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Angular momentum and galaxy formation revisited: effects of variable mass-to-light ratios
Astrophysical Journal Letters (2013)
  • S. M. Fall, Space Telescope Science Institute
  • Aaron J. Romanowsky, San Jose State University

We rederive the relation between the specific angular momentum j sstarf and the mass M sstarf of the stellar matter in galaxies of different morphological types. This is a revision of the j sstarf-M sstarf diagram presented in our recent comprehensive study of galactic angular momentum. In that work, we estimated j sstarf from kinematic and photometric data that extended to large radii and M sstarf from near-infrared luminosities LK with an assumed universal mass-to-light ratio M sstarf/LK . However, recent stellar population models show large variations in M sstarf/LK correlated with B – V color. In the present work, we use this correlation to estimate M sstarf/LK and hence M sstarf from the measured B – V and LK . Our revised j sstarf-M sstarf diagram is similar to our previous one; both disk-dominated and elliptical galaxies follow nearly parallel sequences with $j_\star \propto M_{\star }^{\alpha }$ and α = 0.6 ± 0.1. However, the offset between the sequences is now a factor of about 5, some 30% larger than before (and close to the offset found by Fall in 1983). Thus, our new results place even tighter constraints on the loss of specific angular momentum by galactic disks over their lifetimes

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Copyright © 2013 Institute of Physics. The published version of the article can be found online at:
Citation Information
S. M. Fall and Aaron J. Romanowsky. "Angular momentum and galaxy formation revisited: effects of variable mass-to-light ratios" Astrophysical Journal Letters Vol. 769 Iss. 2 (2013)
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