The Search and Examination of Strong Gravitational Lenses within SDSS

Dr. Michael Scott Talbot
Department of Physics and Astronomy
University of Utah

Strong galaxy-scale gravitational lenses are similar to galaxy-sized telescopes that enable astronomers to observe objects and object details farther and earlier into the universe than capable by ground and space telescopes. More importantly, the arc-shaped images of the magnified object can be modeled to reveal the contribution of dark matter within the lens galaxy and probe the geometry of the expanding universe. These lens-source systems are rare and thus can only be substantially observed within large surveys. The largest lens-yielding surveys used spectroscopic detection methods to search over a million spectra of galaxies within the ‘Sloan Digital Sky Survey,’ finding a total of ~200 confirmed strong galaxy-scale gravitational lenses. We continue the lens search and extend the spectroscopic detection method to search the spectra of the Integral-Field-Unit (IFU) from the ‘Mapping Nearby Galaxies at APO’ (MaNGA) survey. Currently, we have detected 38 lens candidates within the first third of the 10,000 targets the MaNGA survey will observe. The current and future IFU surveys also provide a new opportunity to observe lensing features within narrowband images of the source, enabling potential methods to study lenses without follow-up imaging. If follow-up imaging can be substituted for narrowband imaging, then the search and analysis of lenses can become fully automated and applied within the data pipeline of future IFU surveys.