| Abstract: |
The 511 keV gamma-ray line is crucial for studying positron production and distribution in our Galaxy. While its origin remains unclear, various theoretical scenarios have been proposed, including dark matter decay or annihilation. In this talk, I present preliminary results from analyzing 20 years of INTEGRAL/SPI data, providing the largest statistical sample of 511 keV emission observations to date. To efficiently process ~1.4×10⁵ observations with SPI's coded-mask aperture, we developed a computational framework utilizing GPU acceleration and sparse matrix techniques. Our analysis confirms the spatial components previously suggested from 10-year data analysis: a bright Galactic center, an extended bulge emission (~10-degree scale), and a disk component. Moreover, we are preparing for 511 keV observations with 10x better sensitivity using the upcoming MeV gamma-ray satellite COSI. We will discuss our novel approach to Compton telescope data analysis, introducing sparse modeling and Bayesian methods to gamma-ray astronomy. |
