ROSAT PSPC Observations of MBM 40 and MBM 55
Session 16 -- Molecular Clouds
Display presentation, Wednesday, January 12, 9:30-6:45, Salons I/II Room (Crystal Gateway)

## [16.07] ROSAT PSPC Observations of MBM 40 and MBM 55

T.J. Hearty, J-.P. Caillault, L. Magnani (University of Georgia), J.H.M.M. Schmitt (MPE Garching), D.N. Burrows (Pennsylvania State University), W.T. Sanders (University of Wisconsin)

We have analyzed ROSAT PSPC data in the regions of the translucent high latitude molecular clouds MBM 40 and MBM 55 in the hope of finding X-ray sources which might be tracers of recently formed pre-main sequence stars. Since small high density molecular cores have been found in these clouds, the possibility that these clouds may be forming low-mass stars is enhanced over those translucent molecular clouds without dense condensations. We have detected 18 X-ray sources from the ROSAT All-Sky Survey within a 15 square degree area centered on the IRAS 100$\mu$m contours of MBM 40 and 154 sources within a 112 square degree area on those of MBM 55. Deeper PSPC pointed observations ($\sim$7-9 ksec) of the high density cores in these clouds reveal 16 additional X-ray sources in MBM 40 and 16 additional X-ray sources in MBM 55. Our preliminary investigation indicates that 82 of these X-ray sources are either extragalactic or background or foreground stars. The remaining 122 may be viable PMS candidates but follow-up optical spectroscopy is required to identify their true nature.