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Title: Efficient Long-range Active Galactic Nuclei (AGNs) Feedback Affects the Low-redshift Lyα Forest

Active galactic nuclei (AGNs) feedback models are generally calibrated to reproduce galaxy observables such as the stellar mass function and the bimodality in galaxy colors. We use variations of the AGN feedback implementations in the IllustrisTNG (TNG) andSimbacosmological hydrodynamic simulations to show that the low-redshift Lyαforest can provide constraints on the impact of AGN feedback. We show that TNG overpredicts the number density of absorbers at column densitiesNHI< 1014cm−2compared to data from the Cosmic Origins Spectrograph (in agreement with previous work), and we demonstrate explicitly that its kinetic feedback mode, which is primarily responsible for galaxy quenching, has a negligible impact on the column density distribution (CDD) of absorbers. In contrast, we show that the fiducialSimbamodel, which includes AGN jet feedback, is the preferred fit to the observed CDD of thez= 0.1 Lyαforest across 5 orders of magnitude in column density. We show that theSimbaresults with jets produce a quantitatively better fit to the observational data than theSimbaresults without jets, even when the ultraviolet background is left as a free parameter. AGN jets inSimbaare high speed, collimated, weakly interacting with the interstellar medium (via brief hydrodynamic decoupling), and heated to the halo virial temperature. Collectively these properties result in more » stronger long-range impacts on the intergalactic medium when compared to TNG’s kinetic feedback mode, which drives isotropic winds with lower velocities at the galactic radius. Our results suggest that the low-redshift Lyαforest provides plausible evidence for long-range AGN jet feedback.

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Publication Date:
Journal Name:
The Astrophysical Journal Letters
Page Range or eLocation-ID:
Article No. L17
DOI PREFIX: 10.3847
Sponsoring Org:
National Science Foundation
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