Tenma [Astro B]
Mission OverviewTenma is the eighth Japanese scientific satellite from the Institute of Space and Astronautical Science (ISAS) and the second X-ray astronomy satellite after Hakucho. It was placed into a near circular orbit with a apogee of 501 km, a perigee of 497 km and an inclination angle of 31.5 degrees. Tenma was a spin-stabilized satellite and the FOV of the scientific payload was mostly aligned with the spin-axis (Z-axis). The main objective of Tenma was to perform spectral and temporal observations of galactic and extra-galactic sources with particular emphasis on energy spectra thanks to the improved energy resolution of the on-board instrumentation. The observing efficency was reduced greatly (only daytime operations) after the battery failed in July 1984. Observations continued intermittently until 11 November 1985, when operations were stopped because they were too inefficient. It re-entered on January 19 1989.InstrumentationTenma carried four high-energy experiments. They were:
ScienceThe main science result is the discovery (and/or study) of the iron line region in several classes of X-ray sources. In particular, it discovered such emission from low-mass X -ray binaries (LMXB) and from the galactic ridge. The spectral resolution allowed a distinction to be made from "cold" iron line emission at 6.4 keV believed to arise from X-rays impinging on cold matter and "hot" 6.6-6.7 keV iron emission believed to arise from a hot plasma. The "cold" line was found in pulsars and AGN; the "hot" line was found in LMXB and the galactic ridge.
Page authors: Lorella Angelini Jesse Allen HEASARC Home | Observatories | Archive | Calibration | Software | Tools | Students/Teachers/Public Last modified: Tuesday, 07-Oct-2003 11:15:49 EDT The Astrophysics Science Division (ASD) at NASA's Goddard Space Flight Center (GSFC) seeks a creative, innovative individual with strong teamwork and leadership skills to serve as Director of the High Energy Astrophysics Science Archive Research Center (HEASARC). This will be a permanent civil servant position. + Learn more. |