Campus, PAB 232
The FIRAS instrument aboard the COBE satellite provided exquisite measurements of the spectrum of average background radiation at microwave wavelengths. Going beyond the microwave, studying the monopole of cosmic background radiation across the whole electromagnetic spectrum provides detailed information about all sources of radiation in the Universe. However, the astronomical community studying a given wavelength frequently adopts conventions specific to their field of study, making a comparison of cosmic backgrounds across different wavelengths difficult. Following 1802.03694 we will survey current measurements of the cosmic background radiation at all wavelengths, from radio to gamma-ray. We will discuss the main sources that contribute to this background, from point sources to specific atomic and molecular transitions, and compare their predictions to data. We conclude by discussing what one could learn from going beyond the monopole at every frequency, creating a measurement which in princinciple "(...) encodes the entire statistical history of nuclear, atomic and molecular processes in the Universe."