Cold atomic hydrogen
Hydrogen
A galaxy is a massive, gravitationally boundsystem that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter.
The interstellar medium is enriched with heavy elements by the remnants of supernovas. A supernova is the spectacular explosion at the end of a stars life when it collapses in on itself.
Brian M. Cancellieri has written: 'Interstellar medium' -- subject(s): Interstellar matter
red light from the emission nebula
extinction
Visible light against electrons combined with ionized hydrogen create the "reddening" effect in the Interstellar Medium.
Ginevra Trinchieri has written: 'The environmental impact of intra-cluster medium on the interstellar medium in early type galaxies' -- subject(s): X ray astronomy, Galaxies, Interstellar matter
false.
-- Frequency -- Wavelength. -- Speed. While each of these may vary their inter-relationship does not. Frequency - V Wavelength -L Speed - c VL=c is always true. c= varies depending on the medium through which the light is propagated.
Light, whatever the wavelength, does not need a medium in order to radiate.
chromospore