High Resolution Spectroscopy of the X-ray Photoionized Wind in Cygnus   X-3 with the Chandra High Energy Transmission Grating Spectrometer
  We present a preliminary analysis of the 1--10 keV spectrum of the massive X-ray binary Cyg X-3, obtained with the High Energy Transmission Grating Spectrometer on the Chandra X-ray Observatory. The source reveals a richly detailed discrete emission spectrum, with clear signatures of photoionization-driven excitation.   Among the spectroscopic novelties in the data are the first astrophysical detections of a number of He-like 'triplets' (Si, S, Ar) with emission line ratios characteristic of photoionization equilibrium, fully resolved narrow radiative recombination continua of Mg, Si, and S, the presence of the H-like Fe Balmer series, and a clear detection of a ~ 800 km/s large scale velocity field, as well as a ~1500 km/s FWHM Doppler broadening in the source. We briefly touch on the implications of these findings for the structure of the Wolf-Rayet wind. 
Frits Paerels, Jean Cottam, Masao Sako, Duane A. Liedahl, A. C.   Brinkman, R. L. J. van der Meer, J. S. Kaastra, P. Predehl