scholarly journals Neutron stars velocities and magnetic fields

2018 ◽  
Vol 172 ◽  
pp. 07002
Author(s):  
Daryel Manreza Paret ◽  
A. Perez Martinez ◽  
Alejandro. Ayala ◽  
G. Piccinelli ◽  
A. Sanchez

We study a model that explain neutron stars velocities due to the anisotropic emission of neutrinos. Strong magnetic fields present in neutron stars are the source of the anisotropy in the system. To compute the velocity of the neutron star we model its core as composed by strange quark matter and analice the properties of a magnetized quark gas at finite temperature and density. Specifically we have obtained the electron polarization and the specific heat of magnetized fermions as a functions of the temperature, chemical potential and magnetic field which allow us to study the velocity of the neutron star as a function of these parameters.

2000 ◽  
Vol 195 ◽  
pp. 245-254
Author(s):  
C. Thompson

I describe the evidence that Soft Gamma Repeaters are magnetars—neutron stars in which a decaying magnetic field (rather than rotation) is the dominant source of free energy. The focus here is on the bursting emission of these sources and on direct physical diagnostics of very strong magnetic fields (B ≳ 10 BQED = 4.4 × 1014 G). I also summarize the trapped fireball model of SGR outbursts, the influence of QED processes on their spectra and lightcurves, and the genetic connection between neutron star magnetism and the violent fluid motions in a collapsing supernova core.


Universe ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 48
Author(s):  
Chinatsu Watanabe ◽  
Naotaka Yoshinaga ◽  
Shuichiro Ebata

Neutron star is an important object for us to verify the equation of state of hadronic matter. For a specific choice of equations of state, mass and radius of a neutron star are determined, for which there are constraints from observations. According to some previous studies, since the strong magnetic field acts as a repulsive force, there is a possibility that neutron stars with strong magnetic fields may have relatively heavier masses than other non-magnetized neutron stars. In this paper, the structure of a neutron star with a strong internal magnetic field is investigated by changing its internal functional form to see how much the neutron star can be massive and also how radius of a neutron star can be within a certain range.


1994 ◽  
Vol 03 (03) ◽  
pp. 665-674
Author(s):  
RAMEN KUMAR PARUI

The generation of very strong magnetic fields on the surface of a neutron star has long been an outstanding problem. A spinning neutron star is considered as one of the anticipated gravitational wave sources. Here I have shown the nonlinear behavior of this magnetic field in the interior of both uncharged and charged neutron stars at equilibrium radii and obtained results favouring a gravitational wave source.


2017 ◽  
Vol 13 (S337) ◽  
pp. 213-216
Author(s):  
Wynn C. G. Ho ◽  
Nils Andersson ◽  
Vanessa Graber

AbstractA superconductor of paired protons is thought to form in the core of neutron stars soon after their birth. Minimum energy conditions suggest that magnetic flux is expelled from the superconducting region due to the Meissner effect, such that the neutron star core retains or is largely devoid of magnetic fields for some nuclear equation of state and proton pairing models. We show via neutron star cooling simulations that the superconducting region expands faster than flux is expected to be expelled because cooling timescales are much shorter than timescales of magnetic field diffusion. Thus magnetic fields remain in the bulk of the neutron star core for at least 106 − 107yr. We estimate the size of flux free regions at 107yr to be ≲ 100m for a magnetic field of 1011G and possibly smaller for stronger field strengths.


1996 ◽  
Vol 160 ◽  
pp. 135-136
Author(s):  
Fridolin Weber ◽  
Norman K. Glendenning

The hypothesis that strange quark matter may be the absolute ground state of the strong interaction (not56Fe) has been raised independently by Boder and Witten. If the hypothesis is true, then a separate class of compact stars could exist, which are calledstrange matter stars. The properties of the complete sequence of such stars, which range from compact neutron-star-like strange stars to strange dwarfs to strange planets. The latter two constitute the strange counterparts of ordinary white dwarfs and planets, respectively. The properties of these objects are discussed in this paper.


2020 ◽  
Vol 496 (4) ◽  
pp. 5052-5071 ◽  
Author(s):  
A Y Potekhin ◽  
D A Zyuzin ◽  
D G Yakovlev ◽  
M V Beznogov ◽  
Yu A Shibanov

ABSTRACT Ages and thermal luminosities of neutron stars, inferred from observations, can be interpreted with the aid of the neutron star cooling theory to gain information on the properties of superdense matter in neutron-star interiors. We present a survey of estimated ages, surface temperatures, and thermal luminosities of middle-aged neutron stars with relatively weak or moderately strong magnetic fields, which can be useful for these purposes. The catalogue includes results selected from the literature, supplemented with new results of spectral analysis of a few cooling neutron stars. The data are compared with the theory. We show that overall agreement of theoretical cooling curves with observations improves substantially for models where neutron superfluidity in stellar core is weak.


1996 ◽  
Vol 10 (23) ◽  
pp. 1141-1149 ◽  
Author(s):  
CHOON-LIN HO ◽  
V.R. KHALILOV ◽  
CHI YANG

We obtain the equations that define the equilibrium of a homogeneous relativistic gas of neutrons, protons and electrons in a constant magnetic field as applied to the conditions that probably occur near the center of neutron stars. We compute the relative densities of the particles at equilibrium and the Fermi momentum of electrons in the strong magnetic field as function of the density of neutrons and the magnetic field induction. Novel features are revealed as to the ratio of the number of protons to the number of neutrons at equilibrium in the presence of large magnetic fields.


2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Denis Leahy ◽  
Rachid Ouyed

We present new analysis of the birth rate of AXPs and SGRS and their associated SNRs. Using Kolmogorov-Smirnov statistics together with parametric fits based on a robust estimator, we find a birth rate of ∼1/(1000 years) for AXPs/SGRs and their associated SNRs. These high rates suggest that all massive stars (greater than ∼(23–32)M⊙) give rise to remnants with magnetar-like fields. Observations indicate a limited fraction of high magnetic fields in these progenitors; thus our study is suggestive of magnetic field amplification. Dynamo mechanisms during the birth of the neutron stars require spin rates much faster than either observations or theory indicate. We propose that massive stars produce neutron stars with normal (∼1012 G) magnetic fields, which are then amplified to1014-1015 G after a delay of hundreds of years. The amplification is speculated to be a consequence of color ferromagnetism and to occur with a delay after the neutron star core reaches quark deconfinement density (i.e., the quark-nova scenario). The delayed amplification allows one to interpret simultaneously the high birth rate and high magnetic fields of AXPs/SGRs and their link to massive stars.


2019 ◽  
Vol 34 (29) ◽  
pp. 1950170
Author(s):  
Hao Liang ◽  
Xin-Jian Wen

The magnetic-color-flavor-locked quark matter is investigated in the Nambu–Jona-Lasinio model. Strong nonuniform magnetic fields are employed in order to mimic the spatial dependence of the magnetic field strength at high densities. We find that the gap solution depends strongly on the diquark coupling interaction. Based on the requirement that the parallel pressure should be an increasing function of the chemical potential, an upper limit on the central magnetic field [Formula: see text][Formula: see text]G is obtained, which increases slightly with the diquark interaction strength. Furthermore, much stronger central magnetic field could occur in the stars composed of magnetic-color-flavor matter than that of ordinary strange quark matter.


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