Lyman- Spectra shapes in high redshift and low redshift galaxies

Abstract

Lyman-alpha (Ly) photons were first predicted by Theodore Lyman in 1906 as part of his work on the hydrogen atom spectrum. The Ly transition occurs when an electron in a hydrogen atom falls from the second energy level to the ground state, releasing a photon with a wavelength of 121.6 nanometres. It was not until the 1960s that Ly photons were observed in astronomical sources, including galaxies and quasars. Since then, the Ly line has been recognized as a powerful probe of the intergalactic medium and the properties of galaxies, providing insights into the formation and evolution of structures in the universe. With the development of advanced telescopes and spectrographs, astronomers have been able to study Ly photons in greater detail and at higher redshifts. This has led to new discoveries and a deeper understanding of the universe, including the epoch of reionization and the formation of the first galaxies. Today, Ly studies continue to be an active area of research, with the potential to uncover even more insights into the nature and history of the cosmos. Ly spectral shapes are a crucial tool for unravelling the mysteries of the universe. These spectra provide valuable information about the distribution of gas and the physical properties of galaxies at different epochs. By analysing Ly spectra from galaxies with low and high redshifts, astronomers can gain insights into the formation and evolution of galaxies and the process of cosmic reionization.