| Name: | Atharva Mirashi |
| Affiliation: | Indian Institute of Technology Indore |
| Conference ID: | ASI2025_317 |
| Title: | HI Observations of Dark Matter Deficient Dwarfs Galaxies |
| Authors: | Atharva Mirashi 1, Dr. Narendra Nath Patra 1, Abhinav Narayan 1 |
| Authors Affiliation: | 1 Indian Institute of Technology, Indore- 453552, India |
| Mode of Presentation: | Oral |
| Abstract Category: | Galaxies and Cosmology |
| Abstract: | Recent discoveries of Dark Matter-Deficient galaxies in the local universe challenge the current understanding of galaxy formation and evolution models. Guo et al. (2020) identified 14 such galaxies using the SDSS and Arecibo ALFALFA survey data. They used single-dish HI spectra and optical inclination to estimate the velocity widths and dynamical masses of these galaxies. However, the single-dish observations often can get contaminated for several reasons, and the optical inclinations might not be consistent with the inclination of the HI disk. We conducted interferometric observations of six galaxies from their sample with the uGMRT to resolve this issue. With our observations, we have been able to produce the rotation curve of these galaxies. Our preliminary result indicates that some of these galaxies indeed show a deficiency in dark matter. For example, the ratio of dark matter to baryonic matter in UGC6438 is found to be about 3.6, which is considerably lower than what is seen in other dwarf galaxies (~ 10 or more). In this presentation, I will describe the results for all our sample galaxies and discuss how they pose a challenge to the current understanding of galaxy formation and evolution in the context of the Lambda-CDM model. |
