PROBING THE NATURE OF THE UNIDENTIFIED TeV GAMMA-RAY SOURCE HESS J0632+057 WITH SWIFT
PROBING THE NATURE OF THE UNIDENTIFIED TeV GAMMA-RAY SOURCE HESS J0632+057 WITH SWIFT
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DOI：
10.1088/2041-8205/708/1/l52
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发表时间：
2009-12
期刊：
影响因子：
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通讯作者：
A. Falcone;J. Grube;J. Hinton;J. Holder;G. Maier;R. Mukherjee;J. Skilton;M. Stroh
中科院分区：
文献类型：
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作者：
A. Falcone;J. Grube;J. Hinton;J. Holder;G. Maier;R. Mukherjee;J. Skilton;M. Stroh
新一代TeV伽马射线望远镜已经发现了许多新的来源，包括几个神秘的未知TeV天体。HESS J 0632 +057是一个特别有趣的未确认的TeV源，因为：它是一个点源，它有一个可能的硬谱X射线对应物和位置一致的Be星星，它有长期非常高能量的伽马射线通量变化的证据，它被假定为一个新发现的TeV/X射线双星。我们已经获得了从MJD 54857到54965的斯威夫特X射线望远镜观测结果，试图确定它的性质，并调查它是以前未知的X射线/TeV双星的假设。观测到了与其他三个已知X射线/TeV双星相似的变化和光谱特性，测量到的通量增加了10.3倍。X射线变异性存在于多个时间尺度上，包括几天到几个月;然而，在这些数据探测的时间尺度上没有明确的周期性特征。如果双星调制存在，并且主导了测量的变化，那么轨道周期可能是1054天（这个活动的一半），或者它有一个更短的周期，在连续的高状态上有不同程度的通量调制。如果到目前为止测量到的两个高状态是由于二进制调制，那么有利的周期大约是35-40天。需要进行更多的观测，以确定该物体是否确实是一个双星系统，并确定所测得的变化在多大程度上是由于轨道间耀斑效应或周期性双星调制造成的。
New generation TeV gamma-ray telescopes have discovered many new sources, including several enigmatic unidentified TeV objects. HESS J0632+057 is a particularly interesting unidentified TeV source since: it is a point source, it has a possible hard-spectrum X-ray counterpart and a positionally consistent Be star, it has evidence of long-term very high energy gamma-ray flux variability, and it is postulated to be a newly detected TeV/X-ray binary. We have obtained Swift X-ray telescope observations of this source from MJD 54857 to 54965, in an attempt to ascertain its nature and to investigate the hypothesis that it is a previously unknown X-ray/TeV binary. Variability and spectral properties similar to those of the other three known X-ray/TeV binaries have been observed, with measured flux increases by factors of ∼3. X-ray variability is present on multiple timescales including days to months; however, no clear signature of periodicity is present on the timescales probed by these data. If binary modulation is present and dominating the measured variability, then the period of the orbit is likely to be ⩾54 days (half of this campaign), or it has a shorter period with a variable degree of flux modulation on successive high states. If the two high states measured to date are due to binary modulation, then the favored period is approximately 35–40 days. More observations are required to determine if this object is truly a binary system and to determine the extent that the measured variability is due to inter-orbit flaring effects or periodic binary modulation.