arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1306.6468astro-ph.CO
收藏

AGN反馈是双向的

AGN feedback works both ways

Peter-Christian Zinn, Enno Middelberg, Ray P. Norris, Ralf-Jürgen Dettmar

摘要:

星系生长的模拟需要从活动星系核(AGN)中调用强大的负反馈来抑制恒星的形成,从而防止超大质量系统的过度产生。虽然一些观测提供了这种负反馈的证据,但其他研究发现没有反馈,甚至是正反馈,与更高的AGN光度相关的恒星形成增加。在这里,我们报告了数百个活动星系核和它们的宿主星系在钱德拉深场南使用X射线和无线电数据进行样本选择的分析。结合档案远红外数据作为一个可靠的示踪剂的活动星系核宿主星系的恒星形成活动,我们发现,活动星系核具有明显的射电喷流表现出更高的恒星形成率比纯粹的X射线选择的,即使在相同的X射线光度。这种差异意味着活动星系核的正反馈也起着重要的作用,因此在未来的模拟工作中必须考虑到这一点。我们解释这表明,增强的恒星形成率的射电选择活动星系核的出现,因为喷流诱导的恒星形成,这是暗示我们的活动星系核样品之间的不同喷流功率,而抑制的恒星形成率的X射线选择活动星系核是由加热和光解离的分子气体的热活动星系核吸积盘。

英文摘要:

Simulations of galaxy growth need to invoke strong negative feedback from active galactic nuclei (AGN) to suppress the formation of stars and thus prevent the over-production of very massive systems. While some observations provide evidence for such negative feedback, other studies find either no feedback, or even positive feedback, with increased star formation associated with higher AGN luminosities. Here we report an analysis of several hundred AGN and their host galaxies in the Chandra Deep Field South using X-ray and radio data for sample selection. Combined with archival far infrared data as a reliable tracer of star formation activity in the AGN host galaxies, we find that AGN with pronounced radio jets exhibit a much higher star formation rate than the purely X-ray selected ones, even at the same X-ray luminosities. This difference implies that positive AGN feedback plays an important role, too, and therefore has to be accounted for in all future simulation work. We interpret this to indicate that the enhanced star formation rate of radio selected AGN arises because of jet-induced star formation, as is hinted by the different jet powers among our AGN samples, while the suppressed star formation rate of X-ray selected AGN is caused by heating and photo-dissociation of molecular gas by the hot AGN accretion disc.

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。

↑