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J/A+A/536/A84       X-ray variability of AGN                 (Vagnetti+, 2011)

Ensemble X-ray variability of active galactic nuclei from serendipitous source catalogues. Vagnetti F., Turriziani S., Trevese D. <Astron. Astrophys., 536, A84 (2011)> =2011A&A...536A..84V
ADC_Keywords: Surveys ; Active gal. nuclei ; X-ray sources Keywords: surveys - galaxies: active - quasars: general - X-rays: galaxies Abstract: The X-ray variability of the active galactic nuclei (AGN) has been most often investigated with studies of individual, nearby sources, and only a few ensemble analyses have been applied to large samples in wide ranges of luminosity and redshift. We aim to determine the ensemble variability properties of two serendipitously selected AGN samples extracted from the catalogues of XMM-Newton and Swift, with redshift between ∼0.2 and ∼4.5, and X-ray luminosities, in the 0.5-4.5keV band, between ∼1043erg/s and ∼1046erg/s. We used the structure function (SF), which operates in the time domain, and allows for an ensemble analysis even when only a few observations are available for individual sources and the power spectral density (PSD) cannot be derived. The SF is also more appropriate than fractional variability and excess variance, because these parameters are biased by the duration of the monitoring time interval in the rest-frame, and therefore by cosmological time dilation. Description: For XMM, we use the version presently available is 2XMMi-DR3, the latest incremental update of the second version of the catalogue, with observations made between 2000 February 3 and 2008 October 08. For Swift, we used the preliminary version S3XGF catalogue, comprising GRB fields observed from January 2005 to June 2007. The selected sources was cross-correlated it with the DR7 edition of the SDSS Quasar Catalogue (Schneider et al., 2010, Cat. VII/260) to obtain redshifts and spectral classifications. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 61 412 XMM-Newton sample table2.dat 60 27 Swift sample
See also: IX/41 : XMM-Newton Serendipitous Source Cat. 2XMMi-DR3 (XMM-SSC, 2010) VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010) J/A+A/528/A122 : SwiftFT catalog (Puccetti+, 2011) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 3 I3 --- Seq [1/412] Sequential number, within the table 5- 9 A5 --- --- [2XMM 2XMMi] 11- 26 A16 --- 2XMM 2XMM or 2XMMi designation (JHHMMSS.s+DDMMSS) 28- 33 F6.4 --- z Redshift 35- 36 I2 --- Nep Number of observation epochs 38- 43 F6.2 [mW/m2] logfX X-ray flux in the 0.5-4.5keV band 45- 49 F5.2 [10-7W] logLX X-ray luminosity in the 0.5-4.5keV band 51- 55 F5.2 [d] logtmin Minimum lag τmin between any two epochs of the light curve in the source rest-frame 57- 61 F5.2 [d] logtmax Maximum lag τmax between any two epochs of the light curve in the source rest-frame
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 3 I3 --- Seq [1/27] Sequential number, within the table 5- 11 A7 --- --- [SWIFTFT] 13- 28 A16 --- SWIFTFT SWIFTFT designation (JHHMMSS.s+DDMM.m) 30- 33 F4.2 --- z Redshift 35- 36 I2 --- Nbin Number of time bins 38- 43 F6.2 [mW/m2] logfX X-ray flux in the band 0.5-4.5keV 45- 49 F5.2 [10-7W] logLX X-ray luminosity in the band 0.5-4.5keV 51- 60 A10 --- GRB GRB field
History: From electronic version of the journal
(End) Patricia Vannier [CDS] 21-Feb-2012
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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