Emission Line
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.
Emission lines are used in physics, chemistry, and astronomy to determine what kind of gas is doing the emission. Every element has a different electronic structure, and will thus have a different emission line fingerprint.
Emission lines in accreting binaries
Accreting binary systems (Cataclysmic Variables and X-ray Binaries) are among the strongest sources of X-rays on the sky.
EMISSION LINES
The spectra we encountered in Chapter 3 are examples of continuous spectra.
emission line Bright line in a specific location of the spectrum of radiating material, corresponding to emission of light at a certain frequency. A heated gas in a glass container produces emission lines in its spectrum.
Emission lines and the far-UV spectrum. Since recombination lines (and a few others) are powered ultimately by parts of the spectrum we can't see directly, they may give our only information on what happens between the UV and soft X-ray ranges.
Emission Line: A bright line in a spectrum caused by the emission of photons from atoms.
Emission Nebula: A cloud of gas that is excited by the ultraviolet radiation from hot stars.
EMISSION LINE - More or less narrow range of wavelengths in a spectrum that is brighter than neighboring wavelengths, corresponding to emission of light at a certain frequency.
emission line: A bright line in a spectrum caused by the emission of photons from atoms.
emission nebula: A cloud of glowing gas excited by ultraviolet radiation from hot stars.
Emission Line - A narrow, bright region of the spectrum. Emission lines are produced when electrons in atoms jump from one energy level to lower energy level
Energy Flux - The rate at which a wave carries energy through a given area ...
Emission lines. Specific wavelengths of light that are brighter than adjoining wavelengths seen in spectra.
Ephemeris. A table or list of the predicted position of an object such as a planet.
Emission Lines
Bright lines produced in a spectrum by a luminous source, such as a star or a bright nebula. Compare absorption lines.
Emission Measure (EM) ...
The Emission Line Corona
Click on image for larger version.
Early observations of the visible spectrum of the corona revealed bright emission lines at wavelengths that did not correspond to any known materials.
Narrow Emission Line Galaxy
Neodymium
A toxic silvery element belonging to the lanthanoid series of metals. It occurs in association with other lanthanoids.
Emission lines
Absorption lines
A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from an excess or deficiency of photons in a narrow frequency range, compared with the nearby frequencies.
emission line - A discrete bright spectral line.
ephemeris - A table that gives the position of a celestial body at various times, or other astronomical data.
Emission lines are produced by hot gas. If the hot gas is moving at a pretty good rate of speed, then the Doppler effect comes into play - the emission lines could be shifted to different wavelengths.
Emission Lines: The bright lines seen against a darker background, created when a hot gas emits photons characteristic of the elements of which the gas is composed.
emission line - (n.)
A wavelength at which radiation is emitted, creating a bright line in the spectrum.
emission nebula - (n.) ...
Emission lines with peculiarity
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Emission lines with ^P-Cygni//gr 304.446667, 38.032944^ profile
ev ...
An emission line in the radio region of the spectrum that is due to the "spin-flip" transition in neutral hydrogen atoms. The proton and electron making up a hydrogen atom both spin.
The emission line for Fe XI, occurs at 789.2 nanometres (nm), and the first images of the corona at this wavelength reveal some surprises, ...
These emission lines may come from the surface of the accretion disk itself, or may come from clouds of gas illuminated by the central engine in an ionization cone.
Spectral emission lines suggest an expanding shell of gas surrounding the star.
Other Designations For This Star
Hipparcos Identifier (HIP Number) ...
emission line spectrum bright lines in a spectrum that are produced by hot, thin (low-pressure) gases. Made by electrons jumping down closer to the nucleus.
emission line (NASA SP-7, 1965) A minute range of wavelength (or frequency) in the electromagnetic spectrum within which radiant energy is being emitted by a radiating substance. See spectral line, emission spectrum.
continuum The continuous spectrum that any object would produce if no absorption or emission lines were present. Any body above absolute zero emits a spectrum, the shape of which is dependant on its temperature.
(508-cm) telescope on Mount Palomar in California to observe the positions of these radio sources, astronomers discovered objects the spectra of which showed emission lines that could not be identified.
spectra has been recognized, in which, as well as the usual absorption bands, bright emission lines of hydrogen appear; stars having this particular spectrum are always variable.
If the gas is rarefied, then the photon emitted from an individual atom will be able to escape from the gas without being altered and you will see the appropriate emission lines (Law 2).
