“Roles of Cosmic-Rays in Astrophysics: The History of Our Galaxy” / Jiro Shimoda (ICRR)


番号R5-6 /  IPMU/ILANCE/ICRR joint seminar
日時2023年7月10日(月) 15:30-
場所ICRR large seminar room + Zoom https://u-tokyo-ac-jp.zoom.us/j/87034284601?pwd=ZXFlNzFtcFE2Q0FqaUVWMUJQT2ZJdz09
講演者Jiro Shimoda (ICRR)
タイトル“Roles of Cosmic-Rays in Astrophysics: The History of Our Galaxy”
概要We study the long-term evolution of our galaxy over cosmic time by modeling the star formation, metallicity, cosmic-rays (CRs), outflows, and inflows of the galactic system to obtain various insights into the galactic evolution. Considering the consistencies between the observed Galactic diffuse X-ray emissions (GDXEs) and possible conditions to drive the Galactic wind by CRs, we find that the star formation rate becomes half of the mass accretion rate of the disk. The mass accretion of the disk is modeled by using the results of the dark matter N-body simulations. We find that if the gas accretion is characterized by the dark matter core radius, the rotation curve of the low-mass stars in our galaxy can be explained. These results simultaneously provide consistent amounts of metals and cosmic-rays with the current conditions of our galaxy. The most significant model predictions are that there is unidentified accretion flow with a possible number density of ∼ 0.01 /cc and the (part of) GDXEs originated from the diffuse plasma formed by consuming a roughly tenth of supernova explosion energy. The latter is the science case of future X-ray missions; XRISM, Athena, and JEDI. We also discuss further prospects of our results for the planet formation and observations of external galaxies in terms of multi-messenger astronomy.