Further Simultaneous Observations of the Optical and X-Ray Spectra of SCO X-1

Abstract

Simultaneous observations have again been made of the fluctuating optical and X-ray emission from Sco X-1. Previous measurements and a discussion of possible correlation have been published. Two new measurements are reported here in which the optical intensity was relatively faint (B = 13.14 and 13.22 mag). The X-ray intensity was 2.5 X 1O~ and 2.2 X 1O~ erg cm2 sec' between 2 and 20 keV, and the apparent plasma temperatures (KT) were 7 and 5.5 keV. An extrapolation of the X-ray spec- trum was compared with the observed optical spectrum, yielding agreement. Parameters, viz., plasma radius and density and total energy flux, of a model previously proposed are inferred from the present data. It is noted that the total energy flux is greatest when the object is brightest