Kinematic signatures of impulsive supernova feedback in dwarf galaxies

Jan D. Burger, Jesús Zavala, Laura V. Sales, Mark Vogelsberger, Federico Marinacci, Paul Torrey

Submitted on 7 November 2022


Impulsive supernova feedback and non-standard dark matter models, such as self-interacting dark matter (SIDM), are the two main contenders for the role of the dominant core formation mechanism at the dwarf galaxy scale. Here we show that the impulsive supernova cycles that follow episodes of bursty star formation leave distinct features in the distribution function of stars: groups of stars with similar ages and metallicities develop overdense shells in phase space. If cores are formed through supernova feedback, we predict the presence of such features in star-forming dwarf galaxies with cored host halos. Their systematic absence would favor alternative dark matter models, such as SIDM, as the dominant core formation mechanism.


Comment: 16 pages, 13 figures, arxiv version contains both the letter and the supplemental material \c{opyright} 2022 American Physical Society

Subjects: Astrophysics - Astrophysics of Galaxies; High Energy Physics - Phenomenology


Gas distributions of resulting galaxies after $3\,$Gyr of simulation time for two simulations with different star formation thresholds. We show face-on (left column) and edge-on (right column) projections of the gas density for the CDM simulation with smooth (top row) and bursty (bottom row) star formation. The side-length of the field of view is $20\,$kpc in each panel and we defined a coordinate system such that the z-axis is perpendicular to the gas disc.  Notice how central gas is vertically expelled out of the disc plane in the simulation with bursty star formation. Such galactic outflows are characteristic of violent and impulsive events of supernova-driven energy release.