Published in

Oxford University Press, Monthly Notices of the Royal Astronomical Society, 2(517), p. 2842-2854, 2022

DOI: 10.1093/mnras/stac2788

Links

Tools

Export citation

Search in Google Scholar

Spatially dependent photometric activity of M dwarfs in the solar cylinder

Journal article published in 2022 by Seo-Won Chang ORCID, Christian Wolf ORCID, Christopher A. Onken ORCID
This paper is made freely available by the publisher.
This paper is made freely available by the publisher.

Full text: Download

Green circle
Preprint: archiving allowed
Green circle
Postprint: archiving allowed
Green circle
Published version: archiving allowed
Data provided by SHERPA/RoMEO

Abstract

ABSTRACT We study the relationship between Galactic location (R, Z) and photometric activity for 3.6 million M dwarf stars within 1 kpc of the Sun. For this purpose, we identify 906 unique flare events as a proxy for magnetic activity from the SkyMapper Southern Survey Data Release 3. We adopt vertical distance |Z| from the Galactic disc as a proxy for age and confirm a strong trend of flaring fraction decreasing with growing stellar age. Among M dwarfs within 50 pc of the Sun, we find a flaring fraction of one in 1500, independent of spectral type from M2 to M7, suggesting that these stars are all in a flare-saturated young evolutionary stage. We find a hint of a kink in the slope of the overall flare fraction near 100 pc from the plane, where a steep decline begins; this slope change is visible for mid-type M dwarfs (M3–M5), suggesting it is not an artefact of mixing spectral type. Together with the Sloan Digital Sky Survey Hα emission, this trend is additional evidence that the activity fraction of M dwarfs depends on Galactic height and activity lifetime. While there is a hint of flattening of the overall activity fraction above |Z| ≈ 500 pc, our data do not constrain this further. Within ∼500 pc distance from the Sun, we find no sign of radial disc gradients in flare activity, which may only be revealed by samples covering a larger radial range.