IDENTIFYING LUMINOUS ACTIVE GALACTIC NUCLEI IN DEEP SURVEYS: REVISED IRAC SELECTION CRITERIA

By J. Donley, A. Koekemoer, M. Brusa, P. Capak, C. Cardamone, F. Civano, O. Ilbert, Christopher Impey, J. Kartaltepe, T. Miyaji and 4 more. 2012

417 citations recorded by the source corpus.

Spitzer/IRAC selection is a powerful tool for identifying luminous active galactic nuclei (AGNs). For deep IRAC data, however, the AGN selection wedges currently in use are heavily contaminated by star-forming galaxies, especially at high redshift. Using the large samples of luminous AGNs and high-redshift star-forming galaxies in COSMOS, we redefine the AGN selection criteria for use in deep IRAC surveys. The new IRAC criteria are designed to be both highly complete and reliable, and incorporate the best aspects of the current AGN selection wedges and of infrared power-law selection while excluding high-redshift star-forming galaxies selected via the BzK, distant red galaxy, Lyman-break galaxy, and submillimeter galaxy criteria. At QSO luminosities of log L2–10 keV(erg s−1) ⩾44, the new IRAC criteria recover 75% of the hard X-ray and IRAC-detected XMM-COSMOS sample, yet only 38% of the IRAC AGN candidates have X-ray counterparts, a fraction that rises to 52% in regions with Chandra exposures of 50–160 ks. X-ray stacking of the individually X-ray non-detected AGN candidates leads to a hard X-ray signal indicative of heavily obscured to mildly Compton-thick obscuration (log NH (cm−2) = 23.5 ± 0.4). While IRAC selection recovers a substantial fraction of luminous unobscured and obscured AGNs, it is incomplete to low-luminosity and host-dominated AGNs.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/8891190301f93f7124d40a2d3c69b9fdbbd3f413

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In Astronomy and Astrophysics

1. P. Hopkins
2. L. Hernquist
3. D. M. Alexander
4. P. V. van Dokkum
5. R. Somerville
6. R. Dav'e
7. C. Conroy
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In Nuclear and High Energy Physics

1. D. M. Alexander
2. P. Hopkins
3. L. Hernquist
4. W. N. Brandt
5. G. Hasinger
6. R. Ivison
7. A. Merloni
8. R. Somerville

