标题： eROSITA对A0538-66 Be/X射线双星爆发的探测 显示英文标题

标题： eROSITA detection of flares from the Be/X-ray binary A0538-66

摘要： 2018年，XMM-Newton观测到了Be/X射线双星（Be/XRB）A0538-66的X射线苏醒。它在近日点附近表现出明亮且快速的耀斑，这些特性此前在其他Be/XRB中从未被观测到。我们报告了在eROSITA首次全天巡天期间对A0538-66的观测结果，eROSITA是搭载在Spektrum-Roentgen-Gamma（SRG）卫星上的X射线望远镜（0.2-10 keV）。eROSITA在一个轨道周期内于轨道相位$\phi = 0.29$和$\phi = 0.93$（其中$\phi=0$对应近日点）捕捉到了两次耀斑，峰值光度分别为$\sim 2-4 \times 10^{36}$erg/s（0.2-10 keV），持续时间为$42 \leq \Delta t_{\rm fl} \leq 5.7\times 10^4$s。在$\phi \approx 0.29$处观测到的耀斑表明，中子星可以在远离近日点的位置吸积物质，尽管它预计位于环恒星盘之外，从而为围绕双星系统的等离子体环境提供了重要的新信息。我们还报告了使用REM、OGLE和MACHO望远镜从1993年1月至2020年3月对A0538-66进行的测光监测结果。我们发现，表征光学轨道调制的两个尖峰相对于供体星的位置在轨道上不对称。 显示英文摘要

摘要： In 2018, XMM-Newton observed the awakening in X-rays of the Be/X-ray binary (Be/XRB) A0538-66. It showed bright and fast flares close to periastron with properties that had never been observed in other Be/XRBs before. We report the results from the observations of A0538-66 collected during the first all-sky survey of eROSITA, an X-ray telescope (0.2-10 keV) on board the Spektrum-Roentgen-Gamma (SRG) satellite. eROSITA caught two flares within one orbital cycle at orbital phases $\phi = 0.29$ and $\phi = 0.93$ (where $\phi=0$ corresponds to periastron), with peak luminosities of $\sim 2-4 \times 10^{36}$ erg/s (0.2-10 keV) and durations of $42 \leq \Delta t_{\rm fl} \leq 5.7\times 10^4$ s. The flare observed at $\phi \approx 0.29$ shows that the neutron star can accrete considerably far from periastron, although it is expected to be outside of the circumstellar disk, thus providing important new information about the plasma environment surrounding the binary system. We also report the results from the photometric monitoring of A0538-66 carried out with the REM, OGLE, and MACHO telescopes from January 1993 until March 2020. We found that the two sharp peaks that characterize the orbital modulation in the optical occur asymmetrically in the orbit, relative to the position of the donor star.