| Name: | PRALAY BISWAS |
| Affiliation: | National Centre for Radio Astrophysics |
| Conference ID : | ASI2024_284 |
| Title : | Structure and Kinematics of Star-forming Elliptical Galaxies in SDSS-MaNGA |
| Authors : | Pralay Biswas, Yogesh Wadadekar |
| Authors Affiliation: | National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Post Bag 3, Ganeshkhind, Pune, Maharashtra 411007, India |
| Mode of Presentation: | Poster |
| Abstract Category : | Galaxies and Cosmology |
| Abstract : | Using โspatiallyโ resolved spectroscopy from the Sloan Digital Sky Survey - Mapping Nearby Galaxies at Apache Point Observatory (SDSS-MaNGA), we investigated the properties and different formation modes of star-forming elliptical galaxies. We combined the GALEX-SDSS-WISE Legacy Catalog containing outputs of stellar population synthesis models with morphological results from a deep learning catalog and resolved and integrated properties from the outcomes of Pipe3D run on data from the SDSS-MaNGA Integral Field Spectroscopy survey. We identified a rare population of 59 star-forming elliptical (SF-E) galaxies, our primary sample and also constructed two control samples of star-forming spirals (SF-Sps; 2419 galaxies) and quenched ellipticals (Q-Es; 684 galaxies) to compare with our primary sample. H๐ผ emission line flux of SF-Es is similar to SF-Sps. The D4000 spectral index of SF-Es ranges from 1.2 to 1.8, indicating that they have a mixture of old and young stellar populations. Mass-weighted stellar age and metallicity for the SF-Es are lower in comparison to the Q-Es. 67% of the stellar and gas velocity maps of the primary sample show signs of kinematic disturbance. All of these indicate that SF-Es have acquired metal-poor gas in recent mergers or interactions with other galaxies and are forming a new generation of stars. Further, we subdivided our main sample of SF-Es into four classes based on their ๐ต/๐ and ๐๐๐ values. Bulge-dominated slow rotators, bulge-dominated fast rotators, not completely bulge-dominated fast rotators, and not completely bulge-dominated slow rotators. The properties of the galaxies in these four classes show that they all have their own distinct evolutionary history and modes of formation. Based on these results, we infer that the Hubble diagram does not accurately capture the galaxy evolution processes, and we need a revised morphology diagram like the comb morphology diagram to get a better understanding of galaxy evolution processes. |
