Neutrino Scattering in a Newly Born Neutron Star

Reddy, Sanjay; Prakash, Madappa

doi:10.1086/303804

Cited by 32 publications

(32 citation statements)

References 45 publications

(51 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nucleon blocking and spatial correlations have been inadequately incorporated, and nucleon thermal motions, recoil, and temporal correlations have been ignored. Recent attempts have been made to incorporate a more realistic treatment of the matter (Sawyer 1989 ;Schinder 1990 ;Ra †elt & Seckel 1995 ;Ra †elt, Seckel, & Sigl 1996 ;Janka et al 1996 ;Prakash et al 1997 ;Reddy & Prakash 1997 ;Burrows & Sawyer 1998 and to calculate additional neutrino interactions (e.g., neutrinonucleon bremsstrahlung) (Suzuki 1993 The basic assumption of the shock reheating mechanism is that neutrinos from the core and from the matter accreting onto the core deposit sufficient energy in the heating region on a short enough time scale to drive an explosion. A number of attempts have been made to establish criteria for a successful explosion (Bethe 1993(Bethe , 1995(Bethe , 1997Bruenn 1993 ;Burrows & Goshy 1993 ;Shigeyama 1995 ;Thompson 2000 ;Janka 2001).…”

Section: Supernova Paradigmmentioning

confidence: 99%

General Relativistic Effects in the Core Collapse Supernova Mechanism

Bruenn

Nisco

Mezzacappa

2001

ApJ

107

View full text Add to dashboard Cite

We apply our recently developed code for spherically symmetric, fully general relativistic (GR) Lagrangian hydrodynamics and multigroup Ñux-limited di †usion (MGFLD) neutrino transport to examine the e †ects of GR on the hydrodynamics and transport during collapse, bounce, and the critical shock reheating phase of core collapse supernovae. GR e †ects were examined by performing core collapse simulations from several precollapse models in the Newtonian limit, in a hybrid limit consisting of GR hydrodynamics and Newtonian transport, and in the fully GR limit. Comparisons of models computed with GR versus Newtonian hydrodynamics show that collapse to bounce takes slightly less time in the GR limit and that the shock propagates slightly farther out in radius before receding. After a secondary quasi-static rise in the shock radius, the shock radius declines considerably more rapidly in the GR simulations than in the corresponding Newtonian simulations. During the shock reheating phase, core collapse computed with GR hydrodynamics results in a substantially more compact structure from the center out to the stagnated shock, the shock radius being reduced by a factor of 2 after 300 ms for a 25 model and 600 ms for a 15 model, times being measured from bounce. The inÑow speed of M _ M _ material behind the shock is also increased by about a factor of 2 throughout most of the evolution as a consequence of GR hydrodynamics. Regarding neutrino transport, comparisons show that the luminosity and rms energy of any neutrino Ñavor during the shock reheating phase increases when switching from Newtonian to GR hydrodynamics. This arises from the close coupling of the hydrodynamics and transport and the e †ect of GR hydrodynamics to produce more compact core structures, hotter neutrinospheres at smaller radii. On additionally switching from Newtonian to GR transport, gravitational time dilation and redshift e †ects decrease the luminosities and rms energies of all neutrino Ñavors. This decrease is less in magnitude than the increase in neutrino luminosities and rms energies that arise when switching from Newtonian to GR hydrodynamics, with the result that a fully GR simulation gives higher neutrino luminosities and harder neutrino spectra than a fully Newtonian simulation of the same precollapse model.

show abstract

Section: Supernova Paradigmmentioning

confidence: 99%

General Relativistic Effects in the Core Collapse Supernova Mechanism

Bruenn

Nisco

Mezzacappa

2001

ApJ

107

View full text Add to dashboard Cite

show abstract

“…One of the important microphysical inputs in PNS simulations is the neutrino opacity at supra-nuclear density [1,38,39,40,41,42] Although it was realized over a decade ago that the effects due to degeneracy and strong interactions significantly alter the neutrino mean free paths, it is only recently that detailed calculations have become available [31,43,44,45,46,47,48,49]. The scattering and absorption reactions that contribute to the neutrino opacity are…”

