Dr. Smaranika Banerjee

Binary neutron star (BNS) mergers provide an excellent cosmic laboratory to understand the origin of heavy (Z > 26) elements, which has been a long-standing mystery in astronomy. In the neutron-rich material ejected from the BNS merger, heavy elements are synthesized via rapid neutron capture (r-process). The radioactive decay of such elements produces emission in the ultraviolet-optical-infrared (UVOIR) range, called a kilonova. Such a kilonova is already detected as a follow-up observation of gravitational wave from a BNS merger (GW170817), ushering in the era of multi-messenger astronomy. The observational properties of the kilonova (light curve and spectra) depend on the bound-bound opacity of the heavy elements, which has been the bottleneck for calculating the kilonova light curves. In my talk, I will discuss challenges and the recent progress in modelling kilonova light curves. In addition, I will share my recent work on opacity and light curve calculations of the kilonova starting from early time (t ~ hour).