An x-ray astronomy experiment consisting of three collimated proportional counters and an X-ray Sky Monitor (XSM) was flown aboard the Indian Satellite IRS-P3 launched on March 21, 1996 from SHAR range in India. The Satellite is in a circular orbit of 830 km altitude with an orbital inclination of 98° and has three axis stabilized pointing capability. Each pointed-mode Proportional Counter (PPC) is a multilayer, multianode unit filled with P-10 gas (90% Ar + 10% CH4) at 800 torr and having an aluminized mylar window of 25 micron thickness. The three PPCs are identical and have a field of view of 2°×2° defined by silver coated aluminium honeycomb collimators. The total effective area of the three PPCs is about 1200 cm2. The PPCs are sensitive in 2-20 keV band. The XSM consists of a pin-hole of 1 cm2 area placed 16 cm above the anode plane of a 32 cm×32 cm position sensitive proportional counter sensitive in 3-8 keV interval. The position of the x-ray events is determined by charge division technique using nichrome wires as anodes. The principal objective of this experiment is to carry out timing studies of x-ray pulsars, x-ray binaries and other rapidly varying x-ray sources. The XSM will be used to detect transient x-ray sources and monitor intensity of bright x-ray binaries. Observations of black-hole binary Cyg X-1 and few other binary sources were carried out in early May and July-August 1996 period. Details of the x-ray detector characteristics are presented and preliminary results from the observations are discussed.

We present the results of an rocket-borne observation of far-infrared [CII] line at 157.7 μm from the diffuse inter-stellar medium in the Ursa Major. We also introduce a part of results on the [CII] emission recently obtained by the IRTS, a liquid-helium cooled 15cm telescope onboard the Space Flyer Unit. From the rocket-borne observation we obtained the cooling rate of the diffuse HI gas due to the [CII] line emission, which is 1.3±0.2 × 10-26 ergss-1 H-1atom. We also observed appreciable [CII] emission from the molecular clouds, with average CII/CO intensity ratio of 420. The IRTS observation provided the [CII] line emission distribution over large area of the sky along great circles crossing the Galactic plane at I = 50° and I = 230°. We found two components in their intensity distributions, one concentrates on the Galactic plane and the another extends over at least 20° in Galactic latitude. We ascribe one component to the emission from the Galactic disk, and the another one to the emission from the local interstellar gas. The [CII] cooling rate of the latter component is 5.6 ± 2.2 ×10.