Abstract
We present an analysis of the diffuse emission at 5 GHz in the first quadrant of the Galactic plane using two months of preliminary intensity data taken with the C-Band All Sky Survey (C-BASS) northern instrument at the Owens Valley Radio Observatory, California. Combining C-BASS maps with ancillary data to make temperature-temperature plots we find synchrotron spectral indices of β=−2.65±0.05 between 0.408 GHz and 5 GHz and β=−2.72±0.09 between 1.420 GHz and 5 GHz for −10∘<|b|<−4∘, 20∘
