论文标题
在低红移时合并引起的AGN活性的X射线视图
The X-ray View of Merger-Induced AGN Activity at Low Redshift
论文作者
论文摘要
预计星系合并将触发积聚到中央超级质量黑洞上，最终结合期间发生率最高。以前，我们已经显示出在后培养剂中选择的光学和MID-IR选定活性银河核（AGN）的速率升高，但迄今为止，X射线AGN的患病率尚未以相同的系统方式检查。我们提供了从斯隆数字天空调查中选择的43个合并后星系的XMM-Newton数据，以及430个非相互作用的控制星系，在恒星质量，红移和环境中匹配，以测试可归因于触发的AGN的后生后的硬X射线（2-10 KEV）发射。我们在后培养剂（4.7^{+9.3} _ { - 3.8}％）中发现2个X射线检测，在对照组（2.1^{+1.5} _ { - 1.0}％）中发现了9个检测，超过2.22^{+4.44} _ { - 2.22} _ { - 2.22}，位于90％。因此，虽然我们没有发现在后培养剂中X射线AGN过量的统计显着证据（p = 0.26），但在样本中，我们发现中MID-IR AGN过量〜17倍，与过去的工作一致，并且与观察到的X射线过量过量不一致（P = 2.7 x 10^{-4}）。因此，在后燃料中占主导地位，发光的AGN更为频繁，并且缺乏可比的2-10 keV X射线AGN表明，后螺旋体中的AGN更有可能被严重遮盖。我们的结果与合并后的阶段相一致，其特征是AGN加油，沉重的AGN遮挡和更本质上的发光AGN与理论预测一致。
Galaxy mergers are predicted to trigger accretion onto the central supermassive black holes, with the highest rates occurring during final coalescence. Previously, we have shown elevated rates of both optical and mid-IR selected active galactic nuclei (AGN) in post-mergers, but to date the prevalence of X-ray AGN has not been examined in the same systematic way. We present XMM-Newton data of 43 post-merger galaxies selected from the Sloan Digital Sky Survey along with 430 non-interacting control galaxies matched in stellar mass, redshift, and environment in order to test for an excess of hard X-ray (2-10 keV) emission in post-mergers attributable to triggered AGN. We find 2 X-ray detections in the post-mergers (4.7^{+9.3}_{-3.8}%) and 9 in the controls (2.1^{+1.5}_{-1.0}%), an excess of 2.22^{+4.44}_{-2.22}, where the confidence intervals are 90%. While we therefore do not find statistically significant evidence for an X-ray AGN excess in post-mergers (p = 0.26), we find a factor of ~17 excess of mid-IR AGN in our sample, consistent with past work and inconsistent with the observed X-ray excess (p = 2.7 x 10^{-4}). Dominant, luminous AGN are therefore more frequent in post-mergers, and the lack of a comparable excess of 2-10 keV X-ray AGN suggests that AGN in post-mergers are more likely to be heavily obscured. Our results are consistent with the post-merger stage being characterised by enhanced AGN fueling, heavy AGN obscuration, and more intrinsically luminous AGN, in line with theoretical predictions.
