1997A&A...326L..25K

Query : 1997A&A...326L..25K

1997A&A...326L..25K - Astronomy and Astrophysics, volume 326L25-28 (1997/10-3)

Correlation between variability time scale and X-ray spectral index in AGN.

KOENIG M., STAUBERT R. and WILMS J.

Abstract (from CDS):

We have analysed EXOSAT ME X-ray light curves of a sample of AGN assuming a stochastic process in these sources. The result is a significant anti-correlation between the relaxation timescale τ, derived from this stochastic model fit, and the photon index {GAMMA} of the X-ray spectrum. This establishes for the first time a relationship between variability properties and spectral properties of the emitted X-ray flux of AGN. Even though the physical mechanism for the variations is far from clear, models employing the stochastic superposition of discrete events appear most promising. We propose Comptonization as a possible cause for the relationship.

Abstract Copyright: ∼

Journal keyword(s): X-rays: galaxies

Simbad objects: 17

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Number of rows : 17
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026 		#notes
1 Mrk 335 Sy1 00 06 19.5372339024 +20 12 10.617404076   14.19 13.85     ~ 1344 0
2 ESO 113-45 Sy1 01 23 45.7631533440 -58 48 20.808928944   14.08 13.83 13.34   ~ 965 0
3 M 77 Sy2 02 42 40.7091669408 -00 00 47.859690204 9.70 9.61 8.87 10.1 9.9 ~ 4897 2
4 MCG+01-12-009 Bla 04 33 11.0956735296 +05 21 15.619461552   15.72 15.05 10.08   ~ 2099 2
5 Z 395-23 Sy1 05 16 11.4092471904 -00 08 59.157166920   14.30 13.92     ~ 953 1
6 Z 184-50 BLL 11 04 27.3140835504 +38 12 31.798495872   13.50 12.90 8.31   ~ 2841 1
7 NGC 4051 Sy1 12 03 09.6101337312 +44 31 52.682601288   11.08 12.92 9.94   ~ 2270 1
8 NGC 4151 Sy1 12 10 32.5759813872 +39 24 21.063527532   12.18 11.48     ~ 3938 2
9 NGC 4253 Sy1 12 18 26.5163572920 +29 48 46.531535472   14.34 13.57     ~ 1106 1
10 3C 273 BLL 12 29 06.6998257176 +02 03 08.597629980   13.05 14.830 14.11   ~ 6022 1
11 NGC 4593 Sy1 12 39 39.4435107024 -05 20 39.034988448   13.95 13.15     ~ 1179 0
12 NAME Centaurus A BLL 13 25 27.61521044 -43 01 08.8050291   8.18 6.84 6.66   ~ 4774 3
13 MCG-06-30-015 Sy1 13 35 53.7691256160 -34 17 44.160716796   13.89 13.61 8.9   ~ 1559 0
14 NGC 5506 Bla 14 13 14.8761010056 -03 12 27.556909272   15.25 14.38     ~ 1173 1
15 NGC 5548 Sy1 14 17 59.5400291832 +25 08 12.603122268   14.35 13.73     ~ 2895 0
16 Z 225-7 BLL 16 53 52.21668403 +39 45 36.6088754 14.09 14.15 13.29 8.26   ~ 2304 2
17 2C 1590 BLL 18 45 37.622 +09 53 44.74           ~ 82 1

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