Kirit Karkare (Boston University) - On-Chip Millimeter-Wave Spectroscopy for Line Intensity Mapping: SuperSpec and SPT-SLIM

Answering outstanding questions in cosmology - such as understanding the nature of inflation, dark energy, and reionization - requires observations of ever-increasing volumes of the universe. In this talk I will discuss how we can use line intensity mapping (LIM) of far-IR emission lines to measure large volumes at high redshift. This technique is enabled by advances in millimeter-wave spectrometer technology. I will present two on-chip spectrometer projects: SuperSpec, which pioneered the concept and was deployed to the Large Millimeter Telescope, and SPT-SLIM, a pathfinder LIM experiment at the South Pole. Both projects saw first light in 2025. I will discuss what we’re learning from their first observations and outline the path towards large, dense focal planes with the sensitivity required for next-generation cosmology.

The Astronomy Colloquium covers a wide range of topics and should be accessible to advanced Astronomy Majors. Refreshments will be served from 3:45pm with the presentation beginning at 4:00 pm.