MNRAS-2015-Riguccini-470-85.pdf (1.43 MB)
The composite nature of Dust-Obscured Galaxies (DOGs) at z~2-3 in the COSMOS field: I. A far-infrared view
journal contribution
posted on 2023-06-08, 21:04 authored by Laurie Riguccini, Emeric Le Floc'h, James Mullaney, Karin Menendez-Delmestre, Hervé Aussel, Stefano Berta, Jae Calanog, Peter Capak, Asantha Cooray, Oliver Ilbert, Jeyhan Kartaltepe, Anton Koekemoer, Dieter Lutz, Benjamin Magnelli, Henry McCraken, Seb OliverSeb Oliver, Isaac Roseboom, Mara Salvato, David Sanders, Nick Scoville, Yoshiaki Taniguchi, Ezequiel TreisterDust-Obscured galaxies (DOGs) are bright 24µm-selected sources with extreme obscuration at optical wavelengths. They are typically characterized by a rising power-law continuum of hot dust (TD ~ 200-1000K) in the near-IR indicating that their mid-IR luminosity is dominated by an active galactic nucleus (AGN). DOGs with a fainter 24 µm flux display a stellar bump in the near-IR and their mid-IR luminosity appears to be mainly powered by dusty star formation. Alternatively, it may be that the mid-IR emission arising from AGN activity is dominant but the torus is sufficiently opaque to make the near-IR emission from the AGN negligible with respect to the emission from the host component. In an effort to characterize the astrophysical nature of the processes responsible for the IR emission in DOGs, this paper exploits Herschel data (PACS + SPIRE) on a sample of 95 DOGs within the COSMOS field. We derive a wealth of far-IR properties (e.g., total IR luminosities; mid-to-far IR colours; dust temperatures and masses) based on SED fitting. Of particular interest are the 24 µm-bright DOGs (F 24µm >1mJy). They present bluer far-IR/mid-IR colours than the rest of the sample, unveiling the potential presence of an AGN. The AGN contribution to the total 8-1000µm flux increases as a function of the rest-frame 8µm-luminosity irrespective of the redshift. This confirms that faint DOGs (L 8µm < 10 12 Lo ) are dominated by star-formation while brighter DOGs show a larger contribution from an AGN.
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Publication status
- Published
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- Published version
Journal
Monthly Notices of the Royal Astronomical SocietyISSN
0035-8711Publisher
Oxford University PressExternal DOI
Issue
1Volume
452Page range
470-485Department affiliated with
- Physics and Astronomy Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2015-06-10First Open Access (FOA) Date
2016-09-26First Compliant Deposit (FCD) Date
2015-06-10Usage metrics
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