Sgr A*极端环境中的尘埃产生——MIRI/JWST对富氧渐近巨星分支星IRS~3的观测
Dust production in the harsh environment of Sgr A* - MIRI/JWST observation of the O-rich asymptotic giant branch star IRS~3
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中文总结 AI 辅助
本研究利用JWST/MIRI观测银心内秒差距区域的AGB星IRS 3，开展光谱分析以探究Sgr A*极端辐射环境对尘埃成分及银心物质循环的影响。
中文摘要 AI 辅助
对星际介质（ISM）的研究频繁发现渐近巨星分支（AGB）星包层产生的尘埃信号，表明ISM的尘埃成分与AGB星包层存在关联。研究银河系中心Sgr A*周围极端的辐射主导环境中的这种关系，可揭示这类条件如何影响尘埃成分及银心的物质循环。IRS 3是银心最亮的L波段源，也是银河系内秒差距范围内最突出的AGB星，其嵌入在估计半径约10000 AU的尘埃包层中。我们旨在开展全面的光谱分析，以更精确地约束紧邻Sgr A*的IRS 3包层内的尘埃成分和谱线发射物种。2025年，我们作为 guaranteed time observations（GTO）项目“Mid-Infrared Characterisation of Nearby Iconic galaxy Centres（MICONIC）”的一部分，使用詹姆斯·韦伯空间望远镜（JWST）上的中红外仪器（MIRI）观测了银河系的内秒差距区域；我们利用MIRI中分辨率光谱仪（MRS）研究了投影距离Sgr A*约0.17秒差距的AGB星IRS 3的光谱特征。
英文摘要
Studies of the interstellar medium (ISM) have frequently revealed signatures of the dust produced in the envelopes of asymptotic giant branch (AGB) stars, demonstrating a connection between the dust composition of the ISM and that of AGB stellar envelopes. Investigating this relationship in the extreme, radiation-dominated environment surrounding Sgr A*, the center of our own galaxy, reveals how such conditions might influence dust composition and the recycling of material in galactic centers. IRS 3, the brightest L band source in the Galactic center and most prominent AGB star within the inner parsec of the Milky Way, is embedded in a dusty envelope with an estimated radius of $\sim$10000 AU. We aim to conduct a comprehensive spectral analysis to more tightly constrain the dust composition and line-emitting species within the envelope of IRS 3 in the immediate vicinity of Sgr A*. In 2025, we observed the inner parsec of the Milky Way with the Mid-Infrared Instrument (MIRI) on board the James Webb Space Telescope (JWST) as part of the guaranteed time observations (GTO) program Mid-Infrared Characterisation of Nearby Iconic galaxy Centres (MICONIC). We used the MIRI Medium Resolution Spectrometer (MRS) to study the spectroscopic characteristics of the AGB star IRS 3, located about 0.17 parsecs in projection from Sgr A*.
