Abstract Details

Name: Sioree Ansar
Affiliation: Indian Institute of Astrophysics, Bangalore
Conference ID: ASI2021_370
Title : A pilot study to determine halo spin and concentration for the galaxy UGC 5288 using simulations
Authors and Co-Authors : Sioree Ansar (Indian Institute of Astrophysics), Mousumi Das (Indian Institute of Astrophysics), Sandeep Kumar Kataria (Indian Institute of Astrophysics, Shanghai Astronomical Observatory)
Abstract Type : Oral
Abstract Category : Extragalactic Astronomy
Abstract : We conduct a pilot study to estimate the halo properties- spin and concentration of a low luminosity dwarf barred galaxy UGC-5288 using the observed HI rotation curve and N-body/SPH simulations. These galaxies are rich in gas but show little star formation. They are found to have diffuse stellar disks, large HI gas content and very massive dark matter halos that are thought to have high angular momentum as suggested by galaxy formation theories and simulation studies in the literature. We use the neutral hydrogen (HI) rotation curves to estimate the halo mass and concentration, and use near-infrared images of the optical disks to determine stellar disk mass and sizes. We simulate galaxies with the same structural and dynamical properties as the observed galaxy UGC 5288. We estimate the bar length and ellipticity using the SDSS i-band and z-band images and use them to match the bar's properties in our simulated models of UGC 5288. We determine the region in the halo properties' parameter space - spin and concentration, and disk parameter - scale height, which best represents the structural and dynamical properties of our sample galaxy. We are developing an automated pipeline that can estimate the halo properties for a larger number of observed galaxies using the method presented in this work. We further study the evolution of halo spin distribution with radius and compare the final halo spin at the radius r200, to the theoretically estimated spins for different halo profiles.