Contraints on the Velocity and Spatial Distribution of Helium-like Ions in the Wind of SMC X-1 from Observations with XMM/RGS
Abstract
We present here X-ray spectra of the HMXB SMC X-1 obtained in an observation with the XMM-Newton observatory beginning before eclipse and ending near the end of eclipse. With the Reflection Grating Spectrometers (RGS), we resolve the emission line triplets of nitrogen, oxygen, neon, and magnesium but detect flux only from the intercombination lines of those triplets. From the fluxes of the lines of these triplets, we derive constraints on the distribution of helium-like ions in coordinate and velocity space. Among other results, we find upper limits of order 1 km s-1 for the product of the velocity dispersion of the ions and the solid angle divided by 4π subtended at the neutron star by the helium-like ions.
- Publication:
-
AAS/High Energy Astrophysics Division #8
- Pub Date:
- August 2004
- Bibcode:
- 2004HEAD....8.1712W