Improving Cosmological Parameter Measurements with a Revised Local Flow Model and Near-Infrared Supernova Observations
In order to better measure and constrain cosmological parameters such as the Hubble constant (H0) and the equation-of state parameter of dark energy (w), we study the dominant motions of galaxies hosting Type Ia Supernovae (SNe Ia) in the nearby universe (z < 0.1). With the goal of observing solely the motions indicating the expansion of the universe, we attempt to identify and correct for all motions which are not attributed to the Hubble flow (peculiar motions) including both larger-scale bulk-flow motions from large surveys and small-scale galaxy group motions. We compile a wide variety of peculiar velocity (PV) correction methods and catalogs and compare their ability to improve scatter on the Hubble diagram using low-z SNe. We find that while corrections to both large- and small-scale motions help improve scatter on the Hubble diagram, small-scale corrections for group motions reduce scatter the most. Additionally, using the Dark Energy, H0, and peculiar Velocities using Infrared Light from Supernovae (DEHVILS) survey with observations taken on UKIRT, we present and analyze near-infrared light curves for 104 low-z SNe with the goal of better constraining both H0 and w and improving our understanding of growth-of-structure in the nearby universe.
Hosted by Charlotte Wood
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