The SAMI Galaxy Survey: gas streaming and dynamical M/L in rotationally supported systems ...

• Main Authors: Konstantopoulos, Bryant, Kelvin, Cecil, Ho, Fogarty, Sweet, Green, Owers, Lorente, Moffett, Goodwin, Lawrence, Lange, Cortese, Richards, Allen, Taylor, Bland-Hawthorn, Catinella, Croom, Driver
• Format: Text
• Language: English
• Published: The University of North Carolina at Chapel Hill University Libraries 2016
• Subjects: Starlight; sami
• Online Access: https://dx.doi.org/10.17615/cmnw-v703; https://cdr.lib.unc.edu/concern/articles/zc77sw38p

Line-of-sight velocities of gas and stars can constrain dark matter (DM) within rotationally supported galaxies if they trace circular orbits extensively. Photometric asymmetries may signify non-circular motions, requiring spectra with dense spatial coverage. Our integral-field spectroscopy of 178 galaxies spanned the mass range of the SAMI Galaxy Survey. We derived circular speed curves (CSCs) of gas and stars from non-parametric Diskfit fits out to $r\sim2r_e$. For 12/14 with measured H I profiles, ionized gas and H I maximum velocities agreed. We fitted mass-follows-light models to 163 galaxies by approximating the radial starlight profile as nested, very flattened mass homeoids viewed as a S\'ersic form. Fitting broad-band SEDs to SDSS images gave median stellar mass/light 1.7 assuming a Kroupa IMF vs. 2.6 dynamically. Two-thirds of the dynamical mass/light measures were consistent with star+remnant IMFs. One-fifth required upscaled starlight to fit, hence comparable mass of unobserved baryons and/or DM ...