Download or read book Impact of the Nuclear Equation of State on Models of Rotating Neutron Stars written by and published by . This book was released on 1991 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The impact of the nuclear equation of state on the properties of rotating neutron stars from two different sources, stable rotation at the general relativistic Kepler period and rotation at the gravitational radiation-reaction driven instability mode, is analyzed. For this purpose models of rotating neutron stars are constructed in the framework of Einstein's theory of general relativity by applying a refined version of Hartle's perturbative stellar structure equations. The investigation is based on a representative collection of a total of seventeen nuclear equations of state, covering both non-relativistic as well as relativistic ones. 41 refs., 3 figs., 2 tabs.
Download or read book Neutron Stars 1 written by P. Haensel and published by Springer Science & Business Media. This book was released on 2007-12-06 with total page 633 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book gives an extended review of theoretical and observational aspects of neutron star physics. With masses comparable to that of the Sun and radii of about ten kilometres, neutron stars are the densest stars in the Universe. This book describes all layers of neutron stars, from the surface to the core, with the emphasis on their structure and equation of state. Theories of dense matter are reviewed, and used to construct neutron star models. Hypothetical strange quark stars and possible exotic phases in neutron star cores are also discussed. Also covered are the effects of strong magnetic fields in neutron star envelopes.
Download or read book Impact of a Finite temperature Equation of State on Neutron Stars written by Christian D. Draper and published by . This book was released on 2011 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this research, we study how a finite-temperature nuclear equation of state suitable for astrophysical simulations impacts the oscillation modes of neutron stars. We chose the Shen equation of state (EOS) because it accurately describes both stable and unstable nuclei as well as nuclear incompressibilities. I modified the existing MHD code at BYU, the HAD code, to call a lookup table for the Shen EOS for use at run time, and added a Newton-Raphson method algorithm to convert conserved variables to primitive variables. The algorithm was tested and verified by evolving a stable neutron star for several dynamical times and evolving the same star at different resolutions. The normal mode frequency of the neutron star with the Shen EOS was measured and compared to those for neutron stars with an ideal gas EOS found by Font et. al. We found that the fundamental mode of the neutron star using the Shen EOS was slightly larger than that of the ideal gas EOS. This difference is due to the Shen EOS producing stars that are stiffer, increasing the sound speed.
Download or read book Rotating Neutron Stars and the Equation of State of Dense Matter written by and published by . This book was released on 1990 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: We investigate the properties of non-rotating as well as rotating neutron stars in the framework of Einstein's theory of general relativity. The nuclear equation of state of neutron star matter (electrically charge neutral many-baryon/lepton system) is calculated for the relativistic Hartree- and Hartree-Fock approximations. The influence of two-particle correlations on the equation of state is taken into account, too. An important result is that the limiting rotational frequency of a neutron star is set by instability modes caused by gravitational radiation reaction, which set in well below the Kerplerian frequency. 20 refs., 7 figs., 3 tabs.
Download or read book Relativistic Hydrodynamics written by Luciano Rezzolla and published by OUP Oxford. This book was released on 2013-09-26 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt: Relativistic hydrodynamics is a very successful theoretical framework to describe the dynamics of matter from scales as small as those of colliding elementary particles, up to the largest scales in the universe. This book provides an up-to-date, lively, and approachable introduction to the mathematical formalism, numerical techniques, and applications of relativistic hydrodynamics. The topic is typically covered either by very formal or by very phenomenological books, but is instead presented here in a form that will be appreciated both by students and researchers in the field. The topics covered in the book are the results of work carried out over the last 40 years, which can be found in rather technical research articles with dissimilar notations and styles. The book is not just a collection of scattered information, but a well-organized description of relativistic hydrodynamics, from the basic principles of statistical kinetic theory, down to the technical aspects of numerical methods devised for the solution of the equations, and over to the applications in modern physics and astrophysics. Numerous figures, diagrams, and a variety of exercises aid the material in the book. The most obvious applications of this work range from astrophysics (black holes, neutron stars, gamma-ray bursts, and active galaxies) to cosmology (early-universe hydrodynamics and phase transitions) and particle physics (heavy-ion collisions). It is often said that fluids are either seen as solutions of partial differential equations or as "wet". Fluids in this book are definitely wet, but the mathematical beauty of differential equations is not washed out.
