The AGN, star-forming, and morphological properties of luminous ir-bright/optically-faint galaxies

We present the active galactic nucleus (AGN), star-forming, and morphological properties of a sample of 13 MIR-luminous (∫_24 700 μJy) IR-bright/optically-faint galaxies (IRBGs, ∫_24/f_R≲ 1000). While these z ∼ 2 sources were drawn from deep Chandra fields with >200 ks X-ray coverage, only seven...

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Detalles Bibliográficos
Autores: Donley, J. L., Rieke, G. H., Alexander, D. M., Egami, E., Pérez González, Pablo Guillermo
Tipo de recurso: artículo
Fecha de publicación:2010
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/45102
Acceso en línea:https://hdl.handle.net/20.500.14352/45102
Access Level:acceso abierto
Palabra clave:52
Ultraluminous infrared galaxies
Active galactic nuclei
Deep-field-North
Spitzer midinfrared spectroscopy
Dust-obscured galaxies
Similar-to 2
Polycyclic aromatic-hydrocarbon
Redshift submillimeter galaxies
Supermassive black-holes
Point-source catalogs
Astrofísica
Astronomía (Física)
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oai_identifier_str oai:docta.ucm.es:20.500.14352/45102
network_acronym_str ES
network_name_str España
repository_id_str
spelling The AGN, star-forming, and morphological properties of luminous ir-bright/optically-faint galaxiesDonley, J. L.Rieke, G. H.Alexander, D. M.Egami, E.Pérez González, Pablo Guillermo52Ultraluminous infrared galaxiesActive galactic nucleiDeep-field-NorthSpitzer midinfrared spectroscopyDust-obscured galaxiesSimilar-to 2Polycyclic aromatic-hydrocarbonRedshift submillimeter galaxiesSupermassive black-holesPoint-source catalogsAstrofísicaAstronomía (Física)We present the active galactic nucleus (AGN), star-forming, and morphological properties of a sample of 13 MIR-luminous (∫_24 700 μJy) IR-bright/optically-faint galaxies (IRBGs, ∫_24/f_R≲ 1000). While these z ∼ 2 sources were drawn from deep Chandra fields with >200 ks X-ray coverage, only seven are formally detected in the X-ray and four lack X-ray emission at even the 2σ level. Spitzer InfraRed Spectrograph (IRS) spectra, however, confirm that all of the sources are AGN-dominated in the mid-IR, although half have detectable polycyclic aromatic hydrocarbon (PAH) emission responsible for ∼25% of their mid-infrared flux density. When combined with other samples, this indicates that at least 30%–40% of luminous IRBGs have star formation rates in the ultraluminous infrared galaxy (ULIRG) range (∼100–2000 M_⨀ yr^−1). X-ray hardness ratios and MIR to X-ray luminosity ratios indicate that all members of the sample contain heavily X-ray obscured AGNs, 80% of which are candidates to be Compton thick. Furthermore, the mean X-ray luminosity of the sample, log L_2–10 keV(erg s^−1) ∼44.6, indicates that these IRBGs are Type 2 QSOs, at least from the X-ray perspective. While those sources most heavily obscured in the X-ray are also those most likely to display strong silicate absorption in the mid-IR, silicate absorption does not always accompany X-ray obscuration. Finally, ∼70% of the IRBGs are merger candidates, a rate consistent with that of sub-mm galaxies (SMGs), although SMGs appear to be physically larger than IRBGs. These characteristics are consistent with the proposal that these objects represent a later, AGN-dominated, and more relaxed evolutionary stage following soon after the star-formation-dominated one represented by the SMGs.American Astronomical SocietyUniversidad Complutense de Madrid20102010-08-2020102010-08-20journal articlehttp://purl.org/coar/resource_type/c_6501info:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/20.500.14352/45102reponame:Docta Complutenseinstname:Universidad Complutense de Madrid (UCM)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2info:eu-repo/semantics/openAccessoai:docta.ucm.es:20.500.14352/451022026-06-02T12:44:21Z
dc.title.none.fl_str_mv The AGN, star-forming, and morphological properties of luminous ir-bright/optically-faint galaxies
title The AGN, star-forming, and morphological properties of luminous ir-bright/optically-faint galaxies
spellingShingle The AGN, star-forming, and morphological properties of luminous ir-bright/optically-faint galaxies
Donley, J. L.
