X-RAY-OBSERVATION OF THE JOVIAN IMPACTS OF COMET SHOEMAKER-LEVY-9

An ASCA observation of the Jovian impact of the comet Shoemaker-Levy 9 is reported. Four impacts of H, L, Q1 and R were observed and four im pacts of B, C, G, and Q2 were observed within 60 minutes after their i mpacts. No significant flaring of X-ray emission was observed. Upper l imit X-ray fluxes of 90 % confidence level, averaged 5 minutes just af ter the impacts, were 2.4 x 10(-13) erg sec(-1) cm(-2), 3.5 X 10(-13) erg sec(-1) cm(-2), 1.6 X 10(-13) erg sec(-1) cm(-2) and 2.9 x 10(-13) erg sec(-1) cm(-2) for the impacts of H, L, Q1 and R, respectively, i n the 0.5(0.7 for H and Q1)-10 keV energy range. However, a hint of X- ray enhancement around Jupiter from July 17 to July 19 was detected wi th about 2 similar to 6 x 10(-14) erg sec(-1) cm(-2) in the 0.5-10 keV energy range.