A Spectroscopic Survey of a Sample of Active M Dwarfs

Details A Spectroscopic Survey of a Sample of Active M Dwarfs A Spectroscopic Survey of a Sample of Active M Dwarfs

2002-07-19

arxiv.org/abs/astro-ph/0207412v1

Astronomy and Astrophysics

Astrophysics

38 pages incl. 14 figures and 4 tables, plus 12 pages of table for electronic journal only; LaTeX, aastex.cls. Accepted 07/18/

Scientific paper

10.1086/343055

A moderate resolution spectroscopic survey of Fleming's sample of 54 X-ray selected M dwarfs with photometric distances less than 25 pc is presented. Radial and rotation velocities have been measured by fits to the H-alpha profiles. Radial velocities have been measured by cross correlation. Artificial broadening of an observed spectrum has produced a relationship between H-alpha FWHM and rotation speed, which we use to infer rotation speeds for the entire sample by measurement of the H-alpha emission line. We find 3 ultra-fast rotators (UFRs, vsini > 100km/s), and 8 stars with 30 < vsini < 100 km/s. The UFRs have variable emission. Cross-correlation velocities measured for ultra-fast rotators (UFRs) are shown to depend on rotation speed and the filtering used. The radial velocity dispersion of the sample is 17 km/s. A new double emission line spectroscopic binary with a period of 3.55 days has been discovered, and another known one is in the sample. Three other objects are suspected spectroscopic binaries, and at least six are visual doubles. The only star in the sample observed to have significant lithium is a known TW Hya Association member, TWA 8A. These results show that there are a number of young (< 10^8 yr) and very young (< 10^7 yr) low mass stars in the immediate solar neighbourhood. The H-alpha activity strength does not depend on rotation speed. Our fast rotators are less luminous than similarly fast rotators in the Pleiades. They are either younger than the Pleiades, or gained angular momentum in a different way.

Affiliated with

Also associated with

No associations

Rating

A Spectroscopic Survey of a Sample of Active M Dwarfs does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with A Spectroscopic Survey of a Sample of Active M Dwarfs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Spectroscopic Survey of a Sample of Active M Dwarfs will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-396911