On the contribution of unresolved Galactic stars to the diffuse soft X-raybackground

Using stellar luminosity functions derived from ROSAT data, the contributio ns of Galactic stars to the diffuse X-ray background are calculated for ROS AT PSPC energy bands. The model follows that of Guillout and coworkers but uses ROSAT rather than Einstein data to determine the intrinsic luminosity distributions. The model adequately predicts the numbers of stellar sources observed in deep ROSAT surveys. The contribution of unresolved stellar sou rces to the ROSAT All-Sky Survey at the Galactic poles is 6.85, 4.76, and 4 .91 x 10(-6) counts s(-1) arcmin(-2) in bands R12 (1/4 keV), R45 (3/4 keV), and R67 (1.5 keV), respectively, which is equivalent to 4.66, 31.3, and 26 .9 x 10(-14) ergs cm(-2) s(-1) deg(-2).