Constraining dark matter halo profiles and galaxy formation models using spiral arm morphology. II. dark and stellar mass concentrations for 13 nearby face-on galaxies

Marc S. Seigar, Benjamin L. Davis, Joel Berrier, Daniel Kennefick

    Research output: Contribution to journalArticlepeer-review

    Abstract

    We investigate the use of spiral arm pitch angles as a probe of disk galaxy mass profiles. We confirm our previous result that spiral arm pitch angles (P) are well correlated with the rate of shear (S) in disk galaxy rotation curves. We use this correlation to argue that imaging data alone can provide a powerful probe of galactic mass distributions out to large look-back times. We then use a sample of 13 galaxies, with Spitzer 3.6 μm imaging data and observed Hα rotation curves, to demonstrate how an inferred shear rate coupled with a bulge-disk decomposition model and a Tully-Fisher-derived velocity normalization can be used to place constraints on a galaxy's baryon fraction and dark matter halo profile. Finally, we show that there appears to be a trend (albeit a weak correlation) between spiral arm pitch angle and halo concentration. We discuss implications for the suggested link between supermassive black hole (SMBH) mass and dark halo concentration, using pitch angle as a proxy for SMBH mass.

    Original languageEnglish (US)
    Article number90
    JournalAstrophysical Journal
    Volume795
    Issue number1
    DOIs
    StatePublished - Nov 1 2014

    Keywords

    • dark matter
    • galaxies: fundamental parameters
    • galaxies: halos
    • galaxies: kinematics and dynamics
    • galaxies: spiral
    • galaxies: structure

    ASJC Scopus subject areas

    • Astronomy and Astrophysics
    • Space and Planetary Science

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