Very long baseline interferometry detection of the Galactic black hole binary candidate MAXI J1836-194
Very long baseline interferometry detection of the Galactic black hole binary candidate MAXI J1836-194
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DOI：
10.1111/j.1745-3933.2012.01327.x
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发表时间：
2012-10
影响因子：
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通讯作者：
Jun Yang;Yonghua Xu;Zhixuan Li;Z. Paragi;R. M. Campbell;L. Gurvits;Zhi-qiang Shen;X. Hong;B. Xia;F. Shu
中科院分区：
文献类型：
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作者：
Jun Yang;Yonghua Xu;Zhixuan Li;Z. Paragi;R. M. Campbell;L. Gurvits;Zhi-qiang Shen;X. Hong;B. Xia;F. Shu
X射线瞬态MAXI J1836-194是一个新发现的银河系黑洞双星候选者。和大多数X射线瞬变一样，它是在X射线爆发的开始被发现的。在初始的正则X射线硬态之后，爆发演化到硬中间态，然后回到硬态。现有的RATAN-600无线电监测观测表明，它在几天的时间尺度上是可变的，有一个平坦或倒置的光谱，与光学厚同步加速器发射一致，可能来自中心致密物体附近的自吸收喷流。利用欧洲甚长基线干涉测量（VLBI）网（EVN）在5GHz和中国VLBI网（CVN）在2.3和8.3GHz观测到了X射线爆发末期的硬态瞬态。8.3 GHz观测采用中国新研制的VLBI数据采集系统，记录速率为2048 Mbps，比其它观测记录速率高一倍。我们成功地检测到了低decorative源在两个观测的高置信水平。源是未解决的（=0.5 mas），这是在协议与au规模的紧凑型喷流。
The X-ray transient MAXI J1836-194 is a newly identified Galactic black hole binary candidate. As most X-ray transients, it was discovered at the beginning of an X-ray outburst. After the initial canonical X-ray hard state, the outburst evolved into a hard intermediate state and then went back to the hard state. The existing RATAN-600 radio monitoring observations revealed that it was variable on a time-scale of days and had a flat or inverted spectrum, consistent with optically thick synchrotron emission, possibly from a self-absorbed jet in the vicinity of the central compact object. We observed the transient in the hard state near the end of the X-ray outburst with the European very long baseline interferometry (VLBI) Network (EVN) at 5 GHz and the Chinese VLBI Network (CVN) at 2.3 and 8.3 GHz. The 8.3-GHz observations were carried out at a recording rate of 2048 Mbps using the newly developed Chinese VLBI data acquisition system, twice higher than the recording rate used in the other observations. We successfully detected the low-declination source with a high confidence level in both observations. The source was unresolved (=0.5 mas), which is in agreement with an au-scale compact jet.