| Name: Sougata Sarkar |
| Affiliation: Indian Institute of Science |
| Conference ID: ASI2026_872 |
| Title: Comparative Study of Dark Matter Halos in Nearby Galaxies |
| Abstract Type: Oral |
| Abstract Category: Galaxies and Cosmology |
| Author(s) and Co-Author(s) with Affiliation: Sougata Sarkar(Department of Physics, Indian Institute of Science, Bangalore 560012, India), Prerana Biswas(Indian Institute of Astrophysics, Bangalore 560034, India), Veselina Kalinova(Max-Planck-Institut für Radioastronomie (MPIfR), Auf dem Hügel 69, 53121 Bonn, Germany), Nirupam Roy(Department of Physics, Indian Institute of Science, Bangalore 560012, India), Narendra Nath Patra(Department of Astronomy, Astrophysics and Space Engineering, Indian Institute of Technology Indore, Indore 453552, India), Sushma Kurapati(ASTRON – Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands) |
| Abstract: The distribution of dark matter in the inner regions of galaxies poses a key challenge for small-scale ΛCDM cosmology. While cold dark matter simulations predict cuspy inner density profiles, observations of low surface brightness (LSB) and dwarf galaxies often favour cored profiles, an issue known as the cusp-core problem. We investigate this problem by comparing four dark matter halo profiles: NFW (cuspy), Einasto (intermediate), Burkert (cored), and pseudo-isothermal (pISO) (cored) in a pilot sample of 11 galaxies from the GMRT archive atomic gas survey (GARCIA). We have performed mass modelling using Markov Chain Monte Carlo (MCMC) techniques, utilising rotation curves derived from robust 3D Kinematic modelling. Baryonic contributions from stars derived using stellar kinematics based on $3.6,\mu\mathrm{m}$ or r-band photometry via Multi-Gaussian Expansion (MGE) combined with Jeans Anisotropic Model (JAM) and from gas, calculated directly from the gas surface density (H\,\textsc{i} + He) without assuming any predefined functional form, are included. Our mass modelling shows that all halo profiles provide statistically good fits, yielding consistent estimates of halo mass and stellar mass-to-light ratio. To validate our analysis, we examine the stellar-to-halo mass relation and find broad agreement with empirical models. Non-parametric density profiles derived from baryon-subtracted rotation curves show that NFW fits the inner regions best, while all profiles converge in the outskirts. In this talk, we will present results from an expanded sample of 46 galaxies, adding 35 new galaxies (10 from CALIFA and 25 from GARCIA-II). This larger dataset enables stronger constraints on inner halo structure and provides a sharper test of the cusp–core problem |
