Tully-Fisher relation


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Tully-Fisher relation

[¦təl·ē ′fish·ər ri‚lā·shən]
(astronomy)
A relation between the rotational velocity of a galaxy, as reflected in the width of the 21-centimeter line, and the intrinsic luminosity of the galaxy.
References in periodicals archive ?
We verify the Tully-Fisher relation for the investigated galaxy sample and present the results on Figure 7.
De Blok, "The baryonic tully-fisher relation," Astrophysical Journal, vol.
Olf, "Local group dwarf spheroidals: correlated deviations from the Baryonic Tully-Fisher Relation," Astrophysical Journal, vol.
The observed Tully-Fisher relation (Tully & Fisher 1977) shows that for spiral galaxies [v.sup.[delta].sub.[infinity]], [varies] L, where L is the luminosity of the galaxy and 5 is some constant.
3 shows a comparison of observations and predictions of MOND regarding the Tully-Fisher relation.
Newtonian dynamics predicts different Tully-Fisher relations for these two classes, but they are observed to follow identical relations.
QCM agrees with MOND and the baryonic Tully-Fisher relation for individual galaxies.
Even more surprising, all disk galaxies seem to share the same relationship between their luminosity and the speed with which their disk rotates (known as the Tully-Fisher relation, after its first proponents), regardless of their surface brightness.
The results explain the large disks and slow inner rotation of low-surface-brightness galaxies, and they account for the properties that these galaxies share with normal galaxies, including the Tully-Fisher relation. More important, for the first time we can explain why galaxies form with an incredible range of sizes and surface brightnesses.
This concept was fully developed in 1977 by Brent Tully and Richard Fisher and soon became known as the Tully-Fisher relation. It extended the realm of measurable galaxy distances far beyond the Virgo cluster.
Although the universe was at first assumed to be expanding uniformly, the wholesale use of the Tully-Fisher relation revealed large-scale departures from uniformity.