6533b7d1fe1ef96bd125d72a
RESEARCH PRODUCT
Evidence of a non-conservative mass transfer for XTE J0929-314
Andrea SannaAngelo GambinoA. MarinoT. Di SalvoA. RiggioLuciano BurderiM. MatrangaR. Iariasubject
Astrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencesStars: individual: XTE J0929-314AstrophysicsAstrophysics::Cosmology and Extragalactic Astrophysics01 natural sciencesLuminosityPulsarMillisecond pulsar0103 physical sciencesX-rays: star010303 astronomy & astrophysicsAstrophysics::Galaxy AstrophysicsPhysicsHigh Energy Astrophysical Phenomena (astro-ph.HE)010308 nuclear & particles physicsGravitational waveAstronomy and AstrophysicsAstronomy and AstrophysicGalactic planeOrbital periodX-rays: binarieStars: neutronGalaxyNeutron starSpace and Planetary Scienceindividual: XTE J0929-314; Stars: neutron; X-rays: binaries; X-rays: stars; Astronomy and Astrophysics; Space and Planetary Science [Stars]Astrophysics - High Energy Astrophysical Phenomenadescription
Context. In 1998 the first accreting millisecond pulsar, SAX J1808.4-3658, was discovered and to date 18 systems showing coherent, high frequency (> 100 Hz) pulsations in low mass X-ray binaries are known. Since their discovery, this class of sources has shown interesting and sometimes puzzling behaviours. In particular, apart from a few exceptions, they are all transient with very long X-ray quiescent periods implying a quite low averaged mass accretion rate onto the neutron star. Among these sources, XTE J0929-314 has been detected in outburst just once in about 15 years of continuous monitoring of the X-ray sky. Aims. We aim to demonstrate that a conservative mass transfer in this system will result in an X-ray luminosity that is higher than the observed, long-term averaged X-ray luminosity. Methods. Under the hypothesis of a conservative mass transfer driven by gravitational radiation, as expected for this system given the short orbital period of about 43.6 min and the low mass of the companion implied by the mass function derived from timing techniques, we calculate the expected mass transfer rate in this system and predict the long-term averaged X-ray luminosity. This is compared with the averaged, over 15 years, X-ray flux observed from the system, and a lower limit of the distance to the source is inferred. Results. This distance is shown to be > 7.4 kpc in the direction of the Galactic anticentre, implying a large height, > 1.8 kpc, of the source with respect to the Galactic plane, placing the source in an empty region of the Galaxy. We suggest that the inferred value of the distance is unlikely. (abridged)
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2017-07-14 |