Weekly archive
LRDigestWeekly digests of little red dots and JWST-selected AGN papers, with curated reading notes and archive pages.
654 indexed papers · 430 research notes
Broadband X-ray fits to 26 nearby mid-IR/X-ray-selected Swift-BAT AGN find few securely Compton-thick objects; line-of-sight columns are broadly model-consistent, but torus geometry and statistical intervals materially affect threshold classifications and proxy calibration.
A 255 ks Chandra study resolves NGC 5005’s soft, extended gas from a faint hard nucleus. The authors infer a lightly absorbed, intrinsically weak AGN whose reported broad Hα line persists at an exceptionally low inferred Eddington ratio.
Proposes that both the Milky Way’s Sgr A*+CMZ and JWST-selected little red dots are “electromagnetically tranquil” nuclei: million-solar-mass black holes embedded in dense, cold, molecule-rich cores that are infrared-bright yet X‑ray faint. By aligning scales, gas content, and low-Eddington accretion, the paper argues these environments shield fragile molecules and permit complex organic chemistry near the nucleus. The CMZ example (e.g., nitrile-bearing cloud G+0.693−0.027) motivates the idea that similar chemistry could arise in compact LRD cores. If common, such tranquil nuclei could link early black-hole growth to the formation and delivery of prebiotic molecules in the early universe.
XRISM/Resolve’s 2024-02-25 spectrum of the neutron-star binary GX 13+1 reveals a stratified, highly ionised, Compton-thick wind via dozens of narrow, slightly blueshifted lines from Si–Ni, including high-order Fe XXV/XXVI features above 7 keV. Photoionisation fits require a slow, very dense absorber plus a faster (~700 km/s), more ionised layer to reproduce the Fe XXVI Ly blue wing and residual core flux from wind reprocessing. After correcting for electron-scattering attenuation, the intrinsic luminosity is at or above Eddington, yet the outflow is extremely slow, favouring a thermal‑radiative outer-disc origin over an inner-disc radiation‑pressure (Eddington) wind. The contrast with ultrafast (~0.3c) SMBH winds at similar Eddington ratios points to fundamentally different launch mechanisms across mass scales.
Analyzes Balmer absorption in 14 FeLoBAL quasars (8 new), measuring velocities, widths, and apparent optical depths, and correcting for partial covering to infer true H(n=2) columns. Finds only a weak Eddington ratio–outflow speed trend because most objects are low‑speed “loitering” outflows; dN/dv peaks at low velocities and anticorrelates with luminosity and Eddington ratio. Reports a correlation between Balmer-line width and the optical–IR slope αoi, tying absorber kinematics to SED/accretion state. Notes parallels with Little Red Dots—V‑shaped continua, steep reddening with a scattered blue component, weak hot dust, and X‑ray weakness—hinting at shared conditions that elevate the n=2 population.
Review draws a line between local narrow-line Seyfert 1s and the newly uncovered z>4 type 1 AGN/LRDs: both host low-mass (∼10^6–10^7 M⊙) black holes accreting near or above Eddington and often show features like steep, variable X-rays and, in a subset, relativistic jets. The authors argue jets can help shed angular momentum in super-Eddington flows, making NLS1s practical analogs for early SMBH growth. Radio examples underscore the wide range from host-dominated star-formation morphologies to blazar-like, large-scale jets. Key caveat: some systematic differences remain, plausibly tied to distinct environments and evolutionary paths at high redshift.
Survey of 24 WISE W4–bright, optically faint/red SDSS Stripe 82 candidates confirms 23 luminous Type‑2 quasars at z = 0.88–3.49 using Gemini/GNIRS plus Keck/LRIS and KCWI spectra. About one‑third (8/23) unexpectedly show broad Hα (FWHM > 2000 km/s) while sharing SEDs with JWST “little red dots,” marking them as lower‑z analogues of heavily obscured broad‑line AGN. The sample also exhibits relatively weak [O III] λ5007 given their high bolometric luminosities, and the authors construct a new Type‑2 QSO composite spectrum. Results demonstrate that simple mid‑IR plus extreme r−W4 color selection efficiently recovers a spectroscopically diverse obscured quasar population at cosmic noon, informing SMBH growth demographics that connect to the LRD population.
