Radiation pressure powers quasar broad absorption line winds but fails to drive galaxy feedback
Abstract
Most cosmological simulations invoke quasar-driven winds as the primary mechanism quenching star formation in massive galaxies, assuming wind momentum flux approaches the radiation-pressure maximum, L/c. Using 81,388 broad absorption line troughs from the SDSS-IV DR16 quasar catalog and detailed mock trough spectra, we detect line locking, a spectral signature of radiation-pressure-driven outflows, in 60 to 70 percent of troughs, demonstrating that radiative line driving dominates wind acceleration and ruling out alternative mechanisms. Direct measurement of the wind energy budget yields a median kinetic luminosity of only 0.01 percent of bolometric luminosity, 50 times below the level required for effective feedback. Line-driven quasar winds are therefore insufficiently powerful to quench star formation, challenging the primary physical mechanism invoked for black hole feedback in galaxy formation models.
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BibTeX
@misc{seefeldtgail2026radiation,
title = {{Radiation pressure powers quasar broad absorption line winds but fails to drive galaxy feedback}},
author = {Braden Seefeldt-Gail and Lluís Mas-Ribas and Norman Murray},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.07624},
eprint = {2610.07624},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.07624},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Radiation pressure powers quasar broad absorption line winds but fails to drive galaxy feedback
AU - Braden Seefeldt-Gail
AU - Lluís Mas-Ribas
AU - Norman Murray
PY - 2026
DA - 2026/10/06
PB - arXiv
DO - 10.48550/arxiv.2610.07624
UR - https://arxiv.org/abs/2610.07624
AB - Most cosmological simulations invoke quasar-driven winds as the primary mechanism quenching star formation in massive galaxies, assuming wind momentum flux approaches the radiation-pressure maximum, L/c. Using 81,388 broad absorption line troughs from the SDSS-IV DR16 quasar catalog and detailed mock trough spectra, we detect line locking, a spectral signature of radiation-pressure-driven outflows, in 60 to 70 percent of troughs, demonstrating that radiative line driving dominates wind acceleration and ruling out alternative mechanisms. Direct measurement of the wind energy budget yields a median kinetic luminosity of only 0.01 percent of bolometric luminosity, 50 times below the level required for effective feedback. Line-driven quasar winds are therefore insufficiently powerful to quench star formation, challenging the primary physical mechanism invoked for black hole feedback in galaxy formation models.
ER -