AGN-host galaxy connection: morphology and colours of X-ray selected AGN at z ≤ 2⋆

Context. The connection between active galactic nuclei (AGN) and their host galaxies has been widely studied and found to be of great importance for providing answers to some fundamental questions related to AGN fuelling mechanisms, and both their formation and evolution. Aims. Using X-ray data and...

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Autores: Povic, M., Sánchez-Portal, M., Pérez García, A.M., Bongiovanni, A., Cepa, J., Huertas-Company, M., Lara-López, M.A., Fernández Lorenzo, M., Ederoclite, A., Alfaro, E., Castañeda, H., Gallego, J., González Serrano, José Ignacio|||0000-0003-0795-3026, González, J.J.
Tipo de recurso: artículo
Fecha de publicación:2012
País:España
Institución:Universidad de Cantabria (UC)
Repositorio:UCrea Repositorio Abierto de la Universidad de Cantabria
Idioma:inglés
OAI Identifier:oai:repositorio.unican.es:10902/27115
Acceso en línea:https://hdl.handle.net/10902/27115
Access Level:acceso abierto
Palabra clave:Galaxies: active
Galaxies: Fundamental Parameters
Galaxies: Distances and Redshifts
Galaxies: structure
X-rays: galaxies
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oai_identifier_str oai:repositorio.unican.es:10902/27115
network_acronym_str ES
network_name_str España
repository_id_str
dc.title.none.fl_str_mv AGN-host galaxy connection: morphology and colours of X-ray selected AGN at z ≤ 2⋆
title AGN-host galaxy connection: morphology and colours of X-ray selected AGN at z ≤ 2⋆
spellingShingle AGN-host galaxy connection: morphology and colours of X-ray selected AGN at z ≤ 2⋆
Povic, M.
Galaxies: active
Galaxies: Fundamental Parameters
Galaxies: Distances and Redshifts
Galaxies: structure
X-rays: galaxies
title_short AGN-host galaxy connection: morphology and colours of X-ray selected AGN at z ≤ 2⋆
title_full AGN-host galaxy connection: morphology and colours of X-ray selected AGN at z ≤ 2⋆
title_fullStr AGN-host galaxy connection: morphology and colours of X-ray selected AGN at z ≤ 2⋆
title_full_unstemmed AGN-host galaxy connection: morphology and colours of X-ray selected AGN at z ≤ 2⋆
title_sort AGN-host galaxy connection: morphology and colours of X-ray selected AGN at z ≤ 2⋆
dc.creator.none.fl_str_mv Povic, M.
Sánchez-Portal, M.
Pérez García, A.M.
Bongiovanni, A.
Cepa, J.
Huertas-Company, M.
Lara-López, M.A.
Fernández Lorenzo, M.
Ederoclite, A.
Alfaro, E.
Castañeda, H.
Gallego, J.
González Serrano, José Ignacio|||0000-0003-0795-3026
González, J.J.
author Povic, M.
author_facet Povic, M.
Sánchez-Portal, M.
Pérez García, A.M.
Bongiovanni, A.
Cepa, J.
Huertas-Company, M.
Lara-López, M.A.
Fernández Lorenzo, M.
Ederoclite, A.
Alfaro, E.
Castañeda, H.
Gallego, J.
González Serrano, José Ignacio|||0000-0003-0795-3026
González, J.J.
author_role author
author2 Sánchez-Portal, M.
Pérez García, A.M.
Bongiovanni, A.
Cepa, J.
Huertas-Company, M.
Lara-López, M.A.
Fernández Lorenzo, M.
Ederoclite, A.
Alfaro, E.
Castañeda, H.
Gallego, J.
