Insights Into Neutron Stars From Gravitational Redshifts and Universal Relations

Abstract

The universal relations in neutron stars form an essential entity to understand their properties. The moment of inertia, dimensionless tidal deformability, mass quadrupole moment, and oscillation modes are some of the properties that have been studied previously in the context of universal relations. All of these quantities are measurable; thus, analyzing them is of utmost importance. In this article we provide new universal relations in the context of a neutron star's gravitational redshift. Using the redshift measurements of RBS 1223, RX J0720.4-3125, and RX J1856.5-3754, we provide theoretical estimates of moment of inertia, dimensionless tidal deformability, mass quadrupole moment, the mass of the star times the ratio of angular frequency over the spin angular moment, and the average of the speed of sound squared. In the case of the redshift measurement of RX J0720.4-3125, we found that the theoretical estimate using universal relations aligns closely with the Bayesian estimate. Our findings indicate that such theoretical predictions are highly reliable for observations with low uncertainty and can be used as an alternative for statistical analysis. Additionally, we report a violation of the universality of the dimensionless tidal deformability and average of the speed of sound squared with respect to the gravitational redshift. Our calculations further indicate that, under current astrophysical constraints, the maximum gravitational redshift attainable by neutron stars does not exceed $0.763$.

arXiv comment8 pages, 8 figures, 3 tables; Accepted for publication in European Physical Journal C

References in corpus (41)

• A Massive Pulsar in a Compact Relativistic Binary
• GW170817: Measurements of Neutron Star Radii and Equation of State
• PSR J0030+0451 Mass and Radius from NICER Data and Implications for the Properties of Neutron Star Matter
• Relativistic Shapiro delay measurements of an extremely massive millisecond pulsar
• The Physics of Neutron Stars
• Refined Mass and Geometric Measurements of the High-Mass PSR J0740+6620
• Equation of state and neutron star properties constrained by nuclear physics and observation
• New constraints on radii and tidal deformabilities of neutron stars from GW170817
• Evidence for quark-matter cores in massive neutron stars
• PSR J0952-0607: The Fastest and Heaviest Known Galactic Neutron Star
• Comparing Models of Rapidly Rotating Relativistic Stars Constructed by Two Numerical Methods
• Cold Quark Matter
• I-Love-Q
• Approximate Universal Relations for Neutron Stars and Quark Stars
• Maximum mass, moment of inertia and compactness of relativistic stars
• On the Sound Speed in Neutron Stars
• Equation of state sensitivities when inferring neutron star and dense matter properties
• Construction of Highly Accurate Models of Rotating Neutron Stars - Comparison of Three Different Numerical Schemes
• The Equation of State for the Nucleonic and Hyperonic Core of Neutron Stars
• Spectral Approach to the Relativistic Inverse Stellar Structure Problem II
• Bayesian Inference of Dense Matter Equation of State within Relativistic Mean Field Models using Astrophysical Measurements
• On the compactness of the isolated neutron star RX J0720.4-3125
• A general, scale-independent description of the sound speed in neutron stars
• Holographic compact stars meet gravitational wave constraints
• Moment of inertia -- compactness universal relations in scalar-tensor theories and ${\mathcal{R}}^2$ gravity
• Nearly model-independent constraints on dense matter equation of state in a Bayesian approach
• Decoding Neutron Star Observations: Revealing Composition through Bayesian Neural Networks
• The Masses of Isolated Neutron Stars Inferred from the Gravitational Redshift Measurements
• Bayesian inference of the dense matter equation of state built upon extended Skyrme interactions
• Thermodynamics of Hot Neutron Stars and Universal Relations
• I-Love-$⟨c_s^2⟩$: Approximately universal relations for the average neutron star stiffness
• Universal relations for compact stars with exotic degrees of freedom
• Analyzing the speed of sound in neutron star with machine learning
• Neural Simulation-Based Inference of the Neutron Star Equation of State directly from Telescope Spectra
• Critical mass, moment of inertia and universal relations of rapidly rotating neutron stars with exotic matter
• Universal Relations for rapidly rotating neutron stars using supervised machine-learning techniques
• Prospect of unraveling the first-order phase transition in neutron stars with $f$ and $p_1$ modes
• Universal Relations For Generic Family Of Neutron Star Equations Of State
• Analyzing the dense matter equation of states in the light of the compact object HESS J1731-347
• Effects of strangeness on the chiral pseudocritical line
• The Bulk Properties of Isolated Neutron Stars Inferred from the Gravitational Redshift Measurements

Cited by in corpus (2)

• Universal relation between dipole polarizability of finite nuclei and neutron-star compactness
• Binding energy of compact stars and their non-radial oscillations