论文标题
X射线观测到孤立的黑洞候选OGE-2011-BLG-0462，以及通过重力微透明发现的其他折叠物体
X-ray observations of the isolated black hole candidate OGLE-2011-BLG-0462 , and other collapsed objects discovered through gravitational microlensing
论文作者
论文摘要
通过观察长持续时间重力微透明事件，可以揭示孤立的黑洞和中子星。在银河凸起方向的恒星调查中发现了一些候选人。最近，由于在MilliarcSecond级别增加了天文学信息，因此有可能减少质量和距离的不确定性，以减少其中一些“黑暗”重力透镜的距离，并选择最有希望的候选者。这些孤立的紧凑型物体可能会散发出由星际介质积聚的X射线。使用Chandra，XMM-Newton和积分卫星的数据，我们在孤立的黑洞候选OGLE-2011-BLG-0462中搜索了X射线发射，并在其他一些假定的折叠物体中发现了带有重力微透镜的物体。 OGLE-2011-BLG-0462最近被解释为1.6 kpc的7.1 m_sun黑洞，尽管另一组获得了质量范围（1.6-4.4 m_sun），无法排除大型中子星。 We have derived upper limits on the flux from OGLE-2011-BLG-0462 of 9$\times10^{-15}$ erg cm$^{-2}$ s$^{-1}$ in the 0.5-7 keV range and $\sim2\times10^{-12}$ erg cm$^{-2}$ s$^{-1}$ in the 17-60 KEV范围。隐含的X射线光度与黑洞预期的小辐射效率一致，并散发出中子星的解释。对于其他候选者的软X射线通量，可获得较低的限制，但它们的解释受质量，距离和空间速度的不确定性的影响。
Isolated black holes and neutron stars can be revealed through the observation of long duration gravitational microlensing events. A few candidates have been found in surveys of stars in the direction of the Galactic bulge. Recently, thanks to the addition of astrometric information at milliarcsecond level, it has been possible to reduce the uncertainties in the masses and distances for some of these "dark" gravitational lenses and select the most promising candidates. These isolated compact objects might emit X-rays powered by accretion from the interstellar medium. Using data of the Chandra, XMM-Newton, and INTEGRAL satellites, we searched for X-ray emission in the isolated black hole candidate OGLE-2011-BLG-0462, and in several other putative collapsed objects found with gravitational microlensing. OGLE-2011-BLG-0462 has been recently interpreted as a 7.1 M_sun black hole at a distance of 1.6 kpc, although a different group obtained a mass range (1.6-4.4 M_sun) that cannot exclude a massive neutron star. We have derived upper limits on the flux from OGLE-2011-BLG-0462 of 9$\times10^{-15}$ erg cm$^{-2}$ s$^{-1}$ in the 0.5-7 keV range and $\sim2\times10^{-12}$ erg cm$^{-2}$ s$^{-1}$ in the 17-60 keV range. The implied X-ray luminosity is consistent with the small radiative efficiency expected for a black hole and disfavours a neutron star interpretation. Limits down to a factor about five lower are obtained for the soft X-ray flux of other candidates, but their interpretation is affected by larger uncertainties in the masses, distances and spatial velocities.
