Dark Matter Halos of Disk Galaxies: Constraints from the Tully‐Fisher Relation

Abstract

We investigate structural properties of dark matter halos of disk galaxies, using a well-defined sample of 81 diskdominated galaxies from the SDSS redshift survey. We model the mass-velocity (TF) and fundamental plane (FP) relations of these galaxies, using the observed stellar mass M Ã , disk scale length R d , and optical H rotation velocity at 2.2 R d . We calculate model galaxy populations, defined by the distribution of the stellar diskYtoYtotal mass fraction, m d , and include the effect of adiabatic contraction. We find that models with constant m d underpredict the intrinsic scatter of the TF and FP relations and predict an (unobserved) strong correlation between TF residuals, even with the full range of halo concentration scatter. Introducing a scatter of m d and allowing the mean valuem d to scale with the stellar surface density significantly improves observational match and reduces the predicted residual correlation enough to be consistent with the data. The distribution of angular momentum parameters required to match the observed scale lengths is an output of the models and is narrower than that predicted for halo spin parameters. However, our best-fit models with a Kroupa stellar IMF overproduce the galaxy stellar mass function and predict the virial massto-light ratios lower than those inferred from galaxy-galaxy weak lensing and satellite dynamics. We suggest three possible solutions to these problems: (1) ignoring the effects of adiabatic contraction, (2) adopting a ''light'' stellar IMF with M Ã /L lower by 0.15 dex, or (3) considering the lower halo concentrations expected for a low power spectrum normalization 8 % 0:74. In combination with our proposed correlation ofm d with surface density, any of these solutions yields acceptable residual correlations and relieves most of the observational tension between the TF relation and the galaxy stellar mass function.

The X‐Ray Concentration–Virial Mass Relation

“…While the early-type galaxy and group-cluster mass halos (k10 13 M ) studied here apparently prefer slightly higher concentrations than predicted for typical halos in the concordance ÃCDM model, the opposite is true for late-type galaxies (e.g., Alam et al 2002;van den Bosch et al 2003;Dutton et al 2005;Kuzio de Naray et al 2006;Gnedin et al 2006). This may indicate that a selection or formation time bias operates across the galaxy type spectrum, with late-type galaxies inhabiting the lowconcentration tail of the distribution (although see Napolitano 2004;Napolitano et al 2005).…”

On the galaxy–halo connection in the EAGLE simulation

“…E-mail: harryd2@stanford.edu Despite these successes, however, the conjunction of these models (hereafter "SHAM+MMW") is known to make incorrect predictions for two properties of the galaxy population. The first is the scatter s MSR in the stellar mass-size relation (MSR; de Jong & Lacey 2000; Gnedin et al 2007). SHAM+MMW sets galaxy size proportional to halo spin, λ, and hence requires the scatter in size at fixed mass to be at least as large as that in λ.…”

The baryonic Tully–Fisher relation cares about the galaxy sample

“…Tully & Fisher 1977;Pierce & Tully 1988;Teerikorpi 1995;Giovanelli et al 1997b;Courteau & Rix 1999;Tully & Pierce 2000;Giovanelli et al 1997a;Karachentsev et al 2002;Bedregal et al 2006;Noordermeer & Verheijen 2007;Springob et al 2007;Williams et al 2010;Tully & Courtois 2012;Mocz et al 2012;Rawle et al 2013;Torres-Flores et al 2013;Sorce et al 2013Sorce et al , 2014b to the low luminosity galaxies, is often used to constrain and test galaxy formation and evolution models, with various computational methods, in the ΛCDM scenario as well as in alternative theories (e.g. Steinmetz & Navarro 1999;Mo et al 1998;McGaugh & de Blok 1998;Eisenstein & Loeb 1995;van den Bosch 2000;Mayer & Moore 2004;Gnedin et al 2007;Governato et al 2007;Avila-Reese et al 2008;McGaugh 2012;Aumer et al 2013;Dutton 2012;Desmond & Wechsler 2015). While the TF links galaxy luminosities to their rotation rates, the BTFR adds galaxy gas in the equation to correlate galaxy baryonic masses and rotation rates.…”

“…Zaritsky et al 2014) and others disentangle the intrinsic scatter from the total observational scatter of the BTFR (e.g. Gnedin et al 2007;McGaugh 2012). While it is clear that these three variables (stellar normalization, rotation-rate measurement and observational uncertainties) affect the slope and the scatter of the BTFR and while works dedicated to deriving the BTFR are always careful to use a wide spanning range of spiral galaxy properties (in terms of both rotation rate and mass) not to bias the relation, there is currently no clear attempt known to us to study the impact of the galaxy sample size on the measured slope and intrinsic scatter of the BTFR.…”