文章基本信息

标题：HADES RV Programme with HARPS-N at TNG
其他标题：X. The non-saturated regime of the stellar activity–rotation relationship for M dwarfs★
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作者：E. González-Álvarez ; G. Micela ; J. Maldonado 等
期刊名称：Astronomy & Astrophysics
印刷版ISSN：0004-6361
电子版ISSN：1432-0746
出版年度：2019
卷号：624
DOI：10.1051/0004-6361/201834386
语种：English
出版社：EDP Sciences
摘要：Aims.We extend the relationship between X-ray luminosity (Lx) and rotation period (Prot) found for main-sequence FGK stars, and test whether it also holds for early M dwarfs, especially in the non-saturated regime (Lx∝Prot−2) which corresponds to slow rotators.Methods.We use the luminosity coronal activity indicator (Lx) of a sample of 78 early M dwarfs with masses in the range from 0.3 to 0.75M⊙from the HArps-N red Dwarf Exoplanet Survey (HADES) radial velocity (RV) programme collected from ROSAT andXMM-Newton. The determination of the rotation periods (Prot) was done by analysing time series of high-resolution spectroscopy of the Ca IIH & K and Hαactivity indicators. Our sample principally covers the slow rotation regime with rotation periods from 15 to 60 days.Results.Our work extends to the low mass regime the observed trend for more massive stars showing a continuous shift of theLx∕LbolversusProtpower law towards longer rotation period values, and includes a more accurate way to determine the value of the rotation period at which the saturation occurs (Psat) for M dwarf stars.Conclusions.We conclude that the relations between coronal activity and stellar rotation for FGK stars also hold for early M dwarfs in the non-saturated regime, indicating that the rotation period is sufficient to determine the ratioLx∕Lbol.
关键词：Key wordsenstars: activitystars: low-massstars: rotation