 via HYG86887 1 3.5 via V645 Herc 1 Gamma Serpentis 2 BD+17 2611 (VESTA) Arcturus 3 via V645 Herc 3 via BD+21 2763 3.5 via BD+0 2989, DT Virginis 4 via HYG86887&8 Struve 2135 BD+33 2777 14 Herculis Porimma (Gamma Virginis) 3.5 via BD+45 2247 3 via BD+41 2695 1.5 3.5 BD+60 1623 BD+53 1719 THETIS 1.5 Chi Hercules 2 3.5 1.5 1.5 BD+38 3095 3.5 via BD+46 1189 Mu Herculis 4 via WO 9564 CR Draconis BD+52 2045 3 via BD+43 2796 1.5 3 via Giclas 179-43 BD+36 2393 Queen Isabel Star Sigma Draconis 3.5 via BD+43 2796 CE Bootes 1.5 BD+19 2881 1 1.5 1.5 1.5 2.5 I Bootis via BD+45 2247 BD+47 2112 1 4 via EGWD 329, CR Draconis 3 via LP 272-25 4.5 via Ross 948, L 910-10 44 Bootis Aitkens Double Star 1 ADS 10288 3 via BD+61 2068 1.5 Gilese 625 1.5 Vega 3 via Kuiper 79 3 via Giclas 179-43 4 via BD+46 1189, BD+50 2030 Ross 52 Theta Draconis 2 EV Lacertae Gliese 892 BD+39 2947 3 via BD+18 3421 1.5 0.5 Theta Bootis 1.5 3 via EV Lacertae 2.5 via
  • Andrew Vanderburg

    Andrew Vanderburg

    Andrew Vanderburg Assistant Professor at the University of Wisconsin-Madison 475 N Charter St • Madison, WI 53706 [email protected] • http://www.astro.wisc.edu/ vanderburg/ Appointments Assistant Professor at The University of Wisconsin-Madison August 2020 - present Research Associate at the Smithsonian Astrophysical Observatory September 2017 - present NASA Sagan Postdoctoral Fellow at The University of Texas at Austin September 2017 - August 2020 Postdoctoral Associate at Harvard University July 2017 - September 2017 Education Harvard University Cambridge, MA Ph.D. Astronomy and Astrophysics (2017) August 2013 - May 2017 A.M. Astronomy and Astrophysics (2015) University of California, Berkeley Berkeley, CA B.A. Physics and Astrophysics (2013) August 2009 - May 2013 Research Interests • Searching for and studying small planets orbiting other stars • Determining detailed physical properties of terrestrial planets • Learning about the origins and evolution of planetary systems • Testing theories of planetary migration by studying the architecture of planetary systems • Measuring the prevalence of planets in different galactic environments • Developing and using new data analysis techniques in astronomy, including machine learning and deep learning. Awards • 2020 Scialog Fellow • 2018 NASA Exceptional Public Achievement Medal • 2017 NASA Sagan Fellow • 2016 Publications of the Astronomical Society of the Pacific Outstanding Reviewer Award • 2015 K2 Science Conference Student Researcher Award • 2013 National Science Foundation Graduate
  • IAU WGSN 2019 Annual Report

    IAU WGSN 2019 Annual Report

    IAU Division C Working Group on Star Names 2019 Annual Report Eric Mamajek (chair, USA) WG Members: Juan Antonio Belmote Avilés (Spain), Sze-leung Cheung (Thailand), Beatriz García (Argentina), Steven Gullberg (USA), Duane Hamacher (Australia), Susanne M. Hoffmann (Germany), Alejandro López (Argentina), Javier Mejuto (Honduras), Thierry Montmerle (France), Jay Pasachoff (USA), Ian Ridpath (UK), Clive Ruggles (UK), B.S. Shylaja (India), Robert van Gent (Netherlands), Hitoshi Yamaoka (Japan) WG Associates: Danielle Adams (USA), Yunli Shi (China), Doris Vickers (Austria) WGSN Website: https://www.iau.org/science/scientific_bodies/working_groups/280/ WGSN Email: [email protected] The Working Group on Star Names (WGSN) consists of an international group of astronomers with expertise in stellar astronomy, astronomical history, and cultural astronomy who research and catalog proper names for stars for use by the international astronomical community, and also to aid the recognition and preservation of intangible astronomical heritage. The Terms of Reference and membership for WG Star Names (WGSN) are provided at the IAU website: https://www.iau.org/science/scientific_bodies/working_groups/280/. WGSN was re-proposed to Division C and was approved in April 2019 as a functional WG whose scope extends beyond the normal 3-year cycle of IAU working groups. The WGSN was specifically called out on p. 22 of IAU Strategic Plan 2020-2030: “The IAU serves as the internationally recognised authority for assigning designations to celestial bodies and their surface features. To do so, the IAU has a number of Working Groups on various topics, most notably on the nomenclature of small bodies in the Solar System and planetary systems under Division F and on Star Names under Division C.” WGSN continues its long term activity of researching cultural astronomy literature for star names, and researching etymologies with the goal of adding this information to the WGSN’s online materials.
  • Properties of Planets in Binary Systems the Role of Binary Separation

