A Consistent Set of Empirical Scaling Relations for Spiral Galaxies: The (v max, M oM)-(σ 0, M BH, φ) Relations

Benjamin L. Davis, Alister W. Graham, Françoise Combes

    Research output: Contribution to journalArticlepeer-review


    Using the latest sample of 48 spiral galaxies having a directly measured supermassive black hole mass, M BH, we determine how the maximum disk rotational velocity, v max (and the implied dark matter halo mass, M DM), correlates with the (i) black hole mass, (ii) central velocity dispersion, σ 0, and (iii) spiral-arm pitch angle, φ. We find that , significantly steeper than previously reported, and with a total root mean square scatter (0.58 dex) similar to that about the M BH0 relation for spiral galaxies - in stark disagreement with claims that M BH does not correlate with disks. Moreover, this M BH-v max relation is consistent with the unification of the Tully-Fisher relation (involving the total stellar mass, M ∗,tot) and the steep relation observed in spiral galaxies. We also find that , consistent with past studies connecting stellar bulges (with σ 0 ≈ 100 km s-1), dark matter halos, and a nonconstant v max0 ratio. Finally, we report that , providing a novel formulation between the geometry (i.e., the logarithmic spiral-arm pitch angle) and kinematics of spiral galaxy disks. While the v max-φ relation may facilitate distance estimations to face-on spiral galaxies through the Tully-Fisher relation and using φ as a proxy for v max, the M DM-φ relation provides a path for determining dark matter halo masses from imaging data alone. Furthermore, based on a spiral galaxy sample size that is double the size used previously, the self-consistent relations presented here provide dramatically revised constraints for theory and simulations.

    Original languageEnglish (US)
    Article number64
    JournalAstrophysical Journal
    Issue number1
    StatePublished - May 20 2019


    • black hole physics
    • dark matter
    • galaxies: evolution
    • galaxies: fundamental parameters
    • galaxies: spiral
    • galaxies: structure

    ASJC Scopus subject areas

    • Astronomy and Astrophysics
    • Space and Planetary Science


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