A definitive merger-AGN connection at z ∼ 0 with CFIS: mergers have an excess of AGN and AGN hosts are more frequently disturbed
A definitive merger-AGN connection at z ∼ 0 with CFIS: mergers have an excess of AGN and AGN hosts are more frequently disturbed
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DOI：
10.1093/mnras/stz1431
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发表时间：
2019-05
影响因子：
4.8
通讯作者：
S. Ellison;Akshara Viswanathan;D. Patton;C. Bottrell;A. McConnachie;S. Gwyn;J. Cuillandre
中科院分区：
文献类型：
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作者：
S. Ellison;Akshara Viswanathan;D. Patton;C. Bottrell;A. McConnachie;S. Gwyn;J. Cuillandre
星系合并是否与活动星系核（AGN）的触发有关的问题仍然是一个相当有争议的话题。这个问题可以分为两个不同的问题：1）星系合并能触发活动星系核吗？2)星系合并是活动星系核的主要触发机制吗？完整的AGN-merger连接的图片需要这两个问题都用同一个数据集来解决。在以前的工作中，我们已经表明，从斯隆数字巡天（SDSS）中选择的星系合并显示出过量的光学选择和中红外颜色选择的活动星系核，表明上述问题的答案是肯定的。在这里，我们使用相同的光学和中红外活动星系核选择来解决第二个问题，方法是量化加拿大法国成像调查（CFIS）的低表面亮度r波段图像中形态扰动的频率。只有约30%的光学活动星系核宿主星系的形态受到干扰，这表明最近的相互作用不是主要的触发因素。然而，近60%的中红外活动星系核宿主显示出视觉障碍的迹象，表明相互作用在核喂养中发挥着更重要的作用。中红外和光学选择活动星系核的相互作用部分是一个因素的两个大于质量和红移匹配的非活动星系核控制样本，一个多余的活动星系核光度和宿主星系恒星质量增加。
The question of whether galaxy mergers are linked to the triggering of active galactic nuclei (AGN) continues to be a topic of considerable debate. The issue can be broken down into two distinct questions: 1) Can galaxy mergers trigger AGN? 2) Are galaxy mergers the dominant AGN triggering mechanism? A complete picture of the AGN-merger connection requires that both of these questions are addressed with the same dataset. In previous work, we have shown that galaxy mergers selected from the Sloan Digital Sky Survey (SDSS) show an excess of both optically-selected, and mid-IR colour-selected AGN, demonstrating that the answer to the first of the above questions is affirmative. Here, we use the same optical and mid-IR AGN selection to address the second question, by quantifying the frequency of morphological disturbances in low surface brightness r-band images from the Canada France Imaging Survey (CFIS). Only ~30 per cent of optical AGN host galaxies are morphologically disturbed, indicating that recent interactions are not the dominant trigger. However, almost 60 per cent of mid-IR AGN hosts show signs of visual disturbance, indicating that interactions play a more significant role in nuclear feeding. Both mid-IR and optically selected AGN have interacting fractions that are a factor of two greater than a mass and redshift matched non-AGN control sample, an excess that increases with both AGN luminosity and host galaxy stellar mass.