ASM 2000+25

R. Sunyaev and the Kvant Team, Space Research Institute, U.S.S.R. Academy of Sciences, report: "The MIR-Kvant Rontgen Observatory detected this x-ray nova on May 15 and 17 in the spectral band 4-250 keV. The Pulsar X1 Phoswich device discovered a hard power-law x-ray tail in the spectral band 20-250 keV with flux 0.5 E**-1.7 photons cm**-2 s**-1 keV**-1, where E is the photon energy measured in keV. The Hexe device discovered the same tail in the band 15-150 KeV. On May 17 the GSPC device detected the soft component of the spectrum in the band 4-15 keV. For a thermal bremsstrahlung model the best fit gives a plasma temperature of 1.86 +/- 0.05 keV. The soft component, which was reported earlier by the Ginga Team, corresponds to a luminosity of 3 x 10**36 erg/s for a distance of 1 kpc; the luminosity of the hard component is three times smaller. These values refer only to to the spectral bands mentioned above."