Freeman law: Difference between revisions
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However more recently it has been argued that the Freeman law is an effect of [[selection bias]].<ref name="McGaugh" /><ref>Minnesota State University, "{{cite web |url=http://odin.physastro.mnsu.edu/~eskridge/astr225/week10.html |title=Archived copy |accessdate=2008-01-11 |deadurl=yes |archiveurl=https://web.archive.org/web/20070706235131/http://odin.physastro.mnsu.edu/~eskridge/astr225/week10.html |archivedate=2007-07-06 |df= }}"</ref> |
However more recently it has been argued that the Freeman law is an effect of [[selection bias]].<ref name="McGaugh" /><ref>Minnesota State University, "{{cite web |url=http://odin.physastro.mnsu.edu/~eskridge/astr225/week10.html |title=Archived copy |accessdate=2008-01-11 |deadurl=yes |archiveurl=https://web.archive.org/web/20070706235131/http://odin.physastro.mnsu.edu/~eskridge/astr225/week10.html |archivedate=2007-07-06 |df= }}"</ref> |
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==Fish law== |
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The '''Fish law''' (or Fish's law) in astronomy is the analogue for the Freeman law with disk galaxies replaced by [[Elliptical galaxy|elliptical galaxies]]. It was described in 1964 by Robert A. Fish based on photometric results for 29 elliptical galaxies.<ref>{{cite journal|author=Fish, Robert A.|title=A Mass-Potential Relationship in Elliptical Galaxies and Some Inferences Concerning the Formation and Evolution of Galaxies|journal=The Astrophysical Journal|volume=139|issue=1|year=1964|pages=284–305|bibcode=1964ApJ...139..284F}}</ref> |
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==References== |
==References== |
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Revision as of 15:23, 14 April 2018
The Freeman law is a statement in astronomy which says that disk galaxies have the same surface brightness, Σ at the center. It was described in 1970 by Ken Freeman.[1][2]
The Freeman law was confirmed in year 2010 for a sample of 30000 Sloan Digital Sky Survey galaxy images [3] and it can be used with the Tully-Fisher relation to determine the luminosity and therefore distance of an observed galaxy.
However more recently it has been argued that the Freeman law is an effect of selection bias.[1][4]
Fish law
The Fish law (or Fish's law) in astronomy is the analogue for the Freeman law with disk galaxies replaced by elliptical galaxies. It was described in 1964 by Robert A. Fish based on photometric results for 29 elliptical galaxies.[5]
References
- ^ a b McGaugh et al., "Galaxy Selection and Surface Brightness Distribution" (1995) Astronomical Journal, 110 (1995) 573,
- ^ Freeman, Kenneth C. (1970). "On the disks of spiral and S0 galaxies". The Astrophysical Journal. 160 (3): 811–830. Bibcode:1970ApJ...160..811F.
- ^ Kambiz Fathi, "Revisiting the Freeman Law in the Local Universe" (2010) Astrophysical Journal, 722 (2010) L120,
- ^ Minnesota State University, ""Archived copy". Archived from the original on 2007-07-06. Retrieved 2008-01-11.
{{cite web}}: Unknown parameter|deadurl=ignored (|url-status=suggested) (help)CS1 maint: archived copy as title (link)" - ^ Fish, Robert A. (1964). "A Mass-Potential Relationship in Elliptical Galaxies and Some Inferences Concerning the Formation and Evolution of Galaxies". The Astrophysical Journal. 139 (1): 284–305. Bibcode:1964ApJ...139..284F.
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