González Serrano, José Ignacio|||0000-0003-0795-3026
González, J.J.
author2_role author
author
author
author
author
author
author
author
author
author
author
author
author
dc.contributor.none.fl_str_mv Universidad de Cantabria
dc.subject.none.fl_str_mv Galaxies: active
Galaxies: Fundamental Parameters
Galaxies: Distances and Redshifts
Galaxies: structure
X-rays: galaxies
topic Galaxies: active
Galaxies: Fundamental Parameters
Galaxies: Distances and Redshifts
Galaxies: structure
X-rays: galaxies
description Context. The connection between active galactic nuclei (AGN) and their host galaxies has been widely studied and found to be of great importance for providing answers to some fundamental questions related to AGN fuelling mechanisms, and both their formation and evolution. Aims. Using X-ray data and one of the deepest broad-band optical data sets available, we study how morphology and colours are related to X-ray properties for sources at redshifts z ? 2.0, using a sample of 262 AGN in the Subaru/XMM-Newton Deep Survey (SXDS). Methods. We performed our morphological classification using the galSVM code, which is a new method that is particularly suited to dealing with high-redshift sources. Colour?magnitude diagrams were studied in relationship to redshift, morphology, X-ray obscuration, and X-ray-to-optical flux ratio. We analysed the different regions in the colour?magnitude diagrams, and searched for correlations with the observed properties of AGN populations using models of their formation and evolution. Results. We confirm that a robust and reliable morphological classification of a general galaxy population at high redshift should be based on a multi-parametric approach. At least 50% of X-ray detected AGN at z ? 2.0 analysed in this work reside in spheroidal and bulge-dominated galaxies, while at least 18% have disk-dominated hosts. This suggests that different mechanisms may be responsible for triggering the nuclear activity. When analysing populations of X-ray detected AGN in both colour?magnitude and colour-stellar mass diagrams, the highest number of sources is found to reside in the green valley at redshifts ?0.5?1.5. However, a larger number of low-luminosity AGN have been detected than in previous works owing to the substantial depth of the SXDS optical data. Whether AGN are hosted by early- or late-type galaxies, no clear relationship has been found with the optical colours (independently of redshift), as is typical of normal galaxies. Both early- and late-type AGN cover similar ranges of X-ray obscuration, for both unobscured and obscured sources. Conclusions. Our findings appear to confirm some previous suggestions that X-ray selected AGN residing in the green valley represent a transitional population, quenching star formation by means of different AGN feedback mechanisms and evolving to red-sequence galaxies. They might be hosted by similar sources (the majority of sources being late-type elliptical and lenticular galaxies, and early-type spirals) with similar stellar populations, which are triggered mainly by major and/or minor mergers, and in some cases by means of secular mechanism, as shown in previous numerical simulations. In the aforementioned transition we observe different phases of AGN activity, with some AGN being in the ?QSO-mode? detected as compact, blue, and unobscured in X-rays, and with others passing through different phases before and after the ?QSO-mode?, being obscured and unobscured in X-rays, respectively
publishDate 2012
dc.date.none.fl_str_mv 2012
2012-01-01
dc.type.none.fl_str_mv journal article
http://purl.org/coar/resource_type/c_6501
NA
http://purl.org/coar/version/c_be7fb7dd8ff6fe43
dc.type.openaire.fl_str_mv info:eu-repo/semantics/article
format article
dc.identifier.none.fl_str_mv https://hdl.handle.net/10902/27115
url https://hdl.handle.net/10902/27115
dc.language.none.fl_str_mv Inglés
eng
language_invalid_str_mv Inglés
language eng
dc.rights.none.fl_str_mv open access
http://purl.org/coar/access_right/c_abf2
dc.rights.openaire.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv open access
http://purl.org/coar/access_right/c_abf2
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv EDP Sciences
publisher.none.fl_str_mv EDP Sciences
dc.source.none.fl_str_mv Astronomy & Astrophysics, 2012, 541, A118
reponame:UCrea Repositorio Abierto de la Universidad de Cantabria
instname:Universidad de Cantabria (UC)
instname_str Universidad de Cantabria (UC)
reponame_str UCrea Repositorio Abierto de la Universidad de Cantabria
collection UCrea Repositorio Abierto de la Universidad de Cantabria
repository.name.fl_str_mv
repository.mail.fl_str_mv
