Early-type galaxies (i.e. elliptical and lenticular) are divided into slow and fast rotators according to the appearance of their maps of line-of-sight velocity. Fast rotators show clear ordered rotation, while slow are supported mostly by velocity dispersion. I will speak about our work on investigation of the origin of this diversity. Inspired by cosmological simulations, we assumed that galaxies first form as fast rotators and then mergers transform some of them to slow rotators. We investigated the correlations of a measure of rotational support with various properties of galaxies that are sensitive to mergers. These include stellar ages, the presence of tidal features, and kinematically distinct cores. Each of these parameters is sensitive to a different type of merger and has a different lifetime. The found correlations, or their lack, together with observations of high-redshift universe, are explained the easiest, if the rotation support of early-type galaxies was decreased by multiple minor wet mergers more than 10 Gyr ago.

Location: ASU Spořilov, 101

In the talk I briefly discuss the present day view on the magnetic field evolution of neutron stars and its main observational appearance. Then, I focus on the possibility to find magnetars in binary systems of different kind. Possible candidates include accreting neutron stars (in particular, ultra luminous X-ray sources), gamma-ray sources, and fast radio bursts. I present a scenario in which the existence of a highly magnetized neutron star in a high-mass X-ray binary is possible at an age of a few million years.

Location: Praha-Spořilov

seminar room 101