scholarly journals QUARK STARS AND QUANTUM-MAGNETICALLY INDUCED COLLAPSE

2005 ◽  
Vol 14 (11) ◽  
pp. 1959-1969 ◽  
Author(s):  
A. PÉREZ MARTÍNEZ ◽  
H. PÉREZ ROJAS ◽  
H. J. MOSQUERA CUESTA ◽  
M. BOLIGAN ◽  
M. G. ORSARIA
Keyword(s):  
Neutron Stars ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Quark Matter ◽  
Strange Quark ◽  
Vacuum Energy Density ◽  
Bag Model ◽  
X Ray ◽  
Quark Stars ◽  
Mit Bag Model

Quark matter is expected to exist in the interior of compact stellar objects as neutron stars or even the more exotic strange stars, based on the Bodmer–Witten conjecture. Bare strange quark stars and (normal) strange quark-matter stars, those possessing a baryon (electron-supported) crust, are hypothesized as good candidates to explain the properties of a set of peculiar stellar sources such as the enigmatic X-ray source RX J1856.5-3754, some pulsars such as PSR B1828-11 and PSR B1642-03, and the anomalous X-ray pulsars and soft γ-ray repeaters. In the MIT bag model, quarks are treated as a degenerate Fermi gas confined to a region of space having a vacuum energy density B bag (the Bag constant). In this note, we modify the MIT bag model by including the electromagnetic interaction. We also show that this version of the MIT model implies the anisotropy of the bag pressure due to the presence of the magnetic field. The equations of state of the degenerate quarks gases are studied in the presence of ultra strong magnetic fields. The behavior of a system made up of quarks having (or not) anomalous magnetic moment is reviewed. A structural instability is found, which is related to the anisotropic nature of the pressures in this highly magnetized matter. The conditions for the collapse of this system are obtained and compared to a previous model of neutron stars that is built on a neutron gas having anomalous magnetic moment.

scholarly journals Strange Quark Stars — A Review

2003 ◽  
Vol 214 ◽  
pp. 191-198 ◽  
Author(s):  
R. X. Xu
Keyword(s):  
Neutron Stars ◽  
Quark Matter ◽  
Strange Quark ◽  
Major Part ◽  
Strange Quark Matter ◽  
Strange Stars ◽  
Quark Stars

A pedagogical overview of strange quark matter and strange stars is presented. After a historical notation of the research and an introduction to quark matter, a major part is devoted to the physics and astrophysics of strange stars, with attention being paid to the possible ways by which neutron stars and strange stars can be distinguished in astrophysics. Recent possible evidence for bare strange stars is also discussed.

scholarly journals MASS–RADIUS RELATION FOR MAGNETIZED STRANGE QUARKS STARS

2010 ◽  
Vol 19 (08n10) ◽  
pp. 1511-1519 ◽  
Author(s):  
A. P. MARTÍNEZ ◽  
R. G. FELIPE ◽  
D. M. PARET
Keyword(s):  
Magnetic Field ◽  
Quark Matter ◽  
Strange Quark ◽  
Baryon Density ◽  
Strange Quark Matter ◽  
Strange Quarks ◽  
Quark Stars ◽  
Mit Bag Model ◽  
The Stability ◽  
The Magnetic Field

We review the stability of magnetized strange quark matter (MSQM) within the phenomenological MIT bag model, taking into account the variation of the relevant input parameters, namely, the strange quark mass, baryon density, magnetic field and bag parameter. A comparison with magnetized asymmetric quark matter in β-equilibrium as well as with strange quark matter (SQM) is presented. We obtain that the energy per baryon for MSQM decreases as the magnetic field increases, and its minimum value at vanishing pressure is lower than the value found for SQM, which implies that MSQM is more stable than non-magnetized SQM. The mass–radius relation for magnetized strange quark stars is also obtained in this framework.

scholarly journals Reduction of the Mass of the Proto-Quark Star during Cooling

Particles ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 37-44
Author(s):  
Gevorg Hajyan
Keyword(s):  
Quark Matter ◽  
Finite Temperature ◽  
Supernova Explosion ◽  
Neutrino Emission ◽  
Quark Star ◽  
Bag Model ◽  
Quark Stars ◽  
Mit Bag Model

The integral parameters (mass, radius) of hot proto-quark stars that are formed in supernova explosion are studied. We use the MIT bag model to determine the pressure of up-down and strage quark matter at finite temperature and in the regime where neutrinos are trapped. It is shown that such stars are heated to temperatures of the order of tens of MeV. The maximum possible values of the central temperatures of these stars are determined. It is shown that the energy of neutrinos that are emitted from proto-quark stars is of the order of 250÷300 MeV. Once formed, the proto-quark stars cool by neutrino emission, which leads to a decrease in the mass of these stars by about 0.16–0.25 M⊙ for stars with the rest masses that are in the range Mb=1.22−1.62M⊙.

