Wednesday Colloquium


"Pulsation Modelling of the Binary Evolution Pulsators"

Radosław Smolec (NCAC, Warsaw)

I will present the results of nonlinear modelling of 0.26-solar masses singly-periodic, large-amplitude pulsator with light and radial velocity curves mimicking the typical RR Lyrae curves. The star is a member of the well-detached eclipsing binary system and hence, its basic parameters are well known. I will show that the shape of the radial velocity curve results from resonant mode interaction just as in the case of the Cepheid bump (Hertzsprung) progression. The presence of the resonance strongly constrains the stellar model and allows for independent determination of stellar parameters.


"How philosophy begins? The Rigveda - an ancient Indian text"

Joanna Jurewicz (Department of Oriental Studies, University of Warsaw)

Read about Joanna Jurewicz and her research on:


"Links between Galactic Black Hole Binary and AGN accetion"

Małgorzata Sobolewska (Harvard Smithsonian Center for Astrophysics)

Spectral and temporal signatures of black hole accretion show striking similarities for a wide range of black hole masses. I will present recent evidence for common accretion engine in all classes of accreting black holes coming from the studies of the energy spectra and lightcurves in the optical/X-ray/gamma-ray bands. I will particularly focus on the properties of the so-called hard spectral state.


"A search for nontoroidal topological lensing in the SDSS quasar catalog"

藤井宏和 (Hirokazu Fujii) (University of Tokyo)

Our Universe could possess multiply connected topology on large scales, and in that case multiple images of single objects would be observed (topological lensing). In this talk, we first introduce a four-point statistics of spatial distribution of cosmic objects that is designed to detect nontoroidal (generated by screw motion or glide reflection) flat topologies, and compare it to CMB-based methods. We next present some results of applying the method to SDSS high-z quasars.