Galaxy luminosity function and Tully-Fisher relation: reconciled through rotation-curve studies

The relation between galaxy luminosity L and halo virial velocity v_vir required to fit the galaxy luminosity function differs from the observed Tully-Fisher relation between L and disc speed v_rot. Hence the problem of reproducing the galaxy luminosity function and the Tully-Fisher relation simulta...

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Bibliographic Details
Published inarXiv.org
Main Authors Cattaneo, Andrea, Salucci, Paolo, Papastergis, Emmanouil
Format Paper Journal Article
LanguageEnglish
Published Ithaca Cornell University Library, arXiv.org 10.02.2014
Subjects
Astronomical models
Curve fitting
Dark matter
Dependence
Disk galaxies
Galactic rotation
Luminosity
Physics - Cosmology and Nongalactic Astrophysics
Stellar mass
Tully-Fisher relation
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Summary:The relation between galaxy luminosity L and halo virial velocity v_vir required to fit the galaxy luminosity function differs from the observed Tully-Fisher relation between L and disc speed v_rot. Hence 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_rot and v_vir by fitting observational average rotation curves of disc galaxies binned in luminosity. We show that the v_rot - v_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_rot on v_vir, which arises because the ratio of stellar mass to dark matter mass is a strong function of halo mass.
ISSN:2331-8422
DOI:10.48550/arxiv.1402.2280