Scalar Field Dark Matter: Impact of Supernovae-driven blowouts on the soliton structure of low mass dark matter halos

TL;DR

This study investigates how supernova-driven gas blowouts affect the structure of low-mass dark matter halos in scalar field dark matter models, revealing significant density oscillations and implications for galaxy observations.

Contribution

It is the first to analyze the gravitational effects of supernova feedback on soliton cores in scalar field dark matter halos, including stochastic density fluctuations and their impact on mass inference.

Findings

Single blowouts significantly reduce soliton central density.

Density oscillations are quasi-periodic or stochastic depending on the scenario.

Inferred boson mass from density profiles is within 20% of the true value.

Abstract

We present the first study on the gravitational impact of supernova feedback in an isolated soliton and a spherically symmetric dwarf SFDM halo of virial mass $1\times 10^{10}\mathrm{M_\odot}$. We use a boson mass $m=10^{-22}\mathrm{eV/c^2}$ and a soliton core $r_c \approx 0.7$kpc, comparable to typical half-light radii of Local Group dwarf galaxies. We simulate the rapid gas removal from the center of the soliton by a concentric external time-dependent Hernquist potential. We explore two scenarios of feedback blowouts: i) a massive single burst, and ii) multiple consecutive blowouts injecting the same total energy to the system, including various magnitudes for the blowouts in both scenarios. In all cases, we find one single blowout has a stronger effect on reducing the soliton central density. Feedback leads to central soliton densities that oscillate quasi-periodically for an isolated soliton and stochastically for a SFDM halo. The range in the density amplitude depends on the strength of the blowout, however we observe typical variations of a factor of $\geqslant$2. One important consequence of the stochastic fluctuating densities is that, if we had no prior knowledge of the system evolution, we can only know the configuration profile at a specific time within some accuracy. By fitting soliton profiles at different times to our simulated structures, we found the (1-$\sigma$) scatter of their time-dependent density profiles. For configurations within the 1$\sigma$ range, we find the inferred boson mass is typically less than 20\% different from the real value used in our simulations. Finally, we compare the observed dynamical masses of field dwarf galaxies in our Local Group with the implied range of viable solitons from our simulations and find good agreement.