In physics, emission is the process by which a higher energy quantum mechanical state of a particle becomes converted to a lower one through the emission of a photon, resulting in the production of light. The frequency of light emitted is a function of the energy of the transition.

This page tabulates wavelengths and atomic transition data for emission lines from 700-11,000Å that have historically been observed in the spectra of galaxies, active galactic nuclei (AGN), and quasi-stellar objects (QSOs).

Emission and absorption lines can tell us a great deal about a distant celestial source, but they only occur under certain conditions. Emission lines from an element will appear if there are atoms of the element present

An emission line will appear in a spectrum if the source emits specific wavelengths of radiation. This emission occurs when an atom, element or molecule in an excited state returns to a configuration of lower energy.

2022年4月10日 · Explain how emission line spectra and absorption line spectra are formed; Describe what ions are and how they are formed; Explain how spectral lines and ionization levels in a gas can help us determine its temperature; We can use Bohr’s model of the atom to understand how spectral lines are formed.

2022年9月26日 · The result is an emission spectrum that shows the intensity of emission as a function of wavelength. The shapes of these emission spectra fall into two broad types: line spectra and band spectra.

2021年7月7日 · Let’s go back to simple absorption and emission spectra. We can use a star’s absorption spectrum to figure out what elements it is made of based on the colors of light it absorbs. We can use a glowing nebula’s emission spectrum to figure out what gases it is made of based on the colors it emits.

An emission line results from the emitted photons and appears in a projected spectrum as a line or narrow bar of color. Spectral emission lines are extraordinarily useful in astronomy . Each element has a unique number of protons in the nucleus and electrons orbiting the nucleus.

Emission Lines and Models for AGN. The very existence of strong line emission tells us that there must be strong UV radiation from the AGN, and the line ratios tell us that its spectral shape is quite different from a stellar distribution.

An absorption line occurs when an electron jumps from a lower energy state to a higher energy state, extracting the required photon from an outside source of energy such as the continuous spectrum of a hot, glowing object. An emission line is formed when the electron falls back to a lower energy state, releasing a photon.