A nearby LRD analog is uncovered: the broad-line AGN SDSS J102530.29+140207.3 at z=0.1 shows the hallmark V-shaped SED, broad Balmer emission (FWHM 1000–2000 km/s), and deep Balmer absorption. New GTC optical spectra reveal a G–K-giant-like continuum with a clear CH G-band and unusually deep low-ionization absorption, plus a series of [Fe II] emission lines; similar [Fe II] features are identified in a JWST-selected LRD at z=2.26. Multi-epoch data show small but significant Hα variability, and NuSTAR confirms extreme X-ray weakness consistent with Compton-thick obscuration (NH>10^24 cm^-2). Together these point to a dense, complex nuclear environment that reproduces LRD hallmarks locally and informs early black-hole growth, though the strength of the ionic/atomic/molecular absorptions remains challenging for standard stellar/AGN models.
A BAT-selected local analog set of 21 highly luminous, obscured Seyfert 1.9–2 AGN at z<0.6 (log L_X,2–10keV>44.6) is modeled with NuSTAR, XMM-Newton, Suzaku, and Chandra to recover N_H, Γ, intrinsic L_X, covering factor, Fe Kα, and [NeV] λ3426. The sample is highly variable: 82% vary overall (73% in 2–10 keV flux; 33% in line-of-sight N_H), and 6/12 with M_BH estimates fall in the N_H–λ_Edd “forbidden region,” where they also show enhanced N_H variability/outflow signatures—consistent with a clearing phase. [NeV] λ3426 is detected in 85% and, when renormalized to the same [OIII] peak, is significantly stronger than in JWST-selected z=2–9 narrow-line AGN. These local benchmarks calibrate [NeV]-based obscured AGN searches and frame expectations for future high‑z X-ray follow-up.
Reports three SDSS-selected local little red dots at z=0.1–0.2 with LBT/MODS and Magellan/FIRE follow-up, showing the same hallmarks as high‑z LRDs: compact morphologies, V‑shaped UV–optical SEDs with declining NIR continua, broad H/He lines, full Balmer+Paschen series, and minimal variability. All display blue‑shifted He I absorption; two show Hα and Na D absorption, and two have abundant narrow [Fe II]; J1025+1402 (The Egg) further exhibits extreme Na D, K I, and Ca II triplet absorption consistent with a cool (~5000 K), metal‑enriched envelope. Line diagnostics point to AGN‑powered, metal‑poor narrow lines with little dust, very high‑density inner regions for the broad lines (or unusual dust), and [Fe II] from dense gas between them; two targets are X‑ray non‑detections and WISE photometry implies only weak dust (T ~10^2–10^3 K). The authors propose a largely thermalized cool‑gas envelope plus an extended, high‑density outflow to unify these features, positioning local LRDs as resolvable analogs of early BH growth.
X-ray selected AGNs from zCOSMOS (0.5<z<0.9) are split by obscuration (NH) and excitation (log[OIII]/Hβ>0.5) to compare host properties. Unobscured sources show a clearer rise of the ionization index O32=[OIII]/[OII] with L2–10 keV than obscured ones, while high-excitation obscured AGNs reach higher X-ray luminosities on average. High-excitation systems also have elevated R23, implying lower gas metallicities reminiscent of z~4–6 galaxies. λsBHAR positively correlates with NH, O32, and R23, linking high specific accretion to harder radiation fields in less enriched environments.
This paper presents dense optical/UV monitoring plus X-ray and radio follow-up of the ZTF nuclear transient AT2019cmw (z=0.519), which reached an extraordinary peak bolometric luminosity of ~10^45.6 erg s^-1. Spectra remained featureless while the continuum cooled steadily from ~30 kK to ~10 kK over the first ~300 days, supporting a classification as a luminous, “featureless” TDE in an early-type host. Deep non-detections in X-ray and radio constrain on-axis jets and any visible inner accretion disk. Light-curve modeling (cooling-envelope, with a reprocessing-outflow alternative) favors the disruption of a tens-of-solar-masses star by an SMBH, hinting at localized nuclear star formation despite the quiescent host.
Using VLT/MUSE in both NFM and WFM, this work resolves II Zw 096 into three or more interacting galaxies and maps ionized-gas morphology, kinematics, and excitation across the system. Velocity fields show rotation with strong deviations and widespread shocks, consistent with a collapsing small-group scenario and intense star formation. A compact D1 knot (≤175 pc) that contributes 40–70% of the IR luminosity shows strong multiwavelength evidence for a heavily obscured AGN. Multi-component fits to Hα+[N II] and continuum mapping clarify the internal structure and current merger stage.
