6 papers
Thermal and Dynamical Evolution of Primordial Gas Clouds - On the Formation of First Luminous Objects -
Ryoichi Nishi, Hajime Susa, Hideya Uehara +2
We investigate the thermal and dynamical evolution of primordial gas clouds in the universe after decoupling. Comparing the time-scale of dynamical evolution with that of fragmenta…
Evolution of Primordial Protostellar Clouds --- Quasi-Static Analysis ---
Kazuyuki Omukai, Ryoichi Nishi, Hideya Uehara +1
The contraction processes of metal-free molecular clouds of starlike mass (or cloud cores) are investigated. We calculate radiative transfer of the H_2 lines and examine quasi-stat…
The Thermal Evolution of the Postshock Layer in Pregalactic Clouds
Hajime Susa, Ryoichi Nishi, Hideya Uehara +1
We re-examine the thermal evolution of the postshock layer in primordial gas clouds. Comparing the time scales, we find that the evolutionary paths of postshock regions in primordi…
The Minimum Mass of the First Stars and the Anthropic Principle
Takashi Nakamura, Hideya Uehara, Takeshi Chiba
The lower limit of the mass of the first stars suggested recently may imply the formation of massive stars of mass greater than 8 solar mass irrespective of the details of the init…
Fragmentation of the Primordial Gas Clouds and the Lower Limit on the Mass of the First Stars
Hideya Uehara, Hajime Susa, Ryoichi Nishi +2
We discuss the fragmentation of primordial gas clouds in the universe after decoupling. Comparing the time scale of collapse with that of fragmentation, we obtain the typical mass…
The fragment mass scale of the primordial gas clouds I
Hajime Susa, Hideya Uehara, Ryoichi Nishi
We investigated the thermal evolution of non-spherical primordial gas clouds of mass . We studied two cases: 1) prolate and oblate clouds without angular momentum,…