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Related papers: The spotty donor star in the X-ray transient Cen X…

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We present new high resolution spectroscopy of the low mass X-ray binary Cyg X-2 which enables us to refine the orbital solution and rotational broadening of the donor star. In contrast with Elebert et al (2009) we find a good agreement…

Astrophysics of Galaxies · Physics 2015-05-14 J. Casares , J. I. Gonzalez Hernandez , G. Israelian , R. Rebolo

In this chapter we give an overview of the properties of X-ray binary systems containing a weakly magnetized neutron star. These are old (Giga-years life-time) semi-detached binary systems containing a neutron star with a relatively weak…

High Energy Astrophysical Phenomena · Physics 2023-11-22 Tiziana Di Salvo , Alessandro Papitto , Alessio Marino , Rosario Iaria , Luciano Burderi

We conducted the first long-term (60 days), multiwavelength (optical, ultraviolet, and X-ray) simultaneous monitoring of Cen X-4 with daily Swift observations from June to August 2012, with the goal of understanding variability in the low…

High Energy Astrophysical Phenomena · Physics 2015-06-16 F. Bernardini , E. M. Cackett , E. F. Brown , C. D'Angelo , N. Degenaar , J. M. Miller , M. Reynolds , R. Wijnands

More than 50 years after the dawn of X-ray astronomy, the dynamical parameters of the prototypical X-ray binary Sco X-1 are still unknown. We combine a Monte Carlo analysis, which includes all the previously known orbital parameters of the…

High Energy Astrophysical Phenomena · Physics 2016-11-03 D. Mata Sánchez , T. Muñoz-Darias , J. Casares , D. Steeghs , C. Ramos Almeida , J. A. Acosta Pulido

CONTEXT: The masses previously obtained for the X-ray binary 2S0921-630 inferred a compact object that was either a high-mass neutron star or low-mass black-hole, but used a previously published value for the rotational broadening (vsini)…

Astrophysics · Physics 2009-11-13 T. Shahbaz , C. A. Watson

We analyze observations of eight quiescent low-mass X-ray binaries in globular clusters and combine them to determine the neutron star mass-radius curve and the equation of state of dense matter. We determine the effect that several…

High Energy Astrophysical Phenomena · Physics 2018-02-14 A. W. Steiner , C. O. Heinke , S. Bogdanov , C. Li , W. C. G. Ho , A. Bahramian , S. Han

We present a model of thermal X-ray emission from hot spots on the surface of a rotating compact star with an unmagnetized light-element atmosphere. An application to ROSAT, Chandra, and XMM-Newton X-ray observations of the nearest known…

Astrophysics · Physics 2009-11-11 Slavko Bogdanov , George B. Rybicki , Jonathan E. Grindlay

Symbiotic X-ray binaries form a subclass of low-mass X-ray binary systems consisting of a neutron star accreting material from a red giant donor star via stellar wind or Roche lobe overflow. Only a few confirmed members are currently known;…

High Energy Astrophysical Phenomena · Physics 2015-06-18 A. A. Nucita , S. Stefanelli , F. De Paolis , N. Masetti , G. Ingrosso , M. Del Santo , L. Manni

We calculate temperature profiles and X-ray spectra of accretion disks around rapidly rotating neutron stars considering the full effect of general relativity. Computed disk temperatures and luminosities are compared with the EXOSAT data to…

Astrophysics · Physics 2007-05-23 Sudip Bhattacharyya

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…

Recent Chandra and XMM-Newton observations of a number of X-ray ``dim'' pulsating neutron stars revealed quite unexpected features in the emission from these sources. Their soft thermal spectrum, believed to originate directly from the star…

Astrophysics · Physics 2009-11-13 Silvia Zane , Roberto Turolla

Simultaneous, precise measurements of the mass $M$ and radius $R$ of neutron stars can yield uniquely valuable information about the still uncertain properties of cold matter at several times the density of nuclear matter. One method that…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Ka-Ho Lo , M. Coleman Miller , Sudip Bhattacharyya , Frederick K. Lamb

In an attempt to model the accretion onto a neutron star in low-mass X-ray binaries, we present two-dimensional hydrodynamical models of the gas flow in close vicinity of the stellar surface. First we consider a gas pressure dominated case,…

Astrophysics · Physics 2009-11-13 N. Babkovskaia , A. Brandenburg , J. Poutanen

Recently the first finding of a spin period of an accreting neutron star in M31 is reported. The observed spin period is 1.2 s and it shows 1.27 d modulations due to orbital motion. From the orbital information, the mass donor could not be…

High Energy Astrophysical Phenomena · Physics 2016-09-21 Shigeyuki Karino

Observations of thermonuclear X-ray bursts from accreting neutron stars (NSs) in low-mass X-ray binary systems can be used to constrain NS masses and radii. Most previous work of this type has set these constraints using Planck function…

High Energy Astrophysical Phenomena · Physics 2017-12-06 J. Nättilä , M. C. Miller , A. W. Steiner , J. J. E. Kajava , V. F. Suleimanov , J. Poutanen

We explore, using an exact cooling code, the thermal evolution of a neutron star undergoing episodes of intense accretion, alternated by long periods of quiescence (e.g. Soft X-Ray Transients). We find that the soft component of the…

Astrophysics · Physics 2007-05-23 Andrea Possenti , Monica Colpi , Dany Page , Ulrich Geppert

We calculate the accretion disc temperature profiles, disc luminosities and boundary layer luminosities for rapidly rotating neutron stars considering the full effect of general relativity. We compare the theoretical values of these…

Astrophysics · Physics 2009-11-07 Sudip Bhattacharyya

We present an improved method for determining the mass of neutron stars in eclipsing X-ray pulsar binaries and apply the method to six systems, namely Vela X-1, 4U 1538-52, SMC X-1, LMC X-4, Cen X-3, and Her X-1. In previous studies to…

The determination of fundamental parameters in low-mass X-ray binaries typically relies on measuring the radial velocity curve of the companion star through optical or near-infrared spectroscopy. It was recently suggested that high…

High Energy Astrophysical Phenomena · Physics 2018-07-25 Gabriele Ponti , Stefano Bianchi , Teo Muñoz-Darias , Kirpal Nandra

We explore the population of candidate pre-low-mass X-ray binaries in which a neutron star accretes mass from the wind of a low-mass companion (mass < 2Msun) in the framework of a binary population synthesis study. The simulated…

Astrophysics · Physics 2009-11-07 B. Willems , U. Kolb