| Name: | Basundhara Ghosh |
| Affiliation: | Indian Institute of Science |
| Conference ID : | ASI2024_352 |
| Title : | A linear alignment model for disc galaxies and the resulting ellipticity spectra |
| Authors : | Basundhara Ghosh, Kai Nussbaumer, Eileen Sophie Giesel, Bjoern Malte Schaefer |
| Authors Affiliation: | 1. Basundhara Ghosh: Department of Physics, Indian Institute of Science, Bengaluru - 560012, India
2. Kai Nussbaumer, Eileen Sophie Giesel, Bjoern Malte Schaefer: Zentrum für Astronomie, University of Heidelberg, Heidelberg - 69120, Germany |
| Mode of Presentation: | Poster |
| Abstract Category : | Galaxies and Cosmology |
| Abstract : | Alignments of disc galaxies were thought to result from tidal torquing, where tidal field of the cosmic large-scale structure exert torquing moments onto dark matter haloes, determining their angular momentum and ultimately therefore the orientation of galactic discs. In this model, resulting intrinsic ellipticity correlations are typically present on small scales, but neither observations nor simulations have found empirical evidence; instead, simulations point at the possibility that alignments of disc galaxies follow a similar alignment model like elliptical galaxies. In our article we make the case for linear alignments resulting from tidal distortions of galactic discs, investigate the physical properties of this model and derive the resulting angular ellipticity spectra, as they would appear as a contribution to weak lensing. We discuss in detail on the statistical and physical properties of tidally induced alignments in disc galaxies, as they are relevant for mitigation of alignment contamination in weak lensing data, and comment on alignments of galactic bulges at the cores of disc galaxies. |
