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arXiv 2310.09355astro-ph.EPastro-ph.SR
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JWST观测到的首个白矮星碎片盘

The first white dwarf debris disk observed by JWST

Andrew Swan, Jay Farihi, Kate Y. L. Su, Steven J. Desch

AI总结:

本研究利用JWST首次获取白矮星碎片盘光谱,发现WD 0145+234的星周盘正从2018年碰撞事件恢复至静息态,硅酸盐特征稳定,还发现可能指示水蚀变的碳酸盐暂现特征。

摘要:

本快报报道了JWST(詹姆斯·韦布空间望远镜)对白矮星碎片盘的首次光谱观测,对其显著特征进行了初步评估,并为未来观测提出了建议。受污染的尘埃恒星WD 0145+234曾在2018年其星周盘中发生重大碰撞事件,伴随红外耀发,随后热辐射逐渐减弱。NIRSPEC(近红外光谱仪)时序观测表明,该星周盘正恢复到静息状态,其~1000 K的红外超与大部分已知尘埃白矮星的情况相似。MIRI(中红外仪器)光谱揭示出9-12微米的固态发射特征,与通过Spitzer IRS(斯皮策空间望远镜红外摄谱仪)观测到的碎片盘中的硅酸盐矿物特征一致。间隔一年以上拍摄的光谱中,硅酸盐特征的强度和形态相对于连续谱未发生变化,这与星周碎片的稳态碰撞演化相符。7微米附近存在一个暂现的发射特征,可能由碳酸盐导致,若得到证实将表明其母体曾发生水蚀变。

英文摘要:

This letter reports the first JWST spectroscopy of a white dwarf debris disk, giving a preliminary assessment of the salient features, and recommendations for future observations. The polluted and dusty star WD 0145+234 experienced a major collisional event in its circumstellar disk in 2018, accompanied by an infrared outburst, and subsequently a gradual decrease in thermal emission. Time-series NIRSPEC observations demonstrate that the circumstellar disk is returning to a quiescent state with a T~1000 K infrared excess similar to the bulk of known dusty white dwarfs. MIRI spectroscopy reveals a 9-12 micron solid-state emission feature consistent with silicate minerals as observed in debris disks observed with Spitzer IRS. The strength and morphology of the silicate feature appear unchanged relative to the continuum in spectra taken over a year apart, consistent with steady-state collisional evolution of the circumstellar debris. A tentative emission feature around 7 microns may be due to carbonates, and if confirmed would indicate aqueous alteration in the parent body.

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。

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