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 0902.3365astro-ph.COastro-ph.GA
收藏

VLA对CDFS的巡天:微弱射电源的性质

VLA survey of the CDFS: the nature of faint radio sources

P. Tozzi, K. Kellermann, E. Fomalont, N. Miller, C. Norman, V. Mainieri, P. Padovani, P. Rosati, the VLA-CDFS team

摘要:

本文给出了266个编目射电源的多波长特性,这些源是由CDFS的20和6 cm VLA深度观测确定的,场中心的通量密度极限为42 μJy,1.4 GHz。这些新的观测探测了恒星形成和射电星系/活动星系核人口的微弱末端。X射线数据,包括上限,是确定微弱射电源性质的关键因素。我们发现,而著名的扁平化的无线电数计数低于1兆焦耳主要是由于恒星形成的星系,这些来源和活动星系核构成了一个近似相等的分数分-millijansky天空,相反,一些以前的结果。我们还发现了一个遥远的AGN人口系统失踪的许多以前的研究亚毫流射电源识别。活动星系核包括射电星系,大部分是低功率的Fanaroff-Riley I型,以及一个重要的射电安静成分,约占总样本的五分之一。我们还发现,无线电探测到的X射线活动星系核并不比X射线探测到的活动星系核更模糊。这反对使用无线电测量作为寻找强吸收活动星系核失踪人口的有效方法。

英文摘要:

We present the multiwavelength properties of 266 cataloged radio sources identified with 20 and 6 cm VLA deep observations of the CDFS at a flux density limit of 42 μJy at the field centre at 1.4 GHz. These new observations probe the faint end of both the star formation and radio galaxy/AGN population. X-ray data, including upper limits, turn out to be a key factor in establishing the nature of faint radio sources. We find that, while the well-known flattening of the radio number counts below 1 mJy is mostly due to star forming galaxies, these sources and AGN make up an approximately equal fraction of the sub--millijansky sky, contrary to some previous results. We have also uncovered a population of distant AGN systematically missing from many previous studies of sub-millijansky radio source identifications. The AGN include radio galaxies, mostly of the low-power, Fanaroff-Riley I type, and a significant radio-quiet component, which amounts to approximately one fifth of the total sample. We also find that radio detected, X-ray AGN are not more heavily obscured than the X-ray detected AGN. This argues against the use of radio surveys as an efficient way to search for the missing population of strongly absorbed AGN.

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。

↑