scholarly journals Concept of Gravito-Rotational Acceleration and its Consequences for Compact Stellar Objects

2021 ◽  
Author(s):  
Mohamed Hassani
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Equation Of State ◽  
Orbital Motion ◽  
Rotational Acceleration ◽  
Material Body ◽  
Stellar Objects ◽  
Gravitational Action ◽  
Theories Of Gravity ◽  
Previous Series

In a previous series of papers relating to the Combined Gravitational Action (CGA), we have exclusively studied orbital motion without spin. In the present paper, we apply CGA to any self-rotating material body, i.e., an axially spinning massive object, which itself may be locally seen as a gravito-rotational source because it is capable of generating the gravito-rotational acceleration, which seems to be unknown to previously existing theories of gravity. The consequences of such an acceleration are very interesting, particularly for Compact Stellar Objects. Independently of the equation of state, it is found that the critical and maximum internal magnetic field strength of a stable neutron star cannot exceed the value of 3x1018G.

scholarly journals On the Concept of Gravito-Rotational Acceleration and its Consequences for Compact Stellar Objects

2021 ◽  
Author(s):  
Mohamed Elmansour Hassani
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Orbital Motion ◽  
Rotational Acceleration ◽  
Gravitational Radius ◽  
Material Body ◽  
Stellar Objects ◽  
Gravitational Action ◽  
Theories Of Gravity ◽  
Previous Series

In a previous series of papers relating to the Combined Gravitational Action (CGA), we have exclusively studied orbital motion without spin. In the present paper, we apply CGA to any self-rotating material body, i.e., an axially spinning massive object, which itself may be locally seen as a gravito-rotational source because it is capable of generating the gravito-rotational acceleration, which seems to be unknown to previously existing theories of gravity. The consequences of such an acceleration are very interesting, particularly for Compact Stellar Objects. Independently of the equation of state, it is found that the minimum radius of a stable neutron star is three times its gravitational radius, Rmin = 3GMNS/c2, and its critical and maximum internal magnetic field strength cannot exceed the value of 3×1018 G.

scholarly journals Partially ionized layers of accreted envelopes of weakly and strongly magnetized neutron stars

2000 ◽  
Vol 177 ◽  
pp. 619-620 ◽  
Author(s):  
Alexander Potekhin ◽  
Gilles Chabrier ◽  
Yuri Shibanov
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Equation Of State ◽  
Neutron Stars ◽  
Strong Field ◽  
Ionization Degree ◽  
Occupation Numbers ◽  
Partially Ionized

AbstractWe study equilibrium properties of partially ionized hydrogen atmospheres and subphotospheric layers of weakly (with magnetic fieldB≪ 109G) and strongly (B≫ 1010G) magnetized neutron stars. In both weak- and strong-field cases, the ionization degree, atomic occupation numbers, and equation of state are calculated. These results are used to calculate opacities of neutron-star atmospheres.

scholarly journals Recycled pulsars with multipolar magnetospheres from accretion-induced magnetic burial

2020 ◽  
Vol 499 (3) ◽  
pp. 3243-3254
Author(s):  
A G Suvorov ◽  
A Melatos
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Equation Of State ◽  
Neutron Stars ◽  
Field Line ◽  
Dipole Field ◽  
Multipole Moments ◽  
Millisecond Pulsars ◽  
The Magnetic Field ◽  
Field Strengths

ABSTRACT Many millisecond pulsars are thought to be old neutron stars spun up (‘recycled’) during an earlier accretion phase. They typically have relatively weak (≲109 G) dipole field strengths, consistent with accretion-induced magnetic burial. Recent data from the Neutron Star Interior Composition Explorer indicate that hotspots atop the recycled pulsar PSR J0030–0451 are not antipodal, so that the magnetic field cannot be that of a centred dipole. In this paper it is shown that multipolarity is naturally expected in the burial scenario because of equatorial field line compression. Grad–Shafranov equilibria are constructed to show how magnetic multipole moments can be calculated in terms of various properties, such as the amount of accreted mass and the crustal equation of state.

scholarly journals Binary neutron star mergers and short gamma-ray bursts: Effects of magnetic field orientation, equation of state, and mass ratio

