Search results for "Quàsars"

showing 2 items of 2 documents

Long-term X-ray variability of the microquasar system LS 5039/RX J1826.2−1450

2003

We report on the results of the spectral and timing analysis of a BeppoSAX observation of the microquasar system LS 5039/RX J1826.2-1450. The source was found in a low-flux state with Fx(1-10 keV)= 4.7 x 10^{-12} erg cm^{-2} s^{-1}, which represents almost one order of magnitude lower than a previous RXTE observation 2.5 years before. The 0.1--10 keV spectrum is described by an absorbed power-law continuum with photon-number spectral index Gamma=1.8+-0.2 and hydrogen column density of NH=1.0^{+0.4}_{-0.3} x 10^{22} cm^{-2}. According to the orbital parameters of the system the BeppoSAX observation covers the time of an X-ray eclipse should one occur. However, the 1.6-10 keV light curve does…

HydrogenVariable starschemistry.chemical_elementFOS: Physical sciencesAstrophysicsCompact starAstrophysicsUNESCO::ASTRONOMÍA Y ASTROFÍSICAAccretion rateRadio astronomyQuasarsQuàsarsEstels binaris de raigs XOrbital elementsPhysicsSpectral indexRX J1826.2−1450Astrophysics (astro-ph)X-rayIndividual Star ; LS 5039 ; RX J1826.2−1450 ; 3EG J1824−1514 – X-rays ; Variable stars ;; General–radio continuumAstronomy and AstrophysicsIndividual StarLight curveGeneral–radio continuum:ASTRONOMÍA Y ASTROFÍSICA::Cosmología y cosmogonia [UNESCO]StarsEstelsX-ray binarieschemistrySpace and Planetary ScienceRadioastronomiaLS 50393EG J1824−1514 – X-raysUNESCO::ASTRONOMÍA Y ASTROFÍSICA::Cosmología y cosmogoniaOrder of magnitude:ASTRONOMÍA Y ASTROFÍSICA [UNESCO]
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Orbital X‐Ray Variability of the Microquasar LS 5039

2005

The properties of the orbit and the donor star in the high mass X-ray binary microquasar LS 5039 indicate that accretion processes should mainly occur via a radiatively driven wind. In such a scenario, significant X-ray variability would be expected due to the eccentricity of the orbit. The source has been observed at X-rays by several missions, although with a poor coverage that prevents to reach any conclusion about orbital variability. Therefore, we conducted RossiXTE observations of the microquasar system LS 5039 covering a full orbital period of 4 days. Individual observations are well fitted with an absorbed power-law plus a Gaussian at 6.7 keV, to account for iron line emission that …

PhysicsPhotonAstrophysics::High Energy Astrophysical PhenomenaAstrophysics (astro-ph)FOS: Physical sciencesBinary numberAstronomy and AstrophysicsAstrophysicsCompact starRadiationAstrophysicsEphemerisOrbital periodSynchrotronAccretion (astrophysics)law.inventionX-ray binariesSpace and Planetary SciencelawX-raysRaigs XAstrophysics::Earth and Planetary AstrophysicsQuasarsQuàsarsEstels binaris de raigs XThe Astrophysical Journal
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