GraphNPE recovers a significantly lower central density for Boötes I consistent with a core while Draco remains marginally cuspy, and demonstrates that higher-order velocity moments reduce bias in dynamical modeling.
Breathing FIRE: How Stellar Feedback Drives Radial Migration, Rapid Size Fluctuations, and Population Gradients in Low-Mass Galaxies
5 Pith papers cite this work. Polarity classification is still indexing.
abstract
We examine the effects of stellar feedback and bursty star formation on low-mass galaxies ($M_{\rm star}=2\times10^6-5\times10^{10}{\rm M_{\odot}}$) using the FIRE (Feedback in Realistic Environments) simulations. While previous studies emphasized the impact of feedback on dark matter profiles, we investigate the impact on the stellar component: kinematics, radial migration, size evolution, and population gradients. Feedback-driven outflows/inflows drive significant radial stellar migration over both short and long timescales via two processes: (1) outflowing/infalling gas can remain star-forming, producing young stars that migrate $\sim1{\rm\,kpc}$ within their first $100 {\rm\,Myr}$, and (2) gas outflows/inflows drive strong fluctuations in the global potential, transferring energy to all stars. These processes produce several dramatic effects. First, galaxies' effective radii can fluctuate by factors of $>2$ over $\sim200 {\rm\,Myr}$, and these rapid size fluctuations can account for much of the observed scatter in radius at fixed $M_{\rm star}.$ Second, the cumulative effects of many outflow/infall episodes steadily heat stellar orbits, causing old stars to migrate outward most strongly. This age-dependent radial migration mixes---and even inverts---intrinsic age and metallicity gradients. Thus, the galactic-archaeology approach of calculating radial star-formation histories from stellar populations at $z=0$ can be severely biased. These effects are strongest at $M_{\rm star}\approx10^{7-9.6}{\rm M_{\odot}}$, the same regime where feedback most efficiently cores galaxies. Thus, detailed measurements of stellar kinematics in low-mass galaxies can strongly constrain feedback models and test baryonic solutions to small-scale problems in $\Lambda$CDM.
years
2026 5representative citing papers
A mean-field magnetic polytrope model shows radiation pressure can unbind an n=3 polytrope when the central overpressure exceeds roughly 0.15 times a mass-dependent factor under small radial perturbations.
The paper identifies underproduction of oxygen in low-mass simulated dwarf galaxies as the likely cause of missing OVI in the CGM, based on comparisons across two simulation suites.
Review chapter on SKA observations of RELHICs and dim galaxies to constrain LambdaCDM and baryonic physics via HIMF, HIVF, and bTFR down to 10^6 solar masses.
citing papers explorer
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Dark Matter in Draco and Bo\"otes I: Hints of a Core in an Ultra-Faint Dwarf from Simulation-Based Inference
GraphNPE recovers a significantly lower central density for Boötes I consistent with a core while Draco remains marginally cuspy, and demonstrates that higher-order velocity moments reduce bias in dynamical modeling.
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Non-linear Dynamical Stability of Magnetic Polytropes
A mean-field magnetic polytrope model shows radiation pressure can unbind an n=3 polytrope when the central overpressure exceeds roughly 0.15 times a mass-dependent factor under small radial perturbations.
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The Simulated Oxygen Shortage (SOS): Mapping the Missing OVI in Simulated Dwarf Galaxies to Subgrid Physics
The paper identifies underproduction of oxygen in low-mass simulated dwarf galaxies as the likely cause of missing OVI in the CGM, based on comparisons across two simulation suites.
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The Bright Future of the Dark and Dim Universe
Review chapter on SKA observations of RELHICs and dim galaxies to constrain LambdaCDM and baryonic physics via HIMF, HIVF, and bTFR down to 10^6 solar masses.
- Probing the faint end of simulated galaxy counts at z>3