论文标题
宽区GMRT 610〜MHz Elais N1字段调查
A Wide-area GMRT 610~MHz survey of ELAIS N1 field
论文作者
论文摘要
在本文中，我们介绍了GMRT的Elais \，N1字段的宽区域610 MHz调查，以6个Arcsec的分辨率覆盖了12.8度$^2 $的面积，RMS噪声为$ \ sim 40 $ $ $ $ $ $ $ $ $ $ jy jy beam $^{ - 1} $。这相当于$ \ sim 20 $ $ $ $ $ jy beam $^{ - 1} $ rms噪声为1.4 GHz，光谱指数为$ -0.75 $。调查的主要目的是以$ <$ GHz的频率研究次级通量密度的两极分化天空。此外，一系列其他科学目标，例如对低频$ $ $ $ jy源人群和无线电飞机的一致性的调查。在该地区共有6,400个来源，其中绝大多数紧凑。 GMRT以610 MHz共同检测到的样品，首先是1.4 \的VLA，GHz的中位光谱指数为$ -0.85 \ pm 0.05 $，中位610 MHz通量密度为4.5 mjy。该地区具有大量的辅助数据，可用于表征检测到的来源。多波长的交叉匹配导致光学/IR对应物为$ \ sim 90 $每百分之〜无线电源，其显着分数至少具有光度红移。由于这项调查的敏感性对先前的调查的敏感性提高，因此我们发现了六个巨型无线电来源（GRS），其中三个为$ z \ sim 1 $或更高。这意味着GRS的种群可能比迄今为止已知的更丰富和常见，如果正确，这对亮度函数和无线电源的演变具有影响。我们还确定了一些候选遗物源。
In this paper we present a wide-area 610 MHz survey of the ELAIS\,N1 field with the GMRT, covering an area of 12.8 deg$^2$ at a resolution of 6 arcsec and with an rms noise of $\sim 40$ $μ$Jy beam$^{-1}$. This is equivalent to $\sim 20$ $μ$Jy beam$^{-1}$ rms noise at 1.4 GHz for a spectral index of $-0.75$. The primary goal of the survey was to study the polarised sky at sub-mJy flux densities at $<$ GHz frequencies. In addition, a range of other science goals, such as investigations in to the nature of the low-frequency $μ$Jy source populations and alignments of radio jets. A total of 6,400 sources were found in this region, the vast majority of them compact. The sample jointly detected by GMRT at 610 MHz and by VLA FIRST at 1.4\,GHz has a median spectral index of $-0.85 \pm 0.05$ and a median 610 MHz flux density of 4.5 mJy. This region has a wealth of ancillary data which is useful to characterize the detected sources. The multi-wavelength cross matching resulted optical/IR counterparts to $\sim 90$ per~cent of the radio sources, with a significant fraction having at least photometric redshift. Due to the improved sensitivity of this survey over preceding ones, we have discovered six giant radio sources (GRS), with three of them at $z \sim 1$ or higher. This implies that the population of GRS may be more abundant and common than known to date and if true this has implications for the luminosity function and the evolution of radio sources. We have also identified several candidate extended relic sources.
