6533b7defe1ef96bd1275d0b

RESEARCH PRODUCT

X-ray Flares of EV Lac: Statistics, Spectra, Diagnostics

Paola TestaDavid P. HuenemoerderNorbert S. SchulzRachel A. OstenJeremy J. DrakeFabio Reale

subject

PhysicsHigh Energy Astrophysical Phenomena (astro-ph.HE)Astrophysics::High Energy Astrophysical PhenomenaStellar atmosphereFluxFOS: Physical sciencesAstronomy and AstrophysicsAstrophysicsElectromagnetic radiationSpectral linelaw.inventionStarsAmplitudeSettore FIS/05 - Astronomia E AstrofisicaAstrophysics - Solar and Stellar AstrophysicsSpace and Planetary SciencelawPhysics::Space Physicsstars: activity stars: coronae stars: flare stars: individual: EV Lac X-rays: starsAstrophysics::Solar and Stellar AstrophysicsAstrophysics - High Energy Astrophysical PhenomenaStellar evolutionSolar and Stellar Astrophysics (astro-ph.SR)Flare

description

We study the spectral and temporal behavior of X-ray flares from the active M-dwarf EV Lac in 200 ks of exposure with the Chandra/HETGS. We derive flare parameters by fitting an empirical function which characterizes the amplitude, shape, and scale. The flares range from very short (<1 ks) to long (10 ks) duration events with a range of shapes and amplitudes for all durations. We extract spectra for composite flares to study their mean evolution and to compare flares of different lengths. Evolution of spectral features in the density-temperature plane shows probable sustained heating. The short flares are significantly hotter than the longer flares. We determined an upper limit to the Fe K fluorescent flux, the best fit value being close to what is expected for compact loops.

yearjournalcountryeditionlanguage
2010-06-13
10.1088/0004-637x/723/2/1558http://arxiv.org/abs/1006.2558