Forty eclipsing binaries in the Small Magellanic Cloud: fundamental parameters and Cloud distance     

R. W. Hilditch  I. D. Howarth  T. J. Harries 《Monthly notices of the Royal Astronomical Society》2005,357(1):304-324

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Photometric Studies of Bright Southern Binary Systems: ε Cra and ψ Ori     

R. R. Shobbrook  S. Zola 《Astrophysics and Space Science》2006,304(1-4):43-45

We present results from detailed analyses of new data combined with previously published light curves of ε Cra and ψ Ori. Based on the shape of the secondary minimum of ε CrA we found that the discrepancy between the photometric and spectroscopic mass ratio, although marginal, is statistically significant. We propose a third light as a possible solution and derive the absolute parameters of components. The physical parameters of components of the early-type binary system ψ Ori were also obtained from the light curve modelling. Our solution indicate that ψ Ori is a detached, grazing-eclipse system.  相似文献   

蓝离散星研究现状(Ⅱ):观测特性     

新宇  邓李才  梁艳春 《天文学进展》2006,24(3):223-243

不同恒星系统(银河系晕、疏散星团、球状星团、矮星系)中蓝离散星所表现出的观测特性各不相同,这与恒星系统动力学环境及相应的蓝离散星主导形成机制直接相关。因此,分析研究蓝离散星的不同观测特性,也就成为研究蓝离散星形成机制、恒星及双星系统演化以及恒星系统动力学演化的有效方法。  相似文献   

Jets in neutron star X-ray binaries: a comparison with black holes     

S. Migliari  R. P. Fender 《Monthly notices of the Royal Astronomical Society》2006,366(1):79-91

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Determination of the Ages of Close Binary Stars on the Main Sequence from Evolutionary Model Stars of Claret and Gimenez     

G. N. Dryomova  M. A. Svechnikov 《Astrophysics》2002,45(3):342-357

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Erratum: Speckle observations with PISCO in Merate – I. Astrometric measurements of visual binaries in 2004     

M. Scardia  J.-L. Prieur  M. Sala  M. Ghigo  L. Koechlin  E. Aristidi  F. Mazzoleni 《Monthly notices of the Royal Astronomical Society》2005,362(3):1120-1120

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Short-period AM CVn systems as optical, X-ray and gravitational-wave sources   总被引：1，自引：0，他引：1  

G. Nelemans  L. R. Yungelson  S. F. Portegies Zwart 《Monthly notices of the Royal Astronomical Society》2004,349(1):181-192

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Rapid variability of the arcsec-scale X-ray jets of SS 433     

S. Migliari  R. P. Fender  K. M. Blundell  M. Méndez  M. van der Klis 《Monthly notices of the Royal Astronomical Society》2005,358(3):860-868

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The X-ray spectrum of Cyg X-2     

C.Done  P. T.Z&#;ycki  D. A.Smith 《Monthly notices of the Royal Astronomical Society》2002,331(2):453-462

The spectra of disc accreting neutron stars generally show complex curvature, and individual components from the disc, boundary layer and neutron star surface cannot be uniquely identified. Here we show that much of the confusion over the spectral form derives from inadequate approximations for Comptonization and for the iron line. There is an intrinsic low-energy cut-off in Comptonized spectra at the seed photon energy. It is very important to model this correctly in neutron star systems as these have expected seed photon temperatures (from either the neutron star surface, inner disc or self-absorbed cyclotron) of ≈1 keV, clearly within the observed X-ray energy band. There is also reflected continuum emission which must accompany the observed iron line, which distorts the higher energy spectrum. We illustrate these points by a reanalysis of the Ginga spectra of Cyg X-2 at all points along its Z track, and show that the spectrum can be well fitted by models in which the low-energy spectrum is dominated by the disc, while the higher energy spectrum is dominated by Comptonized emission from the boundary layer, together with its reflected spectrum from a relativistically smeared, ionized disc.  相似文献   

A source of high-velocity white dwarfs     

Melvyn B. Davies  rew King  Hans Ritter 《Monthly notices of the Royal Astronomical Society》2002,333(2):463-468

We investigate whether the recently observed population of high-velocity white dwarfs can be derived from a population of binaries residing initially within the thin disc of the Galaxy. In particular, we consider binaries where the primary is sufficiently massive to explode as a Type II supernova. A large fraction of such binaries are broken up when the primary then explodes as a supernova, owing to the combined effects of the mass loss from the primary and the kick received by the neutron star on its formation. For binaries where the primary evolves to fill its Roche lobe, mass transfer from the primary leads to the onset of a common envelope phase during which the secondary and the core of the primary spiral together as the envelope is ejected. Such binaries are the progenitors of X-ray binaries if they are not broken up when the primary explodes. For those systems that are broken up, a large number of the secondaries receive kick velocities ∼100–200 km s⁻¹ and subsequently evolve into white dwarfs. We compute trajectories within the Galactic potential for this population of stars and relate the birth rate of these stars over the entire Galaxy to those seen locally with high velocities relative to the local standard of rest (LSR) . We show that for a reasonable set of assumptions concerning the Galactic supernova rate and the binary population, our model produces a local number density of high-velocity white dwarfs compatible with that inferred from observations. We therefore propose that a population of white dwarfs originating in the thin disc may make a significant contribution to the observed population of high-velocity white dwarfs.  相似文献