论文标题
NGC 5252中超X射线源的宿主星系的恒星特性
Stellar Properties of the Host Galaxy of an Ultraluminous X-ray Source in NGC 5252
论文作者
论文摘要
NGC 5252中的超X射线源（ULX）被称为核外中质量黑洞的强大候选者。我们介绍了使用William Herschel望远镜获得的ULX的近红外成像数据。使用此数据，我们估计与ULX相关的恒星质量约为10^{7.9 \ pm0.1} m _ {\ rm \ odot} $，这表明它可以是（保留）与NGC 5252之间的相关群体合并的矮人星系，这是一个与NGC 5252的群体合并的过程。由$ 10^5M _ {\ rm \ odot} $ Black Hole提供动力。另外，如果BH质量为$ \ $ \ 10^6M _ {\ rm \ odot} $或更大，则在合并期间，ULX的主机Galaxy必须大量剥离。 ULX $ K_S $ -BAND光度的光度比普通活跃的银河核的预期小两个数量级，观察到[O III]的光度，这也表明ULX缺乏灰尘的圆环。我们讨论这些发现如何提供暗示性证据表明ULX托管中间质量黑洞。
An ultraluminous X-ray source (ULX) in NGC 5252 has been known as a strong candidate for an off-nuclear intermediate-mass black hole. We present near-infrared imaging data of the ULX obtained with the William Herschel Telescope. Using this data we estimate a stellar mass associated with the ULX of $\approx 10^{7.9\pm0.1}M_{\rm \odot}$ , suggesting that it could be (the remnant of) a dwarf galaxy that is in the process of merging with NGC 5252. Based on a correlation between the mass of the central black hole (BH) and host galaxy, the ULX is powered by a $10^5M_{\rm \odot}$ black hole. Alternatively, if the BH mass is $\approx 10^6M_{\rm \odot}$ or larger, the host galaxy of the ULX must have been heavily stripped during the merger. The ULX $K_s$-band luminosity is two orders of magnitude smaller than that expected from an ordinary active galactic nucleus with the observed [O III] luminosity, which also suggests the ULX lacks a dusty torus. We discuss how these findings provide suggestive evidence that the ULX is hosting an intermediate-mass black hole.