52
Ultraluminous infrared galaxies
Active galactic nuclei
Deep-field-North
Spitzer midinfrared spectroscopy
Dust-obscured galaxies
Similar-to 2
Polycyclic aromatic-hydrocarbon
Redshift submillimeter galaxies
Supermassive black-holes
Point-source catalogs
Astrofísica
Astronomía (Física)
title_short The AGN, star-forming, and morphological properties of luminous ir-bright/optically-faint galaxies
title_full The AGN, star-forming, and morphological properties of luminous ir-bright/optically-faint galaxies
title_fullStr The AGN, star-forming, and morphological properties of luminous ir-bright/optically-faint galaxies
title_full_unstemmed The AGN, star-forming, and morphological properties of luminous ir-bright/optically-faint galaxies
title_sort The AGN, star-forming, and morphological properties of luminous ir-bright/optically-faint galaxies
dc.creator.none.fl_str_mv Donley, J. L.
Rieke, G. H.
Alexander, D. M.
Egami, E.
Pérez González, Pablo Guillermo
author Donley, J. L.
author_facet Donley, J. L.
Rieke, G. H.
Alexander, D. M.
Egami, E.
Pérez González, Pablo Guillermo
author_role author
author2 Rieke, G. H.
Alexander, D. M.
Egami, E.
Pérez González, Pablo Guillermo
author2_role author
author
author
author
dc.contributor.none.fl_str_mv Universidad Complutense de Madrid
dc.subject.none.fl_str_mv 52
Ultraluminous infrared galaxies
Active galactic nuclei
Deep-field-North
Spitzer midinfrared spectroscopy
Dust-obscured galaxies
Similar-to 2
Polycyclic aromatic-hydrocarbon
Redshift submillimeter galaxies
Supermassive black-holes
Point-source catalogs
Astrofísica
Astronomía (Física)
topic 52
Ultraluminous infrared galaxies
Active galactic nuclei
Deep-field-North
Spitzer midinfrared spectroscopy
Dust-obscured galaxies
Similar-to 2
Polycyclic aromatic-hydrocarbon
Redshift submillimeter galaxies
Supermassive black-holes
Point-source catalogs
Astrofísica
Astronomía (Física)
description We present the active galactic nucleus (AGN), star-forming, and morphological properties of a sample of 13 MIR-luminous (∫_24 700 μJy) IR-bright/optically-faint galaxies (IRBGs, ∫_24/f_R≲ 1000). While these z ∼ 2 sources were drawn from deep Chandra fields with >200 ks X-ray coverage, only seven are formally detected in the X-ray and four lack X-ray emission at even the 2σ level. Spitzer InfraRed Spectrograph (IRS) spectra, however, confirm that all of the sources are AGN-dominated in the mid-IR, although half have detectable polycyclic aromatic hydrocarbon (PAH) emission responsible for ∼25% of their mid-infrared flux density. When combined with other samples, this indicates that at least 30%–40% of luminous IRBGs have star formation rates in the ultraluminous infrared galaxy (ULIRG) range (∼100–2000 M_⨀ yr^−1). X-ray hardness ratios and MIR to X-ray luminosity ratios indicate that all members of the sample contain heavily X-ray obscured AGNs, 80% of which are candidates to be Compton thick. Furthermore, the mean X-ray luminosity of the sample, log L_2–10 keV(erg s^−1) ∼44.6, indicates that these IRBGs are Type 2 QSOs, at least from the X-ray perspective. While those sources most heavily obscured in the X-ray are also those most likely to display strong silicate absorption in the mid-IR, silicate absorption does not always accompany X-ray obscuration. Finally, ∼70% of the IRBGs are merger candidates, a rate consistent with that of sub-mm galaxies (SMGs), although SMGs appear to be physically larger than IRBGs. These characteristics are consistent with the proposal that these objects represent a later, AGN-dominated, and more relaxed evolutionary stage following soon after the star-formation-dominated one represented by the SMGs.
publishDate 2010
dc.date.none.fl_str_mv 2010
2010-08-20
2010
2010-08-20
dc.type.none.fl_str_mv journal article
http://purl.org/coar/resource_type/c_6501
dc.type.openaire.fl_str_mv info:eu-repo/semantics/article
format article
dc.identifier.none.fl_str_mv https://hdl.handle.net/20.500.14352/45102
url https://hdl.handle.net/20.500.14352/45102
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.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv American Astronomical Society
publisher.none.fl_str_mv American Astronomical Society
dc.source.none.fl_str_mv reponame:Docta Complutense
instname:Universidad Complutense de Madrid (UCM)
instname_str Universidad Complutense de Madrid (UCM)
reponame_str Docta Complutense
collection Docta Complutense
repository.name.fl_str_mv
repository.mail.fl_str_mv
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