JWST/NIRSpec IFU mapping of 3C 293’s inner ~2 kpc separates the gas into a rotating disk (σ ~100 km s−1), a blueshifted broad outflow (σ ~250 km s−1), and a very broad ionized outflow (σ ~640 km s−1). H2 2.12 μm, [Fe II] 1.64 μm, and Paα trace multiphase flows through heavy dust (A_V up to ~35), with H2 inflow along dust lanes at Ṁ_in ~4×10−4 M⊙ yr−1. Peak outflow rates reach 0.08±0.02 M⊙ yr−1 (hot H2) and 6.5±1.7 M⊙ yr−1 (ionized), and the jet-driven outflow carries ≈5% of the radio-jet power—sufficient to suppress star formation. The stellar field is a rotating disk whose kinematic center is offset by ~0.5 arcsec from the NIR continuum peak, consistent with a disturbed, post-merger nucleus.
Reports SDSS J233454.07+145712.9 as a candidate true type‑2 AGN uncovered via a central TDE singled out in 20‑year optical light curves (CSS/PTF/PanSTARRS/ZTF), with a 2009–2013 outburst showing the steep‑rise/smooth‑decline template and otherwise quiescent behavior. TDE modeling (TDEFIT/MOSFIT) favors disruption of a 4.7 Msun main‑sequence star by a 1.17×10^7 Msun black hole, implying an unobscured line‑of‑sight to within ≈20 light‑days of the nucleus. Spectroscopy shows only narrow lines and BPT AGN classification; hypothetical broad Balmer components yield virial masses inconsistent with M–sigma at >6σ, disfavoring hidden BLRs. Together this positions SDSS J2334 as a TT2AGN candidate and demonstrates TDE flares as a practical route to identify BLR‑less nuclei among type‑2 spectra.
Chandra and XMM-Newton data are used to map hot atmospheres around seven local compact ellipticals selected as red‑nugget analogs, probing BH–bulge–halo coupling. Only MRK 1216 and PGC 32873 show luminous, spatially extended halos enabling radial thermodynamic profiles, with MRK 1216’s RGS spectrum hinting at super‑solar α/Fe. The others have faint or undetected halos, several instead showing AGN‑like power‑law emission. On galaxy scaling planes, cEGs follow a slightly steeper M⋆–LX and sit on the lower edge of M⋆–Mvir, implying red nuggets—and possibly their LRD progenitors—host a diverse range of halo atmospheres.
Using JWST/NIRSpec IFU stellar kinematics plus archival long-slit data, the authors model the compact elliptical NGC 4486B and resolve a double nucleus with a velocity-dispersion peak offset from the photometric center. Axisymmetric Schwarzschild modeling of the full LOSVD yields M_BH = 3.6 ± 0.7 × 10^8 M_sun and a host ratio M_BH/M_* ≈ 4–13%, firmly placing the black hole in the overmassive regime. Dark matter within 1 kpc is weakly constrained (M_DM/M_* < 0.5), and the inferred M_BH is unchanged with or without a halo. The system’s location deep in Virgo supports a stripped-core origin, with the caveat that non-equilibrium double-nucleus dynamics are not modeled, so the mass may be a lower limit.
Pang et al. build a slitless-spectrum QSO selector on 3D-HST/G141 by first flagging >6,000 sources with apparently broad lines and then using forward modeling to test whether the “broad” features require a point-like QSO component rather than size-broadened ELG lines. Calibrated on known QSOs, ELGs, and simulations, the criterion recovers ~90% of point-like QSOs with Hα/Hβ while keeping ELG contamination at ~5%. Applied to clean emission-line sources, it yields 19 QSO candidates at z=0.12–1.56 (12 X-ray detections) with broader UV colors and redder optical slopes than SDSS QSOs and MBH≈10^6.9–10^8.3 M⊙, consistent with normal QSOs rather than little red dots. The method boosts QSO completeness at z≈0.8–1.6 in 3D-HST and is directly portable to Euclid and CSST slitless surveys.
Deep XMM-Newton monitoring of the Green Pea SDSS J082247.66+224144.0 (z=0.216) tests for an elusive low-luminosity AGN long hinted by its Γ≈2, L2–10 keV≈10^42 erg s^-1 spectrum. Across 6.2 years (rest-frame), the hard 2–10 keV luminosity remains stable while the soft 0.5–2 keV flux drops by ~60%, yielding a markedly harder second epoch. Swapped-epoch spectral posterior checks and SDSS line decomposition (requiring a broad Hα despite BPT star-forming narrow lines) point to transient, low-column obscuration as the only viable explanation. This work delivers the first conclusive X-ray AGN identification in a Green Pea, strengthening the case that faint AGN could have contributed to reionisation and clarifying local analogs of JWST Little Red Dots.
