J/A+A/525/A127 Properties of X-ray selected AGNs (Tasse+, 2011)
The dependence of X-ray AGN activity on host galaxy properties and environment.
Tasse C., Roettgering H., Best P.N.
<Astron. Astrophys., 525, A127 (2011)>
=2011A&A...525A.127T 2011A&A...525A.127T
ADC_Keywords: Active gal. nuclei ; X-ray sources ; Photometry, SDSS ;
Photometry, infrared
Keywords: galaxies: active - galaxies: fundamental parameters -
quasars: emission lines - X-rays: galaxies -
large-scale structure of Universe
Abstract:
There is mounting evidence that active galactic nuclei (AGN) selected
through optical emission lines or radio luminosities comprise two
distinct AGN populations, whose activity is triggered by different
processes. In two previous papers, we studied the host galaxies and
environment of radio-loud AGN. In this third paper we study the
properties of a sample of Type-2 AGN that were selected on the basis
of their [2-10]keV X-ray luminosity. We find that the X-ray
luminosity function is in good agreement with previous studies and
that the fraction of galaxies hosting an X-ray AGN is a strong
function of the stellar mass of the host galaxy. The shape of this
fraction-mass relation is similar to the fraction of galaxies that are
emission-line AGN, while it differs significantly from the relation
observed for radio-selected AGN. The AGN in our sample tend to be
located in underdense environments where galaxy mergers and
interactions are likely to occur. For all host galaxy masses, the
Type-2 AGN display a strong infrared excess at short (∼3.5um)
wavelengths, suggesting the presence of hot dust possibly associated
with a hot dusty torus. These results add weight to the belief that
the X-ray selection criteria identifies a population of AGN similar to
the emission-line selected population but distinct from the radio
population at high masses.
Description:
In this paper we consider the X-ray catalogue described in great
detail in Pacaud et al. (2006MNRAS.372..578P 2006MNRAS.372..578P, XMM-LSS).
The XMM-LSS field is partially covered by the Wide-1 component of the
CFHTLS. Observations were conducted using the five u*g'r'i'z' broad
band optical filters, with typical exposures of 1h in each filter.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 166 395 Properties of the selected Type-2 X-ray sources
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See also:
J/MNRAS/382/279 : XMM-LSS catalogue. Version I. (Pierre+, 2007)
J/ApJ/591/640 : XMM-LSS low-frequency radio counterparts (Cohen+, 2003)
J/A+A/456/791 : XMM-LSS field at 74 and 325MHz (Tasse+, 2006)
J/A+A/471/1105 : XMM-LSS at 240MHz and 610MHz (Tasse+, 2007)
J/A+A/474/473 : XMM-LSS survey: AGN classifications (Garcet+, 2007)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Name X-ray source name, XNNNN
7- 8 I2 h RAh X-ray source right ascension (J2000)
10- 11 I2 min RAm X-ray source right ascension (J2000)
13- 17 F5.2 s RAs X-ray source right ascension (J2000)
19 A1 --- DE- X-ray source declination sign (J2000)
20- 21 I2 deg DEd X-ray source declination (J2000)
23- 24 I2 arcmin DEm X-ray source declination (J2000)
26- 30 F5.2 arcsec DEs X-ray source declination (J2000)
32- 37 F6.2 [mW/m2] logFxs ?=- X-ray source flux in soft 0.5-2keV band
39- 44 F6.2 [mW/m2] logFxh X-ray source flux in hard 2-10keV band
46- 47 I2 h RAOh Optical counterpart right ascension (J2000)
49- 50 I2 min RAOm Optical counterpart right ascension (J2000)
52- 56 F5.2 s RAOs Optical counterpart right ascension (J2000)
58 A1 --- DEO- Optical counterpart declination sign (J2000)
59- 60 I2 deg DEOd Optical counterpart declination (J2000)
62- 63 I2 arcmin DEOm Optical counterpart declination (J2000)
65- 69 F5.2 arcsec DEOs Optical counterpart declination (J2000)
71 A1 --- l_umag Limit flag on umag
72- 76 F5.2 mag umag ?=- u-band magnitude in AB system (1)
78- 82 F5.2 mag gmag ?=- g-band magnitude in AB system (1)
84 A1 --- l_rmag Limit flag on rmag
85- 89 F5.2 mag rmag r-band magnitude in AB system
91- 95 F5.2 mag imag i-band magnitude in AB system
97 A1 --- l_zmag Limit flag on zmag
98-102 F5.2 mag zmag ?=- z-band magnitude in AB system (1)
104-108 F5.1 % Pid Estimated probability that the X-ray source
is associated with the corresponding optical
candidate
110 A1 --- l_[3.6] Limit flag on [3.6]
111-115 F5.2 mag [3.6] ?=- Spitzer/IRAC 3.6um magnitude (AB) (2)
117 A1 --- l_[4.5] Limit flag on [4.5]
118-122 F5.2 mag [4.5] ?=- Spitzer/IRAC 4.5um magnitude (AB) (2)
124 A1 --- l_[5.8] Limit flag on [5.8]
125-129 F5.2 mag [5.8] ?=- Spitzer/IRAC 5.8um magnitude (AB) (2)
131 A1 --- l_[8.0] Limit flag on [8.0]
132-136 F5.2 mag [8.0] ?=- Spitzer/IRAC 8.0um magnitude (AB) (2)
138-141 F4.2 --- zph Photometric redshift as estimated by ZPEG
143-147 F5.2 [Msun] logM Stellar mass as estimated by ZPEG
in logarithm base-10 scale
149-154 F6.2 [yr-1] logSFR ? Specific SFR as estimated by ZPEG
in logarithm base-10 scale
155 A1 --- n_logSFR [i] i for ∞ logSFR
156-157 A2 --- l_lognH Limit flag on lognH
158-161 F4.1 [cm-2] lognH Estimated hydrogen column density
163-166 F4.1 [10-7W] logLX Estimated rest-frame intrinsic X-ray
luminosity in the 2-10keV band
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Note (1): "---" means the field has not been observed in that band.
Note (2): "---" (standing for 'Not Covered') has been used when the
location of the object is not overlapping with the SWIRE field.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 10-May-2011