{"id":"dcb2daba-6179-4116-af20-aec865ac29fd","arxiv_id":"2505.21630","paper_version":2,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":4,"one_line_summary":"Five newly characterized quasar absorption outflows in DESI spectra sit 4.5 to 31 kpc from their nuclei, and the most energetic (J1407 S1) reaches about 0.47% of Eddington luminosity, near the feedback threshold.","lead":"Researchers used DESI spectra to characterize five gas outflows from four distant quasars, measuring their distances, densities, and energy output. The work shows that at least one outflow may carry enough energy to influence its host galaxy, relevant to how quasars regulate star formation.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"The kpc-scale distances and kinetic luminosities, including J1407 S1's 0.47% L_Edd, depend on an unmeasured SED/Q_H normalization; a ±0.2 dex SED change can shift the feedback claim below the 0.5% threshold, so this systematic must be propagated.","rationale":"Good-faith reading: the authors use a standard AOD/PC plus Cloudy plus Chianti pipeline, and they explicitly flag SED and metallicity sensitivities in Section 3.2.1 and in the Table 3 note. The paper's central physical claim, however, is not the ionization parameters but the absolute distances and energetics, and those are exactly the quantities for which the SED-induced Q_H change is not quantified. The reader's weakest assumption identifies the same concern, so I agree with the CONDITIONAL verdict. I see no basis for rejection: the outflow interpretation is supported by the high electron densities and mini-BAL-like widths, the pipeline is established, and the internal inconsistencies about which system is most energetic are correctable. But the feedback claim is a numerical comparison to a fixed threshold, and the dominant systematic is currently unquantified; until it is propagated, the 'plausibly contributes' statement should be read as conditional. The proposed recomputation is a single, well-defined check that directly settles whether the concern lands.","tokens_in":14970,"tokens_out":9775,"duration_ms":104064,"concrete_test":"Fix the J0831/J1407 S1 labeling, then rerun the full pipeline for J1407 S1 (and ideally all five systems) with the HE0238 and MF87 SEDs: re-derive N_H and U_H in Cloudy, rescale each SED's Q_H to the same observed continuum flux used for the UV-soft SED, and propagate the resulting Q_H, U_H, N_H through Eqs. 6–9. If Edot/LEdd for J1407 S1 remains at or above 5e-3 under both SEDs, the feedback claim is robust; if it drops below about 3e-3 under either SED, the headline claim is not supported at the current confidence.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central claim has two linked parts: the five absorbers are outflows at R = 4.5–31 kpc, and J1407 S1 is feedback-relevant at Edot/LEdd = 4.7e-3, close to the Hopkins & Elvis 2010 threshold of 5e-3. Both parts rest on the absolute scale set by Eq. 6, R = sqrt(Q_H / (4π c n_H U_H)), with Edot ∝ R N_H. Q_H is not measured; it is obtained by scaling the adopted UV-soft SED to the observed continuum at rest wavelengths about 1250–1750 Å (Section 3.3). Section 3.2.1(a) states that replacing UV-soft with other common SEDs (HE0238, MF87) changes the Cloudy-derived N_H and U_H by about ±0.2 dex, and the Table 3 note treats these as systematics separate from the quoted errors. However, the corresponding change in Q_H is not computed, and no SED systematic is propagated into columns (5)–(9). Since Edot depends on N_H and sqrt(Q_H/U_H), a 0.2 dex shift in U_H changes Edot by about 0.1 dex, and the correlated N_H shift can bring the total change to roughly a factor of two; the SED-dependent Q_H adds further uncertainty. For J1407 S1 the adopted Edot/LEdd is 4.7e-3, only 0.3e-3 above the nominal threshold, with a lower statistical bound of 3.0e-3. A factor-of-two downward SED shift therefore removes the claimed crossing. The feedback conclusion is not robust until the SED-induced Q_H uncertainty is quantified and propagated into R and Edot.