Study of Low Energy Gamma-Rays from Supernova Remnants (SM1987A) Abroard Balloons

我们已经有了气球-borne experiments in collaboration with the INPE （Institute of Space）研究)Brazilian balloon group. The major objectives are to launch large stratospheric balloonsand to observe hard X-rays/gamma-rays from astronomical objects such as SN1987A. The detectors wereprepared by the japanese group （Univ. of Tokyo）The launching operation was responsibility of The brazilian side while The radiocommunication was responsibility of the Japanese group.In 1988two balloons launched from Pocos de Caldas on November 24 and 28. One balloon （5x10 ^6ft^3）carried the hard X-ray detector (187kg) and the other (20x10 ^6ft^3) carried the gamma-ray detector（865公斤）.In the last two years，we moved to the INPE balloon base in Cachoerira Paulista (45 00 34w，22 39 44s).我们已经设置了一个通信条件，那是一个经常的campaign for several years。Using the facility我们已经launched balloons carring our new hard X-rays/gamma rays detector （Welcome1）Compound eye1, 670kg)).In 1989, one balloon (6.6X10^6ft^3) was launched on Dec. 22. Unfortunately，due to failure of the electronics in vacuum condition at the ceiling altitude，我们不能take scientific data. The star camera system， command system和其他设备，however worked well and gave us technical information on the detector.In 1990two balloons (6.6 and 8.8X10^6ft^3) were launched on Nov. 14 and Nov. 29. In the第一次飞行，我们无法控制我们的探测器due to failure of the telecommand system and tookbackground data. In the second flight，我们succeeded in observing SN1987A for about 4 hours. Data is now under analysis. The background Dataat the ceiling altitude shows that the sensitivities - a few X10^<-6>/cm^2/s/keV and - 10^<-4>/cm^2/sare attained for the continuum spectrum and line spectrum respectively.这些价值是关于5times superior to the previous type of detectors used in balloon-borne experiments。

We have carried out balloon-borne experiments in collaboration with the INPE (Institute of Space Research) Brazilian balloon group. The major objectives are to launch large stratospheric balloons and to observe hard X-rays/gamma-rays from astronomical objects such as SN1987A. The detectors were prepared by the japanese group (Univ. of Tokyo, ISAS and others). The launching operation was responsibility of the brazilian side while the radio communication was responsibility of the Japanese group.In 1988, two balloons were launched from Pocos de Caldas on November 24 and 28. One balloon (5X10^6ft^3) carried the hard X-ray detector (187kg) and the other (20X10^6ft^3) carried the gamma-ray detector (865 Kg).In the last two years, we moved to the INPE balloon base in Cachoerira Paulista (45 00 34W, 22 39 44S). We have set up a communication facility that allows frequent campaign for several years. Using the facility, we have launched balloons carring our new hard X-rays/gamma rays detector (Welcome1 (Well-type Compound Eye-1, 670kg)).In 1989, one balloon (6.6X10^6ft^3) was launched on Dec. 22. Unfortunately, due to failure of the electronics in vacuum condition at the ceiling altitude, we could not take scientific data. The star camera system, command system and other equipment, however worked well and gave us technical information on the detector.In 1990, two balloons (6.6 and 8.8X10^6ft^3) were launched on Nov. 14 and Nov. 29. In the first flight, we could not control the direction of our detector due to failure of the telecommand system and took background data. In the second flight, we succeeded in observing SN1987A for about 4 hours. Data is now under analysis. The background data at the ceiling altitude shows that the sensitivitiesーa few X10^<-6>/cm^2/s/keV and ー10^<-4>/cm^2/s are attained for the continuum spectrum and line spectrum respectively. These values are about 5 times superior to the previous type of detectors used in balloon-borne experiments.