J/A+A/488/73 Variability-selected AGN in Chandra DFS (Trevese+, 2008)
Variability-selected active galactic nuclei from supernova search in the
Chandra Deep Field South.
Trevese D., Boutsia K., Vagnetti F., Cappellaro E., Puccetti S.
<Astron. Astrophys., 488, 73-81 (2008)>
=2008A&A...488...73T 2008A&A...488...73T
ADC_Keywords: Active gal. nuclei ; X-ray sources ; Photometry ; Redshifts
Keywords: surveys - galaxies: active - galaxies: quasars: general -
X-rays: galaxies
Abstract:
Variability is a property shared by virtually all active galactic
nuclei (AGNs), and was adopted as a criterion for their selection
using data from multi epoch surveys. Low Luminosity AGNs (LLAGNs) are
contaminated by the light of their host galaxies, and cannot therefore
be detected by the usual colour techniques. For this reason, their
evolution in cosmic time is poorly known. Consistency with the
evolution derived from X-ray detected samples has not been clearly
established so far, also because the low luminosity population
consists of a mixture of different object types. LLAGNs can be
detected by the nuclear optical variability of extended objects.
Several variability surveys have been, or are being, conducted for the
detection of supernovae (SNe). We propose to re-analyse these SNe data
using a variability criterion optimised for AGN detection, to select a
new AGN sample and study its properties.
We analysed images acquired with the wide field imager at the 2.2m
ESO/MPI telescope, in the framework of the STRESS supernova survey. We
selected the AXAF field centred on the Chandra Deep Field South where,
besides the deep X-ray survey, various optical data exist, originating
in the EIS and COMBO-17 photometric surveys and the spectroscopic
database of GOODS.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 132 132 Catalogue of the variable objects
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See also:
J/ApJS/139/369 : Chandra Deep Field South. 1 Ms catalog (Giacconi+, 2002)
II/253 : Chandra Deep Field South: multi-colour data (Wolf+, 2004)
J/ApJS/155/271 : Chandra Deep Field-South: Optical spectroscopy (Szokoly+ 2004)
J/ApJS/161/21 : Extended Chandra Deep Field-South survey (Lehmer+, 2005)
J/A+A/449/951 : GOODS-MUSIC sample: multicolour catalog (Grazian+, 2006)
J/A+A/465/1099 : Redshift catalog of 691 objects in CDFS (Ravikumar+, 2007)
J/A+A/479/49 : Supernova rates from STRESS (Botticella+, 2008)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- [TBV2008] Sequential number
5- 6 I2 h RAh Right ascension (J2000)
8- 9 I2 min RAm Right ascension (J2000)
11- 15 F5.2 s RAs Right ascension (J2000)
17 A1 --- DE- Declination sign (J2000)
18- 19 I2 deg DEd Declination (J2000)
21- 22 I2 arcmin DEm Declination (J2000)
24- 27 F4.1 arcsec DEs Declination (J2000)
29- 33 F5.2 mag Vmag1 V magnitude of present work
(rescaled to VEIS)
35- 39 F5.3 mag sigma Standard deviation of the light curve
41- 44 F4.1 mag sigma* Normalized standard deviation of the
light curve
46- 64 A19 --- EIS ?=- EIS name (JHHMMSS.ss+DDMMSS.s)
66- 70 F5.2 mag Umag ? EIS U magnitude in AB system
72- 76 F5.2 mag Bmag ? EIS B magnitude in AB system
78- 82 F5.2 mag Vmag ? EIS V magnitude in AB system
84- 88 F5.2 mag Rmag ? EIS R magnitude in AB system
90- 93 F4.2 --- S ? Sellarity index from EIS catalogue
95- 99 I5 --- [WDK2001] ? COMBO-17 name
101-103 A3 --- Class COMBO-class (1)
105-109 F5.3 --- z ? Spectroscopic redshift
111-116 A6 --- Notes Notes on the nature of the object (2)
118-120 I3 --- XID ? X-ray identification (3)
121 A1 --- r_XID [d] Reference not in Lehmer et al. (2005) (4)
123 A1 --- l_FX Limit flag on FX
124-131 E8.3 mW/m2 FX ? X-ray flux in the (2-8keV) band (3)
132 A1 --- r_FX [de] Reference not Lin ehmer et al. (2005) (4)
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Note (1): COMBO-class as follows:
G = galaxy
Q = QSO
S = star
U = unclear, Wolf et al., 2004, Cat, II/253
Note (2): Notes as follows:
BLAGN = Broad Line AGN
LEX = Low Excitation spectrum
NELG = Narrow Emission Line Galaxy (Szokoly, 2004, J/ApJS/155/271)
q = quasar
em = emission line galaxy (Ravikumar et al., 2007, J/A+A/465/1099)
g = galaxy (Grazian et al., 2006, Cat. J/A+A/449/951
SN = supernova
SNC = supernova candidate (Botticella et al., 2008, J/A+A/479/49)
EN = extranuclear (Hornschemeier et al., 2004ApJ...600L.147H 2004ApJ...600L.147H;
Lehmer et al., 2006AJ....131.2394L 2006AJ....131.2394L)
Note (3): From Lehmer et al., 2005, Cat. J/ApJS/161/21,
[LBA2005] NNN in Simbad, unless otherwise noted
Note (4): References are as follows:
d = from Giacconi et al. (2002, Cat. J/ApJS/139/369),
[GZW2002] XID NNN in Simbad
e = our estimate
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 14-Nov-2008