IT is usually considered that molecular hydrogen does not have an infra-red rotation-vibration spectrum ... pressure is required to obtain it in absorption 1,2.

Hot gases don’t produce a continuous emission spectrum. Black hydrogen absorption lines are at the same wavelength as the bright hydrogen emission lines. Key fact Line emission spectra are ...

the 21 cm emission from neutral hydrogen in directions adjacent to the pulsar's position comes from the whole path length through the galaxy. A comparison of these two types of spectra may ...

Each wavelength carries inherent energy that, if effectively harnessed, holds great potential to facilitate solar hydrogen production ... X-ray absorption spectroscopy, and transient absorption ...