RSAA Colloquia / Seminars / Feast-of-Facts: Friday, 16 June 2017, 14:00-14:20; Duffield Lecture Theatre

Fiona Panther

"Annual Review 2017: Hunting down the origin of Galactic antimatter"

The brightest gamma ray line associated with our Galaxy is produced by the annihilation of ~5*10^43 antimatter positrons each second. Nearly 50 years on from the discovery of this gamma ray line, the origin of the antimatter responsible for producing it has remained mysterious, with a variety of astrophysical phenomena - from supernovae to our Galaxy’s SMBH - implicated. Any explanation for the origin of this Galactic antimatter must not only explain the total rate of positron production in the Galaxy, but must also explain the morphology of the gamma ray line and the overall positron annihilation spectrum. In this talk I will discuss my work on positron propagation in Galactic outflows, and on understanding the stellar populations that host SN1991bg-like supernovae, recently shown to be a compelling source of a large fraction of the diffuse antimatter in our Galaxy. I will also introduce PosMC, a state of the art positron microphysics simulation, and the new python package delilah, designed to streamline the study of supernova host galaxies with IFU data. Finally, I provide a brief summary of my future work with the Dark Energy Survey, using machine learning techniques to identify peculiar sub-luminous supernovae using only photometric data.