Editing Tully–Fisher relation (section)

==History==
The connection between rotational velocity measured spectroscopically and distance was first used in 1922 by [[Ernst Öpik]] to estimate the distance to the [[Andromeda Galaxy]].<ref name=SaidTF/><ref>Opik, Ernst. "An estimate of the distance of the Andromeda Nebula." Astrophysical Journal, 55, 406–410 (1922) 55 (1922).</ref> In the 1970s, Balkowski, C., et al. measured 13 galaxies but focused on using the data to distinguish galaxy shapes rather than extract distances.<ref name=SaidTF/><ref>Balkowski, C., et al. "Neutral hydrogen study of spiral and irregular dwarf galaxies." Astronomy and Astrophysics, Vol. 34, p. 43–52 34 (1974): 43–52.</ref>
The relationship was first published in 1977 by astronomers [[R. Brent Tully]] and [[J. Richard Fisher]].<ref>{{cite journal |last1=Tully |first1=R. B. |last2=Fisher |first2=J. R. |title=A New Method of Determining Distances to Galaxies |journal=[[Astronomy and Astrophysics]] |volume=54 |issue=3 |year=1977 |pages=661–673 |bibcode=1977A&A....54..661T }}</ref> The luminosity is calculated by multiplying the galaxy's [[apparent brightness]] by <math>4\pi d^2</math>, where <math>d</math> is its distance from [[Earth]], and the spectral-line width is measured using [[long-slit spectroscopy]].

A series of collaborative catalogs of galaxy [[peculiar velocity]] values called CosmicFlow uses Tully–Fisher analysis; the Cosmicflow-4 catalog has reached 10000 galaxies.<ref>{{Cite journal |last1=Kourkchi |first1=Ehsan |last2=Tully |first2=R. Brent |last3=Eftekharzadeh |first3=Sarah |last4=Llop |first4=Jordan |last5=Courtois |first5=Hélène M. |last6=Guinet |first6=Daniel |last7=Dupuy |first7=Alexandra |last8=Neill |first8=James D. |last9=Seibert |first9=Mark |last10=Andrews |first10=Michael |last11=Chuang |first11=Juana |last12=Danesh |first12=Arash |last13=Gonzalez |first13=Randy |last14=Holthaus |first14=Alexandria |last15=Mokelke |first15=Amber |date=2020-10-23 |title=Cosmicflows-4: The Catalog of ∼10,000 Tully–Fisher Distances |journal=The Astrophysical Journal |volume=902 |issue=2 |pages=145 |doi=10.3847/1538-4357/abb66b |doi-access=free |arxiv=2009.00733 |bibcode=2020ApJ...902..145K |issn=1538-4357}}</ref> Many values of the [[Hubble constant]] have been derived from Tully–Fisher analysis, starting with the first paper and continuing through 2024.<ref name=SaidTF/>