Speaker
Description
Multi-wavelength observations of different core-collapse Supernovae (SNe) have confirmed the presence of dense Circumstellar Material (CSM) around the progenitor star. The CSM is formed as a result of high mass loss of the progenitor star a few years prior to its death. Interaction of this CSM with high energy particles created in supernova explosion can produce secondary particles like high energy neutrinos and gamma rays. We term such SNe as Young Supernova (YSNe) as this interaction generally lasts for about a year after explosion and estimate the spectra of high energy neutrinos and gamma rays emitted by different types (IIn, II-P, Ib/c, and IIb/II-L) of YSNe. The estimate of the diffuse backgrounds of high energy neutrinos and gamma rays from YSNe shows largest contribution to the diffuse background by type IIn, followed by II-P and Ib/c. Interestingly, the corresponding diffuse neutrino background can also explain very well the IceCube’s diffuse flux. However, the dense CSM of these YSNe attenuate a large fraction of the gamma rays resulting in a ``dark’' source in the diffuse flux and doesn’t create any tension with the Fermi-LAT’s Isotropic Gamma Ray Background (IGRB).
