Astronomy and Astrophysics – Astrophysics
Scientific paper
2000-01-02
Astrophys.J.538:477-488,2000
Astronomy and Astrophysics
Astrophysics
submitted to The Astrophysical Journal
Scientific paper
10.1086/309175
We use cosmological N-body/gasdynamical simulations that include star formation and feedback to examine the proposal that scaling laws between the total luminosity, rotation speed, and angular momentum of disk galaxies reflect analogous correlations between the structural parameters of their surrounding dark matter halos. The numerical experiments follow the formation of galaxy-sized halos in two Cold Dark Matter dominated universes: the standard Omega=1 CDM scenario and the currently popular LCDM model. We find that the slope and scatter of the I-band Tully-Fisher relation are well reproduced in the simulations, although not, as proposed in recent work, as a result of the cosmological equivalence between halo mass and circular velocity: large systematic variations in the fraction of baryons that collapse to form galaxies and in the ratio between halo and disk circular velocities are observed in our numerical experiments. The Tully-Fisher slope and scatter are recovered in this model as a direct result of the dynamical response of the halo to the assembly of the luminous component of the galaxy. We conclude that models that neglect the self-gravity of the disk and its influence on the detailed structure of the halo cannot be used to derive meaningful estimates of the scatter or slope of the Tully-Fisher relation. Our models fail, however, to match the zero-point of the Tully-Fisher relation, as well as that of the relation linking disk rotation speed and angular momentum. These failures can be traced, respectively, to the excessive central concentration of dark halos formed in the Cold Dark Matter cosmogonies we explore and to the formation of galaxy disks as the final outcome of a sequence of merger events. (abridged)
Navarro Julio F.
Steinmetz Matthias
No associations
LandOfFree
Dark Halo and Disk Galaxy Scaling Laws in Hierarchical Universes does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Dark Halo and Disk Galaxy Scaling Laws in Hierarchical Universes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dark Halo and Disk Galaxy Scaling Laws in Hierarchical Universes will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-525923