Section: Neutrino-matter Interaction Ratesmentioning

confidence: 99%

Evolution of a Neutron Star from Its Birth to Old Age

Prakash

Lattimer

Pons

et al. 2001

Lecture Notes in Physics

Self Cite

View full text Add to dashboard Cite

Abstract. The main stages in the evolution of a neutron star, from its birth as a proto-neutron star, to its old age as a cold, catalyzed configuration, are described. A proto-neutron star is formed in the aftermath of a successful supernova explosion and its evolution is dominated by neutrino diffusion. Its neutrino signal is a valuable diagnostic of its internal structure and composition. During its transformation from a hot, leptonrich to a cold, catalyzed remnant, the possibility exists that it can collapse into a black hole, which abruptly terminates neutrino emissions. The essential microphysics, reviewed herein, that controls its evolution are the equation of state of dense matter and its associated neutrino opacities. Several simulations of the proto-neutron star evolution, involving different assumptions about the composition of dense matter, are described. After its evolution into a nearly isothermal neutron star a hundred or so years after its birth, it may be observable through its thermal emission in X-rays during its life in the next million years. Its surface temperature will depend upon the rapidity of neutrino emission processes in its core, which depends on the composition of dense matter and whether or not its constituents exhibit superfluidity and superconductivity. Observations of thermal emission offer the best hope of a determination of the radius of a neutron star. The implications for the underlying dense matter equation of state of an accurate radius determination are explored.

show abstract

“…Observational checks of individual supernovae are presently still required to test the detailed working of a supernova. The present situation is still uncertain and depends on Fe-cores from stellar evolution, the supranuclear equation of state and maximum neutron star mass, related to the total amount of gravitational binding energy release of the collapsed protoneutron star, the resulting total amount of neutrinos, and the time release (luminosity), dependent on neutrino transport via numerical treatment, convective transport, and opacities (Burrows 1990;Herant et al 1994;Janka & Müller 1995Keil & Janka 1995;Burrows et al 1995Burrows et al , 1996Reddy & Prakash 1997;Burrows & Sawyer 1998;Mezzacappa et al 1998;Messer et al 1998;Yamada et al 1999;Pons et al 1999). Three types of uncertainties are inherent in the Fe-group ejecta, related to (i) the total amount of Fe (-group) nuclei ejected and the mass cut between neutron star and ejecta, mostly measured by 56 Ni decaying to 56 Fe, (ii) the total explosion energy which influences the entropy of the ejecta and with it the degree of alpha-rich freeze-out from explosive Si-burning and the abundances of radioactive 44 Ti as well as 48 Cr, the latter decaying later to 48 Ti and being responsible for elemental Ti, and (iii) finally the neutron richness or Y e =< Z/A > of the ejecta, dependent on stellar structure and the delay time between collapse and explosion.…”

Section: Sn II Yields and Their Uncertaintiesmentioning

confidence: 99%

Metal-Poor Halo Stars as Tracers of ISM Mixing Processes During Halo Formation

Argast

Samland

Gerhard

et al.

Eso Astrophysics Symposia

View full text Add to dashboard Cite

Abstract. We introduce a stochastic halo formation model to compute the early chemical enrichment of the interstellar medium (ISM) of the halo. Contrary to 1-zone chemical evolution models, we are able to resolve local inhomogeneities in the ISM caused by single core-collapse supernovae. These inhomogeneities lead to different element abundance patterns in very metal-poor stars, which can be seen as scatter in the abundances of halo stars with metallicities [Fe/H] < 2.0.The early chemical evolution of the halo proceeds in different enrichment phases: At [Fe/H] < −3.0, the halo ISM is unmixed and dominated by local inhomogeneities caused by individual core-collapse supernova (SN) events. For metallicities [Fe/H] > −2.0 the halo ISM is well mixed, showing an element abundance pattern integrated over the initial mass function. In the range −3.0 < [Fe/H] < −2.0 a continuous transition from the unmixed to the well mixed ISM occurs.For some elements (Si, Ca, Eu), the scatter in the elementto-iron ratio [El/Fe] of metal-poor halo stars can be reproduced. Stellar yields of other elements predict a scatter which, compared to the observations, is too large (O, Mg) or too small (Ni). Cr and Mn show a decreasing trend for lower metallicities, which can not be explained by metallicity independent yields, provided that the mixing of the ejecta with the interstellar medium does not depend on progenitor mass. This demonstrates the need for revised, self-consistent SN yields.Finally, we discuss the metallicity distribution in the model. Compared to the 28 very metal-poor stars observed with metallicities in the range −4.0 < [Fe/H] < −3.0, no star is known with confirmed metallicity [Fe/H] < −4.0, while our model predicts 5 ± 2 stars with [Fe/H] < −4.0. These should be present if the halo ISM started at primordial metallicities and no pre-enrichment by population III stars occurred.

show abstract

Neutrino Scattering in a Newly Born Neutron Star

Cited by 32 publications

References 45 publications

General Relativistic Effects in the Core Collapse Supernova Mechanism

General Relativistic Effects in the Core Collapse Supernova Mechanism

Evolution of a Neutron Star from Its Birth to Old Age

Metal-Poor Halo Stars as Tracers of ISM Mixing Processes During Halo Formation

Contact Info

Product

Resources

About