J/A+A/487/475 X-ray variability of AGNs in Lockman Hole (Papadakis+, 2008)
The long-term X-ray variability properties of AGN in the Lockman Hole.
Papadakis I.E., Chatzopoulos E., Athanasiadis D., Markowitz A.,
Georgantopoulos I.
<Astron. Astrophys. 487, 475 (2008)>
=2008A&A...487..475P 2008A&A...487..475P
ADC_Keywords: Active gal. nuclei ; X-ray sources ; Redshifts
Keywords: galaxies: active - X-rays: galaxies
Abstract:
We present the results from a detailed X-ray variability analysis of
66 AGN in the Lockman Hole, which have optical spectroscopic
identifications.
We compare, quantitatively, their variability properties with the
properties of local AGN, and we study the "variability - luminosity"
relation as a function of redshift, and the "variability - redshift"
relation in two luminosity bins.
We use archival data from the last 10 XMM-Newton observations of the
Lockman Hole field to extract light curves in the rest frame, 2-10keV
band. We use the "normalized excess variance" to quantify the
variability amplitude. Using the latest results regarding the AGN
power spectral shape and its dependence on black hole mass and
accretion rate, we are able to compute model "variability -
luminosity" curves, which we compare with the relations we observe.
When we consider all the sources in our sample, we find that their
variability amplitude decreases with increasing redshift and
luminosity.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 91 66 IDs, redshift, spectral and variability
properties of AGN that we study in this work
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See also:
J/A+A/329/482 : ROSAT Deep Survey in the Lockman Hole (Hasinger+, 1998)
J/PASJ/53/445 : ASCA Deep survey in Lockman Hole Field (Ishisaki+, 2001)
J/A+A/393/425 : Spectral analysis of Lockman Hole (Mainieri+, 2002)
J/A+A/398/901 : VLA survey at 6 cm in the Lockman Hole (Ciliegi+, 2003)
J/A+A/413/843 : Far IR survey in the Lockman Hole (Kawara+, 2004)
J/A+A/427/23 : 14.3um survey in the Lockman Hole (Fadda+, 2004)
J/A+A/427/773 : ISOCAM 14.3um Deep Survey in Lockman Hole (Rodighiero+, 2004)
J/AJ/128/1501 : CLASXS: X-ray catalog (Yang+, 2004)
J/A+A/434/801 : X-ray sources near Lockman Hole (Zappacosta+, 2005)
J/A+A/444/79 : XMM observations of Lockman Hole brightest AGNs (Mateos+, 2005)
J/A+A/473/105 : Lockman Hole AGN variability with XMM (Mateos+, 2007)
J/A+A/479/283 : XMM observations of the Lockman Hole (Brunner+, 2008)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- [MBC2005] Source designation (1)
6- 7 I2 h RAh Right ascension (J2000)
9- 10 I2 min RAm Right ascension (J2000)
12- 16 F5.2 s RAs Right ascension (J2000)
18 A1 --- DE- Declination sign
19- 20 I2 deg DEd Declination (J2000)
22- 23 I2 arcmin DEm Declination (J2000)
25- 29 F5.2 arcsec DEs Declination (J2000)
31- 35 F5.3 --- z Redshift
37- 42 F6.3 --- snxs Normalized excess variance
44- 48 F5.3 --- e_snxs Error of snxs
50- 54 F5.2 --- logsnxs Logarithm of the snxs
56- 59 F4.2 --- e_logsnxs Error of the logarithm of snxs
61- 66 F6.1 --- chi2 Chi-square value
67 A1 --- --- [/]
68 I1 --- DOF Degrees of Freedom
70- 71 A2 --- Var [V NV] Variable/Non-Variable source flag
73- 77 F5.2 --- Lx Logarithm of luminosity in the [2-10]keV
rest-frame band (1)
79- 82 F4.2 --- Gamma Power law spectral slope (1)
84- 91 A8 --- Inst Instrument(s) used in each case
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Note (1): as in Table 8 of Mateos et al. (2005, Cat. J/A+A/444/79).
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Acknowledgements:
I.E. Papadakis, jhep(at)physics.uoc.gr
(End) Patricia Vannier [CDS] 29-May-2008