2025/03/06 by Xiaoqing Sun, Stephanie O’Neil, Sun, Xiaoqing +5 · 1 voice
Engineering · #Advanced Measurement and Detection Methods
paper · doi:10.33232/001c.142495
openalex publication_date 2025/07/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The splashback radius is a boundary of a halo that separates infalling and accreted matter. This results in a steep drop in the density profile at , which is a commonly adopted proxy for . Observationally, can be measured through fitting the projected galaxy number density profile of the halo, but there has been some discrepancy between the observed and expected . Therefore, we investigate whether the projection of the density profile onto the plane of the sky could lead to any systematic bias in determining , by studying the true 3-dimensional and projected halo density profiles from the IllustrisTNG simulation. We investigate a range of projection lengths, and find that obtained from projected profiles is close to the true , but has a slight decreasing trend with increasing projection length. We also quantify the prominence of the splashback feature and find how the feature shape changes with projection length.