Citations in the corpus

• The WISE AGN Catalog (2017, background): “…survey of the sky, the majority have been developed for the more recent observatories, such as Spitzer and WISE (Lacy et al. 2004, 2007, 2013; Stern et al. 2005, 2012; Assef et al. 2010, 2013; Jarrett et al. 2011; Donley et al. 2012; Mateos et al. 2012; Messias et al. 2012; Wu et al. 2012).”
• Galaxy Interactions Trigger Rapid Black Hole Growth: an unprecedented view from the Hyper Suprime-Cam Survey (2017, methodology): “However, IR color-color diagrams may fail to readily identify AGN accreting at low Eddington ratios (e.g., Donley et al. 2012; Mateos et al. 2012; Hainline et al. 2016).”
• Mass assembly in quiescent and star-forming galaxies since z ≃ 4 from UltraVISTA (2013, methodology): “%) were flagged as power-law sources using the criteria establishedby Donley et al. (2012).”
• THE RELATION BETWEEN STAR FORMATION RATE AND STELLAR MASS FOR GALAXIES AT 3.5 ⩽ z ⩽ 6.5 IN CANDELS (2014, methodology): “Our samples have been cleaned from a total of 46 objects from X-Ray (Xue et al. 2011), IR (Donley et al. 2012), and radio (Padovani et al. 2011) detected AGN, as flagged by the Dahlen et al. (2013) photo-z catalog.”
• The evolution of the dust and gas content in galaxies (2013, background): “The dust content in AGNs will be investigated in a dedicated forthcoming paper (Vito et al., in prep.).”
• THE MOSFIRE DEEP EVOLUTION FIELD (MOSDEF) SURVEY: REST-FRAME OPTICAL SPECTROSCOPY FOR ∼1500 H-SELECTED GALAXIES AT 1.37 ≤ z ≤ 3.8 ?> (2014, background): “Within a specific magnitude and redshift bin, we upweight galaxies that host an AGN, identified either by IRAC colors (Donley et al. 2012) or by a strong X-ray counterpart.”
• THE CHANDRA COSMOS SURVEY. III. OPTICAL AND INFRARED IDENTIFICATION OF X-RAY POINT SOURCES (2012, background): “The selection of AGN at X-ray wavelengths does not suffer from the heavy contamination by non-active (mainly starforming) galaxies that affects infrared or optical surveys (Donley et al. 2008, 2012).”
• SPECTRAL ENERGY DISTRIBUTIONS OF LOCAL LUMINOUS AND ULTRALUMINOUS INFRARED GALAXIES (2012, methodology): “The revised IRAC color selection by Donley et al. (2012) is designed to incorporate the best aspects of the current IRAC wedges but to minimizie star-forming contamints, and has been adopted here for selecting IRAC AGN candidates (see Eqn.”
• EVIDENCE FOR WIDE-SPREAD ACTIVE GALACTIC NUCLEUS-DRIVEN OUTFLOWS IN THE MOST MASSIVE z ∼ 1–2 STAR-FORMING GALAXIES (2014, methodology): “In total, nine galaxies satisfy the IRAC AGN criteria, with 15 more potential AGNs that lie close to the region delineated in Donley et al. (2012) but formally do not satisfy the criteria.”
• The DEIMOS 10K Spectroscopic Survey Catalog of the COSMOS Field (2018, background): “These include radio sources (“VLA”), Herschel PACS sources (“Herschel”), and power-law AGN candidates (PL AGN, Donley et al. 2012; Chang et al. 2017).”
• Dusty Star Forming Galaxies at High Redshift (2014, background): “These were recently revisited by Donley et al. (2012), under the premise that the previously developed color-selection ‘‘wedges’’ were contaminated by star-forming galaxies given deep enough IRAC data.”
• CONSTRAINING THE LOW-MASS SLOPE OF THE STAR FORMATION SEQUENCE AT 0.5 < z < 2.5 (2014, background): “As all five CANDELS fields have uniform coverage with deep Spitzer/IRAC imaging, we remove all sources that fall within the revised IRAC color–color selections presented in Donley et al. (2012).”
• Tracing the cosmic growth of supermassive black holes to z ∼ 3 with Herschel (2014, methodology): “The stellar mass is inferred from the best-fit template of the 9 Given the monochromatic fluxes (Sλ) at 3.6, 4.5, 5.8 and 8.0 µm, the criteria established by Donley et al. (2012) set the following additional conditions: S3.”
• THE CHANDRA COSMOS LEGACY SURVEY: OPTICAL/IR IDENTIFICATIONS (2015, background): “X-ray data play an important role in the selection of AGN, because at these energies the contamination from non-nuclear emission, mainly due to star-formation processes, is far less significant than in optical and infrared surveys (Donley et al. 2008, 2012; Stern et al. 2012; Lehmer et al. 2012).”
• The HDUV Survey: A Revised Assessment of the Relationship between UV Slope and Dust Attenuation for High-redshift Galaxies (2017, methodology): “Additionally, we use the Donley et al. (2012) Spitzer IRAC selection to isolate any infrared-bright AGN.”
• The faint radio sky: radio astronomy becomes mainstream (2016, background): “Nevertheless, mid-IR (MIR) selection is very important since it identifies also heavily obscured AGN, many of which are missed even by deep X-ray surveys (Donley et al. 2012).”
• Cosmic X-ray surveys of distant active galaxies (2015, methodology): “Color-color selection from MIR photometric data (e.g., Lacy et al 2004; Stern et al 2005; Polletta et al 2006; Hickox et al 2007; Cardamone et al 2008; Donley et al 2008, 2012; Mateos et al 2013).”