AI 中文总结
本研究利用多台设备数据发现麦哲伦桥首个脉动共生超软X射线源J0431-71，证实其为白矮星高吸积率的脉动共生系统，完善了麦哲伦桥致密天体演化的认知。
AI 中文摘要
麦哲伦桥恒星族系是大小麦哲伦星系潮汐相互作用的遗迹，要全面了解该桥恒星族系的演化，需探测在光学波段隐藏的恒星演化致密遗迹。搭载于光谱-伦琴-伽马（Spectrum Roentgen Gamma）天文台的eROSITA仪器开展的全天巡天，利用X射线在麦哲伦桥中发现了大量由致密天体驱动的系统。候选超软X射线源eRASSU J043115.8-711730（以下简称J0431-71）是该巡天的发现成果之一，本文利用XMM-Newton、SALT光谱数据，以及OGLE、ATLAS、ASAS-SN、WISE、GAIA的长期光学-红外测光数据对该源开展更深入研究。J0431-71是高度可变的超软X射线源，经GAIA色星图分类为红巨星；该源表现出：(a)热X射线谱，温度kT约30 eV，0.15-1 keV波段亮态光度为3.2×10^37 erg s^-1；(b)巴耳末发射线、[Fe X]日冕线、HeII发射线及鲍恩荧光混合线；(c)约500-560天的光学红外周期，与X射线-紫外发射相位一致；(d)恒星发射呈现“越亮越红”趋势，周期约520天，表明供体星存在脉动。我们认为J0431-71观测到的光谱和时间特性，符合通过洛希瓣溢流对白矮星的高吸积率过程，使其成为麦哲伦桥中首个发现的共生源。
英文摘要
The Magellanic Bridge stellar population is a relic of the tidal interaction between the Large and Small Magellanic Clouds. A comprehensive view of the evolution of the Bridge stellar population requires probing the compact remnants of stellar evolution, otherwise hidden at optical wavelengths. The all-sky survey conducted by the eROSITA instrument on-board the Spectrum Roentgen Gamma observatory has discovered a significant population of compact-object-powered systems in the Bridge using X-ray. The candidate super-soft source eRASSU J043115.8-711730 (hereafter J0431-71) was discovered as a part of this campaign, and we present here a deeper study of this source using XMM-Newton and SALT spectroscopy, long-term optical-infrared photometry using OGLE, ATLAS, ASAS-SN, WISE, and GAIA data. J0431-71 is a highly variable super-soft X-ray source, classified as a red giant with the GAIA color-magnitude diagram. The source exhibits: (a) a thermal X-ray spectrum with a temperature of kT$\sim$30 eV and a bright state luminosity of $3.2\times10^{37}$~erg~s$^{-1}$ in the 0.15-1 keV band, (b) Balmer emission lines, [Fe X] coronal line, HeII emission, and the Bowen fluorescence blend, (c) an optical and infrared periodicity of $\sim$500-560 days in phase with the X-ray-UV emission, (d) a 'redder-when-brighter' trend in the stellar emission with a $\sim$520 day period indicating a pulsating donor star. We argue that the observed spectral and temporal properties in J0431-71 are consistent with a high-accretion rate onto a white-dwarf via Roche-lobe overflow, making J0431-71 the first symbiotic source discovered in the Bridge.
CommentsAccepted for publication in MNRAS. in press
Journal refMon Not R Astron Soc (2026)
