Speaker
Description
We present a new all-sky model of low-frequency diffuse Galactic emission designed to support high-precision CMB analyses. The model describes the regime where synchrotron, free–free, and spinning dust emission dominate and extends the Planck 2015 diffuse component-separation framework by incorporating a wide set of modern radio and microwave surveys. In total, we jointly fit 35 full- and partial-sky maps at 1° resolution, including S-PASS, C-BASS, and QUIJOTE, together with reprocessed WMAP and Planck data from the Cosmoglobe collaboration, using a Bayesian parametric approach implemented in Commander. We derive spatially varying amplitude and spectral parameter maps for the dominant low-frequency foregrounds in total intensity. The main products include a new full-sky synchrotron amplitude and spectral index solution, an all-sky characterization of spinning dust emission based on a log-normal spectral model, and a reconstructed 4.76 GHz synchrotron map with reduced large-scale systematics relative to previous templates. The resulting model achieves RMS residuals below 10 μK over 95% of the sky up to 353 GHz, with residual angular power spectra well below the CMB signal on the relevant scales. These products provide a consistent description of the transition between radio and microwave emission and establish a new reference for foreground modeling and sky simulations. By reducing systematic uncertainties in low-frequency foregrounds, this framework directly supports robust cosmological parameter inference and cross-correlation studies in the era of high-precision CMB experiments.