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and Samuel
Goldsmith confirmed the presence of the unusual absorption lines, though they were less conclusive about the origin of the lines. Subsequently, the spectra of many other high-redshift quasars were observed to have the same system of narrow absorption lines. Lynds was the first to describe
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atom, spectral lines are formed when an electron transitions between energy levels. The Lyman series of spectral lines are produced by electrons transitioning between the ground state and higher energy levels (excited states). The Lyman-alpha transition corresponds to an electron transitioning
77:. Quasar 4C 05.34 was the farthest object observed to that date, and Lynds noted an unusually large number of absorption lines in its spectrum and suggested that most of the absorption lines were all due to the same
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For quasars at higher redshift the number of lines in the forest is higher, until at a redshift of about 6, where there is so much neutral hydrogen in the intergalactic medium that the forest turns into a
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Patrick McDonald; Uros Seljak; Scott Burles; Schlegel; Weinberg; David Shih; Joop Schaye; Schneider; Brinkmann (2006). "The Lyman-α Forest Power
Spectrum from the Sloan Digital Sky Survey".
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198:), the abundance of heavier elements in the clouds can also be studied. A cloud with a high column density of neutral hydrogen will show typical
225:, such as the dark matter free streaming scale, which for thermal relic dark matter models is closely related to the dark matter particle mass.
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argued that the absorption features are due not to any physical interactions within the quasars themselves, but to absorption inside clouds of
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The Lyman-alpha forest observations can be used to constrain cosmological models. They can also be used to constrain the properties of
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Weinberg, D. H.; et al. (May 2003). "The Lyman-α Forest as a
Cosmological Tool". In S. H. Holt; C. S. Reynolds (eds.).
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A quasar spectrum with Lyman absorbers being continuously redshifted due to cosmic expansion forming a "forest" of lines.
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atom. As the light travels through multiple gas clouds with different redshifts, multiple absorption lines are formed.
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123: = 2). The Lyman-alpha spectral line has a laboratory wavelength (or rest wavelength) of 1216
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The Lyman-alpha absorption lines in the quasar spectra result from intergalactic gas through which the
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The Lyman-alpha forest was first discovered in 1970 by astronomer Roger Lynds in an observation of the
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150:(due to their varying distance from Earth), their absorption lines are observed at a range of
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Burbidge, Geoffrey R.; Adelaide Hewitt (December 1994). "A catalog of quasars near and far".
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Bahcall, John; Samuel
Goldsmith (1971-11-15). "On the Absorption-Line Spectrum of 4c 05.34".
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Carroll, Bradley W.; Ostlie, Dale A. (1996). "The
Interaction of Light and Matter".
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and can be used to determine the frequency and density of clouds containing neutral
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466:. New York, New York: Addison-Wesley Publishing Company, Inc. pp. 134–142.
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Blaauw, Adriaan; Martin
Schmidt (July 1993). "Jan Hendrik Oort (1900–1992)".
182:, as well as their temperature. Searching for lines from other elements like
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A computer simulation of a possible Lyman-alpha forest configuration at
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Emergence of Cosmic Structure: Thirteenth Astrophysics Conference
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567:"Large-scale structure in the Lyman-α forest: a new technique"
491:. AIP Conference Series. Vol. 666. pp. 157–169.
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in the intergalactic medium are at different degrees of
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The Lyman-alpha forest is an important probe of the
572:Monthly Notices of the Royal Astronomical Society
552:"The Lyman Alpha Forest in the Spectra of QSOS"
565:Liske, J; Webb, J. K; Carswell, R. F (1998).
119: = 1) and the first excited state (
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324:"The Absorption-Line Spectrum of 4C 05.34"
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202:around the line and is referred to as a
162:at a different position in the observed
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464:An Introduction to Modern Astrophysics
142:or quasar's light has traveled. Since
81:transition. Follow-up observations by
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621:"Lyman alpha systems and cosmology"
154:. Each individual cloud leaves its
86:them as the "Lyman-alpha forest".
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604:10.1046/j.1365-8711.1998.02048.x
16:Astronomical spectroscopic term
649:Physical cosmological concepts
1:
170:Use as a tool in astrophysics
214:. This shows the end of the
322:Lynds, Roger (1971-03-01).
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115:between the ground state (
43:in the spectra of distant
644:Astronomical spectroscopy
365:The Astrophysical Journal
328:The Astrophysical Journal
204:damped Lyman-alpha system
33:astronomical spectroscopy
271:Astrophys. J. Suppl. Ser
133:electromagnetic spectrum
414:1994S&T....88...32B
250:Lyman continuum photons
144:neutral hydrogen clouds
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212:Gunn–Peterson trough
176:intergalactic medium
595:1998MNRAS.301..787L
507:2003AIPC..666..157W
441:1993PASP..105..681B
402:Sky & Telescope
378:1971ApJ...170...17B
340:1971ApJ...164L..73L
293:2006ApJS..163...80M
245:Lyman alpha emitter
98:Physical background
56:electron transition
240:Lyman break galaxy
127:, which is in the
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94:in superclusters.
37:Lyman-alpha forest
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515:10.1063/1.1581786
473:978-0-201-54730-6
218:of the universe.
92:intergalactic gas
51:arising from the
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235:Lyman-alpha blob
41:absorption lines
39:is a series of
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334:: L73–L78.
223:dark matter
156:fingerprint
152:wavelengths
129:ultraviolet
79:Lyman-alpha
53:Lyman-alpha
638:Categories
626:2009-03-30
557:2009-03-30
256:References
613:119377250
533:118868536
408:(6): 32.
371:: 17–24.
309:118878555
229:See also
196:redshift
180:hydrogen
164:spectrum
148:redshift
112:hydrogen
88:Jan Oort
75:4C 05.34
60:hydrogen
45:galaxies
591:Bibcode
503:Bibcode
437:Bibcode
410:Bibcode
373:Bibcode
336:Bibcode
289:Bibcode
192:silicon
66:History
49:quasars
611:
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188:carbon
184:helium
158:as an
140:galaxy
72:quasar
35:, the
609:S2CID
581:arXiv
529:S2CID
493:arXiv
305:S2CID
279:arXiv
519:ISBN
468:ISBN
190:and
47:and
599:doi
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511:doi
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