The Debris Disk Fraction for M-dwarfs in Nearby, Young, Moving Groups

TL;DR

This study measures debris disk occurrence around M-dwarfs in nearby young moving groups, finding a low fraction in groups younger than 40 million years and none in older groups, suggesting rapid disk dissipation.

Contribution

First comprehensive measurement of debris disk fraction for M-dwarfs in nearby moving groups, highlighting rapid disk dissipation compared to higher-mass stars.

Findings

Debris disk fraction is less than 6% in groups younger than 40 Myr.

No debris disks detected in groups older than 40 Myr.

Debris disks around M-dwarfs dissipate faster than around higher-mass stars.

Abstract

I present the first substantial work to measure the fraction of debris disks for M-dwarfs in nearby moving groups (MGs). Utilising the $AllWISE$ IR catalog, 17 out of 151 MG members are found with an IR photometric excess indicative of disk structure. The M-dwarf debris disk fraction is $\lesssim 6$ per cent in MGs younger than 40\,Myr, and none are found in the groups older than 40\,Myr. Simulations show, however, that debris disks around M-dwarfs are not present above a $WISE$ $W1-W4$ colour of $\sim 2.5$, making calculating the absolute disk fractions difficult. The debris disk dissipation timescale appears to be faster than for higher-mass stars, and mechanisms such as enhanced stellar wind drag and/or photoevaporation could account for the more rapid decline of disks observed amongst M-dwarfs.