Noah Franz

Abstract:

Gravitational lensing occurs when the light from a distant background object is magnified by the mass of a foreground galaxy due to relativistic effects. In spectroscopic surveys, gravitational lenses can be discovered by identifying the features of both the foreground and background sources in a single spectrum. The Dark Energy Spectroscopic Instrument (DESI) is a five-year survey that will obtain spectra from more than 40 million galaxies. We analyze roughly 3,000 spectroscopic lenses of known gravitational lenses observed by DESI. We model the combined spectrum, subtract out the model, and perform a redshift fit on the residual spectrum. We present properties of the residual spectra and discuss prospects for future work.