标题： NGC 7331中一个核X射线源的发现：大质量黑洞的证据 显示英文标题

标题： Discovery of a Nuclear X-Ray Source in NGC 7331: Evidence for a Massive Black Hole

摘要： 使用ROSAT，我们对NGC 7331进行了首次深度X射线观测，发现了一个与之前确定的射电和光学核中心重合的核X射线源。 场中X射线源的位置、光度和流量与之前识别的射电和光学源进行了比较。 对NGC 7331的核进行了分析，以辨别任何支持存在大质量黑洞（MBH）的新证据，并与其他低电离核发射线区（LINER）星系进行了比较。 NGC 7331的核心射电与软X射线辐射的流量比低于我们样本中其他LINERs。 显示英文摘要

摘要： Using ROSAT, we have made the first deep X-ray observations of NGC 7331, discovering a nuclear X-ray source coincident with the previously determined radio and optical nuclear centers. Positions, luminosities, and fluxes of X-ray sources in the field are compared to previously identified radio and optical sources. The nucleus of NGC 7331 has been analyzed to discern any new evidence supporting the presence of a massive black hole (MBH), and comparisons are made with other Low-Ionization Nuclear Emission-line Region (LINER) galaxies. The flux ratio of core radio to soft X-ray emission in NGC 7331 is lower than in other LINERs included in our sample.