The β Pictoris circumstellar disk. XX. Some physical parameters of the gaseous component.
Abstract
New high resolution spectra of β Pictoris have been acquired in the Ca ii triplet lines, arising from the 3D metastable level. In addition to the central circumstellar component at the stellar velocity, we also unambiguously detected redshifted features. These variable components have an unexpected intensity, relatively to the associated absorption measured in the K and H lines, arising from the ground level of Ca ii. In order to realize the observed fractional population [Ca ii]/Ca ii, a simple model of the 3D levels populating processes, including radiative and collisional processes give some constraints on the physical conditions in the observed gas : most of the central absorption occurs in a confined area within 10AU of the star, as already established in Hobbs et al. (???), but also the infalling gas reaches locally high electronic densities and temperatures (T_e_>=15000K and N_e_>=10^6^cm^-3^).
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- May 1995
- Bibcode:
- 1995A&A...297..175M
- Keywords:
-
- Line Spectra;
- Stellar Envelopes;
- Stellar Models;
- Stellar Spectra;
- Abundance;
- Disk Galaxies;
- Gas Flow;
- Red Shift;
- Stability;
- Astrophysics;
- STARS: CIRCUMSTELLAR MATTER;
- STARS: {BETA} PICTORIS