Issue 10 | August 2014 AstroPAH A Newsletter on Astronomical PAHs Editorial

Dear Colleagues,

Welcome to the 10th release of AstroPAH. This August cover features bottles containing PAH samples as Picture of the Month. AstroPAH this month is modest due to the holiday season and as such, our in Focus is on holiday. Nevertheless, science never stops, so we do have a couple of very interesting abstracts; PAH detection in various types of galaxies and the effect of PAH edge structure at 12.7µm. We would further like to draw your attention to the upcoming International Conference on Interstellar Dust, Molecules and Chemistry announced in our Scientific Meetings section. We thank you all for your contributions and please keep them coming. You can send your contributions to AstroPAH any time. The deadline for contributions to appear in the next issue is 12 September 2014. The next issue of AstroPAH will be out on 23 September 2014. For more information on AstroPAH, visit our website:

http://astropah-news.strw.leidenuniv.nl.

Best regards

The Editorial Team

2 AstroPAH - August 2014 | Issue 10 AstroPAH Newsletter Contents

EDITORIAL BOARD: PAH Picture of the Month1 Editorial2 Editor-in-Chief Prof. Alexander Tielens Recent Papers4 Leiden Observatory (The Netherlands) Scientific Meetings6 Executive Editor Dr. Isabel Aleman Leiden Observatory (The Netherlands) Editor Dr. Alessandra Candian PAH Picture of the Month Leiden Observatory (The Netherlands) PAH samples for laboratory use come in con- Editor tainers of different shapes and sizes. These Dr. Elisabetta Micelotta samples may be liquid or solid. A number Institut d’Astrophysique Spatiale of techniques can be used to obtain PAHs CNRS/Universite´ Paris-Sud (France) in the gas phase, for example heating in an Editor oven, laser desorption or electro-spray ioni- Dr. Annemieke Petrignani sation. The flasks shown are a few of the many samples of PAH and derivative species Leiden Observatory and that are available at the FELIX Facility in Radboud University Nijmegen Nijmegen, the Netherlands. From left to (The Netherlands) right: , , methylquino- Editor line, 2,3-benzanthracene, tetraphenylene, Dr. Ella Sciamma-O’Brien and fullerene. NASA Ames Research Center (USA) Credits: Annemieke Petrignani and Isabel Aleman WEBSITE: http://astropah-news.strw.leidenuniv.nl

CONTACT: [email protected]

SUBSCRIBE: Click here to subscribe to AstroPAH

3 Recent Papers

Polycyclic Aromatic with Armchair Edges and the 12.7 µm band A. Candian1, P.J. Sarre2 and A.G.G.M. Tielens1 1 Leiden Observatory, Niels Bohrweg 2, Leiden, The Netherlands 2 School of Chemistry, The University of Nottingham, Nottingham, UK

In this Letter we report the results of Density Functional Theory (DFT) calculations on medium- sized neutral Polycyclic Aromatic (PAH) molecules with armchair edges. These PAH molecules possess strong C-H stretching and bending modes around 3 µm and in the fingerprint region (10-15 µm), and also strong ring deformation modes around 12.7 µm. Pe- rusal of the entries in the NASA Ames PAHs Database (Bauschlicher et al., 2010) shows that ring deformation modes of PAHs are common - although generally weak. We then propose that armchair PAHs with NC >65 are responsible for the 12.7 µm Aromatic Infrared Band in Hii regions and discuss astrophysical implications in the context of the PAH life-cycle.

E-mail: [email protected] ApJ, 2014, 791, L10 http://iopscience.iop.org/2041-8205/791/1/L10/article

Polycyclic aromatic hydrocarbon feature deficit of starburst galaxies in the AKARI North Ecliptic Pole Deep field K. Murata1,2, H. Matsuhara1,2, H. Inami3, T. Wada1, T. Goto4, L. Armus 5, C. Pearson6,7,8, S. Serjeant7, T. Miyaji9 1 Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, 229-8510 Kanagawa, Japan 2 Department of Space and Astronautical Science, The Graduate University for Advanced Studies, Japan 3 National Optical Astronomy Observatory, Tucson, AZ 85719, USA 4 Institute of Astronomy and Department of Physics, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan, R.O.C 5 Spitzer Science Center, Calfornia Institute of Technology, MS 220-6, Pasadena, CA 91125 6 RAL Space, STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX, UK 7 Department of Physical Sciences, The Open University, Milton Keynes, MK7 6AA, UK

