标题： 暗矮椭球星系中暗物质湮灭无线电波信号的严格约束使用TGSS 显示英文标题

标题： Stringent constraint on the radio signal from dark matter annihilation in dwarf spheroidal galaxies using the TGSS

摘要： 弱相互作用大质量粒子（WIMPs）被认为是暗物质的首选候选者之一。 在过去几十年中，搜索整个电磁谱中由于WIMPs湮灭和衰变产生的可检测信号已成为研究重点。 WIMP湮灭为标准模型粒子会通过同步辐射在低射频下产生检测这种信号的可能性。 矮椭圆星系（dSphs）预计包含大量暗物质，这使它们成为寻找这种大尺度弥散射电辐射的有希望的目标。 在这项工作中，我们展示了23个dSph星系在低频（147.5MHz）下的叠加分析，这是塔希里印度射电望远镜-巨型米波射电望远镜天空调查（TIFR-GMRT Sky Survey，TGSS）的一部分。 这些叠加实验中未检测到任何信号，对暗物质参数施加了非常严格的限制。 最佳限制来自于一种新方法，即在按各自半光半径缩放单个dSph星系区域的射电图像后进行叠加。 对于合理的天体物理参数选择，在WIMP质量范围内，热平均截面的限制低于热残留截面值。 使用未来对单个目标以及叠加分析的更深入观测，可能会揭示更多关于WIMP暗物质特性的信息。 显示英文摘要

摘要： Weakly Interacting Massive Particles (WIMPs) are considered to be one of the favoured dark matter candidates. Searching for any detectable signal due to the annihilation and decay of WIMPs over the entire electromagnetic spectrum has become a matter of interest for the last few decades. WIMP annihilation to Standard Model particles gives rise to a possibility of detection of this signal at low radio frequencies via synchrotron radiation. Dwarf Spheroidal Galaxies (dSphs) are expected to contain a huge amount of dark matter which makes them promising targets to search for such large scale diffuse radio emission. In this work, we present a stacking analysis of 23 dSph galaxies observed at low frequency (147.5MHz) as part of the TIFR-GMRT Sky Survey (TGSS). The non-detection of any signal from these stacking exercises put very tight constraints on the dark matter parameters. The best limit comes from the novel method of stacking after scaling the radio images of the individual dSph galaxy fields after scaling them by the respective half-light radius. The constraint on the thermally averaged cross-section is below the thermal relic cross-section value over a range of WIMP mass for reasonable choices of relevant astrophysical parameters. Such analysis using future deeper observation of individual targets as well as stacking can potentially reveal more about the WIMP dark matter properties.