Abscess in the Posterior Mediastinum.

[ITAL]RXTE[/ITAL] Observations of the B[CLC]e[/CLC] Star X-Ray Transient X0726−260 (4U 0728−25): Orbital and Pulse Periods

“…The spectrum that we find from the PCA is typical of X-ray pulsars. The hydrogen column density at 1.1± 0.3 ×10 22 cm −2 , while not strongly constrained, is somewhat higher than but broadly consistent with, the estimates of 0.35±0.02 and 0.44±0.12 × 10 22 cm −2 derived by Negueruela et al (1996) and Corbet & Mason (1984) respectively from measurements of optical reddening.…”

“…The transient X-ray source X0726−260 (=4U0728-25, 3A0726-260) has a Be star optical counterpart that was optically identified by Steiner et al (1984). This star was classified as B0Ve by Corbet & Mason (1984) with a corresponding distance of 4.6±1.3 kpc. Negueruela et al (1996), however, derive a slightly earlier spectral type of O8-9Ve with a distance of 6.1±0.3 kpc.…”