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J/A+A/497/81        Variability-selected AGN in CDFS         (Boutsia+, 2009)

Spectroscopic follow-up of variability-selected active galactic nuclei in the Chandra Deep Field South. Boutsia K., Leibundgut B., Trevese D., Vagnetti F. <Astron. Astrophys., 497, 81-95 (2009)> =2009A&A...497...81B
ADC_Keywords: Surveys ; Active gal. nuclei ; X-ray sources ; Redshifts Keywords: surveys - galaxies: active - quasars: general - X-rays: galaxies Abstract: Supermassive black holes with masses of 105-109M are believed to inhabit most, if not all, nuclear regions of galaxies, and both observational evidence and theoretical models suggest a scenario where galaxy and black hole evolution are tightly related. Luminous AGNs are usually selected by their non-stellar colours or their X-ray emission. Colour selection cannot be used to select low-luminosity AGNs, since their emission is dominated by the host galaxy. Objects with low X-ray to optical ratio escape even the deepest X-ray surveys performed so far. In a previous study we presented a sample of candidates selected through optical variability in the Chandra Deep Field South, where repeated optical observations were performed in the framework of the STRESS supernova survey. The analysis is devoted to breaking down the sample in AGNs, starburst galaxies, and low-ionisation narrow-emission line objects, to providing new information about the possible dependence of the emission mechanisms on nuclear luminosity and black-hole mass, and eventually studying the evolution in cosmic time of the different populations. Description: We obtained new optical spectroscopy for a sample of variability selected candidates with the ESO NTT telescope. We analysed the new spectra, together with those existing in the literature and studied the distribution of the objects in U-B and B-V colours, optical and X-ray luminosity, and variability amplitude. The observing run on La Silla took place from the 1st to the 5th of November 2007. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 59 27 Catalogue of variable sources observed during our spectroscopic follow-up table2.dat 162 68 Catalogue of extragalactic variable objects in the AXAF field with spectroscopic redshift
See also: J/A+A/488/73 : Variability-selected AGN in Chandra DFS (Trevese+, 2008) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
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 Vmag V magnitude 35- 38 F4.2 mag AVmag Vmin-Vmax_ amplitude 40- 43 I4 s Texp Exposure time 45- 48 F4.2 --- Airmass Airmass 50- 53 F4.2 --- z ? Redshift 55- 59 A5 --- Cl Spectroscopic class (G1)
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
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 (from paper I, J/A+A/488/73) 35- 39 F5.3 mag sig Standard deviation of the light curve (from paper I, J/A+A/488/73) 41- 44 F4.1 mag sig* Normalised standard deviation of the light curve (1) 46- 64 A19 --- EIS EIS name (JHHMMSS.ss+DDMMSS.s) 66- 70 F5.2 mag Vmag ? EIS V magnitude, AB system 72- 76 F5.2 mag Rmag ? EIS R magnitude, AB system 78- 82 F5.2 mag (U-B) ? EIS U-B colour index, AB system 84- 88 F5.2 mag (B-V) ? EIS B-V colour index, AB system 90- 93 F4.2 --- S/G ? EIS Stellarity index in the V band 95- 99 I5 --- [WDK2001] ? COMBO-17 identification number 101-103 A3 --- CCl COMBO class (Wolf et al. 2004, Cat. II/253) (2) 105-109 F5.3 --- z ? Spectroscopic redshift 111-115 A5 --- Cl Spectroscopic class (G1) 118-120 I3 --- [LBA2005] ? X-ray identification from Lehmer et al. (2005, Cat. J/ApJS/161/21) 122 A1 --- l_FX Limit flag on FX 123-130 E8.3 mW/m2 FX ? X-ray flux in the 2-8keV band 132 A1 --- l_logLX Limit flag on logLX 133-137 F5.2 [10-7W] logLX ? X-ray luminosity in the 2-8keV band 139-143 F5.2 [10-7W] logLR ? R-band luminosity 145 A1 --- l_log(X/O) Limit flag on log(X/O) 146-151 F6.3 [-] log(X/O) ? X-ray-to-optical flux ratio 153-162 A10 --- Notes Notes (3)
Note (1): Defined as: sigma*=[sigma-s(V)]/[S(sigma(V))] where s(V) and S(sigma(V)) are the ensemble average and standard deviation of sigma, the rms variation. Note (2): COMBO-class as follows: G = galaxy Q = QSO S = star U = unclear Note (3): Notes as follows: c = Observed in our spectroscopic follow-up d = Spectroscopic redshift from Szokoly et al. (2004, Cat. J/ApJS/155/271) e = From Ravikumar et al. (2007, Cat. J/A+A/465/1099) f = From Grazian et al. (2006, cat. J/A+A/449/951) g = From Le Fevre et al. (200, Cat. J/A+A/428/1043) h = From Popesso et al. (2009A&A...494..443P) s = From Treister et al. (2009ApJ...693.1713T) k = Our estimate from the CDFS intensity maps l = Our estimate from the ECDFS intensity maps m = Extra-nuclear (Lehmer et al., 2006AJ....131.2394L) n = XID from Giacconi et al. (2002, Cat. J/ApJS/139/369) p = Detected in radio by Kellermann et al. (2008, Cat. J/ApJS/179/71)
Global notes: Note (G1): Spectroscopic class as follows: BLAGN = Broad Line AGN NELG = Narrow Emission Line Galaxy Gal = galaxy
History: From electronic version of the journal References: Trevese et al., Paper I 2008A&A...488...73T, Cat. J/A+A/488/73
(End) Patricia Vannier [CDS] 24-Aug-2009
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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