ASCA AND ROSAT OBSERVATIONS OF NRAO-140 AND IX-PERSEI

We report the results from observations of NRAO 140 carried out in the X-ray band using ROSAT and ASCA in 1992 and 1994. We find the source to be absorbed by an effective hydrogen column density of similar to 3 x 10(21) atoms cm(-2) during both epochs, consistent with the combine d atomic and molecular column inferred from radio measurements along t his line of sight through the Perseus cloud complex. We compare these results with previous X-ray absorption measurements and briefly commen t upon the origin of the excess absorption which has been seen toward this source. We find the ASCA spectrum of NRAO 140 is well described b y a power law of energy index alpha = 0.73 +/- 0.03 and also yields th e tightest constraint to date on Fe K-shell emission, with 90% confide nce upper limits of 38 and 31 eV for a narrow line at a rest frame ene rgy of 6.4 and 6.7 keV respectively. This, along with a lack of harden ing towards higher energies, suggests that either NRAO 140 is devoid o f cold reprocessing material, the reprocessing material has a geometry in which the imprinted features are weak, and/or the X-ray emission i s relativistically beamed towards us. We also report the detection of a serendipitous source in both the ASCA GIS and ROSAT fields of view. We identify this source as the binary star system IX Per and find its spectrum to be well fitted by a two-temperature Raymond-Smith plasma.