Document Type

Conference Proceeding

Publication Date


Published In

The High Energy Universe At Sharp Focus: Proceedings Of A Meeting Held In Conjunction With The 113th Annual Meeting Of The ASP


High-resolution X-ray spectra of high-mass stars and low-mass T-Tauri stars obtained during the first year of the Chandra mission are providing important clues about the mechanisms which produce X-rays on very young stars. For zeta Puppis (O4 If) and zeta Ori (O9.5 I), the broad, blue-shifted line profiles, line ratios, and derived temperature distribution suggest that the X-rays are produced throughout the wind via instability-driven wind shocks. For some less luminous OB stars, like theta^1 Ori C (O7 V) and tau Sco (B0 V), the line profiles are symmetric and narrower. The presence of time-variable emission and very high-temperature lines in theta^1 Ori C and tau Sco suggest that magnetically confined wind shocks may be at work. The grating spectrum of the classical T-Tauri star TW Hya is remarkable because the forbidden-line emission of He-like Ne IX and O VII is very weak, implying that the X-ray emitting region is very dense, n = 6E+12 cgs, or that the X-rays are produced very close to the ultraviolet hotspot at the base of an accretion funnel. ACIS light curves and spectra of flares and low-mass and high-mass young stellar objects in Orion and rho Ophiuchus further suggest that extreme magnetic activity is a general property of many very young stars.

Published By

Astronomical Society of the Pacific


E. M. Schlegel and S. D. Vrtilek


The High Energy Universe At Sharp Focus: A Symposium On Chandra Science

Conference Dates

July 15-18, 2001

Conference Location

St. Paul, MN


This work is freely available courtesy of the Astronomical Society of the Pacific
This work is a preprint retrieved from at arXiv:astro-ph/0109090..