A flat trend of star formation rate with X-ray luminosity of galaxies hosting AGN in the SCUBA-2 Cosmology Legacy Survey
A flat trend of star formation rate with X-ray luminosity of galaxies hosting AGN in the SCUBA-2 Cosmology Legacy Survey
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DOI：
10.1093/mnras/stz1093
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发表时间：
2019-04
影响因子：
4.8
通讯作者：
J. Ramasawmy;J. Stevens;G. Martin;J. Geach
中科院分区：
文献类型：
--
作者：
J. Ramasawmy;J. Stevens;G. Martin;J. Geach
来自活动星系核(AGN)的反馈过程被认为在调节大质量星系中恒星的形成方面起着至关重要的作用。关于恒星形成是否受到活动星系核反馈的抑制、增强或不受影响，以前的研究使用的是文本{Herschel}，得出的结论相互矛盾。我们使用来自Scuba-2宇宙学遗产调查(S2CLS)的新的深850µm观测，研究了X射线选择的活动星系核的恒星形成，探测了直到$L_{0.5-7~\rMKev}=10^{46}$erg S$^-1}$的星系。在这里，我们给出了一个1957个位于$1<；z<；3$的星系样本的分析结果，使用了S2CLS和附加的七个波长(24-500\mcm)的数据。我们执行堆积分析，通过红移和X射线光度将我们的样品放入库中。通过拟合解析光谱能量分布(SED)来分解冷尘埃和暖尘埃的贡献，我们估计了每个“平均”源的恒星形成率。我们发现，我们样本中的平均活动星系核位于一个恒星形成的宿主星系中，SFR在80-600$M_(-1)$$Year$^{-1}$之间。在每个红移盒中，我们没有看到SFR随X射线光度的变化趋势，而是发现SFR在AGN光度的$\sim$3数量级上呈平坦分布。通过研究瞬时X射线光度和SFRS，我们没有发现活动星系核活动影响宿主星系恒星形成的证据。
Feedback processes from active galactic nuclei (AGN) are thought to play a crucial role in regulating star formation in massive galaxies. Previous studies using \textit{Herschel} have resulted in conflicting conclusions as to whether star formation is quenched, enhanced, or not affected by AGN feedback. We use new deep 850 $\mu$m observations from the SCUBA-2 Cosmology Legacy survey (S2CLS) to investigate star formation in a sample of X-ray selected AGN, probing galaxies up to $L_{0.5-7~\rm keV} = 10^{46}$ erg s$^{-1}$. Here we present the results of our analysis on a sample of 1957 galaxies at $ 1 < z < 3 $, using both S2CLS and ancilliary data at seven additional wavelengths (24--500 \mcm) from \textit{Herschel} and \textit{Spitzer}. We perform a stacking analysis, binning our sample by redshift and X-ray luminosity. By fitting analytical spectral energy distributions (SEDs) to decompose contributions from cold and warm dust, we estimate star-formation rates for each `average' source. We find that the average AGN in our sample resides in a star-forming host galaxy, with SFRs ranging from 80 - 600 $M_{\odot}$ year$^{-1}$. Within each redshift bin, we see no trend of SFR with X-ray luminosity, instead finding a flat distribution of SFR across $\sim$3 orders of magnitude of AGN luminosity. By studying instantaneous X-ray luminosities and SFRs, we find no evidence that AGN activity affects star formation in host galaxies.