Oscar Agertz
Associate Professor / Senior university lecturer / Wallenberg Academy Fellow
INFERNO : Galactic winds in dwarf galaxies with star-by-star simulations including runaway stars
Author
Summary, in English
The formation and evolution of galaxies have proved sensitive to the inclusion of stellar feedback, which is therefore crucial to any successful galaxy model. We present INFERNO, a new model for hydrodynamic simulations of galaxies, which incorporates resolved stellar objects with star-by-star calculations of when and where the injection of enriched material, momentum, and energy takes place. INFERNO treats early stellar kinematics to include phenomena such as walkaway and runaway stars. We employ this innovative model on simulations of a dwarf galaxy and demonstrate that our physically motivated stellar feedback model can drive vigorous galactic winds. This is quantified by mass and metal loading factors in the range of 10–100, and an energy loading factor close to unity. Outflows are established close to the disc, are highly multiphase, spanning almost 8 orders of magnitude in temperature, and with a clear dichotomy between mass ejected in cold, slow-moving (T ≲ 5 × 104 K, v < 100 km s-1) gas and energy ejected in hot, fast-moving (T > 106 K, v > 100 km s-1) gas. In contrast to massive disc galaxies, we find a surprisingly weak impact of the early stellar kinematics, with runaway stars having little to no effect on our results, despite exploding in diffuse gas outside the dense star-forming gas, as well as outside the galactic disc entirely. We demonstrate that this weak impact in dwarf galaxies stems from a combination of strong feedback and a porous interstellar medium, which obscure any unique signatures that runaway stars provide.
Department/s
- Astrophysics
- eSSENCE: The e-Science Collaboration
Publishing year
2023-05-01
Language
English
Pages
2196-2214
Publication/Series
Monthly Notices of the Royal Astronomical Society
Volume
521
Issue
2
Document type
Journal article
Publisher
Oxford University Press
Topic
- Astronomy, Astrophysics and Cosmology
Keywords
- galaxies: evolution
- ISM: jets
- methods: numerical
- outflows
Status
Published
ISBN/ISSN/Other
- ISSN: 0035-8711