The impact of stellar feedback on the density and velocity structure of
the interstellar medium
(2016)cite arxiv:1608.08639Comment: 18 pages, 12 figures, 2 Tables, submitted to MNRAS.Аннотация
We study the role of stellar feedback in shaping the density and velocity
structure of neutral hydrogen (HI) in disc galaxies. For our analysis, we carry
out $4.6$ pc resolution $N$-body+adaptive mesh refinement (AMR)
hydrodynamic simulations of isolated galaxies, set up to mimic a Milky Way
(MW), and a Large and Small Magellanic Cloud (LMC, SMC). We quantify the
density and velocity structure of the interstellar medium using power spectra
and compare the simulated galaxies to observed HI in local spiral galaxies from
THINGS (The HI Nearby Galaxy Survey). We find that observed HI density power
spectra is only reproduced by simulations with efficient stellar feedback,
which influences the gas density field up to large (kpc) scales. Furthermore,
the kinetic energy power spectra in feedback regulated galaxies, regardless of
galaxy mass and size, show scalings in excellent agreement with super-sonic
turbulence ($E(k)k^-2)$ on scales below the thickness of the HI
layer. This is in stark contrast to models without feedback that feature only
large scale galactic turbulence driving. Analysed face-on, the line-of-sight
$E(k)$ in simulated galaxies shows strong signatures of stellar feedback on all
scales. This matches observations on scales $< 1$ kpc, in contrast to models
without feedback (although inclination effects must carefully be accounted
for). We conclude that the neutral gas content of galaxies carries signatures
of stellar feedback on all scales, providing us with a new benchmark for
stellar feedback models in galaxy formation simulations.
Описание
[1608.08639] The impact of stellar feedback on the density and velocity structure of the interstellar medium