论文标题
SDSS矮星系中检测到的X射线AGN
X-ray Detected AGN in SDSS Dwarf Galaxies
论文作者
论文摘要
在这项工作中，我们介绍了X射线选择的X射线（$ Z \ leq 0.25 $）矮星系（$ M_ \ Mathrm {*} \ leq 3 \ times 10^9 \ Mathrm {M_ \ odot} $）。我们定义了一个在MPA-JHU星系目录（基于SDSS DR8）和3xMM DR7的脚印中发现的4,331个矮星系的父样本，对数据进行了仔细的审查，以消除误解并产生了61个dwarf Galaxies，以表现出61个dwarf Galaxies，以表现出核X射线的61个dwaraxies。我们检查了我们X射线选定样品的光发线比率，发现光学AGN诊断无法识别85％的来源。然后，我们根据其特定的积聚率（$ \ propto l_ \ mathrm {x}/m_ \ mathrm {*} $，$ \ propto l_ \ propto l_ \ propto l_ \ mathrm {*} $，它计算了黑洞的增长率，这是Eddington比率的大约示踪剂）。在我们观察到的样本中，我们发现了广泛的特定积聚率。在校正了3xmm敏感性的观察到的样品后，我们找到了宽度X射线发光性和特定的增生速率的进一步证据，该X射线亮度和特定的吸积率（由功率定律描述）。使用此校正后的AGN样品，我们还定义了一个AGN分数，该分数描述了它们在父样本中的相对发生率。我们发现，与X射线照明量之间的星系的主机星系质量（最高$ \ $ 6％）的增加，AGN的分数增加在$ 10^{39} \ Mathrm {erg/s} $和$ 10^{42} {42} \ mathrm {erg/s} $，以及通过较高的for for for for for for for for for for luminiention，以确定for luminiention for for for luminiention，以确定for for luminiention，以至于以下简单范围，我们（$ l_ \ mathrm {x} \ geq 10^{42.4} \ mathrm {erg/s} $）持续不变为$ z \大约0.7 $。
In this work we present a robust quantification of X-ray selected AGN in local ($z \leq 0.25$) dwarf galaxies ($M_\mathrm{*} \leq 3 \times 10^9 \mathrm{M_\odot}$). We define a parent sample of 4,331 dwarf galaxies found within the footprint of both the MPA-JHU galaxy catalogue (based on SDSS DR8) and 3XMM DR7, performed a careful review of the data to remove misidentifications and produced a sample of 61 dwarf galaxies that exhibit nuclear X-ray activity indicative of an AGN. We examine the optical emission line ratios of our X-ray selected sample and find that optical AGN diagnostics fail to identify 85% of the sources. We then calculated the growth rates of the black holes powering our AGN in terms of their specific accretion rates ($\propto L_\mathrm{X}/M_\mathrm{*}$, an approximate tracer of the Eddington ratio). Within our observed sample, we found a wide range of specific accretion rates. After correcting the observed sample for the varying sensitivity of 3XMM, we found further evidence for a wide range of X-ray luminosities and specific accretion rates, described by a power law. Using this corrected AGN sample we also define an AGN fraction describing their relative incidence within the parent sample. We found the AGN fraction increases with host galaxy mass (up to $\approx$ 6%) for galaxies with X-ray luminosities between $10^{39} \mathrm{erg/s}$ and $10^{42} \mathrm{erg/s}$, and by extrapolating the power law to higher luminosities, we found evidence to suggest the fraction of luminous AGN ($L_\mathrm{X} \geq 10^{42.4} \mathrm{erg/s}$) is constant out to $z \approx 0.7$.
