群内介质中作为超新星遗迹的奇射电圈
Odd Radio Circles as supernovae remnants in the intragroup medium
摘要：
在最近发现的弧分大小的圆形弥散射电源中，有一部分（$\sim8$ %）被称为奇射电圈（Odd Radio Circles）或ORC，它们可能是本星系群及其近邻星系群内群内介质中的超新星遗迹。这一估计是基于光学探测率的群内超新星事件在附近（$z \sim 0.1-0.2$）星系群。在本星系群及其邻近的星系群中，预计每百万年约有5400颗群内超新星。对于一个约为$10^{4}$年的射电可探测周期，平均每1000平方度1.3个群内中等超新星遗迹预计将在射电勘测中被探测到，其灵敏度导致了ORC的发现。在群内介质中，距离$\sim3$ Mpc的超新星遗迹的角大小、表面亮度和射电通量可以预期与五个已知的ORC相似。群内超新星遗迹并不存在于星系的致密和寒冷的星际介质中，而是在星系晕或更远的低密度（$10^{-4}-10^{-5}$ cm $^{-3}$）温暖介质（$10^{5}-10^{6}$ K）中演化，并且可能在与银河系和其他附近星系周围的各种潮汐流光相关的漫射恒星光中找到它们的祖先。
英文摘要：
A measurable fraction ($\sim8$ per cent) of recently discovered arcmin-size circular diffuse radio sources termed as Odd Radio Circles or ORCs can be supernovae remnants in the intragroup medium, within the local group and its immediate neighbour groups of galaxies. This estimate is based on the optical detection rate of the intragroup supernovae events in the nearby ($z \sim 0.1-0.2$) galaxy groups. A rate of about 5400 intragroup supernovae per million year is expected within the local and its immediate neighbour groups of galaxies. For a radio detectability period of about $10^{4}$ years, on average 1.3 intragroup medium supernovae remnants per 1000 square degree are expected to be detected in the radio surveys with a sensitivity that led to discovery of ORCs. The angular size, surface brightness and radio flux of the supernova remnants up to a distance of $\sim3$ Mpc in the intragroup medium can be expected to be similar to the five known ORCs. The intragroup supernovae remnants are not residing in the dense and cold interstellar medium of the galaxies but evolving in low density ($10^{-4}-10^{-5}$ cm$^{-3}$) warm medium ($10^{5}-10^{6}$ K) in galactic halos or beyond, and may find their progenitors in the diffuse stellar light associated with various tidal streamers surrounding the Milky-Way and other nearby galaxies.
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。
