Found 13 talks width keyword X-ray binaries

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Tuesday July 20, 2010
The Bowen Survey; detecting donor star signatures in low mass X-ray binaries
Instituto de Astrofísica de Canarias, Spain

Abstract

For most persistent low mass X-ray binaries (LMXBs) and transients in outbursts the optical emission is dominated by reprocessing of the X-rays in the outer accretion disk. This has severely hampered any dynamical studies and thereby our knowledge of their system parameters. A new avenue opened thanks to the discovery of narrow high-excitation emission components arising from the irradiated companion star. These lines are most prominent in the Bowen region (a blend of N III and C III lines between 4630 and 4650 Å). In this talk I will discuss this new technique, give an overview of the main results of our survey on the optically brightest LMXBs, and discuss the implications for their system parameters. Furthermore, I will point out the main limitations of this technique and how they might be overcome.
Archived in: Stars - Keywords:X-ray binaries, mass function, black holes, accretion, accretion discs
Abstract


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Friday November 20, 2009
Optical and NIR studies of short period low mass X-ray binaries (LMXB)
Tuorla Observatory, University of Turku, Finland

Abstract

I present some recent results from our Optical and NIR studies of five short period low-mass X-ray binaries (LMXB's; X1822-371, X1957+115, UW CrB, X1916-05 and X0614+091). Optical photometry and spectroscopy reveal some surprising results on the geometry and evolution of accretions discs in LMXB's. Based on our data, it is increasingly clear that accretion discs in these systems are far from being stable and must undergo substantial precession and/or warping behaviour on timescales less than a day in case of the shortest period systems.
Archived in: Stars, Particle astrophysics, physical data and processes - Keywords:X-ray binaries, binary evolution, accretion, accretion discs
Abstract


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Wednesday October 7, 2009
Rapid Temporal Survey (RaTS) - the search for ultra compact binaries
Armagh Observatory, UK

Abstract

Ultra Compact Binaries are predicted to be the strongest known sources of gravitational waves in the LISA pass-band. Since they are at the short period end of the orbital period distribution (<70 mins), their number is a sensitive test of binary evolutionary models. The best method to detect these short period systems, whose optical light is dominated by an accretion disk and show optical intensity variations on timescales close to their orbital period, is through deep, wide-field, fast-cadence photometric surveys. The RaTS (Rapid Temporal Survey) project is unique in that it is sensitive to variability on timescales as short as 2 mins and systems with V~22. Our strategy and initial results will be presented.
Archived in: Stars - Keywords:LISA, X-ray binaries, late-type stars, accretion, accretion discs
Abstract


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