Caltech-NRAO Stripe 82调查（CNSS）论文I：50度$^2$中的试验性无线电瞬变调查
The Caltech-NRAO Stripe 82 Survey (CNSS) Paper I: The Pilot Radio Transient Survey In 50 deg$^2$
摘要：
我们已经开始了一个多年计划，加州理工学院-NRAO条纹82调查（CNSS），在SDSS条纹82区域搜索Jansky VLA的无线电瞬变。CNSS将在Stripe 82的整个$\sim$ 270 deg $^2$上提供五个历元，最终的深度组合图具有$\sim$ 40 $μ$ μ的均方根噪声和3 GHz频率的目录，并且具有3”的空间分辨率。这第一篇论文介绍了一个50度的条纹82 $^2$区域的初步试点调查的结果，涉及四个时期跨越对数时间尺度之间的一周到1.5年，与组合地图具有35 $μ$ Jy的均方根噪声的中位数。该试验性调查使得能够开发用于快速数据处理的硬件和软件，以及瞬态检测和跟踪，这是完整的270 ° $^2$调查所必需的。对可变源和瞬变源的分类在很大程度上依赖于Stripe 82区域丰富的多波长数据，并辅之以Palomar瞬变工厂对该区域的重复测绘。发现检测到的点源的$3.9^{+0.5}_{-0.9}$ %变化大于30%，与1.4 GHz和5 GHz下的类似研究一致。多波长光度数据和光变曲线表明，这种变化主要是由于激波引起的活动星系核喷流的耀斑。虽然这只是一个试点调查，我们发现了两个真正的瞬变，与RS CVn二进制和dKe星。与现有的无线电测量数据的比较显示，在5-20年的时间尺度上，额外的高度可变和瞬态源，主要与活动星系核活动的恢复。这样的活动星系核的速率可能意味着这些星系中每$\sim$ 40，000年发生一次增强的吸积和喷流活动。我们编制了修订后的无线电瞬变率，并为未来的瞬变调查和联合无线电光学实验提出建议。（节录）
英文摘要：
We have commenced a multi-year program, the Caltech-NRAO Stripe 82 Survey (CNSS), to search for radio transients with the Jansky VLA in the SDSS Stripe 82 region. The CNSS will deliver five epochs over the entire $\sim$270 deg$^2$ of Stripe 82, an eventual deep combined map with a rms noise of $\sim$40 $μ$Jy and catalogs at a frequency of 3 GHz, and having a spatial resolution of 3". This first paper presents the results from an initial pilot survey of a 50 deg$^2$ region of Stripe 82, involving four epochs spanning logarithmic timescales between one week and 1.5 years, with the combined map having a median rms noise of 35 $μ$Jy. This pilot survey enabled the development of the hardware and software for rapid data processing, as well as transient detection and follow-up, necessary for the full 270 deg$^2$ survey. Classification of variable and transient sources relied heavily on the wealth of multi-wavelength data in the Stripe 82 region, supplemented by repeated mapping of the region by the Palomar Transient Factory. $3.9^{+0.5}_{-0.9}$% of the detected point sources were found to vary by greater than 30%, consistent with similar studies at 1.4 GHz and 5 GHz. Multi-wavelength photometric data and light curves suggest that the variability is mostly due to shock-induced flaring in the jets of AGN. Although this was only a pilot survey, we detected two bona fide transients, associated with an RS CVn binary and a dKe star. Comparison with existing radio survey data revealed additional highly variable and transient sources on timescales between 5-20 years, largely associated with renewed AGN activity. The rates of such AGN possibly imply episodes of enhanced accretion and jet activity occurring once every $\sim$40,000 years in these galaxies. We compile the revised radio transient rates and make recommendations for future transient surveys and joint radio-optical experiments. (Abridged)
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。
