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 1503.03489astro-ph.COastro-ph.GA
收藏

SWIFT AGN和星系团巡天I:AGN和星系团的计数

The SWIFT AGN and Cluster Survey I: Number Counts of AGN and Galaxy Clusters

Xinyu Dai, Rhiannon D. Griffin, Christopher S. Kochanek, Jenna M. Nugent, Joel N. Bregman

摘要:

雨燕活动星系核和星系团巡天(SACS)利用125度^2的雨燕XRT偶然观测场,围绕伽马射线暴具有不同的深度,以提供中等深度(4 e-15 erg/s/cm ^2)和面积的巡天,填补了深窄钱德拉/XMM-牛顿巡天和宽浅ROSAT巡天之间的空白。在这里,我们提出了一个目录的22,563个点源和442个扩展源和检查的AGN和星系团人口的数量计数。SACS对活动星系核亮端的计数提供了很好的约束,由于宇宙方差的不确定性可以忽略不计,这些约束与以前的测量结果是一致的。我们使用明智的中红外(MIR)颜色来分类源。对于活动星系核,我们可以粗略地将点源分为红、蓝两类,在软X射线波段(0.5-2 keV)发现的这两类源数量大致相等,但在硬X射线波段(2-8 keV)发现的蓝源数量较少。星系团数量的计数,有5%的宇宙方差的不确定性,也与以前的调查,但跨越一个更大的连续通量范围。对这个星团样本的深光学或红外跟踪观测将显著增加更高红移(z > 0.5)X射线选择的星团的数量。

英文摘要:

The Swift AGN and Cluster Survey (SACS) uses 125 deg^2 of Swift XRT serendipitous fields with variable depths surrounding gamma-ray bursts to provide a medium depth (4e-15 erg/s/cm^2) and area survey filling the gap between deep, narrow Chandra/XMM-Newton surveys and wide, shallow ROSAT surveys. Here we present a catalog of 22,563 point sources and 442 extended sources and examine the number counts of the AGN and galaxy cluster populations. SACS provides excellent constraints on the AGN number counts at the bright end with negligible uncertainties due to cosmic variance, and these constraints are consistent with previous measurements. We use Wise mid-infrared (MIR) colors to classify the sources. For AGN we can roughly separate the point sources into MIR-red and MIR-blue AGN, finding roughly equal numbers of each type in the soft X-ray band (0.5-2 keV), but fewer MIR-blue sources in the hard X-ray band (2-8 keV). The cluster number counts, with 5% uncertainties from cosmic variance, are also consistent with previous surveys but span a much larger continuous flux range. Deep optical or IR follow-up observations of this cluster sample will significantly increase the number of higher redshift (z > 0.5) X-ray-selected clusters.

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。

↑