2016 ◽  
Vol 94 (6) ◽  
Author(s):  
Takumu Kawamura ◽  
Bruno Giacomazzo ◽  
Wolfgang Kastaun ◽  
Riccardo Ciolfi ◽  
Andrea Endrizzi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Equation Of State ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Mass Ratio ◽  
Field Orientation ◽  
Magnetic Field Orientation ◽  
Binary Neutron Star

scholarly journals A Model for the Double System Containing the X-Ray Pulsar Her X-1

1975 ◽  
Vol 67 ◽  
pp. 497-497
Author(s):  
G. S. Bisnovatyi-Kogan ◽  
B. V. Komberg
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Orbital Motion ◽  
Solid Angle ◽  
Central Star ◽  
X Ray ◽  
Opposite Case ◽  
Narrow Angle ◽  
The Earth ◽  
Double System

A model for the double system with the X-ray source Her X-1 is considered. It is supposed that the central star has a sufficiently strong magnetic field for the outflow of the matter to occur in jets. When the neutron star is in the jet the optical depth τx attributable to the X-ray emission due to Compton scattering is greater than unity and the solid angle of the emitted X-radiation is broad, ∼ 180°. In the opposite case, τx < 1, there is a narrow angle of emission and the radiation falls on to the star and is not observed on the Earth. The motion of the neutron star relative to the jet is due to nonsynchronization between the orbital motion and rotation of the central star. If the duration of the whole orbit around the central star is 35 days and the dimension of the jet is about 1/3 of the orbit, then such a model explains features connected with the 35-day cycle.

scholarly journals Detectability of Continuous Gravitational Waves from Magnetically Deformed Neutron Stars

Galaxies ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 101
Author(s):  
Jacopo Soldateschi ◽  
Niccolò Bucciantini
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Equation Of State ◽  
Magnetic Fields ◽  
Neutron Stars ◽  
Gravitational Waves ◽  
Nuclear Physics ◽  
Equations Of State ◽  
The Galaxy ◽  
The Magnetic Field

Neutron stars are known to contain extremely powerful magnetic fields. Their effect is to deform the shape of the star, leading to the potential emission of continuous gravitational waves. The magnetic deformation of neutron stars, however, depends on the geometry and strength of their internal magnetic field as well as on their composition, described by the equation of state. Unfortunately, both the configuration of the magnetic field and the equation of state of neutron stars are unknown, and assessing the detectability of continuous gravitational waves from neutron stars suffers from these uncertainties. Using our recent results relating the magnetic deformation of a neutron star to its mass and radius—based on models with realistic equations of state currently allowed by observational and nuclear physics constraints—and considering the Galactic pulsar population, we assess the detectability of continuous gravitational waves from pulsars in the galaxy by current and future gravitational waves detectors.

scholarly journals On Possible Reduction of Equilibrium Radius of a Neutron Star Influenced by Superstrong Magnetic Field

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Vladimir V. Skobelev
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Electron Gas ◽  
Necessary Condition ◽  
Superstrong Magnetic Field ◽  
Stellar Objects ◽  
New Class ◽  
Short Period ◽  
Equilibrium Radius ◽  
Field Influence

Necessary condition forβ-decay suppression of a neutron in degenerate magnetized electron gas is formulated. Based on this, it is shown that, in superstrong magnetic field, equilibrium radius of a neutron star is approximately several times smaller than without the field influence. Therefore, we can make a prediction that in short-period pulsars, such fields can be observed. In fact, possible existence of new class of stellar objects is noted, the objects with superstrong magnetic field and supersmall radius about 1 km which we namedminimagnetars. They can be detected by gravitational red shift of their radiation.

scholarly journals Waveform systematics in the gravitational-wave inference of tidal parameters and equation of state from binary neutron-star signals

2021 ◽  
Vol 103 (12) ◽  
Author(s):  
Rossella Gamba ◽  
Matteo Breschi ◽  
Sebastiano Bernuzzi ◽  
Michalis Agathos ◽  
Alessandro Nagar
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Gravitational Wave ◽  
Binary Neutron Star
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