Nucleosynthesis, Reionization, and the Mass Function of the First Stars
نویسندگان
چکیده
منابع مشابه
Nucleosynthesis, Reionization, and the Mass Function of the First Stars
We critique the hypothesis that the first stars were very massive stars (VMS; M > 140 M⊙). We review the two major lines of evidence for the existence of VMS: (1) that the relative metal abundances of extremely metal-poor Galactic halo stars show evidence of VMS enrichment, and (2) that the high electronscattering optical depth (τe) to the CMB found by WMAP requires VMS for reionization in a co...
متن کاملefl students gender and socioeconomic status: the use of politeness strategies in the first and second languages
within the components of communicative competence, a special emphasis is put on the “rules of politeness,” specifically the politeness strategies (brown and levinson, 1978) that speakers deploy when performing the request speech act. this is because the degree of imposition that making a request places upon one’s interlocutor(s) has been seen to be influenced by several factors among which, as ...
the analysis of the role of the speech acts theory in translating and dubbing hollywood films
از محوری ترین اثراتی که یک فیلم سینمایی ایجاد می کند دیالوگ هایی است که هنرپیش گان فیلم میگویند. به زعم یک فیلم ساز, یک شیوه متأثر نمودن مخاطب از اثر منظوره نیروی گفتارهای گوینده, مثل نیروی عاطفی, ترس آور, غم انگیز, هیجان انگیز و غیره, است. این مطالعه به بررسی این مسأله مبادرت کرده است که آیا نیروی فراگفتاری هنرپیش گان به مثابه ی اعمال گفتاری در پنج فیلم هالیوودی در نسخه های دوبله شده باز تولید...
15 صفحه اولNucleosynthesis in Intermediate Mass Stars
We discuss nucleosynthesis within 6 M models with Z = 0:02, 0:008 and 0:004. The emphasis is on the AGB phase of evolution, with particular reference to thermal pulses and Hot Bottom Burning. We nd strong CN cycling, with substantial Al production, especially at low metallicities.
متن کاملThe Very First Stars: Formation and Reionization of the Universe
One of the key challenges for the next 10 years is to understand the first sources of light, the first stars and possibly accreting black holes. Their formation ended the cosmic dark ages at redshifts z ! 20 − 30, and signaled the transition from the simple initial state of the universe to one of ever increasing complexity. We here review recent progress in understanding the formation process o...
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: 2004
ISSN: 0004-637X,1538-4357
DOI: 10.1086/422571