Morphological asymmetries of quasar host galaxies with Subaru Hyper Suprime-Cam
Morphological asymmetries of quasar host galaxies with Subaru Hyper Suprime-Cam
复制标题
使用 Subaru Hyper Suprime-Cam 观察类星体宿主星系的形态不对称性
DOI：
10.1093/mnras/stad877
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发表时间：
2023
影响因子：
4.8
通讯作者：
Kawaguchi Toshihiro
中科院分区：
文献类型：
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作者：
Tang Shenli;Silverman John D;Yesuf Hassen M;Ding Xuheng;Li Junyao;Bottrell Connor;Goulding Andy;Omori Kiyoaki Christopher;Toba Yoshiki;Kawaguchi Toshihiro
宿主星系的形态如何影响中心类星体，反之亦然？我们解决这个问题，通过测量2424 SDSS类星体主机在0.2 <z <0.8使用宽带（灰色）图像从超级凸轮斯巴鲁战略计划的不对称性。控制星系（没有类星体）是通过匹配类星体宿主的红移和恒星质量来选择的。一个两步的管道运行分解PSF和Sérsic组件，然后测量每个类星体宿主星系和控制星系的不对称指数（ACAS，Aouter和Ashape）。我们发现，主机的不对称性和AGN的辐射光度（Lbol）之间的一个温和的相关性（斯皮尔曼相关性为0.37），而一个更强的趋势是明显的最高光度（Lbol> 45）。这表现在类星体宿主更不对称，平均而言，当它们拥有一个更大质量和高度吸积的黑洞时。合并部分也正相关与Lboland达到最明亮的35%。与对照星系相比，类星体宿主的不对称性略高（在9.4 σ水平上超过中值0.017），合并分数相似（）。我们量化的依赖性的不对称性的光学波段，这表明合并更有可能被确定与蓝带和相关betweenLboland不对称性也更强，在这样的波段。我们强调，频带的依赖性，指示不断变化的恒星人口，是一个重要的因素，在考虑合并活动星系核活动的影响。
How does the host galaxy morphology influence a central quasar or vice versa? We address this question by measuring the asymmetries of 2424 SDSS quasar hosts at 0.2 <z< 0.8 using broad-band (grizy) images from the Hyper Suprime-Cam Subaru Strategic Program. Control galaxies (without quasars) are selected by matching the redshifts and stellar masses of the quasar hosts. A two-step pipeline is run to decompose the PSF and Sérsic components and then measure asymmetry indices (ACAS,Aouter, andAshape) of each quasar host and control galaxy. We find a mild correlation between host asymmetry and AGN bolometric luminosity (Lbol) for the full sample (spearman correlation of 0.37) while a stronger trend is evident at the highest luminosities (Lbol> 45). This then manifests itself into quasar hosts being more asymmetric, on average, when they harbour a more massive and highly accreting black hole. The merger fraction also positively correlates withLboland reaches up to 35 per cent for the most luminous. Compared to control galaxies, quasar hosts are marginally more asymmetric (excess of 0.017 in median at 9.4σ level) and the merger fractions are similar (). We quantify the dependence of asymmetry on optical band that demonstrates that mergers are more likely to be identified with the bluer bands and the correlation betweenLboland asymmetry is also stronger in such bands. We stress that the band dependence, indicative of a changing stellar population, is an important factor in considering the influence of mergers on AGN activity.