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José A. Pons - One of the best experts on this subject based on the ideXlab platform.
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Neutron Stars—Cooling and Transport
Space Science Reviews, 2015Co-Authors: Alexander Y. Potekhin, José A. Pons, Dany PageAbstract:Observations of thermal radiation from Neutron Stars can potentially provide information about the states of supranuclear matter in the interiors of these Stars with the aid of the theory of Neutron-star thermal evolution. We review the basics of this theory for isolated Neutron Stars with strong magnetic fields, including most relevant thermodynamic and kinetic properties in the stellar core, crust, and blanketing envelopes.
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Neutron Stars cooling and transport
Space Science Reviews, 2015Co-Authors: José A. Pons, Alexander Y. Potekhin, Dany PageAbstract:Observations of thermal radiation from Neutron Stars can potentially provide information about the states of supranuclear matter in the interiors of these Stars with the aid of the theory of Neutron-star thermal evolution. We review the basics of this theory for isolated Neutron Stars with strong magnetic fields, including most relevant thermodynamic and kinetic properties in the stellar core, crust, and blanketing envelopes.
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Neutron Stars - Thermal Emitters
Space Science Reviews, 2014Co-Authors: Alexander Y. Potekhin, Andrea De Luca, José A. PonsAbstract:Confronting theoretical models with observations of thermal radiation emitted by Neutron Stars is one of the most important ways to understand the properties of both, superdense matter in the interiors of the Neutron Stars and dense magnetized plasmas in their outer layers. Here we review the theory of thermal emission from the surface layers of strongly magnetized Neutron Stars, and the main properties of the observational data. In particular, we focus on the nearby sources for which a clear thermal component has been detected, without being contaminated by other emission processes (magnetosphere, accretion, nebulae). We also discuss the applications of the modern theoretical models of the formation of spectra of strongly magnetized Neutron Stars to the observed thermally emitting objects.
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Neutron Stars—Thermal Emitters
Space Science Reviews, 2014Co-Authors: Alexander Y. Potekhin, Andrea De Luca, José A. PonsAbstract:Confronting theoretical models with observations of thermal radiation emitted by Neutron Stars is one of the most important ways to understand the properties of both, superdense matter in the interiors of the Neutron Stars and dense magnetized plasmas in their outer layers. Here we review the theory of thermal emission from the surface layers of strongly magnetized Neutron Stars, and the main properties of the observational data. In particular, we focus on the nearby sources for which a clear thermal component has been detected, without being contaminated by other emission processes (magnetosphere, accretion, nebulae). We also discuss the applications of the modern theoretical models of the formation of spectra of strongly magnetized Neutron Stars to the observed thermally emitting objects.Comment: 39 pages, 5 figures, 1 table, invited topical review, in The Strongest Magnetic Fields in the Universe, ed. V.S. Beskin et al. (Space Sciences Series of ISSI, Springer). In v2, Eq.(7) is corrected. In v.3, a typo in Eq.(38) is fixed and references update
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2D Cooling of magnetized Neutron Stars
Astronomy & Astrophysics, 2008Co-Authors: D. N. Aguilera, José A. Pons, Juan Antonio MirallesAbstract:Context. Many thermally emitting, isolated Neutron Stars have magnetic fields that are larger than 10 13 G. A realistic cooling model that includes the presence of high magnetic fields should be r econsidered. Aims. We investigate the effects of an anisotropic temperature distribution and Joule heating on the cooling of magnetized Neutron Stars. Methods. The 2D heat transfer equation with anisotropic thermal conductivity tensor and including all relevant neutrino emissi on processes is solved for realistic models of the Neutron star interior and crust. Results. The presence of the magnetic field a ffects significantly the thermal surface distribution and the cooling history during both, the early neutrino cooling era and the late photon cooling era. Conclusions. There is a large effect of Joule heating on the thermal evolution of strongly magnetized Neutron Stars. Both magnetic fields and Joule heating play an important role in keeping mag netars warm for a long time. Moreover, this effect is important for intermediate field Neutron Stars and should be considered in radio‐quiet isolated Neutron Stars or high magnetic field ra dio‐pulsars.
Alexander Y. Potekhin - One of the best experts on this subject based on the ideXlab platform.
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Neutron Stars—Cooling and Transport
Space Science Reviews, 2015Co-Authors: Alexander Y. Potekhin, José A. Pons, Dany PageAbstract:Observations of thermal radiation from Neutron Stars can potentially provide information about the states of supranuclear matter in the interiors of these Stars with the aid of the theory of Neutron-star thermal evolution. We review the basics of this theory for isolated Neutron Stars with strong magnetic fields, including most relevant thermodynamic and kinetic properties in the stellar core, crust, and blanketing envelopes.