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"The paper analyzes five low-ionization mini-BAL outflow systems in four intermediate-redshift quasars (2<z<3) using DESI Early Data Release spectra. The authors measure ionic column densities via apparent optical depth and partial coverage methods, derive hydrogen column densities and ionization parameters with Cloudy photoionization modeling, and determine electron densities from Si II*/Si II ratios using the Chianti database. Combining these with a scaled UV-soft SED, they obtain outflow distances of 4.5-31 kpc, mass-flow rates, kinetic luminosities, and momentum flux ratios. The central claim is that these are kpc-scale quasar outflows, with J1407 S1 reaching Edot/LEdd ~ 0.47%, near the Hopkins & Elvis (2010) feedback threshold of 0.5%.","tokens_in":15438,"tokens_out":4065,"duration_ms":36807,"significance":"If the results hold, the paper demonstrates that DESI spectra can uncover kpc-scale quasar outflows and quantify their energetics, adding a small but useful sample to the still-limited census of resolved outflows at intermediate redshift. The measurement pipeline is standard and well-grounded in the quasar-outflow literature, and the paper explicitly discusses the SED and metallicity sensitivity of the photoionization results. However, the strongest conclusion---that one outflow significantly contributes to AGN feedback---is currently compromised by two issues: a clear misassignment of the 0.47% Edot/LEdd value to J0831 instead of J1407 S1 in the prose and conclusions, and an unquantified SED-induced systematic in the distance and energetics that sits exactly on the feedback threshold.","major_comments":[{"comment":"The claim that \"the absorption outflow detected in J0831 with a ratio of 0.47 percent can significantly contribute to feedback processes\" contradicts Table 3: J0831 has Edot/LEdd = 1.5e-3 (0.15%) and momentum ratio 0.37, while J1407 S1 has 4.7e-3 (0.47%) and momentum ratio 1.7. The conclusions repeat this misassignment, stating J0831 has a ratio of ~0.5% and momentum ratio of almost two, while Section 4(iv) simultaneously attributes feedback potential to J1407 S1. This internal inconsistency affects the central feedback claim and must be corrected throughout the text.","section":"Section 3.4 and Section 4(iii)"},{"comment":"The centroid velocities listed in the object notes (J0831: -1700 km/s, J1032: -250 km/s, J1407 S1: -3200 km/s, J1407 S2: -300 km/s, J1609: -470 km/s) disagree with column (1) of Table 3 (J0831: -1100±280, J1032: -1000±400, J1407 S1: -3600±280, J1407 S2: -700±285, J1609: -230±290). Since the outflow velocity enters the kinetic luminosity quadratically in Eq. (9), the authors must reconcile these values and confirm which velocities were used to compute Edot.","section":"Section 3.6 vs Table 3"},{"comment":"The SED-induced systematic is not propagated into the derived distances and energetics. Section 3.2.1 states that replacing the UV-soft SED with other common SEDs changes NH and UH by ~±0.2 dex, but Section 3.3 obtains QH by scaling the same UV-soft SED to the observed continuum, and Table 3 columns (5)-(9) quote only statistical errors. The resulting change in QH is not quantified, nor is the effect on R, Mdot, or Edot. For J1407 S1, Edot/LEdd = 4.7e-3 lies only 0.3e-3 above the 0.5% Hopkins & Elvis threshold, with a lower statistical bound of 3.0e-3; a ~0.2 dex shift in NH and UH plus an SED-dependent QH change can plausibly move the value below the threshold. The authors should either propagate the SED systematic into R and Edot or explicitly weaken the feedback conclusion.","section":"Section 3.3 and Table 3"}],"minor_comments":[{"comment":"The text states that the measured electron densities are \"log(ne) > 1.5 [cm^-3]\", but Table 3 lists log(ne) = 1.45 for J1407 S2; please rephrase to \"log(ne) ≥ 1.45\" or otherwise adjust for consistency.","section":"Section 3.5"},{"comment":"The caption says \"six outflow systems detected in our five quasars\", but the paper presents five outflows in four quasars; please correct.","section":"Figure 4 caption"},{"comment":"The term \"FeloBAL\" appears to be a typo for \"FeLoBAL\" (Fe low-ionization broad absorption line).","section":"Section 3.6.1"},{"comment":"The table note says columns (5)-(9) do not include \"the systemic velocity errors (given in column (1))\", but column (1) lists centroid velocities, not the redshift uncertainties that are given in Table 1; please clarify which systematic is being excluded.","section":"Table 3 note"},{"comment":"The