1943 - Carl Keenan Seyfert identifies six spiral galaxies with unusually broad emission lines, named Seyfert galaxies,
1949 - J.G. Bolton, G.J. Stanley, and O.B. Slee identify NGC 4486 (M87) and NGC 5128 as extragalactic radio sources, ...
The Orbiting Solar Observatory OSO-3 made the first certain detection of celestial gamma rays in 1972, and OSO-7 detected gamma-ray emission lines in the solar spectrum.
The organic radicals given in Table 25 were seen in cometary heads as visual or ultraviolet emission lines or bands.
These filters only pass the two Oxygen III emission lines, the Hydrogen Beta emission line, and the wavelengths between these two, making them most useful for observing emission or planetary nebulae.
Optical photographs subsequently taken of their spectra showed locations for emission lines at wavelengths that were at odds with all celestial sources then familiar to astronomers.
The spectrum from a star could have absorption or emission lines. It is because when atoms are in low pressure, they can only emit or absorb light of certain wavelengths.
Central star temperatures are commonly calculated by using the intensity of nebular emission lines to estimate the amount of ultraviolet radiation from the star and then comparing that to the amount of visual radiation derived from the visual ...
In addition, however, sunlight also contains many bright emission lines, characteristic of hydrogen, calcium and other elements.
A research team of astronomers, has successfully detected a carbon emission line in the most distant radio galaxy known so far in the early universe.
The redshift of an object can be measured by examining the absorption or emission lines in its spectrum. These sets of lines are unique for each atomic element and always have the same spacing.
The spectral type of stars is a system of classification of stars based on the stars' spectra, emission lines that correlate with each star's surface temperature (and color). There are seven major spectral types.
CMY has an advatage of covering forbidden oxygen and hydrogen beta emission lines around 500nm (major components of the light from emission and planetary nebulas) which are frequently excluded by RGB filters.
Astronomers using ISO discovered emission lines from interstellar water vapor in a variety of sources including star forming regions, planetary nebulae and near formed stars.
It was the first planetary nebula to be observed with a spectroscope; the observers were surprised to find emission lines in the spectrum of this object.
A spectrum in which there are no absorption or emission lines.
coronograph
A telescope that blocks light from the disk of a star so that fainter surrounding objects and structures can be observed.
where νobs is the observed frequency of an emission line, and νemit is the emitted frequency of the emission line.
Definition: Seyfert galaxy: A spiral galaxy whose nucleus shows bright emission lines; one of a class of galaxies first described by C. Seyfert.
Space Tragedies9 Planets in Nine DaysAstronomy 101
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Hydrogen Alpha - A specific emission line of ionized hydrogen at 656.3 nanometers. Hydrogen-alpha emissions are responsible for the red color in emission nebulae.
Their spectrum has broad and very intense emission lines, probably indicative of violent surface activity.
In physics, the Lyman series is the series of transitions and resulting emission lines of the hydrogen atom as an electron goes from n = 2 to n = 1 ....
-alpha hydrogen radiation at a wavelength
Wavelength ...
6.08 Gas surrounding a star may absorb energy, causing...
absorption lines.
an explosion.
emission lines.
indigestion.
Seyfert galaxy
A spiral galaxy whose nucleus shows bright emission lines; one of a class of galaxies first described by C. Seyfert.
It is an emission nebula created by a fast stellar wind of a Wolf-Rayet star, an evolved, massive star showing strong emission lines of helium and nitrogen or helium, carbon and oxygen. It is approximately 5,000 light-years distant.
Spectrometers are instruments that spread light out into wavelengths called "spectra," which look something like rainbow-colored bars. Using the spectra, scientists can look for and study the "emission lines" and "absorption lines" that are sort ...
Shell Star
A type of star which is believed to be surrounded by a thin envelope of gas, which is often indicated by bright emission lines in its spectrum.
The VLT spectrum was the first to reveal the far red range where carbon emission lines are predicted; the absence of the lines puts constraints on the role of atmospheric chemistry when life started on earth.
Its nucleus (center) has bright emission lines, including visible wavelengths. The brightness varies over relatively short time periods (less than a year). They may have massive black holes at their centers.
However, the deeper, hot corona of Star Aa is much more variable than that of Star Ab. The extreme ultraviolet spectra of Stars Aa and Ab display the presence of iron emission lines from Fe XV to Fe XXIV (more).
Doppler broadening (NASA SP-7, 1965) The broadening of either an emission line or an absorption line due to random motions of molecules of the gas that is emitting or absorbing the radiant energy. See pressure broadening.
 See also: Emission, Light, Spectrum, Energy, Star
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