IUE observations of the Be stars HD 102567 (4U 1145-61), X Per and GAM Cas.
Hammerschlag-Hensberge, G.; Willis, A. J.; Wilson, R.; Lamers, H. J. G. L. M.; Howarth, I.; van den Heuvel, E. P. J.; Burger, M.; Whitelock, P. A.; Menzies, J.; de Loore, C.; Glencross, W.; van Dessel, E. L.; Sanford, P.
Netherlands, Belgium, United Kingdom, South Africa
Abstract
The first analysis of ultraviolet spectroscopic observation obtained with the IUE satellite of the Be stars HD 102567, X Per, and Gamma Cas, which all are associated with X-ray sources, is presented. The ultraviolet data for HD 102567 (4U 1145-61) consist of low-resolution spectra covering the wavelength range 1150-3200 A. The ultraviolet fluxes are consistent with a reddening of the source of E(B-V)=0.45 magnitude. For this source a complementary program of visible photometry and spectroscopy and X-ray photometry was carried out. During the IUE observations the source 4U 1145-61 was not detectable in X-rays while the spectroscopic observations show dramatic intensity variations of the lower Balmer lines. For the bright Be stars Gamma Cas and X Per high-resolution (0.2 A) ultraviolet spectra covering the wavelength range 1150-3200 A have been obtained. The asymmetric profiles of resonance lines which are present in the spectra of both Gamma Cas and X Per indicate mass loss rates of 7 x 10 to the -9th and 10 to the -8th solar masses/yr, respectively.