Self-consistent Bulge/Disk/Halo Galaxy Dynamical Modeling Using Integral Field Kinematics

• Published in: The Astrophysical Journal
• Main Authors: Taranu, D. S., Obreschkow, D., Dubinski, J. J., Fogarty, L. M. R., van de Sande, J., Catinella, B., Cortese, L., Moffett, A., Robotham, A. S. G., Allen, J. T., Bland-Hawthorn, J., Bryant, J. J., Colless, M., Croom, S. M., D'Eugenio, F., Davies, R. L., Drinkwater, M. J., Driver, S. P., Goodwin, M., Konstantopoulos, I. S., Lawrence, J. S., Lopez-Sanchez, A. R., Lorente, N. P. F., Medling, A. M., Mould, J. R., Owers, M. S., Power, C., Richards, S. N., Tonini, C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Institute of Physics Publishing 2017
• Subjects: Bulge-Disc Decomposition; Fundamental Plane; Elliptic Galaxies; Sauron Project; Halo Models; Sky Survey; Stellar; Systems; Profile; Images; 1912 Space and Planetary Science; 3103 Astronomy and Astrophysics; sami
• Online Access: https://espace.library.uq.edu.au/view/UQ:702276/UQ702276_OA.pdf; https://espace.library.uq.edu.au/view/UQ:702276

We introduce a method for modeling disk galaxies designed to take full advantage of data from integral field spectroscopy (IFS). The method fits equilibrium models to simultaneously reproduce the surface brightness, rotation, and velocity dispersion profiles of a galaxy. The models are fully self-consistent 6D distribution functions for a galaxy with a Srsic profile stellar bulge, exponential disk, and parametric dark-matter halo, generated by an updated version of GalactICS. By creating realistic flux-weighted maps of the kinematic moments (flux, mean velocity, and dispersion), we simultaneously fit photometric and spectroscopic data using both maximumlikelihood and Bayesian (MCMC) techniques. We apply the method to a GAMA spiral galaxy (G79635) with kinematics from the SAMI Galaxy Survey and deep g- and r-band photometry from the VST-KiDS survey, comparing parameter constraints with those from traditional 2D bulge-disk decomposition. Our method returns broadly consistent results for shared parameters while constraining the mass-to-light ratios of stellar components and reproducing the H I-inferred circular velocity well beyond the limits of the SAMI data. Although the method is tailored for fitting integral field kinematic data, it can use other dynamical constraints like central fiber dispersions and H I circular velocities, and is well-suited for modeling galaxies with a combination of deep imaging and H I and/or optical spectra (resolved or otherwise). Our implementation (MagRite) is computationally efficient and can generate well-resolved models and kinematic maps in under a minute on modern processors.