Does gas content alter star formation rate enhancement in galaxy interactions?
Dust, Gas and Star Formation in Galaxies Throughout Cosmic Time
Jillian M. Scudder
University of Sussex
Sara L Ellison, Emmanuel Momjian, Jessica L Rosenberg, David R Patton, Derek Fertig, J Trevor Mendel
Interactions between galaxies in the local universe are well known to trigger significant enhancements to a galaxy's star formation rate (SFR). It has recently been determined that these interaction-driven SFR enhancements are present over a relatively long time frame. However, the strength of the starburst can still vary wildly from galaxy to galaxy and between interacting systems. The magnitude of this boost to the SFR has been tied to certain parameters of the interaction, such as interaction stage and mass ratio. Even with these parameters accounted for, large residual scatter remains in the observed SFR enhancements. Another parameter which could control the strength of the interaction-triggered SFR enhancement is the gas content of the perturbed galaxies; this parameter has been relatively poorly explored. I will present results from a sample of interacting galaxies selected from the Sloan Digital Sky Survey Data Release 7 (SDSS DR7), with new estimates of their HI gas masses from the Jansky Very Large Array (VLA). With the combination of the spectroscopic data from the SDSS and the HI masses from the VLA, we can determine if a strong correlation between star formation enhancement and gas content is present in the observations. To aid in the interpretation of our results, we also make use of a small suite of binary merger simulations. I will present the conclusions drawn from this study, which will help us to understand the role that gas content has upon the star formation rates of interacting galaxies.
13:30 - 15:00