Abstract:
The distribution of dark matter in the inner regions of galaxies poses a key challenge for small-scale Lambda-cold dark
matter (Λ-CDM) cosmology. While CDM simulations predict cuspy inner density profiles, observations of low surface
brightness 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 (Navarro–Frenk–White, cuspy), Einasto (intermediate),
Burkert (cored), and pseudo-isothermal (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 techniques, utilizing rotation
curves derived from robust 3D kinematic modelling. Baryonic contributions from stars derived using stellar kinematics
based on 3.6 μm or r-band photometry via multi-Gaussian expansion combined with Jeans anisotropic model and from
gas, calculated directly from the gas surface density (H i + He) without assuming any pre-defined 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. Future studies with a larger sample
from GARCIA will be helpful in refining this trend and addressing the cusp–core issue in greater depth.
