Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases

Details Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases

Sep 2000

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000a%26a...361..614p&link_type=abstract

Astronomy and Astrophysics, v.361, p.614-628 (2000)

Astronomy and Astrophysics

Astrophysics

29

Stars: Coronae, Stars: Late-Type, X-Rays: Stars, Stars: Activity, Stars: Evolution

Scientific paper

We have investigated the variation of coronal X-ray emission during early post-main-sequence phases for a sample of 120 late-type stars within 100 pc, and with estimated masses in the range 1-3 Msun, based on Hipparcos parallaxes and recent evolutionary models. These stars were observed with the ROSAT/PSPC, and the data processed with the Palermo-CfA pipeline, including detection and evaluation of X-ray fluxes (or upper limits) by means of a wavelet transform algorithm. We have studied the evolutionary history of X-ray luminosity and surface flux for stars in selected mass ranges, including stars with inactive A-type progenitors on the main sequence and lower mass solar-type stars. Our stellar sample suggests a trend of increasing X-ray emission level with age for stars with masses M > 1.5 Msun, and a decline for lower-mass stars. A similar behavior holds for the average coronal temperature, which follows a power-law correlation with the X-ray luminosity, independently of their mass and evolutionary state. We have also studied the relationship between X-ray luminosity and surface rotation rate for stars in the same mass ranges, and how this relationships departs from the Lx ~ vrot2 law followed by main-sequence stars. Our results are interpreted in terms of a magnetic dynamo whose efficiency depends on the stellar evolutionary state through the mass-dependent changes of the stellar internal structure, including the properties of envelope convection and the internal rotation profile.

Affiliated with

Also associated with

No associations

Rating

Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases 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 Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1521896