Download or read book Rotating Relativistic Stars written by John L. Friedman and published by Cambridge University Press. This book was released on 2013-02-11 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: The masses of neutron stars are limited by an instability to gravitational collapse and an instability driven by gravitational waves limits their spin. Their oscillations are relevant to x-ray observations of accreting binaries and to gravitational wave observations of neutron stars formed during the coalescence of double neutron-star systems. This volume includes more than forty years of research to provide graduate students and researchers in astrophysics, gravitational physics and astronomy with the first self-contained treatment of the structure, stability and oscillations of rotating neutron stars. This monograph treats the equations of stellar equilibrium; key approximations, including slow rotation and perturbations of spherical and rotating stars; stability theory and its applications, from convective stability to the r-mode instability; and numerical methods for computing equilibrium configurations and the nonlinear evolution of their oscillations. The presentation of fundamental equations, results and applications is accessible to readers who do not need the detailed derivations.
Download or read book Saturation of the f mode Instability in Neutron Stars written by Pantelis Pnigouras and published by Springer. This book was released on 2018-09-25 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a study of the saturation of unstable f-modes (fundamental modes) due to low-order nonlinear mode coupling. Since their theoretical prediction in 1934, neutron stars have remained among the most challenging objects in the Universe. Gravitational waves emitted by unstable neutron star oscillations can be used to obtain information about their inner structure, that is, the equation of state of dense nuclear matter. After its initial growth phase, the instability is expected to saturate due to nonlinear effects. The saturation amplitude of the unstable mode determines the detectability of the generated gravitational-wave signal, but also affects the evolution of the neutron star. The study shows that the unstable (parent) mode resonantly couples to pairs of stable (daughter) modes, which drain the parent’s energy and make it saturate via a mechanism called parametric resonance instability. Further, it calculates the saturation amplitude of the most unstable f-mode multipoles throughout their so-called instability windows.
Download or read book Physics of Neutron Stars written by A. M. Kaminker and published by Nova Biomedical Books. This book was released on 1995 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physics of Neutron Stars
Download or read book Neutron Stars Strange Stars and the Nuclear Equation of State written by and published by . This book was released on 1992 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: This article consists of three parts. In part one we review the present status of dense nuclear matter calculations, and introduce a representative collection of realistic nuclear equations of state which are derived for different assumptions about the physical behavior of dense matter (baryon population, pion condensation, .possible transition of baryon matter to quark matter). In part two we review recently performed non-rotating and rotating compact star calculations performed for these equations of state. The minimum stable rotational periods of compact stars, whose knowledge is of decisive importance for the interpretation of rapidly rotating pulsars, axe determined. For this purpose two different limits on stable rotation are studied: rotation at the general relativistic Kepler period (below which mass shedding at the star's equator sets in), and, secondly, rotation at the gravitational radiation-reaction instability (at which emission of gravitational waves set in which slows the star down). Part three of this article deals with the properties of hypothetical strange stars. Specifically we investigate the amount of nuclear solid crust that can be carried by a rotating strange star, and answer the question whether such objects can give rise to the observed phenomena of pulsar glitches, which is at the present time the only astrophysical test of the strange-quark-matter hypothesis.
