论文标题
从ASKAP-EMU PILOT调查中发现大量合并群集SPT-CL 2023-5535中的无线电遗物
Discovery of a Radio Relic in the Massive Merging Cluster SPT-CL 2023-5535 from the ASKAP-EMU PILOT SURVEY
论文作者
论文摘要
ASKAP-EMU调查是一项深层广播连续调查，旨在覆盖整个南部的天空，而北方天空的很大一部分则达到$+30^{\ circ} $。在这里，我们报告了从askap-emu Pilot 300平方deg调查（800-1088 MHz）合并群集SPT-CL 2023-5535中发现的无线电遗物。深层高分辨率数据显示，$ \ sim2 $ mpc尺度的无线电光环在东西方向延伸，与群内气体一致。无线电遗物位于该电台光环的西部边缘，在南北方向上延伸了$ \ sim0.5 $ MPC。狭窄带宽内无线电遗物的集成光谱索引为$α^{\ scriptStyle \ rm 1088〜mhz} _ {\ scriptStyle \ rm 800〜mhz} = -0.76 \ pm pm 0.06 $。我们的弱镜头分析表明，系统是巨大的（$ m_ {200} = 1.04 \ pm0.36 \ times 10^{15} m _ {\ odot} $），并且至少由三个子观点组成。我们建议一种场景，其中无线电特征是由于东部和中间子场所之间的碰撞引起的。我们的发现说明了ASKAP-EMU调查在检测星系簇中扩散排放的有效性，完成后，调查将大大增加与弥散无线电排放的合并群集检测的数量。
The ASKAP-EMU survey is a deep wide-field radio continuum survey designed to cover the entire southern sky and a significant fraction of the northern sky up to $+30^{\circ}$. Here, we report a discovery of a radio relic in the merging cluster SPT-CL 2023-5535 at z=0.23 from the ASKAP-EMU pilot 300 sq. deg survey (800-1088 MHz). The deep high-resolution data reveal a $\sim2$ Mpc-scale radio halo elongated in the east-west direction, coincident with the intracluster gas. The radio relic is located at the western edge of this radio halo stretched $\sim0.5$ Mpc in the north-south orientation. The integrated spectral index of the radio relic within the narrow bandwidth is $α^{\scriptstyle \rm 1088~MHz}_{\scriptstyle \rm 800~MHz}=-0.76 \pm 0.06$. Our weak-lensing analysis shows that the system is massive ($M_{200}=1.04\pm0.36\times 10^{15} M_{\odot}$) and composed of at least three subclusters. We suggest a scenario, wherein the radio features arise from the collision between the eastern and middle subclusters. Our discovery illustrates the effectiveness of the ASKAP-EMU survey in detecting diffuse emissions in galaxy clusters and when completed, the survey will greatly increase the number of merging cluster detections with diffuse radio emissions.
