Shock-generated X-Ray Emission in Radiatively Driven Winds: A Model for Tau Scorpii
Abstract
A one-dimensional radiation-hydrodynamics code is used to numerically investigate the structure and evolution of shocks in the winds of hot stars. Results are presented for the specific case of Tau Sco, a well-studied main-sequence B star for which there are X-ray data from the Einstien satellite's Solid State Spectrometer. A phenomenological radiative acceleration term and a mass-loss rate consistent with UV observations, are used to determine the time dependence of the temperatures within and X-ray emission from an isolated shock region. The driving acceleration leads to the formation of a two-component shock zone with 'forward' and 'reverse' shocks, each with their own characteristic temperature. A denser cold region forms between the two shocks, which could potentially account for the presence of narrow absorption features that are observed in the UV P Cygni profiles of many hot stars. The X-ray emission spectra from the shocks in the calculations are in good general agreement with two-temperature model fits to Einstein X-ray observations.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1989
- DOI:
- 10.1086/168197
- Bibcode:
- 1989ApJ...347.1090M
- Keywords:
-
- Early Stars;
- Shock Wave Propagation;
- Stellar Atmospheres;
- Stellar Winds;
- X Ray Astronomy;
- Magnetohydrodynamics;
- Stellar Models;
- X Ray Spectra;
- Astrophysics;
- SHOCK WAVES;
- STARS: EARLY-TYPE;
- STARS: INDIVIDUAL CONSTELLATION NAME: TAU SCORPII;
- STARS: WINDS;
- STARS: X-RAYS;
- X-RAYS: SPECTRA