| Name: | Amit Kumar |
| Affiliation: | Inter University Centre for Astronomy & Astrophysics |
| Conference ID : | ASI2024_901 |
| Title : | Subhalo mass depletion in dense galaxy clusters: Upper limit on orphan satellites |
| Authors : | Amit Kumar1, Surhud More1,2, Divya Rana1, Tomomi Sunayama3 |
| Authors Affiliation: | 1 Amit Kumar, Surhud More, Divya Rana (Inter-University Center for Astronomy & Astrophysics, Pune 411007, India)
2 Surhud More (Kavli Institute for the Physics and Mathematics of the Universe (WPI), 5-1-5 Kashiwanoha, 2778583, Japan)
3 Tomomi Sunayama (Nagoya University, Furo-cho, Chikusa-ku, 464-8601, Nagoya, Aichi, Japan) |
| Mode of Presentation: | Oral |
| Abstract Category : | Galaxies and Cosmology |
| Abstract : | We investigate the matter distribution around satellite galaxies evolving in dense galaxy clusters, using the weak gravitational lensing technique. We explore the effect of environmental
processes on the dark matter mass around SDSS redMaPPer satellites, by comparing it to the distribution around a control sample of galaxies matched to satellites in photometric properties, but residing in a non-cluster environment. In order to understand the impact of host potential on the subhalo mass of the satellite, we bin satellite galaxies as a function of projected separation from the cluster center. We see hints of a difference in the mass of the subhalo of the satellite compared to the halo masses of galaxies in our control sample, especially in the innermost cluster-centric radial bin (0.1 < R > 0.3 [$h^{-1}\rm Mpc$]). We use these measurements to put a first-ever upper limit on the prevalence of galaxies that have lost their subhalo entirely, i.e. orphan galaxies, at different distances from the cluster center.
We also perform a similar comparative analysis using the galaxy catalog from one empirical model, the UniverseMachine. We run a mock cluster finder that mimics the optical cluster finding technique of the redMaPPer algorithm, on quenched star-forming galaxies from this simulated
galaxy catalog. We find the orphan fraction from the UniverseMachine is marginally consistent with the upper limits in the innermost regions of galaxy clusters spanning [0.1, 0.3]$h^{-1}\rm Mpc$. We observe that the orphan fraction is significantly higher than the upper limits in the outer regions of galaxy clusters beyond 0.3$h^{-1}\rm Mpc$. We also discuss ways to distinguish any physical effects that could result in orphan galaxies from any numerical effects in the empirical model. |