sentence \"Note that since we use the corrected formulas that consider the Civ blue-shift, the large SED-dependent systematic error in BH masses is removed\" is unclear because the SED sensitivity of QH is not addressed in that context; consider adding a reference or brief explanation.","section":"Section 3.4"}],"recommendation":"major_revision","confidential_remarks":"The misassignment of the feedback values in Section 3.4 and Section 4 is the kind of error that likely stems from copy-pasting text from a companion paper, but it is load-bearing because the conclusions currently attribute the main result to the wrong object. The SED-systematic issue is more substantive and requires either a quantitative propagation or a softened claim. The paper is otherwise within the scope of MNRAS and uses standard, credible methods."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"You should know this paper is a straightforward application of well-established methods to DESI EDR spectra of four quasars, producing five new kpc-scale outflow systems. What is genuinely new are the five systems themselves: their N_H, U_H, n_e, distances, and energetics have not appeared before. The column density work is careful, the use of Si II*/Si II with Chianti for n_e is standard, and the argument that these are outflows rather than CGM absorbers is reasonably supported by the high electron densities and velocity widths. The paper also does the right thing by acknowledging that the adopted SED, abundance, and constant-density assumptions introduce systematics, even if it fails to propagate them.\n\nThe soft spots are real but correctable. The biggest problem is an internal inconsistency: Section 3.4 and the Conclusions attribute the 0.47% Eddington ratio and momentum ratio of ~2 to J0831, but Table 3 and even the abstract put those numbers on J1407 S1. That is not a nuance; it flips which object drives the feedback claim. The centroid velocities in the object notes also disagree with Table 3 for nearly every system. These errors are fixable, but they make the prose unreliable until rewritten.\n\nThe deeper scientific concern is that the distance scale and energetics rest on Q_H derived from scaling the UV-soft SED to the observed continuum, and the SED-induced uncertainty is not propagated into the distance or energetics. Section 3.2.1 says other common SEDs shift N_H and U_H by about 0.2 dex, but columns 5-9 of Table 3 use only the statistical errors. A factor-of-two shift in the derived kinetic luminosity would move J1407 S1 below the 0.5% L_Edd feedback threshold, so the highlight claim is fragile until the authors compute Q_H and the resulting R and Edot for each plausible SED and add that as a systematic error. This is not a reason to reject the paper; the central result that these absorbers are on kpc scales likely survives, but the feedback significance may not.\n\nSample selection is also under-described: I still do not know how many quasars were searched in the DESI VACs or how these five systems were selected from that sample. That is worth a short paragraph.\n\nWho should read this? Anyone working on quasar absorption outflows and AGN feedback will want the measurements. It deserves a serious referee, but I would send it back for major revision: fix the misassignments, propagate the SED systematics, and clarify the selection. If the authors do that, the five systems become a useful addition to the outflow census.","headline":"Five new DESI-based outflow measurements, but the feedback headline is assigned to the wrong object in two sections and the SED systematic that sets the distance scale is never propagated.","tokens_in":15955,"tokens_out":3309,"would_cite":true,"duration_ms":36955,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"DESI spectra show five quasar absorption outflows at kiloparsec distances from their nuclei, with the most energetic reaching about 0.47 percent of Eddington luminosity.","keywords":["quasar outflows","absorption lines","AGN feedback","DESI","mini-broad absorption lines","photoionization modeling","electron number density","kinetic luminosity"],"falsifier":"Measure the rest-frame 1250 to 1750 Å continuum and ionizing spectral energy distribution of J1407+5110 and the other three quasars, then redo the $Q_H$ scaling and the photoionization fits; if the true ionizing photon rate is lower by more than about 0.2 dex, J1407 S1's kinetic luminosity drops below the 0.5 percent Eddington feedback threshold.","tokens_in":14821,"feed_emoji":"🔭","tokens_out":13266,"duration_ms":130052,"temperature":0.7,"pith_summary":"This paper aims to show that five low-ionization absorption systems seen in DESI spectra of four quasars at redshifts $2<z<3$ are genuine outflows launched by the active nuclei, not unrelated intervening gas. From absorption-line ratios the authors derive hydrogen column densities $\\log N_H = 20.0$-$20.7$ cm$^{-2}$, ionization parameters $\\log U_H = -2.7$ to $-2.1$, and electron densities $\\log n_e = 1.45$-$2.85$ cm$^{-3}$, which put the gas at 4.5 to 31 kpc from the nucleus. Their kinetic luminosities range from $1.8\\times10^{-6}$ to $4.7\\times10^{-3}$ of the Eddington luminosity, and the most energetic system, J1407 S1, sits near the 0.5 percent level at which outflows are thought to contribute to AGN feedback. If correct, the result shows that ground-based survey spectra can locate kiloparsec-scale, feedback-relevant outflows in the moderate-redshift quasar population.","feed_headline":"Quasar outflows found 4.5-31 kpc out; one nears feedback threshold","feed_subtitle":"DESI spectra fix five outflows' places and powers, and one reaches 0.47% of the Eddington luminosity.","key_machinery":"The load-bearing mechanism is the excited-to-resonance line ratio of Si II, combined with pairs of ions from the same element (Al II/Al III, C II/C II*) in a grid of photoionization models. The Si II* $\\lambda1264.74$ to Si II $\\lambda1260.42$ column ratio depends mainly on electron density rather than on column density or abundance, so atomic-data calculations convert it into $n_e$. The photoionization grid then fixes $N_H$ and $U_H$, and the geometric relation $R = (Q_H/(4\\pi c n_H U_H))^{1/2}$ turns the SED-scaled ionizing photon rate $Q_H$ into a distance. Distance plus observed velocity and $N_H$ yields the mass-flow rate, momentum flux, and kinetic luminosity, which are compared with Eddington luminosity through a 0.5 percent threshold for feedback relevance. The five systems are mini-BALs, defined as outflow troughs 500 to 2000 km s$^{-1}$ wide, and their high measured $n_e$ together with their line widths argue for an AGN origin.","core_discovery":"On its own terms, the paper establishes that each of the five absorption systems is a photoionized outflow powered by its quasar. Using the apparent optical depth and partial coverage methods on DESI Early Data Release spectra, the authors measure ionic columns of Al II, Al III, Si II, Si II*, C II, C II*, and Fe II. A grid of photoionization models finds $\\log N_H = 20.0$ to $20.7$ cm$^{-2}$ and $\\log U_H = -2.7$ to $-2.1$; the ratio of excited to ground Si II gives $\\log n_e = 1.45$ to $2.85$ cm$^{-3}$. Scaling the UV-soft spectral energy distribution to the observed continuum gives the hydrogen-ionizing photon rate $Q_H$, and the relation $R = (Q_H/(4\\pi c n_H U_H))^{1/2}$ yields distances of 4.5 to 31 kpc. From these the authors compute mass-flow rates of about 15 to 63 $M_\\odot$ yr$^{-1}$ and kinetic luminosities from $1.8\\times10^{-6}$ to $4.7\\times10^{-3} L_{\\rm Edd}$. The J1407 S1 system, with kinetic luminosity about 0.47 percent of Eddington (within errors of the 0.5 percent feedback threshold) and momentum flux ratio about 1.7, is the case the authors identify as plausibly contributing to feedback.","pith_inferences":["If the full DESI survey turns up ground-plus-excited Si II and C II troughs in even a small fraction of quasars, the handful of kiloparsec-scale outflows with measured energetics could grow into a statistical sample, letting feedback efficiency be mapped against quasar luminosity, redshift, and outflow velocity.","The paper's own SED-sensitivity test implies an unquantified systematic error in the distances and Eddington ratios; measuring the true SEDs would be the direct way to decide whether J1407 S1 really crosses the feedback threshold.","A high-resolution echelle spectrum of J1407 S1 could test the constant-density and partial-coverage assumptions directly, showing whether the derived $n_e$ and $R$ survive non-black saturation in the troughs.","Because