Galaxy luminosity function and Tully-Fisher relation: reconciled through rotation-curve studies
- Laboratoire d'Astrophysique de Marseille, UMR 6110 CNRS, Universite d'Aix-Marseille, 38 Rue F. Joliot-Curie, F-13388 Marseille Cedex 13 (France)
- Department of Astrophysics, SISSA, Via Beirut, 2-4, I-34014 Trieste (Italy)
- Center for Radiophysics and Space Research, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States)
The relation between galaxy luminosity L and halo virial velocity v {sub vir} required to fit the galaxy luminosity function differs from the observed Tully-Fisher relation between L and disk speed v {sub rot}. Because of this, the problem of reproducing the galaxy luminosity function and the Tully-Fisher relation simultaneously has plagued semianalytic models since their inception. Here we study the relation between v {sub rot} and v {sub vir} by fitting observational average rotation curves of disk galaxies binned in luminosity. We show that the v {sub rot}-v {sub vir} relation that we obtain in this way can fully account for this seeming inconsistency. Therefore, the reconciliation of the luminosity function with the Tully-Fisher relation rests on the complex dependence of v {sub rot} on v {sub vir}, which arises because the ratio of stellar mass to dark matter mass is a strong function of halo mass.
- OSTI ID:
- 22351333
- Journal Information:
- Astrophysical Journal, Vol. 783, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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