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Neutron Stars cooling and transport
Space Science Reviews, 2015Co-Authors: José A. Pons, Alexander Y. Potekhin, Dany PageAbstract:Observations of thermal radiation from Neutron Stars can potentially provide information about the states of supranuclear matter in the interiors of these Stars with the aid of the theory of Neutron-star thermal evolution. We review the basics of this theory for isolated Neutron Stars with strong magnetic fields, including most relevant thermodynamic and kinetic properties in the stellar core, crust, and blanketing envelopes.
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Neutron Stars - Thermal Emitters
Space Science Reviews, 2014Co-Authors: Alexander Y. Potekhin, Andrea De Luca, José A. PonsAbstract:Confronting theoretical models with observations of thermal radiation emitted by Neutron Stars is one of the most important ways to understand the properties of both, superdense matter in the interiors of the Neutron Stars and dense magnetized plasmas in their outer layers. Here we review the theory of thermal emission from the surface layers of strongly magnetized Neutron Stars, and the main properties of the observational data. In particular, we focus on the nearby sources for which a clear thermal component has been detected, without being contaminated by other emission processes (magnetosphere, accretion, nebulae). We also discuss the applications of the modern theoretical models of the formation of spectra of strongly magnetized Neutron Stars to the observed thermally emitting objects.
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Neutron Stars—Thermal Emitters
Space Science Reviews, 2014Co-Authors: Alexander Y. Potekhin, Andrea De Luca, José A. PonsAbstract:Confronting theoretical models with observations of thermal radiation emitted by Neutron Stars is one of the most important ways to understand the properties of both, superdense matter in the interiors of the Neutron Stars and dense magnetized plasmas in their outer layers. Here we review the theory of thermal emission from the surface layers of strongly magnetized Neutron Stars, and the main properties of the observational data. In particular, we focus on the nearby sources for which a clear thermal component has been detected, without being contaminated by other emission processes (magnetosphere, accretion, nebulae). We also discuss the applications of the modern theoretical models of the formation of spectra of strongly magnetized Neutron Stars to the observed thermally emitting objects.Comment: 39 pages, 5 figures, 1 table, invited topical review, in The Strongest Magnetic Fields in the Universe, ed. V.S. Beskin et al. (Space Sciences Series of ISSI, Springer). In v2, Eq.(7) is corrected. In v.3, a typo in Eq.(38) is fixed and references update
Dany Page - One of the best experts on this subject based on the ideXlab platform.
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Neutron Stars—Cooling and Transport
Space Science Reviews, 2015Co-Authors: Alexander Y. Potekhin, José A. Pons, Dany PageAbstract:Observations of thermal radiation from Neutron Stars can potentially provide information about the states of supranuclear matter in the interiors of these Stars with the aid of the theory of Neutron-star thermal evolution. We review the basics of this theory for isolated Neutron Stars with strong magnetic fields, including most relevant thermodynamic and kinetic properties in the stellar core, crust, and blanketing envelopes.
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Neutron Stars cooling and transport
Space Science Reviews, 2015Co-Authors: José A. Pons, Alexander Y. Potekhin, Dany PageAbstract:Observations of thermal radiation from Neutron Stars can potentially provide information about the states of supranuclear matter in the interiors of these Stars with the aid of the theory of Neutron-star thermal evolution. We review the basics of this theory for isolated Neutron Stars with strong magnetic fields, including most relevant thermodynamic and kinetic properties in the stellar core, crust, and blanketing envelopes.
Fridolin Weber - One of the best experts on this subject based on the ideXlab platform.
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Stellar Structure Models of Deformed Neutron Stars
International Journal of Modern Physics: Conference Series, 2017Co-Authors: Omair Zubairi, David Wigley, Fridolin WeberAbstract:Traditional stellar structure models of non-rotating Neutron Stars work under the assumption that these Stars are perfect spheres. This assumption of perfect spherical symmetry is not correct if the matter inside Neutron Stars is described by an anisotropic model for the equation of state. Certain classes of Neutron Stars such as Magnetars and Neutron Stars which contain color-superconducting quark matter cores are expected to be deformed making them oblong spheroids. In this work, we investigate the stellar structure of these deformed Neutron Stars by deriving stellar structure equations in the framework of general relativity. Using a non-isotropic equation of state model, we solve these structure equations numerically in two dimensions. We calculate stellar properties such as masses and radii along with pressure profiles and investigate changes from standard spherical models.
