The edges of dark matter halos: Challenges and opportunities

by Prof. Surhud More (IUCAA)

Friday 25 Jul 2025, 14:30 → 16:00 Asia/Kolkata

A (304)

The boundaries of dark matter halos show a sharp fall off in density at the outskirts. I will discuss the physics behind this feature called the splashback radius, and our efforts to detect it in observations over the last decade. The splashback radius combined with the measure of its halo mass allows a direct access to its mass accretion history. Given the importance of mass accretion rates to cosmology and to the formation and evolution of galaxies within the halo, accurate detection of splashback radius is important. I will present the challenges in the detection of these boundaries using samples of optically selected galaxy clusters, and how the inference of the such boundaries can be affected by choices of background subtractions carried out during the optical selection. I will also present our recent efforts to use galaxy clusters in SZ and X-rays and first efforts to translate these measurements in to the accretion rates of galaxy clusters.