Investigation of astrophysical origin of p-nuclei

Hayakawa, Takehito; Iwamoto, Nobuyuki  ; Kajino, Toshitaka*; Shizuma, Toshiyuki; Umeda, Hideyuki*; Nomoto, Kenichi*

About 99% of nuclides heavier than an iron group were dominantly synthesized by neutron capture nucleosynthesis processes. In contrast, there is 35 p-nuclei, which cannot be synthesized by the neutron capture reactions. Among the 35 p-nuclei, evidence that 27 p-nuclei are synthesized by photon-induced reactions in supernova explosions was found. However, the origin of the other 8 p-nuclei has been remained as an open question. Here we discuss the method to understand these origin by using astronomical observation and meteorite analyses. We suggest a primitive meteorite analysis for the study of Mo, Ru, and Sm origins. Since Mo and Ru (Sm) locate near the neutron magic number of N=50 (82), their origins may be correlated. There are two isotopes of In-113 and In-115 and astronomical observation of these two isotope ratio is useful for understanding the origin of these nuclei.