The cooling of shock-compressed primordial gas
نویسندگان
چکیده
منابع مشابه
The cooling of shock-compressed primordial gas
We find that at redshifts z > ∼ 10, HD line cooling allows strongly-shocked primordial gas to cool to the temperature of the cosmic microwave background (CMB). This temperature is the minimum value attainable via radiative cooling. Provided that the abundance of HD, normalized to the total number density, exceeds a critical level of ∼ 10, the CMB temperature floor is reached in a time which is ...
متن کاملH D 3 cooling in primordial gas
Simulations of the thermal and dynamical evolution of primordial gas typically focus on the role played byH2 cooling. H2 is the dominant coolant in low-density primordial gas and it is usually assumed that it remains dominant at high densities. However, H2 is not an effective coolant at high densities, owing to the low critical density at which it reaches local thermodynamic equilibrium and to ...
متن کاملH 2 -cooling of Primordial Gas Triggered by Uv Irradiation
We investigate the formation of molecular hydrogen (H 2) in a primordial H+He gas cloud irradiated by a power-law UV ux. We nd that at high densities (> 1 cm 3) and low temperatures (< 10 4 K), the background radiation enhances the formation of H 2 and results in molecular cooling dominating over photoionization heating. This process could accelerate the collapse and fragmentation of dense obje...
متن کاملIs H+3 cooling ever important in primordial gas?
Studies of the formation of metal-free Population III stars usually focus primarily on the role played by H2 cooling, on account of its large chemical abundance relative to other possible molecular or ionic coolants. However, while H2 is generally the most important coolant at low gas densities, it is not an effective coolant at high gas densities, owing to the low critical density at which it ...
متن کاملRadiative cooling functions for primordial molecules
Cooling of primordial gas plays a crucial role in the birth of the first structures in our Universe. Due to the low fractional abundance of molecular species at high redshifts, spontaneous emission rather than collisions represents the most efficient way to cool the pristine plasma. In the present work, radiative cooling functions are evaluated for the diatomic species HD, HD+, HeH+, LiH and Li...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 2006
ISSN: 0035-8711,1365-2966
DOI: 10.1111/j.1365-2966.2005.09846.x