Gravitational Microlensing and Degeneracy Problem: New Method for Breaking the Degeneracy Using Gaia Catalogue

امیرحسین دهقانی (دانشکده فیزیک دانشگاه صنعتی شریف )

Abstract:  Detection of light blending in a gravitational field, previously predicted by general relativity, stimulated a new line of research for astronomers. In 1986, Paczynski, regarding the dark matter problem, investigated the possibility of observing lensing of a source star light by gravitational field of another star in the Milky Way galaxy. In a simple microlensing event, the only observable parameter that has physical information is the Einstein crossing time; a characteristic time scale of microlensing events. This parameter is a function of lens mass, lens and source distance and their relative velocity. Several methods have been proposed to overcome this degeneracy problem. In this talk, after presenting a brief review of basic formalism and physics, I will show different methods of microlensing degeneracy breaking and will finally present my proposal which is mainly based on Gaia observations. The results show a continuum in mass distribution of lenses with some candidates for neutron stars and black holes.

 

یکشنبه 3 آذر 1398، ساعت 15:00

دانشکده فیزیک، طبقه اول کلاس فیزیک 3