Gas kinematics in FIRE simulated galaxies compared to spatially unresolved HI observations.

The shape of a galaxy's spatially unresolved, globally integrated 21-cm emission line depends on its internal gas kinematics: galaxies with rotationally supported gas discs produce double-horned profiles with steep wings, while galaxies with dispersion-supported gas produce Gaussian-like profiles with sloped wings. Using mock observations of simulated galaxies from the FIRE project, we show that one can therefore constrain a galaxy's gas kinematics from its unresolved 21-cm line profile. In particular, we find that the kurtosis of the 21-cm line increases with decreasing and that this trend is robust across a wide range of masses, signal-to-noise ratios, and inclinations.

SIDM on FIRE: hydrodynamical self-interacting dark matter simulations of low-mass dwarf galaxies.

We compare a suite of four simulated dwarf galaxies formed in 10 M haloes of collisionless cold dark matter (CDM) with galaxies simulated in the same haloes with an identical galaxy formation model but a non-zero cross-section for DM self-interactions. These cosmological zoom-in simulations are part of the Feedback In Realistic Environments (fire) project and utilize the fire-2 model for hydrodynamics and galaxy formation physics. We find the stellar masses of the galaxies formed in self-interacting dark matter (SIDM) with = 1 cm g are very similar to those in CDM (spanning ≈ 10 M) and all runs lie on a similar stellar mass-size relation.

Dwarf galaxy mass estimators versus cosmological simulations.

We use a suite of high-resolution cosmological dwarf galaxy simulations to test the accuracy of commonly used mass estimators from Walker et al. (2009) and Wolf et al. (2010), both of which depend on the observed line-of-sight velocity dispersion and the 2D half-light radius of the galaxy, .