Spectroscopy of the Pistol and Quintuplet stars in the Galactic centre
Abstract
We present initial results of a spectroscopic study of the Pistol and of the cocoon stars in the Quintuplet Cluster. From ISOCAM CVF 5--17 μm spectroscopy of the field of the Pistol Star, we have discovered a nearly spherical shell of hot dust surrounding this star, a probable LBV. This shell is most prominent at λ >~ 12 μm, and its morphology clearly indicates that the shell is stellar ejecta. Emission line images show that most of the ionised material is along the northern border of this shell, and its morphology is very similar to that of the Pistol H ii region (Yusef-Zadeh & Morris, 1987). We thus confirm that the ionisation comes from very hot stars in the core of the Quintuplet Cluster. An SWS spectrum of the Pistol Nebula indicates a harder ionising radiation than could be provided by the Pistol Star, but which is consistent with ionisation from Wolf-Rayet stars in the Quintuplet Cluster. The CVF 5--17 μm spectra of the cocoon stars in the Quintuplet do not show any emission feature that could help elucidate their nature.
- Publication:
-
The Universe as Seen by ISO
- Pub Date:
- March 1999
- DOI:
- 10.48550/arXiv.astro-ph/9812046
- arXiv:
- arXiv:astro-ph/9812046
- Bibcode:
- 1999ESASP.427..723M
- Keywords:
-
- GALACTIC CENTRE;
- QUINTUPLET;
- PISTOL;
- LBVS;
- Astrophysics
- E-Print:
- 4 pages, 4 postscript figures, special macros iso98.sty and twocolumn.sty. For proceedings of "The Universe as seen by ISO" Symposium, Paris, Oct 98