Using the Circumgalactic Medium of Dwarf Galaxies as a Calorimetric Dark Matter Detector
Abstract
Many well-motivated dark matter (DM) scenarios, including dark photon DM, axion-like particles, sterile neutrinos, and primordial black holes, can deposit energy into ordinary matter and significantly raise the thermal energy of astrophysical gas. We present a simple, model-independent implementation of DM-induced heating in the RAMSES hydrodynamic simulation code, parameterized by an effective local heat-transfer rate Γheat. Using simulations of an isolated gas-rich dwarf galaxy with properties similar to WLM, we find that DM heating substantially alters the thermal structure of the circumgalactic medium (CGM) while leaving the star formation rate and the dense ISM nearly unchanged. For Γheat = 10−27 to 10−25 s−1, the neutral hydrogen column at 10 kpc is suppressed by 0.6 to 3.9 dex relative to the control simulation. Similarly, the C II and Si II column densities decrease by 4.1 and 5.5 dex, and by 2.2 and 3.0 dex for C IV and Si IV. These signatures are accessible to quasar absorption-line spectroscopy, so CGM observations of nearby field dwarf galaxies provide a promising avenue for constraining dark matter models that inject heat into ordinary matter.
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BibTeX
@misc{mintz2026using,
title = {{Using the Circumgalactic Medium of Dwarf Galaxies as a Calorimetric Dark Matter Detector}},
author = {Abby Mintz and Digvijay Wadekar and Romain Teyssier},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.15748},
eprint = {2609.15748},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.15748},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Using the Circumgalactic Medium of Dwarf Galaxies as a Calorimetric Dark Matter Detector
AU - Abby Mintz
AU - Digvijay Wadekar
AU - Romain Teyssier
PY - 2026
DA - 2026/09/14
PB - arXiv
DO - 10.48550/arxiv.2609.15748
UR - https://arxiv.org/abs/2609.15748
AB - Many well-motivated dark matter (DM) scenarios, including dark photon DM, axion-like particles, sterile neutrinos, and primordial black holes, can deposit energy into ordinary matter and significantly raise the thermal energy of astrophysical gas. We present a simple, model-independent implementation of DM-induced heating in the RAMSES hydrodynamic simulation code, parameterized by an effective local heat-transfer rate Γ_heat. Using simulations of an isolated gas-rich dwarf galaxy with properties similar to WLM, we find that DM heating substantially alters the thermal structure of the circumgalactic medium (CGM) while leaving the star formation rate and the dense ISM nearly unchanged. For Γ_heat = 10^−27 to 10^−25 s^−1, the neutral hydrogen column at 10 kpc is suppressed by 0.6 to 3.9 dex relative to the control simulation. Similarly, the C II and Si II column densities decrease by 4.1 and 5.5 dex, and by 2.2 and 3.0 dex for C IV and Si IV. These signatures are accessible to quasar absorption-line spectroscopy, so CGM observations of nearby field dwarf galaxies provide a promising avenue for constraining dark matter models that inject heat into ordinary matter.
ER -