Studies on the pulsar and circumstellar ring of the supernova 1987A

点击翻译按钮获取中文摘要

The aim of this research is to study two new problems raised by SN1987A.These are : (1) the properties of a newly born pulsar (rotation and magnetic field) and its detectability, and (2) the origin and properties of the ring-like circumstellar matter discovered by the Hubble Space Telescope and the prediction of the collision between the supernova ejecta and the ring.(1). The light curves of 50-140keV hard X-rays observed with GRO (Compton Gamma-Ray Observatory) and the optical light curve, which has shown interesting behavior, have provided new materials for the radioactive elements and pulsar activity. I obtained the ^<57>Co/^<56>Co ratio and constraint on the pulsar luminosity. I also estimated the detectability of pulsar activity with ASCA.(2). I also carried out the 2D numerical simulation of the collision between the supernova ejecta and the circumstellar ring.Supernova 1993J which appeared in the neaby galaxy M81 has also provided new problems as SN 1987A.(1). For SN 1993J,I have also predicted that a new born pulsar can be observed with ASCA depending on its luminosity.(2) I also carried out the simulation of the collision between the supernova ejecta and circumstellar matter and calculated X-ray flux expected from hot plasmas formed in such a collision. The results have been compared with the observations by ASCA,ROSAT,and OSSE,from which I inferred the circumstellar matter densities and explosion energy.