An ALMA Survey of M-dwarfs in the Beta Pictoris Moving Group with two new debris disc detections
An ALMA Survey of M-dwarfs in the Beta Pictoris Moving Group with two new debris disc detections
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ALMA 对绘架座移动群中的 M 矮星进行的巡天，发现了两个新的碎片盘
DOI：
10.1093/mnras/stad3083
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发表时间：
2023
影响因子：
4.8
通讯作者：
Cronin-Coltsmann P
中科院分区：
文献类型：
--
作者：
Cronin-Coltsmann P
之前的远红外调查在他们的样本中发现了很少（如果有的话）M-矮星碎片盘。有人质疑 M 矮星盘是否比早期类型更不常见，或者低检测率是否源于这些研究可用的波长和灵敏度。高灵敏度、长波长的阿塔卡马大型毫米/亚毫米阵列 (ALMA) 可以揭示这个问题。本文介绍了在 7 波段 (880 μm) 处使用 ALMA 对年轻和附近的绘架座β移动群中的 M 型矮星进行的调查。从观测样本中，我们检测到两个新的亚毫米过量，它们可能构成 GJ 2006 A 和 AT Mic A 周围未解决的碎片盘，以及盘分数光度和温度的模型分布。从包括 AU Mic 在内的 36 个 M 矮星的科学样本中，我们发现椎间盘检出率为 4/36 或 11.1%，在进行完整性调整后升至 23.1%。我们得出的结论是，该检测率与 G 型和 K 型恒星周围圆盘的检测率一致，并且圆盘特性也可能与早期类型恒星一致。我们还得出结论，M 矮星拥有碎片盘的可能性并非较小，但它们的探测需要比以前采用的更长的波长和更高的灵敏度观测。
Previous surveys in the far-infrared have found very few, if any, M-dwarf debris discs among their samples. It has been questioned whether M-dwarf discs are simply less common than earlier types, or whether the low detection rate derives from the wavelengths and sensitivities available to those studies. The highly sensitive, long-wavelength Atacama Large Millimetre/submillimetre Array (ALMA) can shed light on the problem. This paper presents a survey of M-dwarf stars in the young and nearby Beta Pictoris Moving Group with ALMA at Band 7 (880 μm). From the observational sample, we detect two new sub-mm excesses that likely constitute unresolved debris discs around GJ 2006 A and AT Mic A and model distributions of the disc fractional luminosities and temperatures. From the science sample of 36 M-dwarfs including AU Mic, we find a disc detection rate of 4/36 or 11.1per cent that rises to 23.1per cent when adjusted for completeness. We conclude that this detection rate is consistent with the detection rate of discs around G- and K-type stars and that the disc properties are also likely consistent with earlier type stars. We additionally conclude that M-dwarf stars are not less likely to host debris discs, but instead their detection requires longer wavelength and higher sensitivity observations than have previously been employed.