Gravitational collapse and neutrino emission of Population III massive stars

Ken'ichiro Nakazato, Kohsuke Sumiyoshi, Shoichi Yamada

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

Population III (Pop III) stars are the first stars in the universe. They do not contain metals, and their formation and evolution may be different from that of stars of later generations. In fact, according to the theory of star formation, Pop III stars might have very massive components (∼ 100-10000 M). In this paper, we compute the spherically symmetric gravitational collapse of these Pop III massive stars. We solve the general relativistic hydrodynamics and neutrino transfer equations simultaneously, treating neutrino reactions in detail. Unlike supermassive stars (≳10 5 M), the stars of concern in this paper become opaque to neutrinos. The collapse is simulated until after an apparent horizon is formed. We confirm that the neutrino transfer plays a crucial role in the dynamics of gravitational collapse and find also that the β-equilibration leads to a somewhat unfamiliar evolution of electron fraction. Contrary to the naive expectation, the neutrino spectrum does not become harder for more massive stars. This is mainly because the neutrino cooling is more efficient and the outer core is more massive as the stellar mass increases. Here the outer core is the outer part of the iron core falling supersonically. We also evaluate the flux of relic neutrinos from Pop III massive stars. As expected, the detection of these neutrinos is difficult for the currently operating detectors. However, if ever observed, the spectrum will enable us to obtain information on the formation history of Pop III stars. We investigate 18 models covering the mass range of 300-104 M, making this study the most detailed numerical exploration of spherically symmetric gravitational collapse of Pop III massive stars. This will also serve as an important foundation for multidimensional investigations.

Original languageEnglish
Pages (from-to)519-533
Number of pages15
JournalAstrophysical Journal
Volume645
Issue number1 I
DOIs
Publication statusPublished - Jul 1 2006

Fingerprint

Population III stars
gravitational collapse
massive stars
neutrinos
outer core
stars
supermassive stars
hydrodynamics
cooling
iron
electron
metal
history
stellar mass
falling
horizon
star formation
coverings
universe
histories

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Gravitational collapse and neutrino emission of Population III massive stars. / Nakazato, Ken'ichiro; Sumiyoshi, Kohsuke; Yamada, Shoichi.

In: Astrophysical Journal, Vol. 645, No. 1 I, 01.07.2006, p. 519-533.

Research output: Contribution to journalArticle

Nakazato, Ken'ichiro ; Sumiyoshi, Kohsuke ; Yamada, Shoichi. / Gravitational collapse and neutrino emission of Population III massive stars. In: Astrophysical Journal. 2006 ; Vol. 645, No. 1 I. pp. 519-533.
@article{40ace8364dcc4c3cb39c1f851b0d0ee0,
title = "Gravitational collapse and neutrino emission of Population III massive stars",
abstract = "Population III (Pop III) stars are the first stars in the universe. They do not contain metals, and their formation and evolution may be different from that of stars of later generations. In fact, according to the theory of star formation, Pop III stars might have very massive components (∼ 100-10000 M⊙). In this paper, we compute the spherically symmetric gravitational collapse of these Pop III massive stars. We solve the general relativistic hydrodynamics and neutrino transfer equations simultaneously, treating neutrino reactions in detail. Unlike supermassive stars (≳10 5 M⊙), the stars of concern in this paper become opaque to neutrinos. The collapse is simulated until after an apparent horizon is formed. We confirm that the neutrino transfer plays a crucial role in the dynamics of gravitational collapse and find also that the β-equilibration leads to a somewhat unfamiliar evolution of electron fraction. Contrary to the naive expectation, the neutrino spectrum does not become harder for more massive stars. This is mainly because the neutrino cooling is more efficient and the outer core is more massive as the stellar mass increases. Here the outer core is the outer part of the iron core falling supersonically. We also evaluate the flux of relic neutrinos from Pop III massive stars. As expected, the detection of these neutrinos is difficult for the currently operating detectors. However, if ever observed, the spectrum will enable us to obtain information on the formation history of Pop III stars. We investigate 18 models covering the mass range of 300-104 M⊙, making this study the most detailed numerical exploration of spherically symmetric gravitational collapse of Pop III massive stars. This will also serve as an important foundation for multidimensional investigations.",
author = "Ken'ichiro Nakazato and Kohsuke Sumiyoshi and Shoichi Yamada",
year = "2006",
month = "7",
day = "1",
doi = "10.1086/504282",
language = "English",
volume = "645",
pages = "519--533",
journal = "Astrophysical Journal",
issn = "0004-637X",
number = "1 I",

