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- 07.11. Maksat Satybaldiev (IFY, NTNU): Study of X-ray flares from the wind-fed X-ray binaries
Abstract: X-ray binary systems are an interesting class of objects. They consist of a compact object (neutron star or black hole) accreting material from the massive companion star's wind. Such systems serve as "dirty laboratories" - their observational manifestations involve a complex interplay between the stellar wind and the magnetic and gravitational fields of the compact object. Studying such systems is important for understanding the properties of extreme objects, especially neutron stars and their magnetospheres, as well as accretion processes, stellar evolution, and the structure and interaction of stellar winds. In my talk, I will present the results of an analysis of two wind-fed X-ray binaries: the Supergiant Fast X-ray Transient IGR J16195-4945 and the Red Supergiant X-ray Binary 3A 1954+319.
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- 14.11. Raphaël Mignon-Risse (IFY, NTNU): Towards multi-messenger observations of accreting binary black holes
Abstract: Despite the re-birth of multi-messenger astronomy, no unambiguous electromagnetic (EM) counterpart to binary black hole (BBH) merger has been reported. Supermassive BBHs are potential targets because they should be embedded in gas-rich media provided by their host galaxies merging together. However, their accretion properties and EM/multi-messenger signatures are not firmly identified because few numerical codes are able to model accretion and emission around BBHs in General Relativity (GR). In this talk, I will present e-NOVAs, standing for "extended Numerical Observatory for Violent Accreting systems" as it has been recently extended to work with any type of spacetime. It is the first European code to evolve an analytical BBH metric as it solves the equations of GR-magnetohydrodynamics and to compute synthetic observations in the same metric via GR ray-tracing. Using e-NOVAs, I will study a BBH circumbinary disk evolution and its EM observables. I will briefly present the accretion structures that could potentially help us distinguishing BBHs. I will show if their spectro-timing properties could be used as an EM signature allowing us to distinguish BBHs from other transient sources in the future. Finally, I will briefly present the first project I will be carrying out here at NTNU.
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