在X射线发光活动星系核中没有明显的亚毫米波段恒星形成特征
No clear submillimetre signature of suppressed star formation amongst X-ray luminous AGNs
摘要:
许多理论模型需要强大的活动星系核(AGN)来抑制遥远星系中的恒星形成,并再现今天大质量星系的观测特性。最近一项基于Herschel-SPIRE亚毫米波观测的研究声称为这一图像提供了直接支持,该研究报告称,在钱德拉深场北(CDF-N)中,z=1-3处最明亮的活动星系核(Lx>10^44 erg/s)的平均恒星形成率(SFR)显著下降。在这封信中,我们使用COSMOS和CDF-S场中的Herschel-SPIRE 250 μ m数据扩展了这些结果,使Lx>10^44 erg/s时的源数提高了一个数量级。根据我们的分析,我们没有发现在z=1-3时Lx>10^44 erg/s的活动星系核中存在抑制恒星形成的强有力证据。在Lx~10^43-10^45 erg/s的宽X射线光度范围内,活动星系核的平均SFR是恒定的(在z~2; ~100-200 Msol/yr时,平均SFR与典型的恒星形成星系一致<SFRs>)。我们认为,以前的CDF-N结果可能是由于低的数字统计。我们讨论我们的结果在当前的理论模型的背景下。
英文摘要:
Many theoretical models require powerful active galactic nuclei (AGNs) to suppress star formation in distant galaxies and reproduce the observed properties of today's massive galaxies. A recent study based on Herschel-SPIRE submillimetre observations claimed to provide direct support for this picture, reporting a significant decrease in the mean star-formation rates (SFRs) of the most luminous AGNs (Lx>10^44 erg/s) at z=1-3 in the Chandra Deep Field-North (CDF-N). In this letter we extend these results using Herschel-SPIRE 250um data in the COSMOS and CDF-S fields to achieve an order of magnitude improvement in the number of sources at Lx>10^44 erg/s. On the basis of our analysis, we find no strong evidence for suppressed star formation in Lx>10^44 erg/s AGNs at z=1-3. The mean SFRs of the AGNs are constant over the broad X-ray luminosity range of Lx~10^43-10^45 erg/s (with mean SFRs consistent with typical star-forming galaxies at z~2; <SFRs>~100-200 Msol/yr). We suggest that the previous CDF-N results were likely due to low number statistics. We discuss our results in the context of current theoretical models.
机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。