Radio variability in the phoenix deep survey at 1.4 GHz
Radio variability in the phoenix deep survey at 1.4 GHz
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1.4 GHz 凤凰深部勘测中的无线电变异性
DOI：
10.1093/mnras/stw1486
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发表时间：
2016
影响因子：
4.8
通讯作者：
B. Gaensler
中科院分区：
文献类型：
--
作者：
P. Hancock;Jason A. Drury;M. Bell;T. Murphy;B. Gaensler
我们使用凤凰深测的档案数据来研究1.4GHz频率下1mJy/波束以上的可变射电源群。鉴于本调查与其他此类调查的相似性，我们借此机会调查文献中出现的相互矛盾的结果。之前用甚大阵列（VLA）进行的两次变异性调查获得了1mJy/beam的灵敏度。然而，一项调查发现，在几十年的时间尺度上，射电变量的面密度是在不到几年的时间尺度上进行的第二次调查的4倍。在凤凰号深场，我们测量到在6个月到8年的时间尺度上，可变射电源的密度为$\rho =0.98\数学{度}^{-2}$。我们利用WISE红外交叉id，并将所有变量源识别为某种描述的AGN。我们认为，以前的VLA结果之间的差异是由于每次调查所探测的时间尺度不同，1.4 GHz的无线电变异性在2 - 5年的时间尺度上最大。
We use archival data from the Phoenix Deep Survey to investigate the variable radio source population above 1mJy/beam at 1.4GHz. Given the similarity of this survey to other such surveys we take the opportunity to investigate the conflicting results which have appeared in the literature. Two previous surveys for variability conducted with the Very Large Array (VLA) achieved a sensitivity of 1mJy/beam. However, one survey found an areal density of radio variables on timescales of decades that is a factor of ~4 times greater than a second survey which was conducted on timescales of less than a few years. In the Phoenix deep field we measure the density of variable radio sources to be $\rho =0.98\mathrm{deg}^{-2}$ on timescales of 6 months to 8 years. We make use of WISE infrared cross-ids, and identify all variable sources as an AGN of some description. We suggest that the discrepancy between previous VLA results is due to the different time scales probed by each of the surveys, and that radio variability at 1.4 GHz is greatest on timescales of 2 - 5 years.