4 AstroPAH - August 2014 | Issue 10 8 Oxford Astrophysics, Oxford University, Keble Road, Oxford OX1 3RH, UK 9 Instituto de Astronom´ıa, Universidad Nacional Autonoma´ de Mexico,´ Ensenada, Baja California, Mexico We study the behaviour of Polycyclic Aromatic Hydrocarbon emission in galaxies at z = 0.3 − 1.4 using 1868 samples from the revised catalogue of AKARI North Ecliptic Pole deep survey. The continuous filter coverage at 2-24 µm makes it possible to measure 8 µm luminosity, which is dominated by Polycyclic Aromatic Hydrocarbon emission, for galaxies at up to z = 2. We compare the IR8 (≡ LIR/L(8)) and 8 µm to 4.5 µm luminosity ratio (νL(8)/νL(4.5)) with the starburstiness, RSB, defined as excess of specific star formation rate over that of main- sequence galaxy. All AGN candidates were excluded from our sample using an SED fitting. We found νL(8)/νL(4.5) increases with starburstiness at log RSB <0.5, and stays constant at higher starburstiness. On the other hand, IR8 is constant at log RSB < 0, while it increases with starburstiness at log RSB >0. This behaviour is seen in all redshift range of our study. These results indicate that starburst galaxies have deficient Polycyclic Aromatic Hydrocarbon emission compared with main-sequence galaxies. We also find galaxies with extremely high νL(8)/νL(4.5) ratio have only moderate starburstiness. These results suggest that starburst galaxies have compact star-forming regions with intense radiation which destroys PAHs and/or have dusty HII regions resulting in a lack of ionising photons.

E-mail: [email protected] A&A, 566, id.A136 (2014) http://ads.nao.ac.jp/abs/2014A%26A...566A.136M

5 AstroPAH - August 2014 | Issue 10 Scientific Meetings

International Conference on Interstellar Dust, Molecules and Chemistry (IDMC-2014)

Tezpur, Assam, India 15 - 18 December, 2014

Objectives:

The interstellar medium (ISM) consists of a mixture of ions, atoms, molecules, dust grains, cosmic rays, and (galactic) magnetic fields. Thus it is a treasure trove for the study of a wide variety of physical phenomenon. The ISM also plays a crucial role in star and planet formation. The interplay between stars and the ISM determines the lifespan of active star formation and evolution. Recent advances in observational, laboratory, theoretical studies have opened up several avenues of work, made attractive by the possibilities of diverse interdisciplinary interac- tions. The conference intends to provide platform for expert discussions and presentations with ample opportunities for young and motivated students and researchers to interact and to take up challenging problems in this field.

Broad Topics:

• ISM Overview - Constituents, Observational diagnostics • Dust in ISM - Composition, Starlight extinction - observations & models • ISM Molecules and Spectroscopy • Star Formation - The Role of the ISM • Dust and molecules in external galaxies • Laboratory Astrophysics and Astrochemistry • Quantum Chemistry

Invited Speakers:

Gazi Ahmed, Tezpur University, India B. G. Anandarao, PRL, Ahmedabad, India Robert Botet, University of Paris, France Jan Cami, University of Western Ontario, Canada Jose Cernicharo, INTA, Madrid, Spain Ranjan Gupta, IUCAA, Pune, India Eric Herbst, University of Virginia, USA

6 AstroPAH - August 2014 | Issue 10 Christine Joblin, University of Toulouse, France Aigen Li, University of Missouri, USA Ashish Mahabal, Caltech, USA Jayant Murthy, IIA, Bangalore, India D. K. Ojha, TIFR, Mumbai, India Marina Prokopyeva, St. Petersburgh, Russia Shantanu Rastogi, Gorakhpur University, India Gael¨ Rouille,´ University of Jena, Germany Itsuki Sakon, University of Tokyo, Japan Ashoke Sen, Assam University, India U. J. Sofia, American University, Washington N. C. Wickramasinghe, Cardiff University, U.K D. B. Vaidya, Ahmedabad, India

Important Dates:

Participation is limited so intention to participate may be communicated by October 01, 2014. Abstracts must be submitted by October 15, 2014

Scientific Organising Commitee (SOC):

A. J. Choudhury, Tezpur, India Ranjan Gupta, IUCAA, India Thomas Henning, MPIA, Germany (Co-Chair) Ajit Kembhavi, IUCAA, India Eric Herbst, Virginia, USA Hiroshi Kimura, CPS, Japan Shantanu Rastogi, Gorakhpur, India (Co-Chair) Peter Sarre, Nottingham, UK Ashok Sen, Silcher, India Takashi Onaka, Tokyo, Japan

Contact:

E-mail: emailto:[email protected] Website: http://www.iucaa.ernet.in/∼idmc2014

AstroPAH Newsletter http://astropah-news.strw.leidenuniv.nl Next issue: 23 September 2014 [email protected] Submission deadline: 12 September 2014

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