X-Ray Spectroscopy of η Carinae with XMM-Newton
Abstract
We present XMM-Newton observations of the luminous star η Carinae, including a high-resolution soft X-ray spectrum of the surrounding nebula obtained with the Reflection Grating Spectrometer (RGS). The European Photon Imaging Camera (EPIC) image of the field around η Car shows many early-type stars and diffuse emission from hot, shocked gas. The EPIC spectrum of the star is similar to that observed in previous X-ray observations and requires two temperature components. The RGS spectrum of the surrounding nebula shows K-shell emission lines from hydrogen- and helium-like nitrogen and neon and L-shell lines from iron but little or no emission from oxygen. The observed emission lines are not consistent with a single temperature, but the range of temperatures observed is not large, spanning ~0.15-0.6 keV. We obtain upper limits for oxygen line emission and derive a lower limit of N/O>9. This is consistent with previous abundance determinations for the ejecta of η Car and with theoretical models for the evolution of massive, rotating stars.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 2003
- DOI:
- 10.1086/346183
- arXiv:
- arXiv:astro-ph/0209087
- Bibcode:
- 2003ApJ...585.1015L
- Keywords:
-
- Stars: Abundances;
- Stars: Individual: Constellation Name: η Carinae;
- Techniques: Spectroscopic;
- X-Rays: Stars;
- Astrophysics
- E-Print:
- 20 pages, 8 figures, accepted by ApJ