Investigating the Effect of Bursty Star Formation on the Size Fluctuation in Local Low-mass Galaxies

Low-mass galaxies (M_* < 10⁹ M_Sun) are ideal testbeds for the dark matter and star formation theory. Given their shallower gravitational potential wells and lower escape velocities, low-mass galaxies are highly susceptible to stellar feedback as compared to their more massive counterparts. Implementing stellar feedback into dark-matter simulations suggests that outflows driven by feedback can cause gravitational potential fluctuations as well as variations in the stellar and gas kinematics of the galaxies. Here we analyze the effect of bursty star formation on the galaxy’s size fluctuation by comparing a sample of observed local low-mass galaxies with their simulated FIRE analogs. We use the dynamic time warping (DTW) technique to estimate the similarity and time shift between the size and star formation time series in the simulated galaxies. Our findings provide fundamental insights about the galaxies’ size response to the star formation change, and also provide approaches to observationally examine this prediction using star formation indicators with different timescales.