Stellar Coronal Spectroscopy with the Chandra HETGS
Abstract
Spectroscopy with the Chandra High Energy Transmission Grating Spectrometer (HETGS) provides detail on coronal emission and activity through resolution of emission lines from a variety of ions. We are beginning to see trends in activity regarding abundances emission measures and variability. We have observed the long period system IM Pegasi (P=25d) to search for rotational modulation. We saw none but did see long-duration flares. We will present details on the variability emission measure and abundances in its corona. We expect to have preliminary results from HETGS spectroscopy of VW Cep (P=0.28d; scheduled in June'03) which is a partially eclipsing binary having high enough velocity amplitude to study Doppler shifts. This will help us determine coronal extent. In contrast to these active binaries TW Hya the only low mass Classical T Tauri star for which high resolution X-ray spectra have been obtained displays high densities and a relatively cool emission measure. We interpret its spectrum as due to accretion from its circumstellar disk. Observations of TV Crt (HD 98800) a weak-lined T Tauri star are forthcoming (March'03) and we will present preliminary results. The three objects under study will probe activity at long and short periods and in youthful environments.
- Publication:
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Stars as Suns : Activity, Evolution and Planets
- Pub Date:
- January 2004
- DOI:
- 10.48550/arXiv.astro-ph/0310319
- arXiv:
- arXiv:astro-ph/0310319
- Bibcode:
- 2004IAUS..219..238H
- Keywords:
-
- Astrophysics
- E-Print:
- 5 pages, 2 figures