| Abstract : | Understanding the kinematics and the mass modelling of galaxies aids in understanding both the baryonic and dark matter halo features of nearby galaxies. Despite many observational studies, mass modelling of galaxies has always been challenging due to different limitations, e.g., the large and different scatters in the mass-to-light ratio in different bands make it difficult to estimate the distribution of the stellar mass accurately. Apart from that, most of the previous studies involving mass modelling are based on rotation curves derived from two-dimensional velocity fields from HI (e.g., Lelli et al. 2016) or Hα (e.g., Korsaga et al. 2019) spectroscopic observation, which often is affected by beam smearing and projection effect. However, kinematic modelling done by fitting the “Tilted ring model” to three-dimensional data cube is not affected by these issues. We present 3D kinematic modelling of a pilot sample of eleven galaxies from the GMRT archive atomic gas survey (GARCIA) (Biswas et al. 2022) using two different publicly available pipelines (FAT, Kamphuis et al. (2015) and BBarolo, Di Teodoro & Fraternali 2015) and compare the results. We model the observed HI rotation curve using 3.6 μm infrared data and SDSS r-band data for stellar contribution, HI surface density profile for gas, and Navarro-Frenk-White (NFW) profile for dark matter halo. We use Markov Chain Monte Carlo (MCMC) optimization method for mass modelling and parameter estimation and discuss the results for individual galaxies. Further, the best-fit parameters from this 3D kinematic modelling and mass modelling are used to revisit one of the most important scaling relations, the Baryonic Tully-Fisher relation (BTFR) (Tully & Fisher 1977; McGaugh et al. 2000). Our study depicts the importance of doing 3D kinematic modelling over 2D modelling for mass modelling and using various parameters found in 3D kinematic modelling for establishing BTFR. |
