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Nuclear 11.3 μm PAH emission in local active galactic nuclei

Alonso-Herrero, A. and Ramos Almeida, C. and Esquej, P. and Roche, P. F. and Hernán-Caballero, A. and Hönig, S. F. and González-Martín, O. and Aretxaga, I. and Mason, R. E. and Packham, C. and Levenson, N. A. and Rodríguez-Espinosa, J. M. and Siebenmorgen, R. and Pereira-Santanella, M. and Díaz-Santos, T. and Colina, L. and Alvarez, C. and Telesco, C. M. (2014) Nuclear 11.3 μm PAH emission in local active galactic nuclei. Monthly Notices of the Royal Astronomical Society, 443 (3). pp. 2766-2782. ISSN 0035-8711.

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We present Gran Telescopio CANARIAS CanariCam 8.7 μm imaging and 7.5–13 μm spectroscopy of six local systems known to host an active galactic nucleus (AGN) and have nuclear star formation. Our main goal is to investigate whether the molecules responsible for the 11.3 μm polycyclic aromatic hydrocarbon (PAH) feature are destroyed in the close vicinity of an AGN. We detect 11.3 μm PAH feature emission in the nuclear regions of the galaxies as well as extended PAH emission over a few hundred parsecs. The equivalent width (EW) of the feature shows a minimum at the nucleus but increases with increasing radial distances, reaching typical star-forming values a few hundred parsecs away from the nucleus. The reduced nuclear EWs are interpreted as due to increased dilution from the AGN continuum rather than destruction of the PAH molecules. We conclude that at least those molecules responsible for the 11.3 μm PAH feature survive in the nuclear environments as close as 10 pc from the AGN and for Seyfert-like AGN luminosities. We propose that material in the dusty tori, nuclear gas discs, and/or host galaxies of AGN is likely to provide the column densities necessary to protect the PAH molecules from the AGN radiation field.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Alonso-Herrero, A.0000-0001-6794-2519
Aretxaga, I.0000-0002-6590-3994
Packham, C.0000-0001-7827-5758
Levenson, N. A.0000-0003-4209-639X
Díaz-Santos, T.0000-0003-0699-6083
Colina, L.0000-0002-9090-4227
Additional Information:© 2014 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2014 June 24. Received 2014 June 2; in original form 2014 April 22. We thank Ric Davies for sharing with us the VLT/SINFONI image of NGC 6240. We are extremely grateful to the GTC staff for their constant and enthusiastic support. We thank the referee for comments that helped to improve this work. AA-H and AH-C are partly funded by the Universidad de Cantabria through the Augusto G. Linares programme. AA-H and AH-C acknowledge financial support from the Spanish Plan Nacional grant AYA2012-31447, AA-H and PE from grant AYA2009-05705-E, CRA from grant AYA2010-21887-C04.4 (Estallidos), PE from grant AYA2012-31277, and LC from grant AYA2012-32295. CRA acknowledges financial support from the Marie Curie Intra European Fellowship within the 7th European Community Framework Programme (PIEF-GA-2012-327934) and SFH from the Marie Curie International Incoming Fellowship within the 7th European Community Framework Programme (PIIF-GA-2013-623804). The Dark Cosmology Centre is funded by the DNRF. IA is partially funded by CONACyT grant SEP-CB-2011-01-167291. NAL and REM are supported by the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., on behalf of the international Gemini partnership of Argentina, Australia, Brazil, Canada, Chile, and the United States of America. CP acknowledges support from UTSA to help enable this research. This work is based on observations made with the GTC, installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, in the island of La Palma. It is also based partly on observations obtained with the Spitzer Space Observatory, which is operated by JPL, Caltech, under NASA contract 1407. This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by JPL, Caltech, under contract with the National Aeronautics and Space Administration. The CASSIS is a product of the Infrared Science Center at Cornell University, supported by NASA and JPL.
Funding AgencyGrant Number
Universidad de Cantabria Augusto G. Linares programmeUNSPECIFIED
Plan Nacional de Astronomıa y AstrofısicaAYA2012-31447
Plan Nacional de Astronomıa y AstrofısicaAYA2009-05705-E
Plan Nacional de Astronomıa y AstrofısicaAYA2010-21887-C04.4
Plan Nacional de Astronomıa y AstrofısicaAYA2012-31277
Plan Nacional de Astronomıa y AstrofısicaAYA2012-32295
Marie Curie FellowshipPIEF-GA-2012-327934
Marie Curie FellowshipPIIFGA- 2013-623804
Consejo Nacional de Ciencia y Tecnología (CONACYT)SEP-CB-2011- 01-167291
Gemini ObservatoryUNSPECIFIED
Subject Keywords:galaxies: active; galaxies: individual: Mrk 1066; galaxies: individual: Mrk 1073; galaxies: individual: NGC 2273; galaxies: individual: Arp 299; galaxies: individual: NGC 6240; galaxies: individual: IRAS 17208−0014; galaxies: Seyfert; infrared: galaxies
Issue or Number:3
Record Number:CaltechAUTHORS:20141114-091542676
Persistent URL:
Official Citation:Alonso-Herrero, A., Ramos Almeida, C., Esquej, P., Roche, P. F., Hernán-Caballero, A., Hönig, S. F., . . . Telesco, C. M. (2014). Nuclear 11.3 μm PAH emission in local active galactic nuclei. Monthly Notices of the Royal Astronomical Society, 443(3), 2766-2782. doi: 10.1093/mnras/stu1293
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:51750
Deposited By: Jason Perez
Deposited On:14 Nov 2014 22:13
Last Modified:09 Mar 2020 13:19

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