For a long time I was thinking the Dispersion graphs were packed. But, the way frequencies, show and unshow themselves, is making me think there's something out there we're not seeing. How can we use false color to look at the frequency response of different regions of space? It may be key to seeing smaller objects that absorb RF on it's way to Earth. There is a microwave table of elements, and when something blocks a frequency from space, space is the radar transmitter, and that's background noise, and our Radio Telescope, is the receiver. How we know that there's something out there, is simple, certain frequencies are absorbed by certain materials and as a result, we find a quiet spot.
So, we need to RF table of elements, emission is the same bands as absorption, and it's that simple. The cold matter, absorbs the same wavelengths of energy transmitted by any plasma in space at a higher temperature. Element per element, it's all the same, hot it transmits on the same bands it would absorb if cold.