Gravity Group Lunch Seminar | Yilun Guan (Pittsburgh) & Brandon Hensley (Princeton) "The ACT View of the Galactic Center"

We present new maps of the Galactic Center in total intensity and polarization made with the Atacama Cosmology Telescope (ACT). We combine dedicated, arcminute-resolution ACT observations over a 32 deg^2 field with Planck intensity and polarization data at similar frequencies to produce maps with fidelity on both small and large angular scales. In this talk, we first describe the mapmaking procedure, including a novel treatment of bright sources that will be used in future ACT data releases. We then showcase detailed new views of known radio and submillimeter sources in the Galactic center, including supernova remnants, pulsar wind nebulae, molecular clouds, and non-thermal radio filaments, highlighting in particular how ACT reveals the small-scale morphology of Galactic magnetic fields. Finally, we discuss future prospects for leveraging CMB data for Galactic science analyses in ACT, Simons Observatory, and beyond.