Seminario DAS: Probing the Comic Baryons with the Fast Radio Bursts

Speaker: Dr. Ilya Khrykin
Affiliation: Instituto de Física, Pontificia Universidad Católica de Valparaíso

Abstract: The Fast Radio Bursts (FRB) are extragalactic, extremely bright, millisecond radio pulses of yet unknown nature. They constitute a unique probe of various astrophysical and cosmological phenomena via the characteristic dispersion (DM) and Faraday rotation (RM) measures that encode information about the ionized gas in various environments along the line-of-sight. For instance, FRBs were paramount in resolving the so-called ‘missing baryons problem’, yet the major questions remained regarding the relative distribution of cosmic baryons in the diffuse IGM vs CGM of the galactic halos.  Unraveling the exact partition of cosmic baryons would, for instance, inform the models of galaxy formation and feedback mechanisms. However, constraining the relative distribution of cosmic baryon is challenging due to the large cosmic variance induced by the unknown density field and intervening galactic halos along the FRB sightlines. In my talk, I will discuss how this issue can be mitigated by measuring the spectroscopic redshift distribution of foreground galaxies in front of localized FRBs in order to map out the cosmic web as well as characterize the intervening galactic halos. I will describe the FLIMFLAM, an ongoing multi-facility spectroscopic survey that maps the foregrounds of localized FRBs primarily detected by CRAFT/ASKAP and localized by the F^4 collaboration. I will present the analysis of the FLIMFLAM’ first data release and show the first direct constraints on the relative partition of cosmic baryons between the CGM and IGM, as well as the estimate on the average host galaxy contribution to the dispersion measure. I will also give an overview of the current status of the FRB field.