Speaker
Description
I will begin by introducing the C-BASS survey and its role as a key low-frequency radio dataset for Galactic foreground studies, before presenting a new all-sky model of low-frequency diffuse Galactic emission describing the regime where synchrotron, free-free, and spinning dust emission dominate. The model extends the Planck 2015 diffuse component-separation by incorporating more recent radio and microwave surveys. We fit 35 full- and partial-sky maps, at 1 degree resolution, including S-PASS (2.30 GHz), C-BASS (4.76 GHz), and QUIJOTE (10-20 GHz), together with reprocessed WMAP and Planck LFI data from the Cosmoglobe collaboration and Planck HFI channels. Using a Bayesian parametric approach with Commander, we derive spatially varying amplitude and spectral parameter maps for the dominant low-frequency foreground components in total intensity. The main products of this work are: (i) a new full-sky synchrotron amplitude and spectral index solution, (ii) an all-sky characterisation of spinning dust emission based on a single-component log-normal spectral model, including peak frequency and width, and (iii) a new all-sky reconstruction at 4.76 GHz providing a tracer of diffuse synchrotron emission with reduced systematics relative to the Haslam map (408 MHz). These products describe the transition between radio and microwave emission and provide a new reference for foreground modelling and sky-simulation applications.