The long-term optical behavior of Mkn 421
The long-term optical behavior of Mkn 421
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DOI：
10.1051/aas:1997173
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发表时间：
1996-10
期刊：
影响因子：
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通讯作者：
F. K. Liu;B. Liu;G. Xie
中科院分区：
文献类型：
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作者：
F. K. Liu;B. Liu;G. Xie
来自 22 个出版物的 BL Lac 天体 Mkn 421 的 B 波段可用数据被用来构建历史光变曲线，其历史可以追溯到 1900 年。人们发现，光变曲线非常复杂，由一组持续时间非常长的爆发组成。 Mkn 421 的亮度从 11.6 等到超过 16 等不等。用尤尔克维奇计算循环现象周期的方法进行分析，揭示了光变曲线中的两种行为。第一个是非周期性的，其强度在几小时到几天的时间尺度上发生快速、剧烈的变化。第二个是周期性的，周期可能为 23:1 1:1 年。另一个可能的周期 15:3 0:7 年并不是很重要。我们测试了尤尔科维奇方法的稳健性。由于方法和观测窗口的原因，在 Mkn 421 和其他物体的光变曲线中发现的大约一年的周期是一个虚假周期。我们尝试解释质量为 2 10 6 M 的大质量黑洞周围细长吸积盘的热不稳定性下的 23:11:1 年周期。
All data available in B band for the BL Lac object Mkn 421 from 22 publications are used to construct a historical light curve, dating back to 1900. It is found that the light curve is very complicated and consists of a set of outbursts with very large duration. The brightness of Mkn 421 varies from 11.6 magnitude to more than 16 magnitude. Analyses with Jurkevich method of comput- ing periods of cyclic phenomena reveal in the light curve two kinds of behaviors. The rst one is non-periodic with rapid, violent variations in intensity on time scales of hours to days. The second one is periodic with a possible period of 23:1 1:1 years. Another possible period of 15:3 0:7 years is not very signicant. We have tested the robust- ness of the Jurkevich method. The period of about one year found in the light curves of Mkn 421 and of other objects is a spurious period due to the method and the ob- serving window. We try to explain the period of 23:11:1 years under the thermal instability of a slim accretion disk around a massive black hole of mass 2 10 6 M.