Probing activity and rotation of M dwarfs with X-rays and photometric timeseries
Abstract
The activity-rotation relation of M dwarfs provides observational evidence of the stellar dynamo,which is poorly understood for fully convective stars. It is known that the X-ray activity-rotationrelation has a two-regime behavior with saturation for faster rotating stars and with a Lx decreasefor slower rotation. However, the number of M dwarfs with sensitive X-ray and rotation measure-ments has for a long time been very limited. New XMM-Newton, Chandra and eROSITA X-ray observationswith K2 mission and TESS rotation periods analyzed in my work have substantially increased the numberof low activity and fast/slow rotation stars that have been dicult to assess in the past. Combiningthe new data with a systematic update and homogenization of the literature data has enabledme to examine the activity-rotation relation in different mass bins within the M dwarf regime.Several interesting findings emerged, including a non-constant Lx-level in the saturated regime and amass-dependence of the slope in the unsaturated regime.
- Publication:
-
The 20.5th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun (CS20.5)
- Pub Date:
- March 2021
- DOI:
- 10.5281/zenodo.4562059
- Bibcode:
- 2021csss.confE..52M