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spelling AGN-host galaxy connection: morphology and colours of X-ray selected AGN at z ≤ 2⋆Povic, M.Sánchez-Portal, M.Pérez García, A.M.Bongiovanni, A.Cepa, J.Huertas-Company, M.Lara-López, M.A.Fernández Lorenzo, M.Ederoclite, A.Alfaro, E.Castañeda, H.Gallego, J.González Serrano, José Ignacio|||0000-0003-0795-3026González, J.J.Galaxies: activeGalaxies: Fundamental ParametersGalaxies: Distances and RedshiftsGalaxies: structureX-rays: galaxiesContext. The connection between active galactic nuclei (AGN) and their host galaxies has been widely studied and found to be of great importance for providing answers to some fundamental questions related to AGN fuelling mechanisms, and both their formation and evolution. Aims. Using X-ray data and one of the deepest broad-band optical data sets available, we study how morphology and colours are related to X-ray properties for sources at redshifts z ? 2.0, using a sample of 262 AGN in the Subaru/XMM-Newton Deep Survey (SXDS). Methods. We performed our morphological classification using the galSVM code, which is a new method that is particularly suited to dealing with high-redshift sources. Colour?magnitude diagrams were studied in relationship to redshift, morphology, X-ray obscuration, and X-ray-to-optical flux ratio. We analysed the different regions in the colour?magnitude diagrams, and searched for correlations with the observed properties of AGN populations using models of their formation and evolution. Results. We confirm that a robust and reliable morphological classification of a general galaxy population at high redshift should be based on a multi-parametric approach. At least 50% of X-ray detected AGN at z ? 2.0 analysed in this work reside in spheroidal and bulge-dominated galaxies, while at least 18% have disk-dominated hosts. This suggests that different mechanisms may be responsible for triggering the nuclear activity. When analysing populations of X-ray detected AGN in both colour?magnitude and colour-stellar mass diagrams, the highest number of sources is found to reside in the green valley at redshifts ?0.5?1.5. However, a larger number of low-luminosity AGN have been detected than in previous works owing to the substantial depth of the SXDS optical data. Whether AGN are hosted by early- or late-type galaxies, no clear relationship has been found with the optical colours (independently of redshift), as is typical of normal galaxies. Both early- and late-type AGN cover similar ranges of X-ray obscuration, for both unobscured and obscured sources. Conclusions. Our findings appear to confirm some previous suggestions that X-ray selected AGN residing in the green valley represent a transitional population, quenching star formation by means of different AGN feedback mechanisms and evolving to red-sequence galaxies. They might be hosted by similar sources (the majority of sources being late-type elliptical and lenticular galaxies, and early-type spirals) with similar stellar populations, which are triggered mainly by major and/or minor mergers, and in some cases by means of secular mechanism, as shown in previous numerical simulations. In the aforementioned transition we observe different phases of AGN activity, with some AGN being in the ?QSO-mode? detected as compact, blue, and unobscured in X-rays, and with others passing through different phases before and after the ?QSO-mode?, being obscured and unobscured in X-rays, respectivelyAcknowledgements. We thank the anonymous referee for a detailed analysis of the paper and constructive comments. We also thank Isabel Márquez Pérez, Josefa Masegosa Gallego, Jack Sulentic, and Ascensión del Olmo Orozco for long and very useful discussions. This work was supported by the Spanish Plan Nacional de Astronomía y Astrofísica under grant AYA2011-29517-C03- 01. J.I.G.S. acknowledges financial support from the Spanish Ministry of Science and Innovation under project AYA2008-06311-C02-02. M.P. acknowledges Junta de Andaluca and Spanish Ministry of Science and Innovation through projects PO8-TIC-03531 and AYA2010-15169. We thank the SXDS, CDF-S, and COMBO-17 teams for making their data available to the astronomical community. We acknowledge support from the Faculty of the European Space Astronomy Centre (ESAC). We thank XMM-Newton Helpdesk for their helpful comments during the X-ray data reduction. This research has made use of software provided by the XMM-Newton Science Operations Centre and Chandra X-ray Center (CXC) in the application packages SAS and CIAO, respectively. IRAF is distributed by the National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy (AURA) under cooperative agreement with the National Science Foundation. This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation.EDP SciencesUniversidad de Cantabria20122012-01-01journal articlehttp://purl.org/coar/resource_type/c_6501NAhttp://purl.org/coar/version/c_be7fb7dd8ff6fe43info:eu-repo/semantics/articlehttps://hdl.handle.net/10902/27115Astronomy & Astrophysics, 2012, 541, A118reponame:UCrea Repositorio Abierto de la Universidad de Cantabriainstname:Universidad de Cantabria (UC)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2info:eu-repo/semantics/openAccessoai:repositorio.unican.es:10902/271152026-06-02T12:39:31Z
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