Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
The implications of the new Z=0 stellar models and yields on the early metal pollution of the intergalactic medium
Autore:
Abia, C; Dominguez, I; Straniero, O; Limongi, M; Chieffi, A; Isern, J;
Indirizzi:
Univ Granada, Dept Fis Teor & Cosmos, E-18071 Granada, Spain Univ GranadaGranada Spain E-18071 Teor & Cosmos, E-18071 Granada, Spain Osserv Astron Collurania, I-64100 Teramo, Italy Osserv Astron Collurania Teramo Italy I-64100 nia, I-64100 Teramo, Italy Osserv Astron Roma, I-00040 Monte Porzio Catone, Italy Osserv Astron RomaMonte Porzio Catone Italy I-00040 orzio Catone, Italy CNR, Inst Astrophys Spaziale, I-00133 Rome, Italy CNR Rome Italy I-00133CNR, Inst Astrophys Spaziale, I-00133 Rome, Italy CSIC, Inst Estudis Espacias Catalunya, Barcelona, Spain CSIC Barcelona Spain Inst Estudis Espacias Catalunya, Barcelona, Spain
Titolo Testata:
ASTROPHYSICAL JOURNAL
fascicolo: 1, volume: 557, anno: 2001,
parte:, 1
pagine: 126 - 136
SICI:
0004-637X(20010810)557:1<126:TIOTNZ>2.0.ZU;2-5
Fonte:
ISI
Lingua:
ENG
Soggetto:
LYMAN-ALPHA FOREST; HUBBLE DEEP FIELD; POOR STARS; METALLICITY EVOLUTION; OXYGEN ABUNDANCES; EARLY UNIVERSE; HIGH-REDSHIFT; WHITE-DWARFS; LOWER LIMIT; HALO;
Keywords:
galaxies : abundances; galaxies : formation; galaxies : intergalactic medium; nuclear reactions, nucleosynthesis, abundances stars : luminosity function, mass function;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
86
Recensione:
Indirizzi per estratti:
Indirizzo: Abia, C Univ Granada, Dept Fis Teor & Cosmos, E-18071 Granada, Spain Univ Granada Granada Spain E-18071 osmos, E-18071 Granada, Spain
Citazione:
C. Abia et al., "The implications of the new Z=0 stellar models and yields on the early metal pollution of the intergalactic medium", ASTROPHYS J, 557(1), 2001, pp. 126-136

Abstract

Motivated by the recent detection of metals in different components of thehigh-redshift universe and by the abundance ratios measured in the extremely metal-poor stars of our Galaxy, we study the nucleosynthesis constraintsthat this imposes on an early generation of stars (Population III). To do so we take into account the chemical yields obtained from homogeneous evolutionary calculations of zero-metal stars in the mass range 3 less than or similar to m/M. less than or similar to 40 (Limongi et al.; Chieffi et al.). We also consider the role played by metal-free very massive objects (m > 100 M.). Using both analytical and numerical chemical evolution models, we confront model predictions from the different choices of the mass function proposed for Population III with the observational constraints. We show thatlow values of star formation efficiency (< 1%) are required so as not to exceed the minimum metallicity ([C/H] <approximate to> -2.4) measured in thehigh-redshift systems for any of the initial mass functions (IMFs) proposed. We also show that the observational constraints require Omega (sr) < 3 x10(-3)<Omega>(b), confirming previous claims that the possible contribution of the stellar remnants from Population III to the baryonic dark matter is insignificant. At present, however, the scarcity of abundance measurements for high-redshift systems does not permit us to put severe limitations onthe nature of the initial mass function for Population III. In fact, overabundances of a-elements with respect to iron of the order of those measuredin damped Ly alpha systems are obtained for any of the IMFs tested. Nevertheless, to account for the very large [C, N/Fe] ratios found in a considerable number of extremely metal-poor stars of our Galaxy, an IMF peaking at the intermediate stellar mass range (4-8 M.) is needed.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/12/20 alle ore 13:06:38