期刊
ASTRONOMY & ASTROPHYSICS
卷 402, 期 3, 页码 929-947出版社
EDP SCIENCES S A
DOI: 10.1051/0004-6361:20030264
关键词
BL Lacertae objects : individual : Mrk 421; X-rays : galaxies; radiation mechanisms : non-thermal
We present the results of a detailed spectral and temporal analysis of the currently available XMM-Newton observations of the bright BL Lac object Mrk 421 using mainly the EPIC-PN data. The source was found in various intensity states differing by up to a factor of five in count rates. In general, the source is more variable and shows a harder spectrum during higher intensities than when it is in lower states. The spectrum is very complex and cannot be fitted adequately by a broken power law or a continuously curved model. We find that the flux variations on time scales ofgreater than or similar tofew thousand seconds are associated with significant and sometimes very complex spectral changes. The spectral variability rate is not the same in all cases and is correlated with the source flux state: the spectral variations per unit time increase with the source flux. The Cross-Correlation analysis shows that the soft and hard band light curves are often well correlated near zero lag, in other cases the hard band variations lead the soft band variations by typically similar to5 min, in two cases we find the soft band leading the hard band variations. The delays appear to be correlated to the flares' duration: the shorter the flare, the smaller the delay.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据