Ther‐Process in the Early Galaxy
نویسندگان
چکیده
منابع مشابه
The R-process in the Early Galaxy
We report Sr, Pd and Ag abundances for a sample of metal-poor field giants and analyze a larger sample of Y, Zr, and Ba abundances. The [Y/Zr] and [Pd/Ag] abundance ratios are similar to those measured for the r-process-rich stars CS 22892-052 and CS 31082-001. The [Pd/Ag] ratio is larger than predicted from the solar-system r-process abundances. The constant [Y/Zr] and [Sr/Y] values in the fie...
متن کاملThe Astrophysics of Early Galaxy Formation
Hydrogen in the universe recombined about half a million years after the Big Bang, and cooled down to a temperature of a few kelvins until the first non-linearities developed, and evolved into stars, galaxies, and black holes that lit up the universe again. In currently popular cold dark matter flat cosmologies (ΛCDM), some time beyond a redshift of 10 the gas within halos with virial temperatu...
متن کاملImplications for Early Galaxy Assembly
We present an analysis of the structures, sizes, star formation rates, and local environmental properties of galaxies at z ∼ 4 − 6 (τuniverse < 2 Gyr), utilising deep Hubble Space Telescope imaging of the Hubble Ultra Deep Field. The galaxies we study are selected with the Lyman-break drop-out technique, using galaxies which are B-,V-, and i−drops, which effectively selects UV bright starbursti...
متن کاملSimulations of Early Galaxy Formation
We present the predictions for the photometric and emission line properties of galaxies present during the latter stages of reionization from z = 8 → 6. These preliminary predictions are made from cosmological hydrodynamic simulations that include star formation and feedback, but not the effects of radiative transfer. We find significant numbers of galaxies that have stellar masses exceeding 10...
متن کاملEarly Preheating and Galaxy Formation
Winds from pregalactic starbursts and ‘miniquasars’ may pollute the intergalactic medium (IGM) with metals and raise its temperature to a much higher adiabat than expected from photoionization, and so inhibits the formation of early galaxies by increasing the cosmological Jeans mass. We compute the thermal history of the IGM when it experiences a period of rapid, homogeneous “preheating” at hig...
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: The Astrophysical Journal
سال: 2002
ISSN: 0004-637X,1538-4357
DOI: 10.1086/342829