the mass-flow rate and kinetic luminosity scale linearly with the assumed global covering factor, the energetic results are only as secure as that geometric assumption; an independent estimate of the covering factor would tighten the feedback comparison."],"forward_implications":["DESI's moderate-resolution spectra can supply the ionic columns, densities, and distances needed to characterize low-ionization quasar outflows, extending this kind of measurement to very large samples.","If the five systems are representative, kiloparsec-scale outflows with kinetic luminosities up to about 0.5 percent of Eddington exist in quasars at redshifts 2 to 3, tying AGN winds directly to galaxy-scale feedback.","The measured electron densities, all above $\\log n_e \\approx 1.45$, separate these absorbers from circumgalactic and interstellar gas, supporting their identification as AGN outflows rather than unrelated intervening material.","Outflows with much lower Eddington ratios, such as J1609 at about $1.8\\times10^{-6}$, show that not every quasar outflow is feedback-efficient, so feedback models should allow a wide distribution of outflow powers."],"supporting_citations":[{"why":"Supplies the Early Data Release spectra and survey calibration from which all measurements are made.","marker":"DESI Collaboration et al. (2024)"},{"why":"Provides the DESI value-added catalog used to select the four quasars showing ground and excited state troughs.","marker":"Filbert et al. (2024)"},{"why":"Sets the UV-soft SED and comparable outflow-survey methodology that the photoionization modeling follows.","marker":"Xu et al. (2019)"},{"why":"Describes the spectral synthesis code used to generate the photoionization grid in the $N_H$-$U_H$ plane.","marker":"Gunasekera et al. (2023)"},{"why":"Supplies the atomic data that convert the Si II* / Si II column ratio into electron number density.","marker":"Dere et al. (1997, 2019)"},{"why":"Establishes the ion-pair analysis strategy and error treatment adopted here for the column density measurements.","marker":"Dehghanian et al. (2025a)"},{"why":"Provides the improved systemic redshifts used to set outflow velocities against the quasar rest frame.","marker":"Wu & Shen (2023)"},{"why":"Defines the 0.5 percent of Eddington kinetic luminosity threshold used to judge feedback significance.","marker":"Hopkins & Elvis (2010)"},{"why":"Supplies the equations for mass-flow rate, momentum flux, and kinetic luminosity used in the energetics section.","marker":"Borguet et al. (2012)"}],"fun_headline_variants":["Quasar outflow nears feedback threshold at 0.47% Eddington","DESI reveals five quasar outflows up to 31 kpc away","One quasar outflow's kinetic power near feedback limit","Quasar outflows range 4.5-31 kpc; one near feedback"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The distances and Eddington ratios depend on assuming a particular unmeasured spectral shape, the UV-soft SED, and on scaling the ionizing photon rate to the observed continuum, so if the true spectrum is different, the kiloparsec distances and the 0.47 percent feedback claim for J1407 S1 could slide below the threshold.","fun_headline_variants_meta":{"raw":{"variants":["Quasar outflow nears feedback threshold at 0.47% Eddington","DESI reveals five quasar outflows up to 31 kpc away","One quasar outflow's kinetic power near feedback limit","Quasar outflows range 4.5-31 kpc; one near feedback"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000925,"raw_usage":{"total_tokens":4112,"prompt_tokens":1243,"completion_tokens":2869,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":859,"completion_tokens_details":{"reasoning_tokens":2800}},"tokens_in":859,"tokens_out":2869,"duration_ms":19405,"temperature":1.0,"reasoning_tokens":2800,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-07T13:26:36.085310+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Measure the rest-frame 1250 to 1750 Å continuum and ionizing spectral energy distribution of J1407+5110 and the other three quasars, then redo the $Q_H$ scaling and the photoionization fits; if the true ionizing photon rate is lower by more than about 0.2 dex, J1407 S1's kinetic luminosity drops below the 0.5 percent Eddington feedback threshold.","supporting_citations":[],"review_version":1}