Download or read book Properties of Massive Neutron Stars written by Susan Elizabeth Kotowski and published by . This book was released on 2012 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutron stars have been of interest since Landau proposed their existence in the early 1930's. Soon after, Baade and Zwicky theorized the origins of neutron stars and Tolman, Oppenheimer, and Volkoff modeled neutron stars. It wasn't until until the 1960's when Bell and Hewish found the first pulsar that theoretical neutron stars could be compared to observable results. Since then scientists have found 2000 neutron stars with masses as high as 2 M[circled dot operator]. The models for neutron stars have improved with our understanding of nuclear matter. The equations of state for nuclear matter that describe pressure as a function of energy have been altered for neutron stars. Not all models for nuclear matter fit with neutron star data. This study examines how the models fit the observed masses. The models have been divided into groups based on their treatment of the many body problem. For each model the rotating and non-rotating cases have been examined to see the effects of rotation on the properties of a neutron star at certain masses. Though all neutron stars give insight into super dense matter, this paper will focus on neutron stars near 2 M [circled dot operator] . We see shifts in all properties when moving from the non-rotating to the rotating case. After comparing the resulting masses for each equation of state to the recently found 1.97 [plus or minus] 0.04 M[circled dot operator] neutron star, we can predict the properties of such a massive neutron star. We will also be able to rule out models for the equation of state that do not create large enough stars. About half of the models studied can create non-rotating neutron stars of at least 2.0 M[circled dot operator], while nearly all of the models can create rapidly rotating neutron stars of the same mass.
Download or read book Equation of State of Neutron Star Matter Limiting Rotational Periods of Fast Pulsars and the Properties of Strange Stars written by and published by . This book was released on 1993 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper the following items will be treated: The present status of dense nuclear matter calculations and constraints on the behavior of the associated equation of state at high densities from data on rapidly rotating pulsars. Recent finding of the likely existence of a mixed phase of baryons and quarks forming a coulomb lattice in the dense cores of neutron stars. Review of important findings of recently performed calculations of rapidly rotating compact stars. These are constructed in the framework of general relativity theory for a representative collection of realistic nuclear equations of state. Establish the minimum-possible rotational periods of gravitationally bound neutron stars and self-bound strange stars. Its knowledge is of fundamental importance for the decision between pulsars that can be understood as rotating neutron stars and those that cannot (signature of hypothetical self-bound matter of which strange stars are the likely stellar candidates. Investigate the properties of sequences of strange stars. Specifically, we answer the question whether such objects can give rise to the observed phenomena of pulsar glitches, which is at the present time the only astrophysical test of the strange-quark-matter hypothesis.
Download or read book Sensitivity of Neutron Star Properties to the Equation of State written by Farrooh Fattoyev and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: The subject of this doctoral dissertation is to study the equations of state of nuclear and neutron-star matter. We tackle this problem by employing several models of the relativistic effective interactions. The relativistic effective interactions and their applications to the ground-state properties of medium to heavy nuclei have enjoyed enormous success for the past three decades. With just a few model parameters calibrated to the ground state properties of the closed-shell nuclei, these models exhibit and encode a great amount of physics. However, theses models are untested far away from their narrow window of applicability. In particular, while these models tend to agree on the saturation properties of symmetric nuclear matter, they largely disagree on its density and isospin dependence, especially in the region of high densities and large proton-neutron asymmetries. In order to better understand the properties of nuclear matter at these extreme regions of isospin asymmetry and high-densities, we will apply these models to predict several neutron star properties. Since the matter in the neutron stars are very neutron-rich, while the density of matter in neutron stars spans over a wide range of magnitudes, these compact objects remain unique laboratories for probing the equation of state of neutron-rich matter under conditions unattainable by terrestrial experiments. Thus it is expected that at least the following neutron star properties must be sensitive to the underlying equation of state- maximum mass, typical radii, moments of inertia (both total and crustal), redshifts, and cooling mechanism. We present numerical solutions and in some cases also analytical solutions to each of the properties above. In particular, the sensitivity of the stellar moment of