Fragmentation of the Primordial Gas Clouds and the Lower Limit on the Mass of the First Stars

نویسندگان

  • HIDEYA UEHARA
  • HAJIME SUSA
  • RYOICHI NISHI
  • MASAKO YAMADA
  • TAKASHI NAKAMURA
چکیده

We discuss the fragmentation of primordial gas clouds in the universe after decoupling. Comparing the timescale of collapse with that of fragmentation, we obtain the typical mass of a fragment both numerically and analytically. We show that the estimated mass gives the minimum mass of a fragment that is formed from the primordial gas cloud and essentially determined by the Chandrasekhar mass. Subject headings: galaxies: formation—molecular processes— stars: formation

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Thermal and Dynamical Evolution of Primordial Gas Clouds On the Formation of First Luminous Objects

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 fragmentation, we can estimate the typical fragmentation scale. We propose the following scenario of the formation process of first luminous objects consisting of large number stars. First, by pancake collapse of the overdensi...

متن کامل

Primordial Star Formation under Far-Ultraviolet Radiation

Thermal and chemical evolution of primordial gas clouds irradiated with farultraviolet (FUV; hν < 13.6 eV) radiation is investigated. In clouds irradiated by intense FUV radiation, sufficient hydrogen molecules to be important for cooling are never formed. However, even without molecular hydrogen, if the clouds are massive enough, they start collapsing via atomic hydrogen line cooling. Such clo...

متن کامل

Effects of The Equation of State on the Formation of Star Clusters

We study the effect of varying the equation of state on the formation of stellar clusters in turbulent molecular clouds, using three-dimensional, smoothed particle hydrodynamics simulations. Our results show that the equation of state helps determine how strongly self-gravitating gas fragments. The degree of fragmentation decreases with increasing adiabatic index γ in the range 0.2 < γ < 1.4, a...

متن کامل

The thermal evolution of primordial gas clouds : A clue to galaxy formation

The thermal evolution of the primordial gas cloud is investigated. First, we study non-spherical primordial gas clouds of mass M = 10 6 M . We study two cases: 1) prolate and oblate clouds without angular momentum, 2) initially spherical, oblate and prolate clouds with angular momentum. In the spherical case, the magnitude of the angular momentum is the key quantity which determines the fragmen...

متن کامل

Binary Formation in Star-Forming Clouds with Various Metallicities

Cloud evolution for various metallicities is investigated by three-dimensional nested grid simulations, in which the initial ratio of rotational to gravitational energy of the host cloud β0 (= 10 –10) and cloud metallicity Z (= 0–Z⊙) are parameters. Starting from a central number density of nc = 10 4 cm, cloud evolution for 48 models is calculated until the protostar is formed (nc ≃ 10 23 cm) o...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 1996