}

TY - JOUR

T1 - Gravitational collapse and neutrino emission of Population III massive stars

AU - Nakazato, Ken'ichiro

AU - Sumiyoshi, Kohsuke

AU - Yamada, Shoichi

PY - 2006/7/1

Y1 - 2006/7/1

N2 - Population III (Pop III) stars are the first stars in the universe. They do not contain metals, and their formation and evolution may be different from that of stars of later generations. In fact, according to the theory of star formation, Pop III stars might have very massive components (∼ 100-10000 M⊙). In this paper, we compute the spherically symmetric gravitational collapse of these Pop III massive stars. We solve the general relativistic hydrodynamics and neutrino transfer equations simultaneously, treating neutrino reactions in detail. Unlike supermassive stars (≳10 5 M⊙), the stars of concern in this paper become opaque to neutrinos. The collapse is simulated until after an apparent horizon is formed. We confirm that the neutrino transfer plays a crucial role in the dynamics of gravitational collapse and find also that the β-equilibration leads to a somewhat unfamiliar evolution of electron fraction. Contrary to the naive expectation, the neutrino spectrum does not become harder for more massive stars. This is mainly because the neutrino cooling is more efficient and the outer core is more massive as the stellar mass increases. Here the outer core is the outer part of the iron core falling supersonically. We also evaluate the flux of relic neutrinos from Pop III massive stars. As expected, the detection of these neutrinos is difficult for the currently operating detectors. However, if ever observed, the spectrum will enable us to obtain information on the formation history of Pop III stars. We investigate 18 models covering the mass range of 300-104 M⊙, making this study the most detailed numerical exploration of spherically symmetric gravitational collapse of Pop III massive stars. This will also serve as an important foundation for multidimensional investigations.

AB - Population III (Pop III) stars are the first stars in the universe. They do not contain metals, and their formation and evolution may be different from that of stars of later generations. In fact, according to the theory of star formation, Pop III stars might have very massive components (∼ 100-10000 M⊙). In this paper, we compute the spherically symmetric gravitational collapse of these Pop III massive stars. We solve the general relativistic hydrodynamics and neutrino transfer equations simultaneously, treating neutrino reactions in detail. Unlike supermassive stars (≳10 5 M⊙), the stars of concern in this paper become opaque to neutrinos. The collapse is simulated until after an apparent horizon is formed. We confirm that the neutrino transfer plays a crucial role in the dynamics of gravitational collapse and find also that the β-equilibration leads to a somewhat unfamiliar evolution of electron fraction. Contrary to the naive expectation, the neutrino spectrum does not become harder for more massive stars. This is mainly because the neutrino cooling is more efficient and the outer core is more massive as the stellar mass increases. Here the outer core is the outer part of the iron core falling supersonically. We also evaluate the flux of relic neutrinos from Pop III massive stars. As expected, the detection of these neutrinos is difficult for the currently operating detectors. However, if ever observed, the spectrum will enable us to obtain information on the formation history of Pop III stars. We investigate 18 models covering the mass range of 300-104 M⊙, making this study the most detailed numerical exploration of spherically symmetric gravitational collapse of Pop III massive stars. This will also serve as an important foundation for multidimensional investigations.

UR - http://www.scopus.com/inward/record.url?scp=33746889046&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33746889046&partnerID=8YFLogxK

U2 - 10.1086/504282

DO - 10.1086/504282

M3 - Article

AN - SCOPUS:33746889046

VL - 645

SP - 519

EP - 533

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1 I

ER -