Zooming in on the circumgalactic medium with GIBLE: Tracing the origin and evolution of cold clouds
Year: 2025
Type: article
Abstract: We used the GIBLE suite of cosmological zoom-in simulations of Milky Way-like galaxies with additional super-Lagrangian refinement in the circumgalactic medium (CGM) to quantify the origin and evolution of CGM cold gas clouds. The origin of z = 0 clouds can be traced back to recent (≲2 Gyr) outflows from the central galaxy (∼45%), condensation out of the hot phase of the CGM in the same time frame (∼45%), and to a lesser degree to satellite galaxies (≲5%). We find that in situ condensation results from rapid cooling around local overdensities primarily seeded by the dissolution of the previous generation of clouds into the hot halo. About ≲10% of the cloud population is long-lived, with their progenitors having already assembled ∼2 Gyr ago. Collective cloud-cloud dynamics are crucial to their evolution, with coalescence and fragmentation events occurring frequently (≳20 Gyr−1). These interactions are modulated by non-vanishing pressure imbalances between clouds and their interface layers. The gas content of clouds is in a constant state of flux, with clouds and their surroundings exchanging mass at a rate of ≳103 M⊙ Myr−1, depending on cloud relative velocity and interface vorticity. Furthermore, we find that a net magnetic tension force acting against the density gradient is capable of inhibiting cloud-background mixing. Our results show that capturing the distinct origins of cool CGM clouds, together with their physical evolution, requires high-resolution cosmological galaxy formation simulations with both stellar and supermassive black hole feedback-driven outflows.
Source: Astronomy and Astrophysics
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
Funders: National Aeronautics and Space Administration, International Max Planck Research School for Environmental, Cellular and Molecular Microbiology, Deutsche Forschungsgemeinschaft, Universität Heidelberg, International Max Planck Research School for Advanced Methods in Process and Systems Engineering, Max-Planck-Institut für Astronomie
OpenAlex ID: W4410737372