arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 2309.06830astro-ph.HE
收藏

利用IXPE、NICER和Swift/XRT揭示LMC X-3的X射线偏振性质

Unveiling the X-ray polarimetric properties of LMC X-3 with IXPE, NICER, and Swift/XRT

Akash Garg, Divya Rawat, Mariano Méndez

AI总结:

本文利用IXPE、NICER和Swift/XRT首次测得河外黑洞X射线双星LMC X-3的X射线偏振,发现偏振度随能量升高并在5 keV以上突增,支持静态板层冕几何结构。

摘要:

即将开展的成像X射线偏振测量探测器(IXPE)对X射线双星的观测为研究其背后的吸积几何结构提供了一种新工具。本文报告了河外黑洞X射线双星LMC X-3的首次X射线偏振测量结果。我们在2-8 keV能段测得偏振度约为3%,偏振角约为135°,统计显著性达到7σ水平。该偏振测量结果显著超过了该源在2-8 keV能段以99%置信水平确定的最小可探测偏振阈值1.2%。对NICER、Swift/XRT和IXPE数据的同时光谱-偏振拟合揭示存在一个温度约为1 keV的吸积盘和一个幂律指数约为2.4的康普顿化成分,证实了该源的软态性质。偏振度随能量增加而增大,从2-5.7 keV能段的约3%上升到5.7-8 keV能段的约9%,而偏振角与能量无关。观测到的能量依赖关系以及偏振度在5 keV以上的突然跃升支持LMC X-3的康普顿化介质具有静态板层冕几何结构的观点。

英文摘要:

The incoming Imaging X-ray Polarimetry Explorer (IXPE) observations of X-ray binaries provide a new tool to investigate the underlying accretion geometry. Here we report the first measurements of X-ray polarization of the extra-galactic black-hole X-ray binary LMC X$-$3. We find a polarization fraction of $\sim 3%$ at a polarization angle of $\sim 135^\circ$ in the $2-8$ keV energy band with statistical significance at the 7$σ$ level. This polarization measurement significantly exceeds the minimum detectable polarization threshold of 1.2% for the source, ascertained at a 99% confidence level within the $2-8$ keV energy band. The simultaneous spectro-polarimetric fitting of NICER, Swift/XRT, and IXPE revealed the presence of a disc with a temperature of $\sim$1 keV and a Comptonized component with a power-law index of $\sim$ 2.4, confirming the soft nature of the source. The polarization degree increases with energy from $\sim$3% in the $2-5.7$ keV band to $\sim$9% in the $5.7-8$ keV band, while the polarization angle is energy independent. The observed energy dependence and the sudden jump of polarization fraction above 5 keV supports the idea of a static slab coronal geometry for the Comptonizing medium of LMC X$-$3.

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。

↑