J/A+A/501/485 X-ray properties of Chandra red galaxies (Campisi+, 2009)
On the nature of red galaxies: the Chandra perspective.
Campisi M.A., Vignali C., Brusa M., Daddi E., Comastri A., Pozzetti L.,
Alexander D.M., Renzini A., Arimoto N., Kong X.
<Astron. Astrophys., 501, 485-494 (2009)>
=2009A&A...501..485C 2009A&A...501..485C
ADC_Keywords: X-ray sources ; Infrared sources ; Galaxies, photometry
Keywords: galaxies: active - galaxies: nuclei - quasars: general -
X-rays: galaxies
Abstract:
We present the X-ray properties of the extremely red objects (ERO)
population observed by Chandra with three partially overlapping
pointings (up to ∼90ks) over an area of ∼500arcmin2, down to a
0.5-8keV flux limit of ∼10-15erg/cm2/s. We selected EROs using a
multi-band photometric catalog down to a Ks-band magnitude of
∼19.3 (Vega system); 14 EROs were detected in X-rays, corresponding to
∼9% of the overall X-ray source population (149 X-ray sources) and to
∼5% of the ERO population (288). The X-ray emission of all X-ray
detected EROs is consistent with that of an active galactic nucleus
(AGN) (≳3.5x1042erg/s at photometric redshifts z>1), in agreement
with previous X-ray observations, with an indication of increasing
absorption between the three X-ray brightest EROs and the 11 X-ray
faintest EROs.
Description:
The "Daddi field", centered on 14:49:29+09:00:00 (J2000),
was observed in the Ks band with the ESO NTT 3.5m telescope at La
Silla in 1999, using the SOFI camera.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 82 149 X-ray properties of the sources detected by
Chandra in the "Daddi field"
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See also:
B/chandra : The Chandra Archive Log (CXC, 1999-)
J/MNRAS/330/1 : HST observations of Extremely Red Objects (Smith+, 2002)
J/ApJ/581/844 : Radio and Infrared observations of EROs (Smail+, 2002)
J/PASJ/55/1079 : BVRi'z'JHKs photometry of ERO objects (Miyazaki+, 2003)
J/ApJ/586/765 : HST K-selected extremely red galaxies (Yan+, 2003)
J/MNRAS/377/787 : SDSS Luminous Red Galaxies (Barber+, 2007)
J/AJ/130/2647 : Tidal features of 126 nearby red galaxies (van Dokkum+ 2005)
J/ApJ/627/621 : Catalog of Extremely Red Objects (Sawicki+, 2005)
J/MNRAS/354/L25 : MgII absorbers in SDSS QSOs (Bouche+, 2004)
J/MNRAS/380/1608 : LRG catalog (Lopes+, 2007)
J/MNRAS/381/211 : Radio galaxies in the 2SLAQ LRG Survey (Sadler+, 2007)
J/MNRAS/392/1265 : Coma cluster faint red galaxies spectroscopy (Smith+, 2009)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- XID X-ray identification number in the
Chandra mosaic
5- 14 F10.6 deg RAdeg Right ascension in decimal degrees (J2000)
16- 24 F9.6 deg DEdeg Declination in decimal degrees (J2000)
26- 29 F4.1 arcmin theta Off-axis angle at the source position
averaged over the Chandra observations
31- 35 F5.1 ct Counts Source net counts in the 0.5-8keV band
36 A1 --- n_Counts [hs] s when counts in 0.5-2keV band,
h when counts in 2-8kev band
38- 41 F4.1 ks ExpTime Exposure time at the source position
43- 50 E8.3 mW/m2 F(0.5-8) ? Flux in the 0.5-8keV band (1)
52 A1 --- l_F(0.5-2) Limit flag on F(0.5-2) (2)
53- 60 E8.3 mW/m2 F(0.5-2) ? Flux in the soft 0.5-2keV band (1)
62 A1 --- l_F(2-8) Limit flag on F(2-8) (2)
63- 70 E8.3 mW/m2 F(2-8) ? Flux in the hard 2-8keV band (1)
71 A1 --- n_F(2-8) [h] h when flux in the 2-10keV band
72 A1 --- l_HR Limit flag on HR
73- 77 F5.2 --- HR ? Hardness ratio (H-S/H+S)
79- 82 F4.2 --- e_HR ? rms uncertainty on HR
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Note (1): Fluxes obtained from the count-rate conversion, assuming a
power-law model with Gamma=1.8/2.0/1.4/1.4.
Note (2): The upper limits (at the 95% confidence level) to the counts,
hence the reported fluxes, were computed according to Kraft et al.
(1991ApJ...374..344K 1991ApJ...374..344K). Only five sources are detected in the full band
without being detected in the two sub-bands considered in this work
(because of the adopted detection threshold).
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 31-Aug-2009