Orbit-based dynamical models of Segue 1 favor a central intermediate-mass black hole of 4 ± 1.5 × 10^5 M⊙, reproducing the stellar kinematics with a near-isotropic orbital structure. Zero–black-hole models both fit worse and require an extremely compact dark halo (scale radius ~100 pc) plus highly radial stellar orbits, while the BH model is also supported by a central rotation spike of 9.0 ± 2.4 km s−1. The tracer profile is built from number counts with tidal-stream subtraction and deprojection, and the stellar mass-to-light ratio remains poorly constrained, underscoring non-stellar mass dominance. Taken together, Segue 1 looks like a tidally stripped nuclear remnant and a nearby analog of Little Red Dots with overmassive black holes.
SRGA J230631.0+155633 is a z=0.4389, type 2, radio‑loud quasar uncovered by SRG/ART‑XC (4–12 keV) and followed up near‑simultaneously with ART‑XC and Swift/XRT in June 2023, revealing heavy absorption with N_H ≈ 2×10^23 cm^-2. Its intrinsic 2–10 keV luminosity declined from (6^{+6}_{−3})×10^45 erg s^-1 during the 2020–2021 all‑sky scans to (1.0^{+0.8}_{−0.3})×10^45 erg s^-1 in 2023, indicating strong rest‑frame ~1 yr variability while remaining quasar‑luminous. Radio imaging shows a core plus two extended lobes consistent with a giant FR II radio galaxy. Multi‑wavelength constraints imply L_bol ~6×10^46 erg s^-1 and M_BH ~1.4×10^9 M_⊙ (λ_Edd ~0.3), making this one of the most luminous obscured quasars out to z ≈ 0.5 and a nearby laboratory for buried SMBH growth.
Subaru/HSC narrow-band NB718/NB973 imaging plus Magellan LDSS3 follow-up reveal “Oxyster,” a CGM oxygen nebula next to a disturbed, interacting starburst at z=0.924, extending ~30 kpc in [O II] and ~20 kpc in [O III]. On the luminosity–size plane it outscales low‑z ENLRs and evokes a high‑z Voorwerp analog, but shows uniformly low O32 and no Hβ. HST/JWST imaging and SED fitting place the 2–6×10^10 Msun host above the main sequence with <5% AGN contribution and no X-ray/radio AGN, while standard photoionization/shock models cannot reproduce the luminosities, low O32, and Hβ non‑detection. The authors favor a recent (<10^8 yr) starburst plus a low‑luminosity AGN (~10^42 erg s^-1), underscoring narrow-band searches as a route to CGM mapping around non‑AGN systems near z~1.
Using ~3.1 deg^2 of ultra-deep HSC plus (near-)IR imaging, the authors assemble a ground-based sample of Little Red Dots at 2≲z≲4 and measure their abundance for M5500<-22.5. They find a sharp decline in number density from ~10^-4.5 cMpc^-3 at z>4 to ~10^-5.3 at 2.7<z<3.7 and ~10^-5.7 at 1.7<z<2.7, extending LRD demographics below z~4. A Magellan/FIRE spectrum of DEEP23-z2LRD1 (z_spec=2.26) shows broad Hα (FWHM≈2400 km s^-1) plus nearly symmetric narrow Hα absorption and extremely narrow [OIII] (FWHM≈140 km s^-1), consistent with an accreting BH in a low-mass host. Because ground-based resolution limits can admit contaminants, the paper stresses that spectroscopy is required to firm up the z<4 LRD number densities.
Using 82 X-ray AGN within 4 r500 of 164 XXL clusters (z ≲ 1) and deep HSC imaging, the authors classify host morphologies (Statmorph + visual) and assess obscuration and SFR via X-ray hardness ratios, optical spectra, and SEDs. They find a moderately significant excess of cluster AGN hosted by merging/disturbed galaxies relative to non-active cluster members and field AGN, with the signal concentrated in the outskirts (≈1–2 r500). Clusters also show a higher share of X-ray-hard (likely obscured) AGN than the field, especially in the outskirts. Together, the results point to mergers/interactions in cluster outskirts as key drivers of both AGN triggering and obscuration.
