A variability study of the Seyfert 2 galaxy NGC 6300 with XMM-Newton

被引:15
作者
Awaki, H
Murakami, H
Leighly, KM
Matsumoto, C
Hayashida, K
Grupe, D
机构
[1] Ehime Univ, Fac Sci, Dept Phys, Matsuyama, Ehime 7908577, Japan
[2] Univ Oklahoma, Dept Phys & Astron, Norman, OK 73019 USA
[3] Osaka Univ, Fac Sci, Dept Astrophys, Toyonaka, Osaka 5600043, Japan
[4] Ohio State Univ, Dept Astron, Columbus, OH 43210 USA
关键词
galaxies : individual (NGC 6300); galaxies : Seyfert; X-rays : galaxies;
D O I
10.1086/433161
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present the results of timing analysis of the XMM-Newton observation of the Seyfert 2 galaxy NGC 6300. The hard X-ray spectrum above 2 keV consists of a Compton-thin absorbed power law, as is often seen in Seyfert 2 galaxies. We clearly detected rapid time variability on a timescale of about 1000 s from the light curve above 2 keV. The excess variance of the time variability (sigma(rms)(2)) is calculated to be similar to 0.12, and the periodogram of the light curve is well represented by a power-law function with a slope of 1.75. In contrast to previous results from Seyfert 2 nuclei, these variability characteristics are consistent with those of Seyfert 1 galaxies. This consistency suggests that NGC 6300 has a black hole mass and accretion properties similar to Seyfert 1 galaxies. Using the relation between time variability and central black hole mass by Hayashida et al., the black hole mass of NGC 6300 is estimated to be similar to 2.8 x 10(5) M-circle dot. Taking the uncertainty of this method into account, the black hole mass is less than 10(7) M-circle dot. Taking the bolometric luminosity of 3.3 x 10(43) ergs s(-1) into consideration, this yields an accretion rate of > 0.03 of the Eddington value, comparable to estimates from Seyfert 1 galaxies using this method. The time variability analysis suggests that NGC 6300 actually has a Seyfert 1 nucleus obscured by thick matter and more generally provides a new pillar of support for the unified model of Seyfert galaxies based on obscuration.
引用
收藏
页码:793 / 798
页数:6
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