TY - JOUR
T1 - An ALMA Survey of M-dwarfs in the Beta Pictoris Moving Group with two new debris disc detections
AU - Cronin-Coltsmann, Patrick F.
AU - Kennedy, Grant M.
AU - Kral, Quentin
AU - Lestrade, Jean François
AU - Marino, Sebastian
AU - Matrà, Luca
AU - Wyatt, Mark C.
N1 - Publisher Copyright:
© The Author(s) 2023.
PY - 2023/12/1
Y1 - 2023/12/1
N2 - 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 11.1+−37.34 per cent that rises to 23.1+−58.53 per 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.
AB - 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 11.1+−37.34 per cent that rises to 23.1+−58.53 per 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.
KW - circumstellar matter
KW - stars: individual: GJ 2006A and AT Mic
KW - submillimetre: planetary systems
UR - http://www.scopus.com/inward/record.url?scp=85177171509&partnerID=8YFLogxK
U2 - 10.1093/mnras/stad3083
DO - 10.1093/mnras/stad3083
M3 - Article
AN - SCOPUS:85177171509
SN - 0035-8711
VL - 526
SP - 5401
EP - 5417
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -