Tsukuba Uchu Forum

123rd Uchu Forum


A multifaceted study of the remnants of first stars

Takanobu Kirihara

University of Tsukuba, Center for Computational Sciences


The first stars play a particularly important role in the history of the universe because they are the first luminous objects in our universe and the first to produce heavy elements. However, no direct observational traces of them have yet been obtained. Now, the operation of a new generation of multi-wavelength instruments is underway, and we are at the stage where the discovery of the remnants of the first stars is imminent. In addition, the detection of gravitational wave events by the gravitational wave interferometers LIGO and VIRGO has ushered in a new era in which gravitational waves are used as discovery tools. Therefore, there is an urgent need to deepen our understanding of first stars by connecting theory and observation. In this study, we approach the problem from various angles from the theoretical point of view toward the observational demonstration of detecting the remnants first stars.

The studies presented in this talk focus on the following three points:

  1. Discriminability of heavy elements ejected by supernova explosions of massive first stars in the low-redshift intergalactic medium.
  2. Evolution and coalescence of first stellar binary stars in the protostellar stage, which is expected to be the origin of gravitational wave sources.
  3. Pollution of stellar surfaces of low-mass first stars by interstellar matter.