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arXiv 2402.15438astro-ph.EPastro-ph.SR
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新发现的极端碎片盘中揭示出丰富的亚微米颗粒

Abundant sub-micron grains revealed in newly discovered extreme debris discs

A. Moór, P. Ábrahám, K. Y. L. Su, T. Henning, S. Marino, L. Chen, Á. Kóspál, N. Pawellek, J. Varga, K. Vida

AI总结:

本文通过小规模巡天新发现四个极端碎片盘,并结合VLT/VISIR测光证实八个EDD均显示亚微米颗粒的10μm固态发射特征,提出双星伴星可能触发较老系统中的晚期巨型碰撞。

摘要:

极端碎片盘(EDDs)是主序星周围明亮且温暖的星周尘埃结构。它们可能代表了在类地行星区域中大型星子或行星体之间发生的巨型碰撞的结果,因此为窥探这些事件之后的情形提供了难得的机会。在此,我们报告一项小规模巡天的结果,其目的是增加已知EDD的数量,研究八个EDD中约10μm处的固态特征是否存在,并将它们归类为二氧化硅主导或硅酸盐主导的组别。我们识别出四个新的EDD,并推导出它们的基本性质。对于这些天体以及另外四个先前已知的盘,我们利用VLT/VISIR在三个窄带滤光片中的测光来研究约10μm处的光谱能量分布,并得出结论:所有八个天体很可能都表现出来自亚微米颗粒的固态发射特征。我们发现其中四个盘可能属于硅酸盐主导的子类。考虑到整个EDD样本的年龄分布,我们发现它们的出现率仅在300 Myr之后才开始下降,这表明早期普遍认为这些天体与岩质行星形成有关的图景可能并非唯一,并且对于较老的天体(>100 Myr)可能涉及其他过程。由于大多数较老的EDD系统具有宽轨道、偏心的伴星,我们提出双星性可能在触发晚期巨型碰撞中发挥作用。

英文摘要:

Extreme debris discs (EDDs) are bright and warm circumstellar dusty structures around main sequence stars. They may represent the outcome of giant collisions occuring in the terrestrial region between large planetesimals or planetary bodies, and thus provide a rare opportunity to peer into the aftermaths of these events. Here, we report on results of a mini-survey we conducted with the aim to increase the number of known EDDs, investigate the presence of solid-state features around 10μm in eight EDDs, and classify them into the silica or silicate dominated groups. We identify four new EDDs and derive their fundamental properties. For these, and for four other previously known discs, we study the spectral energy distribution around 10μm by means of VLT/VISIR photometry in three narrow-band filters and conclude that all eight objects likely exhibit solid-state emission features from sub-micron grains. We find that four discs probably belong to the silicate dominated subgroup. Considering the age distribution of the entire EDD sample, we find that their incidence begins to decrease only after 300 Myr, suggesting that the earlier common picture that these objects are related to the formation of rocky planets may not be exclusive, and that other processes may be involved for older objects (>100 Myr). Because most of the older EDD systems have wide, eccentric companions, we suggest that binarity may play a role in triggering late giant collisions.

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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