    Properties of Planets in Binary Systems the Role of Binary Separation

    A&A 462, 345–353 (2007) Astronomy DOI: 10.1051/0004-6361:20066319 & c ESO 2007 Astrophysics Properties of planets in binary systems The role of binary separation S. Desidera1 and M. Barbieri1,2 1 INAF – Osservatorio Astronomico di Padova, Vicolo dell’ Osservatorio 5, 35122 Padova, Italy e-mail: [email protected] 2 Dipartimento di Fisica, Università di Padova, Italy Received 29 August 2006 / Accepted 1 October 2006 ABSTRACT Aims. The statistical properties of planets in binaries were investigated. Any difference to planets orbiting single stars can shed light on the formation and evolution of planetary systems. As planets were found around components of binaries with very different separation and mass ratio, it is particularly important to study the characteristics of planets as a function of the effective gravitational influence of the companion. Methods. A compilation of planets in binary systems was made; a search for companions orbiting stars recently shown to host planets was performed, resulting in the addition of two further binary planet hosts (HD 20782 and HD 109749). The probable original properties of the three binary planet hosts with white dwarfs companions were also investigated. Using this updated sample of planets in binaries we performed a statistical analysis of the distributions of planet mass, period, and eccentricity, fraction of multiplanet systems, and stellar metallicity for planets orbiting components of tight and wide binaries and single stars. Results. The only highly significant difference revealed by our analysis concerns the mass distribution of short-period planets. Massive planets in short period orbits are found in most cases around the components of rather tight binaries.
  • 3-D Starmap 12.0 All Stars Within 12 Parsecs (40 Light-Years) of Sol

    3-D Starmap 12.0 All Stars Within 12 Parsecs (40 Light-Years) of Sol

    3-D Starmap 12.0 All stars within 12 parsecs (40 light-years) of Sol. All units are in parsecs. (1 parsec = 3.26 light-years) Stars are plotted in cartesian x,y,z coordinates. GJ 1243 X-Y plane is the plane of the galaxy. 1.9:11.6:2.1 +x is Coreward, -x is Rimward, NN 4201 +y is Spinward, -y is Trailing 2.9:11.3:-4.1 Star data is from HYG database. 2.1 2.9 Stars circled in green are likely to host 11.0 1.8 human-habitable planets, according to NN 4098 1.6 5.4:10.9:2.3 GJ 1234 the HabCat database. 3.8:10.8:2.4 Gray lines link each star with its two closest neighbors. 1.7 24 Iota Pegasi 1.4:10.6:-4.8 Green lines link habitable stars with their two 2.5 NN 4122 closest habitable neighbors. 4.3:10.5:0.8 Gl 4 B Links are labeled with their distance in parsecs. -4.7:10.3:-3.3 1.5 GJ 1288 0.3 -2.9:10.2:-6.1 1.5 Winchell Chung: Nyrath the nearly wise 1.2 Gl 4 10.0 http://www.projectrho.com/starmap.html 1.2 -4.6:10.0:-3.2 1.0 Gl 851 GJ 1223 2.0:9.7:-5.8 0.9 4.8:9.7:5.1 GJ 1004 GJ 1238 NN 4048 1.7 Gl 766 NN 4070 -4.8:9.6:-2.3 -3.0:9.6:4.5 4.2:9.6:4.42.0 4.9:9.6:0.2 5.3:9.6:3.1 2.8 1.0 3.0 Gl 671 0.4 1.8 3.9 4.0:9.4:6.9 2.4 Gl 909 BD+38°3095 3.7 -5.1:9.2:2.4 3.2 4.2:9.2:4.5 GJ 1253 -0.6:9.1:1.9 0.9 Gl 82 1.9 Gl 47 9.0 -8.0:9.0:-0.7 -6.1:9.0:-0.3 1.8 1.6 1.7 2.8 3.3 3.2 4.8 1.5 1.2 1.2 4.8 GJ 1053 NN 3992 -7.9:8.7:2.8 0.8 1.7 3.5 4.5:8.7:6.9 V 547 Cassiopeiae GJ 1206 -5.2:8.6:0.8 0.2:8.6:6.9 2.9 Gl 63 -7.0:8.5:-1.0 1.1 2.0 1.8 1.8 1.7 1.7 BD+61°195 NN 4247 3.4 GJ 1235 0.9 GJ 1232 -5.7:8.3:-0.1 3.1 1.0:8.3:-3.2 5.8:8.3:0.5 6.7:8.3:0.7 Hip 109119 GJ
  • Chemically Tagging the Hyades Supercluster

    Chemically Tagging the Hyades Supercluster

    Astronomy & Astrophysics manuscript no. hy1˙v23 c ESO 2018 November 19, 2018 Chemically tagging the Hyades Supercluster: A homogeneous sample of F6-K4 kinematically selected northern stars⋆ H.M. Tabernero1, D. Montes1, and J.I. Gonz´alez Hern´andez1,2,3 1 Dpto. Astrof´ısica, Facultad de CC. F´ısicas, Universidad Complutense de Madrid, E-28040 Madrid, Spain. e-mail: [email protected] 2 Instituto de Astrof´ısica de Canarias, C Via Lactea s/n, E-38200 La Laguna, Tenerife, Spain 3 Dept. Astrof´ısica, Universidad de La Laguna (ULL), E-38206 La Laguna, Tenerife, Spain Received 17 June, 2011 ; accepted 17 April, 2012 ABSTRACT Stellar kinematic groups are kinematical coherent groups of stars that might have a common origin. These groups are dispersed throughout the Galaxy over time by the tidal effects of both Galactic rotation and disc heating, although their chemical content remains unchanged. The aim of chemical tagging is to establish that the abundances of every element in the analysis are homogeneus among the members. We study the case of the Hyades Supercluster to compile a reliable list of members (FGK stars) based on our chemical tagging analyisis. For a total of 61 stars from the Hyades Supercluster, stellar atmospheric parameters (Teff, log g, ξ, and [Fe/H]) are determined using our code called StePar, which is based on the sensitivity to the stellar atmospherics parameters of the iron EWs measured in the spectra. We derive the chemical abundances of 20 elements and find that their [X/Fe] ratios are consistent with Galactic abundance trends reported in previous studies.