SIMBAD references

Radio continuum emission is a dust-unbiased tracer of both thermal and non-thermal processes in the interstellar medium. We present new maps of the free-free and synchrotron emission in the Magellanic Clouds (MCs) at 0.166, 1.4, and 4.8 GHz with no prior assumption about the radio non-thermal spectrum. The maps were constructed using a de-reddened H α map as a template for the thermal radio emission, which we subtract from maps of the total radio continuum emission. To de-redden the H α emission, it is important to know the fraction of dust surface density that attenuates the H α emission along the line of sight, f_d. This fraction is obtained by comparing the dust opacity obtained through the infrared emission spectrum and the Balmer decrement method. In star-forming regions, the median f_d is about 0.1, which is lower than that in diffuse regions by a factor of three. We obtain a global thermal radio fraction, f_th, of 30 per cent (35 per cent) in the LMC (SMC) at 1.4 GHz. Furthermore, we present maps of the equipartition magnetic field strength with average values of ≃10.1 µG in the LMC and ≃5.5 µG in the SMC. The magnetic field is proportional to the star-formation rate to the power of 0.24 and 0.20 for the LMC and SMC, respectively. This study shows that non-thermal processes control the interstellar medium in the MCs.