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X-ray emission at the low-mass end - Results from an extensive Einstein Observatory survey

1993; IOP Publishing; Volume: 414; Linguagem: Inglês

10.1086/173127

1538-4357

Marco Barbera, G. Micela, S. Sciortino, Jr. Harnden F. R., R. Rosner,

Astronomical Observations and Instrumentation

view Abstract Citations (67) References (60) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS X-Ray Emission at the Low-Mass End: Results from an Extensive Einstein Observatory Survey Barbera, M. ; Micela, G. ; Sciortino, S. ; Harnden, F. R., Jr. ; Rosner, R. Abstract We have used available IPC data and a critical compilation of cataloged optical data to measure the 0.16-3.5 keV X-ray emission from 88 K and 169 M stars of luminosity classes IV, V, and VI within 25 pc from the Sun. The IPC detected 54 out of the 88 K stars, 70 out of the 138 M stars with M(v) less than 13.4, and 15 out of the 31 fainter M stars. We have identified a subsample of surveyed stars that is statistically representative of the population of K and M stars in the solar neighborhood. On the basis of this subsample (1) we have shown the occurrence of a drop in the level of X-ray emission for M stars later than approximately M5; (2) we have built unbiased maximum likelihood X-ray luminosity functions for the K, early M, and late M stars; (3) we have confirmed, both for K and M stars, the decrease of X-ray luminosity with increasing stellar age in the range of ages of disk population stars: and (4) we have shown that no obvious correlation is present between X-ray and bolometric luminosities in the entire representative samples of K and M stars, but only within flare stars which also seem to mark a saturation in X-ray luminosity level. Publication: The Astrophysical Journal Pub Date: September 1993 DOI: 10.1086/173127 Bibcode: 1993ApJ...414..846B Keywords: Emission Spectra; Late Stars; X Ray Sources; X Ray Stars; Heao 2; Proportional Counters; Sky Surveys (Astronomy); Solar Neighborhood; Stellar Luminosity; Stellar Rotation; Astrophysics; STARS: LATE-TYPE; X-RAYS: STARS full text sources ADS | data products CDS (1)