A Chandra/LETGS survey of main-sequence stars
The Astrophysical Journal, 2018•iopscience.iop.org
We analyze the X-ray spectra of 19 main-sequence stars observed by Chandra using its
LETGS configuration. Emission measure (EM) distributions are computed based on
emission line measurements, an analysis that also yields evaluations of coronal
abundances. The use of newer atomic physics data results in significant changes compared
to past published analyses. The stellar EM distributions correlate with surface X-ray flux (FX)
in a predictable way, regardless of spectral type. Thus, we provide EM distributions as a …
LETGS configuration. Emission measure (EM) distributions are computed based on
emission line measurements, an analysis that also yields evaluations of coronal
abundances. The use of newer atomic physics data results in significant changes compared
to past published analyses. The stellar EM distributions correlate with surface X-ray flux (FX)
in a predictable way, regardless of spectral type. Thus, we provide EM distributions as a …
Abstract
We analyze the X-ray spectra of 19 main-sequence stars observed by Chandra using its LETGS configuration. Emission measure (EM) distributions are computed based on emission line measurements, an analysis that also yields evaluations of coronal abundances. The use of newer atomic physics data results in significant changes compared to past published analyses. The stellar EM distributions correlate with surface X-ray flux (F X) in a predictable way, regardless of spectral type. Thus, we provide EM distributions as a function of F X, which can be used to estimate the EM distribution of any main-sequence star with a measured broadband X-ray luminosity. Comparisons are made with solar EM distributions, both full-disk distributions and spatially resolved ones from active regions (ARs), flares, and the quiet Sun. For moderately active stars, the slopes and magnitudes of the EM distributions are in excellent agreement with those of solar ARs for
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