SCALING PROPERTY IN COLD COMPACT STARS

2000 ◽  
Vol 15 (20) ◽  
pp. 1341-1346 ◽  
Author(s):  
R. SHARMA ◽  
S. MUKHERJEE ◽  
S. D. MAHARAJ
Keyword(s):  
Neutron Stars ◽  
Strange Quark ◽  
Scaling Behavior ◽  
Exotic Matter ◽  
Compact Stars ◽  
Bag Model ◽  
Model Calculations ◽  
Quark Stars ◽  
Scaling Property ◽  
Simple Scaling

We point out a simple scaling property in the mass–radius relationship in cold compact stars. This property my be considered as a generalization of the scaling observed by Witten for strange quark stars. A particular model which explicitly exhibits this scaling behavior has been discussed. The model is relevant for neutron stars as well as stars made up of exotic matter, in particular, quark stars and other composites based on Bag model calculations.

scholarly journals Strange Star Equations of State Revisited

2005 ◽  
Vol 22 (4) ◽  
pp. 292-297 ◽  
Author(s):  
Debora P. Menezes ◽  
Don B. Melrose
Keyword(s):  
Neutron Stars ◽  
Quark Matter ◽  
Equations Of State ◽  
Bag Model ◽  
Strange Stars ◽  
Strange Matter ◽  
Strong Force ◽  
Mit Bag Model ◽  
Central Energy ◽  
Weakly Dependent

AbstractMotivated by recent suggestions that strange stars can be responsible for glitches and other observational features of pulsars, we review some possible equations of state and their implications for models of neutron, hybrid, and strange stars. We consider the MIT bag model and also strange matter in the colour–flavour locked phase. The central energy densities for strange stars are higher than the central densities of ordinary neutron stars. Strange stars are bound by the strong force and so can also rotate much faster than neutron stars. These results are only weakly dependent on the model used for the quark matter. If just one of the existing mass-to-radius ratio constraint is valid, most neutron stars equations of state are ruled out, but all the strange stars equations of state presented in this work remain consistent with the constraint.

scholarly journals COMPACT STARS AND MAGNETIZED CFL MATTER

2011 ◽  
Vol 20 (supp02) ◽  
pp. 84-92 ◽  
Author(s):  
AURORA PÉREZ MARTíNEZ ◽  
RICARDO GONZÁLEZ FELIPE ◽  
DARYEL MANREZA PARET
Keyword(s):  
Magnetic Field ◽  
Neutron Stars ◽  
Ground State ◽  
Quark Matter ◽  
Strange Quark ◽  
Strange Quark Matter ◽  
Compact Stars ◽  
Mit Bag Model ◽  
The Stability ◽  
The Magnetic Field

The stability of the color flavor locked phase in the presence of a strong magnetic field is investigated within the phenomenological MIT bag model. It is found that the minimum value of the energy per baryon in a color flavor locked state at vanishing pressure is lower than the corresponding one for unpaired magnetized strange quark matter and, as the magnetic field increases, the energy per baryon decreases. This implies that magnetized color flavor locked matter is more stable and could become the ground state inside neutron stars. The anisotropy of the pressures is discussed. The mass-radius relation for such stars is also studied.

Strange Quark Matter as Dark Matter

2019 ◽  
Vol 22 (4) ◽  
pp. 311-317
Author(s):  
Hidezumi Terazawa
Keyword(s):  
Dark Matter ◽  
Quark Matter ◽  
Strange Quark ◽  
Strange Quark Matter ◽  
Quark Stars

New forms of matter such as super-hypernuclei (strange quark matter) and superhypernuclear stars (strange quark stars) as candidates for dark matter are discussed in some detail, based on the so-called "Bodmer–Terazawa–Witten hypothesis" assuming that they are stable absolutely or quasi-stable (decaying only weakly).

Population Synthesis of Neutron Stars, Strange (Quark) Stars, and Black Holes

2002 ◽  
Vol 567 (1) ◽  
pp. L63-L66 ◽  
Author(s):  
Krzysztof Belczynski ◽  
Tomasz Bulik ◽  
Włodzimierz Kluźniak
Keyword(s):  
Black Holes ◽  
Neutron Stars ◽  
Strange Quark ◽  
Population Synthesis ◽  
Quark Stars

scholarly journals Structure of Quark Stars

2012 ◽  
Vol 8 (S291) ◽  
pp. 61-66 ◽  
Author(s):  
Fridolin Weber ◽  
Milva Orsaria ◽  
Hilario Rodrigues ◽  
Shu-Hua Yang
Keyword(s):  
Neutron Stars ◽  
Electric Fields ◽  
Heavy Ions ◽  
Strange Quark ◽  
Electron Gas ◽  
Central Star ◽  
Strange Quarks ◽  
Quark Stars ◽  
Star Density ◽  
High Electric Fields

AbstractThis paper gives an brief overview of the structure of hypothetical strange quarks stars (quark stars, for short), which are made of absolutely stable 3-flavor strange quark matter. Such objects can be either bare or enveloped in thin nuclear crusts, which consist of heavy ions immersed in an electron gas. In contrast to neutron stars, the structure of quark stars is determined by two (rather than one) parameters, the central star density and the density at the base of the crust. If bare, quark stars possess ultra-high electric fields on the order of 1018 to 1019 V/cm. These features render the properties of quark stars more multifaceted than those of neutron stars and may allow one to observationally distinguish quark stars from neutron stars.

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