RECORD
The low redshift Lyman-$\alpha$ Forest as a constraint for models of AGN feedback
Astrophysics of Galaxies · Submitted 20 Apr 2022
abstract compiled · 2026-09-23 · no language-model review
The authors' main claim Our study suggests that the $z=0.1$ Lyman-$\alpha$ forest observables can be used as a diagnostic of AGN feedback models.
The compiled record
The paper's own sentences, arranged. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.
Open the compiled record
The abstract, sentence by sentence
We study the sensitivity of the $z=0.1$ Lyman-$\alpha$ Forest observables, such as the column density distribution function (CDD), flux PDF, flux power spectrum, and line width distribution, to sub-grid models of active galactic nuclei (AGN) feedback using the Illustris and IllustrisTNG (TNG) cosmological simulations. The two simulations share an identical Ultraviolet Background (UVB) prescription and similar cosmological parameters, but TNG features an entirely reworked AGN feedback model. Due to changes in the AGN radio mode model, the original Illustris simulations have a factor of 2-3 fewer Lyman-$\alpha$ absorbers than TNG at column densities $N_{\rm HI}< 10^{15.5}$ cm$^{-2}$. We compare the simulated forest statistics to UV data from the Cosmic Origins Spectrograph (COS) and find that neither simulation can reproduce the slope of the absorber distribution. Both Illustris and TNG also produce significantly smaller line width distributions than observed in the COS data. We show that TNG is in much better agreement with the observed $z=0.1$ flux power spectrum than Illustris. We explore which statistics can disentangle the effects of AGN feedback from alternative UVB models by rescaling the UVB of Illustris to produce a CDD match to TNG. While this UVB rescaling is degenerate with the effect of AGN feedback on the CDD, the amplitude and shape of the flux PDF and 1D flux power spectrum change in a way distinct from a scaling of the UVB. Our study suggests that the $z=0.1$ Lyman-$\alpha$ forest observables can be used as a diagnostic of AGN feedback models.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | We study the sensitivity of the $z=0.1$ Lyman-$\alpha$ Forest observables, such as the column density distribution function (CDD), flux PDF, flux power spectrum, and line width distribution, to sub-grid models of active galactic nuclei (AGN) feedback using the Illustris and IllustrisTNG (TNG) cosmological simulations. | contribution 0.97 | 0.94 | 0.05 | asserted 0.88 |
| s1 | The two simulations share an identical Ultraviolet Background (UVB) prescription and similar cosmological parameters, but TNG features an entirely reworked AGN feedback model. | method 0.78 | 0.17 | 0.02 | asserted 1.00 |
| s2 | Due to changes in the AGN radio mode model, the original Illustris simulations have a factor of 2-3 fewer Lyman-$\alpha$ absorbers than TNG at column densities $N_{\rm HI}< 10^{15.5}$ cm$^{-2}$. | result 1.00 | 0.64 | 0.04 | asserted 1.00 |
| s3 | We compare the simulated forest statistics to UV data from the Cosmic Origins Spectrograph (COS) and find that neither simulation can reproduce the slope of the absorber distribution. | result 0.99 | 0.94 | 0.08 | asserted 1.00 |
| s4 | Both Illustris and TNG also produce significantly smaller line width distributions than observed in the COS data. | result 1.00 | 0.89 | 0.05 | asserted 1.00 |
| s5 | We show that TNG is in much better agreement with the observed $z=0.1$ flux power spectrum than Illustris. | result 1.00 | 0.93 | 0.17 | asserted 1.00 |
| s6 | We explore which statistics can disentangle the effects of AGN feedback from alternative UVB models by rescaling the UVB of Illustris to produce a CDD match to TNG. | method 0.72 | 0.93 | 0.04 | asserted 0.72 |
| s7 | While this UVB rescaling is degenerate with the effect of AGN feedback on the CDD, the amplitude and shape of the flux PDF and 1D flux power spectrum change in a way distinct from a scaling of the UVB. | result 0.93 | 0.92 | 0.11 | asserted 1.00 |
| s8 | Our study suggests that the $z=0.1$ Lyman-$\alpha$ forest observables can be used as a diagnostic of AGN feedback models. | interpretation 0.99 | 0.74 | 0.90 | hedged possibility 1.00 |
What was examined, and what was not
- arXiv listing abstract v2
- full text
- figures and tables
- references and citing sentences
- relations to other papers
- P abstract
- S sections
- T body sentences
- C citations
- R cross-paper relations
The paper
Original abstract
We study the sensitivity of the $z=0.1$ Lyman-$\alpha$ Forest observables, such as the column density distribution function (CDD), flux PDF, flux power spectrum, and line width distribution, to sub-grid models of active galactic nuclei (AGN) feedback using the Illustris and IllustrisTNG (TNG) cosmological simulations. The two simulations share an identical Ultraviolet Background (UVB) prescription and similar cosmological parameters, but TNG features an entirely reworked AGN feedback model. Due to changes in the AGN radio mode model, the original Illustris simulations have a factor of 2-3 fewer Lyman-$\alpha$ absorbers than TNG at column densities $N_{\rm HI}< 10^{15.5}$ cm$^{-2}$. We compare the simulated forest statistics to UV data from the Cosmic Origins Spectrograph (COS) and find that neither simulation can reproduce the slope of the absorber distribution. Both Illustris and TNG also produce significantly smaller line width distributions than observed in the COS data. We show that TNG is in much better agreement with the observed $z=0.1$ flux power spectrum than Illustris. We explore which statistics can disentangle the effects of AGN feedback from alternative UVB models by rescaling the UVB of Illustris to produce a CDD match to TNG. While this UVB rescaling is degenerate with the effect of AGN feedback on the CDD, the amplitude and shape of the flux PDF and 1D flux power spectrum change in a way distinct from a scaling of the UVB. Our study suggests that the $z=0.1$ Lyman-$\alpha$ forest observables can be used as a diagnostic of AGN feedback models.
Human review
References
How the literature uses it
4 arXiv papers cite this in 6 sentences
Discussion
Know something about this paper? Leave a comment, or highlight any passage above to comment on it.