Jet Feedback in Star-Forming Galaxies

Round 1

Reviewer 1 Report

The author summarizes efforts from the last decades in the understanding of interaction of AGN jets with their host galaxies. Both positive and negative feedback is discussed at all scales. Discussion is also devoted to large halos, lobes and wind shells.

The layout seems initially a bit confusing, and is only understood at the end of the article, when the summary is laid out. To facilitate the flow of the reading I would suggest to include some sentences or paragraphs to help connect the different sections in a more fluid manner. I also encourage to include a last paragraph in the introduction to summarize the text flow and guide the reader through the different sections and the link among them.

Other than the above, the text reads well and is properly written. Therefore, I have only minor comments as follows:

Section 4, line 141: Define the cooling function \Delta

165: [...] is denser "than" the jet.

233: "In this picture, it is probably not surprising that star formation dominates" ->  It may be good to discuss this part a bit better.

Author Response

I thank both referees for reading the manuscript and their helpful comments.

All changes in text highlighted in magenta where latex allows. Keywords were
added and the acknowledgements updated. In addition to the changes
in response to the referees explained below, I have also corrected some typos, and
slightly modified Fig. 4. There was a typo, and I have added the halo heating in the
final stage.

Reviewer 1:

1) The layout seems initially a bit confusing, ...
-> An overview paragraph has been added at the end of Sect. 1. Some additional
guidance for the reader is now provided at the end of most sections.

2) Section 4, line 141: Define the cooling function \Delta
-> Passage re-phrased.

3) 165: [...] is denser "than" the jet.
-> Corrected.

4) 233: "In this picture, it is probably not surprising that star formation dominates" -> It may be good to discuss this part a bit better.
-> Rephrased for clarity. The idea is to connect gaseous outflows in radio
lobes with star formation also spatially associated. The suggested
mechanism is that this gas first does not necessarily form stars,
but when the turbulence has decayed, stars may form, explaning the finding from Day et al.

Reviewer 2 Report

This article reviews the status of our understanding of how jet feedback operates in star-forming galaxies across a broad range of environments. Feedback from ISM to CGM/cluster scales is considered, with discussion drawn from multi-wavelength observational studies and theoretical enquiries. The manuscript constitutes an accessible and concise review of the field and will be useful to the community. I believe the manuscript is suitable for publication in Galaxies. However, before this article progresses to the next stage, there are a few comments I would like the author to consider. 

 Comments:

1. Slightly expanded discussion of indirect AGN feedback would be welcome - currently the discussion around Line 42-47, page 2 is a little bit limited. Mention could be made here of recent studies e.g. Raouf et al. 2017MNRAS.471..658R, which discuss the impact of AGN jet feedback on the surrounding gas and how this shapes star formation and the life and death of many galaxy types. Additionally, simulations (e.g. Yang & Reynolds 2016ApJ...829...90Y) have investigated how feedback from AGN jets in clusters can heat the intracluster medium, including the effects of bubbles and soundwaves (e.g. Iqbal et al. 2023MNRAS.518.2735I, Wang & Yang 2022MNRAS.512.5100W) and subsequent moderation of bursty AGN activities in cool-core clusters (e.g. Chen et al. 2019MNRAS.489.1939C). 

 2. Section 1, page 1, lines 20-23: “…, but typically do not require AGN feedback at least for massive galaxies” – It would be useful to indicate the mass range being referred to here. 

3. Line 33: “AGN feedback via jets, sometimes called the radio mode,…” – I would suggest to rephrase this to “AGN feedback via jets, sometimes called radio mode feedback,…”

4. Page 4, line 115 – “This phase takes about 10^5 to 10^6 yr for jets with typical energy fluxes (10^43-46 erg/s)…” It would be helpful if a reference could be provided for these timescale estimates.

5. Figure 2: It would be informative to indicate the gas temperature and show pressure compared to the ambient medium here too, if available (e.g. Figure 6 of Gaibler et al. 2012).

6. Page 5, second paragraph - The discussion surrounding radio lobes in the circum-galactic medium could be expanded slightly to also consider possible counterpart structures at other wavelengths. In particular, in addition to the Circinus galaxy, M31 may also be mentioned where possible lobe or bubble-like structures extending to kpc scales have been studied in gamma-rays (see Pshirkov et al. 2016MNRAS.459L..76P), and NGC 3097 in X-rays which hosts a kpc-scale nuclear superbubble, see Cecil et al. 2002ApJ...576..745C  (although it is not clear whether this is driven predominantly by the AGN or the nuclear starburst – e.g. Ho et al. 1997ApJS..112..315H), and NGC 891 also in X-rays (Hodges-Kluck et al. 2018ApJ...866..126H). More speculatively, detection prospects for similar circumgalactic bubble/lobes at wavelengths including radio were also discussed in Owen et al. 2022MNRAS.516.1539O for nearby edge-on spiral galaxies, although it is unclear whether any/all of those selected galaxies actually host radio lobes.

7. Page 8, line 232: “gas masses of up to the order of 10^10” – the unit is missing here (presumably solar masses?)

8. Page 9, “…interaction with molecular and other clouds”. Mention could also be made here (or earlier on in the manuscript) of jet-star interactions, e.g. Wang et al. 2022Univ....9....1W

9. Page 10, acknowledgements – currently this is still the default MDPI template text and should be updated.

Author Response

I thank both referees for reading the manuscript and their helpful comments.

All changes in text highlighted in magenta where latex allows. Keywords were
added and the acknowledgements updated. In addition to the changes
in response to the referees explained below, I have also corrected some typos, and
slightly modified Fig. 4. There was a typo, and I have added the halo heating in the
final stage.

Reviewer 2:

1. Slightly expanded discussion of indirect AGN feedback ...
->This was indeed a bit brief, main part attached to the summary as outlook.
I have moved this to a new section and expanded slightly along the lines
suggested by the referee. However, I would not like to remain focussed
on star-forming galaxies and have therefore limited the discussion
of clusters. I have, however, now included some discussion of protoclusters,
which often have radio galaxies with high star formation rates, as well
as the extended quiescent halos around high-redshift radio galaxies.

2. ...  It would be useful to indicate the mass range being referred to here.
-> Done.

3. " Line 33: “AGN feedback via jets, sometimes called the radio mode,...” – I would suggest to rephrase this to “AGN feedback via jets, sometimes called radio mode feedback,...”
-> done.

4. ... helpful if a reference could be provided for these timescale estimates.
-> Done.

5  Figure 2: It would be informative to indicate the gas temperature and show pressure...
-> Figure and caption amended.

6. The discussion surrounding radio lobes in the circum-galactic medium could be expanded slightly ...
-> References added - thanks!

7. ... the unit is missing here (presumably solar masses?)
-> Correct, added.

8. Page 9, “...interaction with molecular and other clouds”. Mention could also be made here (or earlier on in the manuscript) of jet-star interactions, e.g. Wang et al. 2022Univ....9....1W
-> Thanks for the suggestion, but I actually think this single-star interaction is,
while certainly interesting, not so relevant in the context of the overall topic here.

9Page 10, acknowledgements – currently this is still the default MDPI template text and should be updated.
-> Done.