An Energetic Consistency Test for Feedback-Driven Gas Loss in Milky Way Dwarf Satellites
Abstract
Dwarf spheroidal galaxies (dSphs) contain little detectable cold gas, but the relative roles of stellar feedback, reionization, and environmental effects in their gas loss remain uncertain. We apply an order-of-magnitude energy-budget test to nine Milky Way dwarf satellites using published color--magnitude-diagram star formation histories (SFHs), galaxy-level velocity dispersions, effective radii, and integrated V-band luminosities. For each galaxy and halo prescription, we define the energy-equivalence time τE, when a crossing exists, as the first elapsed time at which the cumulative effective energy from core-collapse supernovae equals the adopted gas binding energy. This quantity is an energetic diagnostic rather than a direct measurement of wind launch. Under the fiducial parameters, all nine galaxies reach the nominal threshold under the kinematic--size prescription K+B16, yet star formation often continues long after threshold crossing. We compare the corresponding lookback time tE,lb with t90,lb, the lookback time at which 90\% of the total initial stellar mass had formed. Because both times are derived from the same cumulative SFH, their temporal proximity is interpreted descriptively rather than as independent evidence of feedback-driven quenching. Whether the threshold is reached depends on the adopted halo mass, radius, retained gas fraction, and supernova--gas coupling efficiency. These results distinguish the availability of sufficient cumulative feedback energy from the processes that determine the timing of quenching.
Related
- ARRAKIHS: The observability of tidally stripped satellites in a Milky Way-like halo
- The tidal features of the classical Milky Way satellites: Expected in MOND but inconsistent with cold dark matter models
- Simulations agree: the Milky Way's satellites are disrupting
- The missing ultra-faint satellites of the Milky Way
- The Merian Survey: A Statistical Census of Bright Satellites of Sub-Milky Way-Mass Galaxies
BibTeX
@misc{matsui2026energetic,
title = {{An Energetic Consistency Test for Feedback-Driven Gas Loss in Milky Way Dwarf Satellites}},
author = {Sena A. Matsui and Tsutomu T. Takeuchi and Suchetha Cooray and Kiyoaki Christopher Omori},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.21186},
eprint = {2610.21186},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.21186},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - An Energetic Consistency Test for Feedback-Driven Gas Loss in Milky Way Dwarf Satellites
AU - Sena A. Matsui
AU - Tsutomu T. Takeuchi
AU - Suchetha Cooray
AU - Kiyoaki Christopher Omori
PY - 2026
DA - 2026/10/15
PB - arXiv
DO - 10.48550/arxiv.2610.21186
UR - https://arxiv.org/abs/2610.21186
AB - Dwarf spheroidal galaxies (dSphs) contain little detectable cold gas, but the relative roles of stellar feedback, reionization, and environmental effects in their gas loss remain uncertain. We apply an order-of-magnitude energy-budget test to nine Milky Way dwarf satellites using published color--magnitude-diagram star formation histories (SFHs), galaxy-level velocity dispersions, effective radii, and integrated V-band luminosities. For each galaxy and halo prescription, we define the energy-equivalence time τ_E, when a crossing exists, as the first elapsed time at which the cumulative effective energy from core-collapse supernovae equals the adopted gas binding energy. This quantity is an energetic diagnostic rather than a direct measurement of wind launch. Under the fiducial parameters, all nine galaxies reach the nominal threshold under the kinematic--size prescription K+B16, yet star formation often continues long after threshold crossing. We compare the corresponding lookback time t_E,lb with t_90,lb, the lookback time at which 90\% of the total initial stellar mass had formed. Because both times are derived from the same cumulative SFH, their temporal proximity is interpreted descriptively rather than as independent evidence of feedback-driven quenching. Whether the threshold is reached depends on the adopted halo mass, radius, retained gas fraction, and supernova--gas coupling efficiency. These results distinguish the availability of sufficient cumulative feedback energy from the processes that determine the timing of quenching.
ER -