The authors PSF-isolate nuclear mid-IR emission in 21 nearby (z<0.05) AGN with a new tool (MRSPSFisol) and fit the continuum using multiple dust libraries. Twelve nuclei achieve good fits (chi2/dof<2), typically with a flared-disk model combining clumpy and smooth dust and allowing grain size to vary; two prefer disk+wind and one the classical clumpy torus. About 40% resist all models because of extreme silicate profiles plus pervasive water-ice and aliphatic hydrocarbon absorption, pointing to missing chemistry. This establishes JWST/MRS as a clean nuclear isolator and shows that next-generation dust models must capture more complex compositions.
This letter benchmarks secure dynamical black hole masses in a z~2 lensed quiescent galaxy and six local red‑nugget relics against recent 4<z<11 AGN, quasar, and Little Red Dot samples on the M_BH-M_star and M_BH-sigma_* planes. The relics and the z~2 quiescent system land on both the local bulge M_BH-M_star relation and the 4<z<7 Pacucci et al. relation, while luminous QSOs and broad-line AGN follow Pacucci et al. more closely and LRDs scatter across all three; on M_BH-sigma_* most sources sit above the local median except the lensed system. The authors argue the bulge relation was already in place at high z and that differing evolutionary pathways—compact-core assembly by z~2 followed by dry-merger stellar-mass growth versus ongoing BH and star formation in AGN—govern positions on scaling planes. Given large systematics in single‑epoch high‑z masses, they emphasize dynamical detections in relics and strongly lensed galaxies as a complementary, less biased probe of early scaling relations.
JWST/MIRI–MRS spectroscopy of the dusty starburst–AGN composite SSTXFLS J172458.3+591545 (z=0.494) yields the first combined extragalactic detections of CO2, CO, XCN, and H2O ices, with gas‑phase CO alongside solid CO. Ice-band profiles match Galactic/local templates, and their decomposition (polar‑dominated XCN and CO complexes) plus the silicate depth imply a compact, dense, cold nucleus with n>10^5 cm^-3, T≈20–90 K, and A_V≈6–7; [NeV]/[NeVI] confirm a deeply buried AGN. The authors introduce τ_Si versus τ_CO2/τ_Si as a diagnostic that jointly traces total dustiness and dust clumpiness along the line of sight. Together, these results showcase MIRI’s power to map dust composition and geometry well beyond the local Universe.
Using 63 deg² from Euclid’s Quick Data Release (Q1) plus IRAC and ground-based griz, the team fits two power laws to photometry to isolate little red dots with blue UV and red optical slopes while removing extended sources, strong line emitters, and artifacts. They assemble 3341 LRD candidates at z=0.33–3.6 (29 with IRAC), and derive a rest‑frame UV luminosity function that rises from high z down to z≈1.5–2.5 before declining toward lower redshift. Comparing to quasar UV LFs shows LRDs are not the dominant AGN population at z<4 for M_UV<-21. A noted caveat is that evolution inferred from the IRAC‑detected subsample is limited by small numbers and IRAC’s resolution, motivating follow‑up.
NuSTAR timing of the eclipsing IP V902 Mon reveals a clear X‑ray eclipse in energy‑resolved lightcurves, phase‑coincident with AAVSO/CV optical minima. Joint NuSTAR+XMM‑Newton spectroscopy requires heavy local absorption (N_H ~1e23 cm^-2) and a strong 6.4 keV Fe Kα line with EW ≈0.7 keV. The authors favor an accretion‑disk‑corona–like, very high‑inclination geometry in which the direct accretion‑column emission is blocked at all phases and we see only scattered/reprocessed X‑rays. This positions V902 Mon as a reflection‑dominated IP where eclipse timing can localize the extended pre‑shock region a few WD radii above the plane.
JWST MIRI/MRS and NIRSpec/IFU 3–28 μm spectroscopy isolates the western nucleus of Arp 220 and reveals a forest of rovibrational absorptions, enabling column densities and rotational temperatures for 10 species, with optically thick C2H2, HCN, and HNC and columns ≈10× higher than Spitzer. A warm HCN component with Trot ≈ 330 K points to radiative excitation by a hot, ~20 pc inner core veiled by cooler dust. The chemistry resembles hot cores with added shocks, placing the absorbing gas in the inner starburst disk directly encasing the core. No X-ray–driven chemistry or extreme excitation is found, arguing against an energetically dominant buried AGN in this band.
