Projects per year
Abstract / Description of output
The classical definition of the virial temperature of a galaxy halo
excludes a fundamental contribution to the energy partition of the halo:
the kinetic energy of nonthermal gas motions. Using simulations of
low-redshift, ∼L* galaxies from the Figuring Out Gas &
Galaxies In Enzo (FOGGIE) project that are optimized to resolve
low-density gas, we show that the kinetic energy of nonthermal motions
is roughly equal to the energy of thermal motions. The simulated FOGGIE
halos have ∼2× lower bulk temperatures than expected from a
classical virial equilibrium, owing to significant nonthermal kinetic
energy that is formally excluded from the definition of Tvir.
We explicitly derive a modified virial temperature including nonthermal
gas motions that provides a more accurate description of gas
temperatures for simulated halos in virial equilibrium. Strong bursts of
stellar feedback drive the simulated FOGGIE halos out of virial
equilibrium, but the halo gas cannot be accurately described by the
standard virial temperature even when in virial equilibrium. Compared to
the standard virial temperature, the cooler modified virial temperature
implies other effects on halo gas: (i) the thermal gas pressure is
lower, (ii) radiative cooling is more efficient, (iii) O vi
absorbing gas that traces the virial temperature may be prevalent in
halos of a higher mass than expected, (iv) gas mass estimates from X-ray
surface brightness profiles may be incorrect, and (v) turbulent motions
make an important contribution to the energy balance of a galaxy halo.
Original language | English |
---|---|
Article number | 121 |
Pages (from-to) | 1-23 |
Number of pages | 23 |
Journal | Astrophysical Journal |
Volume | 922 |
Issue number | 2 |
DOIs | |
Publication status | Published - 25 Nov 2021 |
Keywords / Materials (for Non-textual outputs)
- astro-ph.GA
Fingerprint
Dive into the research topics of 'Figuring Out Gas & Galaxies In Enzo (FOGGIE). V. The Virial Temperature Does Not Describe Gas in a Virialized Galaxy Halo: The Virial Temperature Does Not Describe Gas in a Virialized Galaxy Halo'. Together they form a unique fingerprint.Projects
- 1 Active