The HELLAS2XMM Survey. II. Multiwavelength Observations of P3: An X-Ray-bright, Optically Inactive Galaxy

By A. Comastri, M. Mignoli, P. Ciliegi, P. Severgnini, R. Maiolino, M. Brusa, F. Fiore, A. Baldi, S. Molendi, R. Morganti and 4 more. 2002

135 citations recorded by the source corpus.

Recent X-ray surveys have clearly demonstrated that a population of optically dull, X-ray-bright galaxies is emerging at 2-10 keV fluxes of the order of 10-14 ergs cm-2 s-1. Although they might constitute an important fraction of the sources responsible for the hard X-ray background, their nature is still unknown. With the aim of better understanding the physical mechanisms responsible for the observed properties, we have started an extensive program of multiwavelength follow-up observations of hard X-ray, optically quiet galaxies discovered with XMM-Newton. Here we report the results of what can be considered the first example of this class of objects: CXOU J031238.9-765134, originally discovered by Chandra, and optically identified by Fiore et al. (2000) with an apparently normal early-type galaxy at z = 0.159, usually known as FIORE P3. Analysis of the broadband energy distribution suggests the presence of a heavily obscured active nucleus.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/848c7fac5a5b2004decd542369fbf02ef14a5ae4

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. D. M. Alexander
2. W. N. Brandt
3. P. Hopkins
4. L. Hernquist
5. Mara Salvato
6. P. Capak
7. A. Koekemoer
8. R. Hickox

In Nuclear and High Energy Physics

1. D. M. Alexander
2. W. N. Brandt
3. G. Hasinger
4. A. Merloni
5. T. Miyaji
6. L. Hernquist
7. P. Hopkins
8. F. E. Bauer

Citations in the corpus

• The Fall of Active Galactic Nuclei and the Rise of Star-forming Galaxies: A Close Look at the Chandra Deep Field X-Ray Number Counts (2004, background): “Thus, the ‘‘not obviously type 1’’ category is probably too loose to provide much insight, since it is likely to include not only classic narrowline AGNs (type 2), but also slightly more luminous versions of Compton-thick AGNs like NGC 4945 and NGC 6240 (e.g., Matt et al. 2000), XBONGS (Comastri et ”
• DEEP EXTRAGALACTIC X-RAY SURVEYS (2005, background): “…and perhaps most may just be normal Seyfert galaxies where dilution by host-galaxy light hinders optical detection of the AGN (e.g., Moran et al. 2002; Severgnini et al. 2003), but some have high-quality follow-up observations and appear to be truly remarkable objects (e.g., Comastri et al. 2002).”
• THE CHANDRA COSMOS SURVEY. III. OPTICAL AND INFRARED IDENTIFICATION OF X-RAY POINT SOURCES (2012, background): “In addition to obscured AGN, unobscured X-ray Bright Optically Normal Galaxies (XBONGs) also haveX/O > 1 (e.g. Comastri et al. 2002, Civano et al. 2007, Trump et al. 2009c).”
• The HELLAS2XMM survey IV. Optical identifications and the evolution of the accretion luminosity in the Universe (2003, background): “…sizeable samples of of “rare” objects, such as high luminosity, highly obscured type 2 QSO (and also of other rare sources like the X-ray bright, optically normal galaxies, XBONGs, Fiore et al. 2000; Comastri et al. 2002) a much wider area needs to be covered, of the order of a few square degrees.”
• Optical and Infrared Properties of the 2 Ms Chandra Deep Field North X-Ray Sources (2003, background): “5–2keV/fR) d 1 (Barger et al. 2002; Rosati et al. 2002).”
• THE 22 MONTH SWIFT-BAT ALL-SKY HARD X-RAY SURVEY (2009, background): “These are probably low-z counterparts to the X-ray bright, optically normal (XBONG) sources discovered in the Chandra and XMMNewton deep fields (Barger et al. 2005; Comastri et al. 2002).”
• The X-Ray Spectral Properties of SCUBA Galaxies (2005, background): “…of AGNs, giving a direct ‘‘window’’ on the emission regions closest to the SMBH (e.g., Mushotzky et al. 1993), and it can provide a secure AGN identification in sources in which the optical signatures and counterparts are weak or even nonexistent (e.g., Alexander et al. 2001; Comastri et al. 2002).”
• “Hidden” Seyfert 2 Galaxies and the X-Ray Background (2002, background): “The possibility that some host-galaxy light is excluded in the spectra of these objects is probably offset by the fact that their host galaxies are quite luminous — nine of the ten “normal” galaxies in the Comastri et al. (2002b) study have LB greater than a few times 1043 ergs s−1.”
• THE XMM-NEWTON WIDE-FIELD SURVEY IN THE COSMOS FIELD (XMM-COSMOS): DEMOGRAPHY AND MULTIWAVELENGTH PROPERTIES OF OBSCURED AND UNOBSCURED LUMINOUS ACTIVE GALACTIC NUCLEI (2010, background): “…motivated by the fact that both obscured and unobscured AGN can be misclassified in spectroscopic studies, given that the host galaxy light may over-shine the nuclear emission (as in the cases of the XBONG; Moran et al. 2002, Comastri et al. 2002, Severgnini et al. 2003, Civano et al. 2007).”
• THE CHANDRA COSMOS LEGACY SURVEY: OPTICAL/IR IDENTIFICATIONS (2015, background): “Finally, a third class of objects is defined, formed by unobscured X-ray Bright, Optically Normal Galaxies (XBONGs, see Elvis et al. 1981, Comastri et al. 2002; Civano et al. 2007; Trump et al. 2009b).”
• The XMM-Newton Wide-Field Survey in the COSMOS Field. III. Optical Identification and Multiwavelength Properties of a Large Sample of X-Ray-Selected Sources (2006, background): “…sources are preferentially identified with nearby galaxies, in which the optical luminosity is mainly due to the integrated stellar light; for the majority of them, the high-level of observed X–ray flux suggests that some activity is taking place in their nuclei (see, e.g. Comastri et al. 2002).”
• BAT AGN Spectroscopic Survey. I. Spectral Measurements, Derived Quantities, and AGN Demographics (2017, background): “These sources are consistent with X-ray bright optically normal galaxies (e.g. XBONGS, Comastri et al. 2002).”
• The Relationship of Hard X-Ray and Optical Line Emission in Low-Redshift Active Galactic Nuclei (2005, background): “The ‘‘X-ray–bright, optically normal galaxies’’ (Levenson et al. 2001; Comastri et al. 2002; Maiolino et al. 2003; Brusa et al. 2003) are evidently not a major component of the local AGN population.”
• Optical Spectroscopy and X-Ray Detections of a Sample of Quasars and Active Galactic Nuclei Selected in the Mid-Infrared from Two Spitzer Space Telescope Wide-Area Surveys (2006, background): “X-ray surveys too find a population of AGN which lack opical evidence for AGN activity, the X-ray bright, optically-normal galaxies (XBONGs) (e.g. Comastri et al. 2002).”
• IDENTIFYING LUMINOUS ACTIVE GALACTIC NUCLEI IN DEEP SURVEYS: REVISED IRAC SELECTION CRITERIA (2012, background): “…with narrow optical emission lines, those with no emission lines yet X-ray luminosities exceeding 2× 1042 ergs s−1 (e.g., optically dull AGN, Moran et al. 2002; Comastri et al. 2002), and those lacking optical spectra yet best-fit by a galaxy-dominated template are classified as “optical Type 2”.”