Several objective prism spectra of objects known to have large ultraviolet or X-ray fluxes are discussed. A marked Balmer excess and H alpha emission are found in X Per(= 3U 0352 + 30) and in the similar Be star HD 200775. No Balmer discontinuity is detectable in HD 226868 (Cyg X-1) during the low X-ray states, in HZ 43 (MX 1313 + 29), and in the hot subluminous star BD + 37 deg 1977. Comparison with the far ultraviolet spectrum of this star (Carnochan et al., 1975) leads to the conclusion that the star is slightly reddened (EB-V = 0.15 plus or minus 0.05) with an optical-ultraviolet energy distribution close to a 100,000 K black-body.
Viotti, R., Altamore, A., Baratta, G.B. (1977). A Spectrophotometric Study of Ultraviolet and X-ray Sources with Objective Prism Plates. ASTRONOMY & ASTROPHYSICS, 61, 133-136.
A Spectrophotometric Study of Ultraviolet and X-ray Sources with Objective Prism Plates
ALTAMORE, Aldo;
1977-01-01
Abstract
Several objective prism spectra of objects known to have large ultraviolet or X-ray fluxes are discussed. A marked Balmer excess and H alpha emission are found in X Per(= 3U 0352 + 30) and in the similar Be star HD 200775. No Balmer discontinuity is detectable in HD 226868 (Cyg X-1) during the low X-ray states, in HZ 43 (MX 1313 + 29), and in the hot subluminous star BD + 37 deg 1977. Comparison with the far ultraviolet spectrum of this star (Carnochan et al., 1975) leads to the conclusion that the star is slightly reddened (EB-V = 0.15 plus or minus 0.05) with an optical-ultraviolet energy distribution close to a 100,000 K black-body.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
