"Possible Detection of Apparent Superluminal Inward Motion in Markarian 421 after the Giant X-Ray Flare in 2010 February
"Possible Detection of Apparent Superluminal Inward Motion in Markarian 421 after the Giant X-Ray Flare in 2010 February
复制标题
“2010 年 2 月巨大 X 射线耀斑后，可能在 Markarian 421 中检测到明显的超光速向内运动
DOI：
10.1088/0004-637x/759/2/84
复制
发表时间：
2012
影响因子：
4.9
通讯作者：
and K. Fujisawa
中科院分区：
文献类型：
--
作者：
K. Niinuma;M. Kino;H. Nagai;N. Isobe;K. E. Gabanyi;K. Hada;S. Koyama;K. Asada;T. Oyama;and K. Fujisawa
利用日本VLBI网22 GHz阵列对2010年2月中旬发生的TeV耀变体Mrk 421最大X射线耀斑进行了甚长基线干涉测量（VLBI）跟踪观测。在2010年3月7日至5月31日之间，以大约20天的间隔进行了总共五次观测。在我们的多历元VLBI观测得到的总强度图像中，没有直接看到与耀斑相关的新生成分。然而，能够识别出位于地核西北1.1mas处的一个喷流分量，其自行可以测量为-1.66 ±0.46 mas yr-1，相当于-3.48 ±0.97c的视速度。在这里，这个负速度表明喷流分量显然是朝着核心移动的。作为最合理的解释，我们讨论了表观负速度可能是由一个新的组成部分的喷射，这是不能解决与我们的观察。在这种情况下，所获得的新分量的多普勒因子约为10-20，这与通常通过该源的谱能量分布的模型拟合估计的多普勒因子一致。
We report on the very long baseline interferometry (VLBI) follow-up observations using the Japanese VLBI Network array at 22 GHz for the largest X-ray flare of TeV blazar Mrk 421 that occurred in 2010 mid-February. The total of five epochs of observations were performed at intervals of about 20 days between 2010 March 7 and May 31. No newborn component associated with the flare was seen directly in the total intensity images obtained by our multi-epoch VLBI observations. However, one jet component located at∼ 1 mas northwest from the core was able to be identified, and its proper motion can be measured as− 1.66±0.46 mas yr− 1, which corresponds to an apparent velocity of− 3.48±0.97c. Here, this negative velocity indicates that the jet component was apparently moving toward the core. As the most plausible explanation, we discuss that the apparent negative velocity was possibly caused by the ejection of a new component, which could not be resolved with our observations. In this case, the obtained Doppler factor of the new component is around 10–20, which is consistent with the ones typically estimated by model fittings of spectral energy distribution for this source.