inertia to the neutron-star matter equation of state is examined using accurately-calibrated relativistic mean-field models. We probe this sensitivity by tuning both the density dependence of the symmetry energy and the high density component of the equation of state, properties that are at present poorly constrained by existing laboratory data. Particularly attractive is the study of the fraction of the moment of inertia contained in the solid crust. Analytic treatments of the crustal moment of inertia reveal a high sensitivity to the transition pressure at the core-crust interface. Motivated by a recent astrophysical measurement of the pressure of cold matter above nuclear-matter saturation density, we compute the equation of state of neutron-star matter using various accurately calibrated relativistic models. We found the predictions of these models to be in fairly good agreement with the measured equation of state. In the effort to explain the observational data we introduce a new relativistic effective interaction that is simultaneously constrained by the properties of finite nuclei, their collective excitations, and neutron-star properties. By adjusting two of the empirical parameters of the theory, one can efficiently tune the neutron skin thickness of $^{208}$Pb and the maximum neutron star mass. The new effective interaction is moderately soft at intermediate densities and relatively stiff at high densities. It is fitted to a neutron skin thickness in $^{208}$Pb of only $R_{rm n} - R_{rm p} = 0.16$ fm and a moderately large maximum neutron star mass of 1.94 $M_{rm Sun}$ consistent with the latest observation. Last, theoretical uncertainties in the predictions of relativistic mean-field models are estimated using a chi-square minimization procedure that is implemented by studying the small oscillations around the chi-square minimum. It is shown that such statistical analysis provides access to a wealth of information that would normally remain hidden. The power of covariance analysis is illustrated in two relativistic mean field models. By performing this analysis one obtains meaningful theoretical uncertainties for both model parameters and predicted observables. Moreover, it is shown, how covariance analysis is able to establish robust correlations between physical observables.
Download or read book Rapidly Rotating Neutron Stars in General Relativity written by Gregory B. Cook and published by . This book was released on 1993 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of the Equation of State and the Composition on the Thermal Evolution of Neutron Stars written by Mehmet Tuncer Unver and published by . This book was released on 2013 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: Even though the neutron stars have been studied for over six decades there is little consensus over the mechanisms involved in their thermal evolution. Similarly, despite decades of study, the behavior of exotic particles, especially under highly degenerate situations, garner little consensus in academia. We combined these two fields in the study of observational data in an attempt to identify involvement of specific exotic particles in neutron star thermal evolution. We generated various equations of state (EOS) that lie within the theoretically established limits for the pion condensates and hyperons, and attempted to find thermal evolution regimens that are consistent with observations that cannot be explained by standard neutron star cooling models. Our chosen observations are; the Cassiopeia-A (Cas-A) supernova remnant for our pion model, and various low mass X-ray binaries (LMXB) for our hyperon and pion models. Our results strongly suggest the involvement of these aforementioned exotic particles in thermal evolution and related problems of certain neutron stars that lead to their unusual thermal behavior.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 880 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Compact Stars written by Norman K. Glendenning and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: A whole decades research collated, organised and synthesised into one single book! Following a 60-page review of the seminal treatises of Misner, Thorne, Wheeler and Weinberg on general relativity, Glendenning goes on to explore the internal structure of compact stars, white dwarfs, neutron stars, hybrids, strange quark stars, both the counterparts of neutron stars as well as of dwarfs. This is a self-contained treatment and will be of interest to graduate students in physics and astrophysics as well as others entering the field.
Download or read book Nuclear Equation Of State Lecture Notes Of The Workshop written by Ahmad Ansari and published by World Scientific. This book was released on 1996-03-22 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the diversified and changing scenarios of the current frontiers of nuclear physics research, the topic 'Nuclear Equation of State' occupies the pivotal position. The present series of lectures by well known experts in this field span a wide area ranging from low energy to ultrarelativistic energy, with application to astrophysical phenomena like supernovae explosions, neutron star and other stellar processes, phase transitions in quantum chromodynamics, and properties of quark-gluon plasma. The present status of the VUU model for the intermediate energy heavy-ion collisions is also reviewed.
