All at Once: Transient Pulsations, Spin-down, and a Glitch from the Pulsating Ultraluminous X-Ray Source M82 X-2
All at Once: Transient Pulsations, Spin-down, and a Glitch from the Pulsating Ultraluminous X-Ray Source M82 X-2
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DOI：
10.3847/1538-4357/ab6d00
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发表时间：
2019-05
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影响因子：
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通讯作者：
M. Bachetti;T. Maccarone;M. Brightman;M. Brumback;F. Fürst;F. Harrison;M. Heida;G. Israel;M. Middleton;J. Tomsick;N. Webb;D. Walton
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文献类型：
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作者：
M. Bachetti;T. Maccarone;M. Brightman;M. Brumback;F. Fürst;F. Harrison;M. Heida;G. Israel;M. Middleton;J. Tomsick;N. Webb;D. Walton
第一个被确定的脉冲超亮x射线源（PULX）是M82 X-2。自2014年发现M82油田以来，NuSTAR在2015年至2016年期间对M82油田进行了15次观测。在本文中，我们报告了所有这些数据集的脉动搜索结果，并且只发现了一个新的检测。这一新的探测使我们能够细化源的轨道周期，并测量2014年至2016年之间的平均自旋下降速率为~ - 6 × 10 - 11 Hz s - 1，这与2014年观测期间看到的强自旋上升形成对比，代表了首次在PULX系统中检测到自旋下降。由于这个新探测允许改进的轨道解，我们也能够在2014年原始数据集的其他部分检测到脉动。我们发现一个小故障叠加在已经报告的非常强和可变的自旋向上上——这是在PULX系统中发现的第一个积极的小故障。我们在当前领先的PULXs模型的背景下讨论了这些新发现。
The first pulsating ultraluminous X-ray source (PULX) to be identified is M82 X-2. After the discovery in 2014, NuSTAR observed the M82 field 15 times throughout 2015 and 2016. In this paper, we report the results of pulsation searches in all of these data sets and find only one new detection. This new detection allows us to refine the orbital period of the source and measure an average spin-down rate between 2014 and 2016 of ∼−6 × 10−11 Hz s−1, which is in contrast to the strong spin-up seen during the 2014 observations, representing the first detection of spin-down in a PULX system. Thanks to the improved orbital solution allowed by this new detection, we are also able to detect pulsations in additional segments of the original 2014 data set. We find a glitch superimposed on the very strong and variable spin-up already reported—the first positive glitch identified in a PULX system. We discuss the new findings in the context of current leading models for PULXs.