XMM-Newton view of PKS 2155-304: Characterizing the X-ray variability properties with EPIC pn

	XMM-Newton view of PKS 2155-304: Characterizing the X-ray variability properties with EPIC pn
	Zhang, YH1 ; Treves, A 2; Celotti, A 3; Tan YP(覃一平)4 ; Bai JM(白金明)4
刊名	ASTROPHYSICAL JOURNAL
	2005-08-20
卷号	629 期号:2 页码:686-699
关键词	BL Lacertae objects : general BL Lacertae objects : individual ( PKS 2155-304) galaxies : active methods : data analysis X-rays : galaxies
ISSN号	0004-637X
通讯作者	Zhang, YH (reprint author), Tsinghua Univ, Dept Phys, Beijing 100084, Peoples R China.
产权排序	第四完成单位
英文摘要	Starting from XMM-Newton EPIC pn data, we present the X-ray variability characteristics of PKS 2155-304 using a simple analysis of the excess variance, sigma(2)(XS), and of the fractional rms variability amplitude, F(var). The scatter in sigma(2)(XS) and F(var), calculated using 500 s long segments of the light curves, is smaller than the scatter expected for red-noise variability. This alone does not imply that the underlying process responsible for the variability of the source is stationary, since the real changes of the individual variance estimates are possibly smaller than the large scatters expected for a red-noise process. In fact, the averaged sigma(2)(XS) and F(var), which reduce the fluctuations of the individual variances, also change with time, indicating nonstationary variability. Moreover, both the averaged sigma(XS) ( absolute rms variability amplitude) and the averaged F(var) show linear correlation with source flux, but in an opposite sense: sigma(XS) correlates with flux, but F(var) anticorrelates with flux. These correlations suggest that the variability process of the source is strongly nonstationary, as random scatters of variances should not yield any correlation. Spectra of F(var) were constructed to compare variability amplitudes in different energy bands. We found that the fractional rms variability amplitude of the source, when significant variability is observed, increases logarithmically with the photon energy, indicating significant spectral variability. The point-to-point variability amplitude may also track this trend, suggesting that the slopes of the power spectral density of the source are energy-independent. Using the normalized excess variance, the black hole mass of PKS 2155-304 was estimated to be about 1.45x10(8) M(circle dot). This is compared and contrasted with the estimates derived from measurements of the host galaxies.
学科主题	Astronomy & Astrophysics
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	ACTIVE GALACTIC NUCLEI ; BLACK-HOLE MASSES ; BL-LACERTAE OBJECTS ; SEYFERT 1 GALAXIES ; HOST GALAXIES ; SPECTRAL VARIABILITY ; TIME-SERIES ; TEV BLAZARS ; NARROW-LINE ; LONG
收录类别	SCI
原文出处	http://iopscience.iop.org/0004-637X/629/2/686/
语种	英语
WOS记录号	WOS:000231159500009
公开日期	2016-05-03
内容类型	期刊论文
源URL	[http://ir.ynao.ac.cn/handle/114a53/6990]
专题	云南天文台_星系研究组
作者单位	1.Department of Physics and Tsinghua Center for Astrophysics, Tsinghua University, Beijing 100084, China 2.Dipartimento di Scienze, Università degli Studi dell'Insubria, via Valleggio 11, I-22100 Como, Italy 3.International School for Advanced Studies, SISSA/ISAS, via Beirut 2-4, I-34014 Trieste, Italy 4.National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, P.O. Box 110, Kunming, Yunnan 650011, China
推荐引用方式 GB/T 7714	Zhang, YH,Treves, A,Celotti, A,et al. XMM-Newton view of PKS 2155-304: Characterizing the X-ray variability properties with EPIC pn[J]. ASTROPHYSICAL JOURNAL,2005,629(2):686-699.
APA	Zhang, YH,Treves, A,Celotti, A,Tan YP,&Bai JM.(2005).XMM-Newton view of PKS 2155-304: Characterizing the X-ray variability properties with EPIC pn.ASTROPHYSICAL JOURNAL,629(2),686-699.
MLA	Zhang, YH,et al."XMM-Newton view of PKS 2155-304: Characterizing the X-ray variability properties with EPIC pn".ASTROPHYSICAL JOURNAL 629.2(2005):686-699.