제목 : Small nascent galaxies in the debris of interacting systems
연사 : Chandreyee Sengupta 박사님 (Yonsei University)
언어 : English
Tidal interactions between pairs of galaxies, where at least one of them is gas rich, can result in tidal stripping of large amounts of HI from their potential. Most of this stripped HI may eventually fall back into the potential of one of the pair or the new galaxy formed by their merger or be
incorporated into the intra–group medium (IGM). But if the environmental conditions are favourable, self-gravitating bodies with masses typical of dwarf galaxies, called Tidal Dwarf Galaxies (TDG), may form within the tidally stripped gas. These are gas rich small galaxies with higher metallicities
compared to normal dwarfs. Modeling of TDG formation predicts their dark matter content to be much lower than in normal dwarfs.
As nascent galaxies, these objects are ideal laboratories to study star formation, star-gas correlation, galaxy formation and effects of the absence of
dark matter on galaxy and star formation. Using the Giant Metrewave Radio Telescope (GMRT), we are conducting an HI survey of a sample of interacting systems, a subset of which host TDGs. I will be speaking about our results from this ongoing survey and how they help our current understanding of TDGs. Additionally I will discuss the limitations of HI spectroscopy in TDG studies and the necessity of CO and H-alpha spectroscopy to understand TDGs.