Resolved spectral variations of the centimetre-wavelength continuum from the ρ Oph W photodissociation region

Centimetre-wavelength radio continuum emission in excess of free–free, synchrotron, and Rayleigh–Jeans dust emission (excess microwave emission, EME), and often called ‘anomalous microwave emission’, is bright in molecular cloud regions exposed to UV radiation, i.e. in photodissociation regions (PDRs). The EME correlates with infrared (IR) dust emission on degree angular scales. Resolved observati...