Detecting and Interpreting Faint Tidal Features Around RESOLVE Galaxies (2016)
Undergraduates: Callie Hood, Elaine Snyder the RESOLVE team and the CS82 team
Faculty Advisor: Sheila Kannappan
Department: Physics & Astronomy
In the paradigm of modern cosmology, galaxy interactions play a key role in galaxy growth through galaxy-galaxy mergers and cannibalization of smaller neighbors. For decades, numerical simulations have shown how stellar light can trace these merging events through morphological features created by strong tides during the interactions. Thus, a robust search for tidal features in galaxy images can help construct a fossil record of the history of recent galaxy accretions, as well as a test for theories of long-term galaxy evolution in our current cosmological understanding. We present an initial study of the frequency of faint tidal features around galaxies in the REsolved Spectroscopy of a Local VolumE (RESOLVE) survey. Our sample consists of 321 galaxies of the RESOLVE-B subvolume which overlap with the pointings of the CHFT Stripe 82 (CS82) survey. CS82 images of each galaxy were masked, smoothed, and visually inspected for signs of tidal features such as streams or shells. We find that around 21% of the galaxies demonstrate this faint substructure with data of this depth and seeing, setting a lower limit on the frequency of such features in this sample. We explore the significance of tidal features through possible relationships to other galaxy characteristics and environments.