Galaxy properties are known to correlate most tightly with the galaxy effective stellar velocity dispersion {sigma}e. Here, we look for additional trends at fixed {sigma}e using 1339 galaxies (M_*>~6x10^9^M{sun}) with different morphologies in the MaNGA (DR14) sample with integral-field spectroscopy data. We focus on the gradients ({gamma}_rms={sigma}(R_e_/4)/{sigma}e) of the stellar root-mean-square velocity (V_rms_=sqrt(V^2^+{sigma}^2^)), which we show traces the total mass density gradient {gamma}tot derived from dynamical models and, more weakly, the bulge fraction. We confirm that {gamma}rms increases with {sigma}e, age, and metallicity. We additionally find that these correlations still exist at fixed {sigma}e, where galaxies with larger {gamma}rms are found to be older and more metal-rich. It means that mass density gradients contain information of the stellar population which is not fully accounted for by {sigma}e. This result puts an extra constraint on our understanding of galaxy quenching. We compare our results with galaxies in the IllustrisTNG hydrodynamical simulations and find that, at fixed {sigma}e, similar trends exist with age, the bulge fraction, and the total mass density slope but, unlike observations, no correlation with metallicity can be detected in the simulations.
Cone search capability for table J/MNRAS/495/4820/tables1 (Related parameters of 1339 MaNGA galaxies)