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Quark Deconfinement in Rotating Neutron Stars
Universe, 2017Co-Authors: Richard D. Mellinger, Fridolin Weber, William Spinella, Gustavo A. Contrera, Milva G. OrsariaAbstract:In this paper, we use a three flavor non-local Nambu–Jona-Lasinio (NJL) model, an improved effective model of Quantum Chromodynamics (QCD) at low energies, to investigate the existence of deconfined quarks in the cores of Neutron Stars. Particular emphasis is put on the possible existence of quark matter in the cores of rotating Neutron Stars (pulsars). In contrast to non-rotating Neutron Stars, whose particle compositions do not change with time (are frozen in), the type and structure of the matter in the cores of rotating Neutron Stars depends on the spin frequencies of these Stars, which opens up a possible new window on the nature of matter deep in the cores of Neutron Stars. Our study shows that, depending on mass and rotational frequency, up to around 8% of the mass of a massive Neutron star may be in the mixed quark-hadron phase, if the phase transition is treated as a Gibbs transition. We also find that the gravitational mass at which quark deconfinement occurs in rotating Neutron Stars varies quadratically with spin frequency, which can be fitted by a simple formula.
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Rotation and cooling of Neutron Stars
Astronomische Nachrichten, 2014Co-Authors: Rodrigo Negreiros, Stefan Schramm, Fridolin WeberAbstract:Driven by the loss of energy, isolated rotating Neutron Stars (pulsars) are gradually slowing down to lower frequencies, which increases the tremendous compression of the matter inside of them. This increase in compression changes both the global properties of rotating Neutron Stars as well as their hadronic core compositions. Both effects may register themselves observationally in the thermal evolution of such Stars, as demonstrated in this work. The rotation-driven particle process which we consider here is the direct Urca (DU) process, which is known to become operative in Neutron Stars if the number of protons in the stellar core exceeds a critical limit of around 11 % to 15 %. We find that Neutron Stars spinning down from moderately high rotation rates of a few hundred Hertz may be creating just the right conditions where the DU process becomes operative, leading to an observable effect (enhanced cooling) in the temperature evolution of such Neutron Stars. We will also study the thermal evolution of Neutron Stars whose spherical symmetry has been broken due to non-zero rotation. For this we will derive the energy balance and transport equations, taking into account the metric of a rotating fluid distribution and solve these equations numerically. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
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Properties of high-density matter in Neutron Stars
Modern Physics Letters A, 2014Co-Authors: Fridolin Weber, William Spinella, Gustavo A. Contrera, Milva Orsaria, Omair ZubairiAbstract:This short review aims at giving a brief overview of various states of matter that have been suggested to exist in the ultra-dense centers of Neutron Stars. Particular emphasis is put on the role of quark deconfinement in Neutron Stars and on the possible existence of compact Stars made of absolutely stable strange quark matter (strange Stars). Astrophysical phenomena, which distinguish Neutron Stars from quark Stars, are discussed and the question of whether or not quark deconfinement may occur in Neutron Stars is investigated. Combined with observed astrophysical data, such studies are invaluable to delineate the complex structure of compressed baryonic matter and to put firm constraints on the largely unknown equation of state of such matter.
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Rotating Neutron Stars
arXiv: Astrophysics, 2007Co-Authors: Fridolin Weber, Philip RosenfieldAbstract:Because of the tremendous densities that exist in the cores of Neutron Stars, a significant fraction of the matter in the cores of such Stars is likely to exist in the form of hyperons. Depending on spin frequency, the hyperon content changes dramatically in rotating Neutron Stars, as discussed in this paper.
Juan Antonio Miralles - One of the best experts on this subject based on the ideXlab platform.
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2D Cooling of magnetized Neutron Stars
Astronomy & Astrophysics, 2008Co-Authors: D. N. Aguilera, José A. Pons, Juan Antonio MirallesAbstract:Context. Many thermally emitting, isolated Neutron Stars have magnetic fields that are larger than 10 13 G. A realistic cooling model that includes the presence of high magnetic fields should be r econsidered. Aims. We investigate the effects of an anisotropic temperature distribution and Joule heating on the cooling of magnetized Neutron Stars. Methods. The 2D heat transfer equation with anisotropic thermal conductivity tensor and including all relevant neutrino emissi on processes is solved for realistic models of the Neutron star interior and crust. Results. The presence of the magnetic field a ffects significantly the thermal surface distribution and the cooling history during both, the early neutrino cooling era and the late photon cooling era. Conclusions. There is a large effect of Joule heating on the thermal evolution of strongly magnetized Neutron Stars. Both magnetic fields and Joule heating play an important role in keeping mag netars warm for a long time. Moreover, this effect is important for intermediate field Neutron Stars and should be considered in radio‐quiet isolated Neutron Stars or high magnetic field ra dio‐pulsars.
