Query : 2009A&A...505..755R

2009A&A...505..755R - Astronomy and Astrophysics, volume 505, 755-762 (2009/10-2)

The X-ray spectrum of the classical TTauri star TW Hydrae observed by LETGS aboard Chandra.


Abstract (from CDS):

I present the analysis of the X-ray spectrum of the classical TTauri star TW Hydrae, and determine emission measure distributions, elemental abundances, electron temperatures, densities, and line fluxes. TW Hya was observed in the wavelength range 5-175Å by CHANDRA-LETGS. I performed a multi-temperature fit, based on a collisional ionisation equilibrium (CIE) model for optically thin plasmas. I measured line fluxes by fitting a Gaussian line profile, folded through the response matrix, to the observed line features and I applied these values to establish plasma properties. No line features were established in the spectrum above 40Å. Due to the absence of line features above 40Å NH is calculated to be somewhat higher than assumed so far. The observed ``coronal'' temperature covers a range from about 1.5 to 20MK. The abundance pattern shows a very strong enhancement of Ne and some enhancement of N. From forbidden-intercombination line ratios of OVII and of NeIX I obtain a value for the electron density of ne≃1012cm–3. This is higher than the value for electron densities in coronal plasmas of older late type main-sequence stars. A blackbody component was added to describe the shape of the continuum around 15Å better. The emitted X-ray luminosity is in the order of 1030erg/s.

Abstract Copyright:

Journal keyword(s): techniques: spectroscopic - stars: individual: TW Hya - stars: coronae

Simbad objects: 2

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Number of rows : 2
N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2023
1 * alf Aur SB* 05 16 41.35871 +45 59 52.7693 1.33 0.88 0.08 -0.52 -0.96 G3III: 1167 0
2 V* TW Hya TT* 11 01 51.9053285064 -34 42 17.033218380   11.94 10.50 10.626 9.18 K6Ve 1810 1

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