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Related papers: Refined Neutron-Star Mass Determinations for Six E…

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Observational identification of black holes as members of binary systems requires the knowledge of the upper limit on the gravitational mass of a neutron star. We use modern equations of state for neutron star matter, fitted to experimental…

Astrophysics · Physics 2009-10-28 Vassiliki Kalogera , Gordon Baym

Reliable neutron star mass measurements are key to determining the equation-of-state of cold nuclear matter, but these are rare. "Black Widows" and "Redbacks" are compact binaries consisting of millisecond pulsars and semi-degenerate…

A population of obscured supergiant High Mass X-ray Binaries (sgHMXBs) has been discovered by INTEGRAL. X-ray wind tomography of IGR J17252-3616 inferred a slow wind velocity to account for the enhanced obscuration. The main goal of this…

High Energy Astrophysical Phenomena · Physics 2012-10-11 A. Manousakis , R. Walter , J. M. Blondin

A recent analysis of photospheric radius expansion X-ray bursts from the low-mass X-ray binary 4U 1746-37 reported unusually small mass and radius estimates for the neutron star, suggesting it could be a quark star or quark-cluster star.…

High Energy Astrophysical Phenomena · Physics 2026-05-15 Kwang Hyun Sung , Myungkuk Kim , Young-Min Kim , Kyujin Kwak , Chang-Hwan Lee

I discuss constraints on the equation of state of matter at supra-nuclear densities that can be derived from observations of neutron stars. I focus on recent work on Vela X-1, which may well be substantially more massive than the canonical…

Astrophysics · Physics 2007-05-23 M. H. van Kerkwijk

We report on the detailed modelling of the X-ray spectra of three likely neutron stars. The neutron stars, observed with XMM-Newton are found in three quiescent X-ray binaries in the globular clusters: omega Cen, M 13 and NGC 2808. Whether…

Astrophysics · Physics 2009-11-13 N. A. Webb , D. Barret

We present phase resolved optical spectroscopy and X-ray timing of the neutron star X-ray binary EXO 0748-676 after the source returned to quiescence in the fall of 2008. The X-ray light curve displays eclipses consistent in orbital period,…

High Energy Astrophysical Phenomena · Physics 2015-05-13 C. G. Bassa , P. G. Jonker , D. Steeghs , M. A. P. Torres

Context. The properties of the X-ray emission lines are a fundamental tool for studying the nature of the matter surrounding the neutron star and the phenomena that produce these lines. Aims. The aim of this work is to analyze the X-ray…

High Energy Astrophysical Phenomena · Physics 2010-12-06 J. J. Rodes-Roca , K. L. Page , J. M. Torrejón , J. P. Osborne , G. Bernabéu

We determine an empirical dense matter equation of state from a heterogeneous dataset of six neutron stars: three type I X-ray bursters with photospheric radius expansion, studied by Ozel et al., and three transient low-mass X-ray binaries.…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Andrew W. Steiner , James M. Lattimer , Edward F. Brown

We report near-infrared radial velocity measurements of the recently identified donor star in the high mass X-ray binary system OAO 1657-415 obtained in the H band using ISAAC on the VLT. Cross-correlation methods were employed to construct…

Solar and Stellar Astrophysics · Physics 2015-05-27 A. B. Mason , J. S. Clark , A. J. Norton , P. A. Crowther , T. M. Tauris , N. Langer , I. Negueruela , P. Roche

We analyse four XMM-Newton observations of the neutron-star low-mass X-ray binary EXO 0748$-$676 in quiescence. We fit the spectra with an absorbed neutron-star atmosphere model, without the need for a high-energy (power-law) component;…

High Energy Astrophysical Phenomena · Physics 2017-08-16 Zheng Cheng , Mariano Mendez , Maria Diaz-Trigo , Elisa Costantini

X-ray eclipse mapping is a promising modelling technique, capable of constraining the mass and/or radius of neutron stars (NSs) or black holes (BHs) in eclipsing binaries and probing any structure surrounding the companion star. In…

High Energy Astrophysical Phenomena · Physics 2022-05-25 Amy H. Knight , Adam Ingram , Matthew Middleton

We investigate the distribution of neutron star masses in different populations of binaries, employing Bayesian statistical techniques. In particular, we explore the differences in neutron star masses between sources that have experienced…

High Energy Astrophysical Phenomena · Physics 2022-07-22 Feryal Ozel , Dimitrios Psaltis , Ramesh Narayan , Antonia Sierra Villarreal

Recent observations from NICER in X-rays and LIGO/Virgo in gravitational waves have provided critical constraints on the mass, radius, and tidal deformability of neutron stars, imposing stringent limits on the equation of state (EOS) and…

High Energy Astrophysical Phenomena · Physics 2025-10-03 R. Moradi , Y. Wang , F. Rastegarnia , E. S. Yorgancioglu , Shu-Xu Yi , B. Eslam Panah , S. N. Zhang

We calculate the maximum mass of neutron stars for three different equations of state (EOS) based on generalized Skyrme functionals that are simultaneously fitted to essentially all the 2003 nuclear mass data (the rms deviation is 0.58 MeV…

Nuclear Theory · Physics 2012-12-05 N. Chamel , A. F. Fantina , J. M. Pearson , S. Goriely

Thermal emission during X-ray bursts is a powerful tool to determine neutron star masses and radii, if the Eddington flux and the apparent radius in the cooling tail can be measured accurately, and distances to the sources are known. We…

High Energy Astrophysical Phenomena · Physics 2015-03-17 Valery Suleimanov , Juri Poutanen , Mikhail Revnivtsev , Klaus Werner

We present a new method to measure the radius-to-mass ratio (R/M) of weakly magnetic, disc-accreting neutron stars by exploiting the occultation of parts of the inner disc by the star itself. This occultation imprints characteristic…

This study investigates the timing and spectral characteristics of X-ray bursts from the neutron star system EXO 0748-676 using the NuSTAR observatory's FPMA and FPMB instruments in the 3-79 keV range. We identify Type I X-ray bursts driven…

High Energy Astrophysical Phenomena · Physics 2024-10-15 Nirpat Subba , Nishika Subba , Jyoti Paul , Pankaj Sharma , Monika Ghimiray

The measurement or constraint of the masses of neutron stars and their binary companions tests theories of neutron star structure and of pulsar formation and evolution. We have measured the rate of the general relativistic advance of the…

Astrophysics · Physics 2009-10-22 S. E. Thorsett , Z. Arzoumanian , M. M. McKinnon , J. H. Taylor

In the past few years, new observations of neutron stars and neutron-star mergers have provided a wealth of data that allow one to constrain the equation of state of nuclear matter at densities above nuclear saturation density. However,…

High Energy Astrophysical Phenomena · Physics 2021-11-18 Peter T. H. Pang , Ingo Tews , Michael W. Coughlin , Mattia Bulla , Chris Van Den Broeck , Tim Dietrich