|Speaker:||Hiroya Yamaguchi (RIKEN)|
|Title:||Recent studies on supernova nucleosynthesis with X-ray observations of supernova remnants|
|Date:||Thu, Aug 06, 2009, 13:30 - 14:30|
|Place:||Seminar Room at IPMU Prefab. B|
Most of the heavy elements in the present universe had been generated in stars, and were ejected to interstellar space by supernova (SN) explosions. Thus, we are motivated to study the nucleosynthesis and explosion mechanisms of SNe, in order to understand the chemical evolution of the universe. Since supernova remnants (SNRs) at the age of a few hundreds or thousands years are generally bright in X-ray band and dominated by the emission from ejecta, they provide fruitful information about the elements synthesized by the SNe.
I present recent results on the X-ray observations of SNRs in our Galaxy and in the Large Magellanic Cloud. In Type Ia SNRs, such as Tycho and SN1006, there are some evidences of the layered composition structure In which higher-Z elements are more concentrated toward the center of the remnant.
By contrast, in several core-collapse SNRs, for example, CasA and PupA, the abundance structure is somewhat complex; an asymmetric ejecta distribution and/or significant mixing effects are suggested.
This talk also presents recent Suzaku (the Japanese X-ray astronomy satellite) discoveries of low abundant elements, chromium and manganese, from several Type Ia SNRs. The manganese is the first element with odd mass number that has been discovered from Type Ia remnants. The abundance of such an element would depend on progenitor's metallicity.