论文标题
昏迷集群中星系的RAM压力剥离的无线电尾巴
The ram pressure stripped radio tails of galaxies in the Coma cluster
论文作者
论文摘要
先前的研究表明,在ram压力(RPS)气体和嵌入的年轻恒星的星系簇中有大量的星系群。我们观察到1.4 GHz的连续体和HI发射,其在昏迷集群的两个磁场中的B构造中非常大的阵列研究RPS星系的无线电性能。这两个领域的最佳连续性敏感性分别为6和8 $μ$ jy每4''光束,比以前发表的最高4和3倍。无线电连续体尾巴在20个RPS星系中的10个(8个)中发现,明确揭示了剥离尾巴中相对论电子和磁场的存在。我们的结果还暗示,尾巴比银河系具有陡峭的频谱。与RPS星系的主体相比,相对于其H $α$排放的1.4 GHz连续体增强了$ \ sim $ 7。与星形星系相比,RPS星系的1.4 GHz连续体相对于其IR发射的$ \ sim 2 $ 2也得到了增强。增强可能与尾巴的RAM压力和湍流有关。我们此外,在三个RPS星系和其他RPS星系的上限中呈现HI检测。 D100剥离尾巴中的冷气主要由分子气体主导,这可能是高环境压力的结果。在我们的数据中,没有发现与超扩散星系相关的无线电排放的证据。
Previous studies have revealed a population of galaxies in galaxy clusters with ram pressure stripped (RPS) tails of gas and embedded young stars. We observed 1.4 GHz continuum and HI emission with the Very Large Array in its B-configuration in two fields of the Coma cluster to study the radio properties of RPS galaxies. The best continuum sensitivities in the two fields are 6 and 8 $μ$Jy per 4'' beam respectively, which are 4 and 3 times deeper than those previously published. Radio continuum tails are found in 10 (8 are new) out of 20 RPS galaxies, unambiguously revealing the presence of relativistic electrons and magnetic fields in the stripped tails. Our results also hint that the tail has a steeper spectrum than the galaxy. The 1.4 GHz continuum in the tails is enhanced relative to their H$α$ emission by a factor of $\sim$7 compared to the main bodies of the RPS galaxies. The 1.4 GHz continuum of the RPS galaxies is also enhanced relative to their IR emission by a factor of $\sim$2 compared to star-forming galaxies. The enhancement is likely related to ram pressure and turbulence in the tail. We furthermore present HI detections in three RPS galaxies and upper limits for the other RPS galaxies. The cold gas in D100's stripped tail is dominated by molecular gas, which is likely a consequence of the high ambient pressure. No evidence of radio emission associated with ultra-diffuse galaxies is found in our data.