Using >55,000 type 1 DESI quasars at 0.25<z<0.8, the authors show that Fe emission strength (R_Fe) tracks Eddington ratio and derive iron-corrected R–L relations for Hβ, then calibrate Mg II masses against the Hβ-based results. Relative to canonical single-epoch scalings, black hole masses are overestimated by ~1.5× on average and up to ~5× for super-Eddington objects, which raises the super-Eddington fraction to ~5% (vs. 0.4%). The Mg II relation adds a −0.34 R_Fe term and is applied to build a ~0.5M-quasar DESI catalog at 0.6<z<1.6. If these iron-corrected relations hold at high z, z≥6 quasar masses would drop by a mean factor of ~2.3, easing early SMBH growth tension.
Uses local BASS analogs with well-characterized 0.5–195 keV spectra, forward-modeled into the CCLS redshift–luminosity–exposure space and re-fit with the CCLS pipeline to quantify obscuration biases. Finds Chandra would miss 53.3% (563/1056) of simulated obscured (NH>10^22 cm^-2) sources, and even detected ≥30-count spectra have NH systematically overestimated. The strongest failure mode is for CT best-fits (NH≥10^24 cm^-2), where 66.7% (18/27) are actually unobscured (NH<10^22 cm^-2). Results imply deep <10 keV surveys overstate the rise of the obscured fraction and the fraction of luminous obscured AGN, motivating forward modeling, multi-wavelength obscuration tracers, and higher-sensitivity missions like AXIS.
Tests a proxy-based black hole mass estimator for obscured AGN that infers FWHM_bHα from the narrow-line ratio L[O III]/L_nHβ and λL5100 from either intrinsic 2–10 keV X-rays or narrow lines, using 99 local Swift-BAT/BASS AGN. The two λL5100 proxies differ by a mean −0.32 ± 0.68 dex (narrow-line estimate lower than X-ray), implying ≈2× MBH uncertainty from the luminosity choice. Compared to virial masses from broad Paschen lines (14 Paα, 12 Paβ), the proxy MBH is higher by 0.39 ± 0.44 dex and 0.48 ± 0.51 dex, respectively, though still within the scatter. σ*-based MBH for 151 BASS AGN agrees on average within 0.08 dex but with large ≈0.74 dex scatter, so the method scales to large samples with overall ≈3–5× uncertainty and a possible mild high bias needing more data.
HST UV spectra (COS/STIS) for 13 z<0.7 quasars with large H-beta velocity offsets are compared to contemporaneous optical Balmer profiles to test supermassive black hole binary (SBHB) versus single-BH disk-like BLR scenarios. The authors isolate broad components and ask whether UV resonance lines (e.g., Lyα, C IV) share the same velocity offset as Balmer lines set by [O III]. They find three objects with strong SBHB support, five tentative, one disfavored, and four inconclusive due to severely absorbed UV profiles. This cross-wavelength line-profile test tightens SBHB vetting by demanding consistent Doppler shifts across independent broad lines.
NuSTAR multi-epoch X-ray spectra of five CLAGNs (ESO 362-G18, NGC 1365, NGC 4151, NGC 5548, NGC 7582) are fit with phenomenological and clumpy-torus models to track Γ, L2–10 keV/LEdd, and NH,los. The authors find a positive Γ–(L2–10 keV/LEdd) correlation and, for four objects, a strong anti-correlation between NH,los and L2–10 keV/LEdd, with ESO 362-G18 standing out as an exception. They argue this links changing-obscuration to accretion-driven evolution: a disc wind that strengthens with accretion rate pushes line-of-sight clouds outward, lowering NH at moderate inclinations. The trends persist across model choices, tying CLAGN absorption changes to the same engine that drives changing-state behavior.
Simulating JWST/NIRCam narrow- and medium-band [O III] maps at z≈2–3 using MUSE datacubes of nine nearby AGN, the authors show NIRCam can recover classic ionization-cone morphologies. They then apply this to 27 known AGN in GOODS-S (z=2.4–3.4), identifying six systems with [O III]+Hβ morphologies consistent with cones and characteristic NLR sizes of 1–2.5 kpc. The simulations quantify how cosmological dimming and instrument noise bias high‑z NLR size measurements low, depressing the local NLR size–AGN luminosity relation by about a factor of two. This establishes a practical medium-band imaging path to select cone candidates and calibrate NLR size trends at cosmic noon.