Weekly issue

Week 36, 2026

Aug 31 – Sep 6, 2026

Week 36, 2026 includes 14 curated papers, centered on LRD, spectroscopy, high-z.

2609.00113v1

Weighing Little Red Dots with Transient Events

Vinh Tran, Xuejian Shen, Oliver Zier, Anna de Graaff, Rohan P. Naidu, Mark Vogelsberger

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Tran et al. propose using stellar transients to independently weigh Little Red Dots, whose black-hole masses remain uncertain because broad Balmer-line virial estimates may be distorted by dense gas and poorly constrained geometry. They calculate tidal disruption event and quasi-periodic eruption rates for three LRD populations: genuinely overmassive black holes, systems on local black-hole–stellar-mass relations, and a substantially larger obscured population of lower-mass black holes. With a Hernquist distribution containing a Bahcall–Wolf cusp, the hidden low-mass population predicts markedly higher surface densities, reaching 3.37 × 10^-2 TDEs and 4.96 × 10^-1 QPE births yr^-1 deg^-2, making wide-field Euclid, Roman, and LSST light curves a potential discriminator of early black-hole demographics and LRD gas envelopes.

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Key figures to inspect

Figure 3. This figure defines the paper’s three competing black-hole–host-mass prescriptions by placing reported LRD measurements, electron-scattering-calibrated masses, envelope and quasi-star models, and local versus inferred intrinsic scaling relations on the same plane. It is essential context for understanding what the transient-rate scenarios physically represent.
Figure 4. This figure shows how the rest-frame TDE rate depends on black-hole mass, stellar mass, and the assumed inner stellar-density slope. It provides the loss-cone physics behind why a steep Bahcall–Wolf-like cusp and a low-mass black-hole population can strongly alter the observable transient yield.
Figure 5. This figure gives the corresponding QPE birth rates after replacing the tidal-disruption loss-cone scale with the much larger gas-photosphere scale. It makes clear why QPEs can be enhanced by orders of magnitude relative to TDEs and ties the proposed observable directly to extended dense envelopes around LRD black holes.
Figure 6. This is the conclusion-driving population-level comparison: per-square-degree TDE and QPE rates for all three LRD scenarios are set against annual survey-area thresholds. It shows that the obscured, numerous low-mass black-hole scenario predicts systematically higher TDE rates, while density-profile and size assumptions leave the overmassive and local-scaling cases comparatively degenerate.

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2609.00115v1

Early Supermassive Black Holes and Little Red Dots Require Free-Fall Growth

Junehyoung Jeon, Volker Bromm, Michael Boylan-Kolchin, Julian B. Muñoz

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Jeon et al. build an analytic halo-inflow model to ask whether early black holes can be supplied with enough gas at small radii, contrasting ideal cold-stream free fall with shock-heated Bondi-Hoyle inflow. Free-fall cold-mode accretion supplies the observed masses of JWST AGN and high-redshift quasars in plausible halo populations, whereas shock-heated inflow would require implausibly rare hosts. In particular, the rare halos capable of sustaining extreme inflow reproduce massive-quasar abundances, while halos that can fuel super-Eddington growth of roughly 10^7 solar-mass SMBHs align with LRD number densities. The model interprets the declining LRD abundance toward lower redshift as cold-mode accretion shutting down as host halos grow, although its free-fall mass budgets are upper limits because gas reaching halo centers need not all accrete onto the SMBH.

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Key figures to inspect

Figure 2. This is the paper's central abundance test: it compares the redshift-dependent density of halos meeting a required inflow rate under free-fall and Bondi-Hoyle prescriptions, directly against quasar, LRD, and DCBH constraints. It makes the key claim visually clear that super-Eddington LRD interpretations require near-free-fall supply and that the low-redshift LRD decline can follow the end of cold-mode inflow.
Figure 3. This cumulative-growth comparison shows that free-fall inflow can assemble the black-hole masses inferred for JWST AGN, LRDs, and luminous quasars along constant-number-density halo tracks. It also highlights the changing cold-mode boundary, including the tension for the most massive quasars as their hosts become too massive to retain cold-mode accretion at later epochs.
Figure 4. The accretion-built black-hole mass functions provide the population-level consequence of the model, showing that free fall can reach the most massive early AGN but can overproduce the observed active BH mass function at later times. The figure carries the paper's principal caveat: these are supply-based upper limits, since central gas delivery, SMBH accretion, and AGN duty cycle are not equivalent.
Figure 5. This host-halo versus accumulated-black-hole-mass diagnostic gives the most direct physical comparison with clustering-based host constraints. Observed high-redshift AGN and quasar hosts fall below or within the free-fall ceiling yet substantially above the Bondi-Hoyle prediction, reinforcing the conclusion that near-free-fall growth is necessary.

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2609.00112v1

Skyfire: A Spectroscopic Census of Little Red Dots and Broad-Line AGN in the CEERS Field

Dale D. Kocevski, Anthony J. Taylor, Masafusa Onoue, Kohei Inayoshi, Steven L. Finkelstein, Guillermo Barro, Jingsong Guo, Pablo Arrabal Haro, Jonathan R. Trump, Rebecca L. Larson, Mark Dickinson, Casey Papovich, Fabio Pacucci, Pablo G. Perez-Gonzalez, Michaela Hirschmann, Elizabeth J. McGrath, Brenda L. Jones, Nikko J. Cleri, Kelcey Davis, Mauro Giavalisco, Norman A. Grogin, Taylor A. Hutchison, Jeyhan S. Kartaltepe, Allison Kirkpatrick, Gene C. K. Leung, Rachel S. Somerville, Stephen M. Wilkins

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Skyfire uses 21 hours of JWST/NIRSpec G395M spectroscopy across five CEERS pointings to build a systematic census of compact broad-line AGN candidates spanning red LRDs, blue extreme-emission-line galaxies, and X-ray AGN. Among 178 measured redshifts, the program identifies 34 broad-line sources at 2.7 < z < 6.5, including 18 LRDs, raising the spectroscopic completeness of CEERS LRDs with βopt > −0.02 to 73%. Broad-line incidence stays high beyond the canonical red LRD cuts and continues into the Little Blue Dot regime, favoring a continuous LRD–LBD population; with a revised βopt ≥ −0.52 selection, 80.9% of F444W < 26.5 candidates are broad-line emitters, whereas only 3 of 17 compact high-EW EELGs show broad lines.

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Key figures to inspect

Figure 5. This is the paper’s central selection-space diagnostic: broad-line detections remain common below the canonical red optical-slope and color cuts, visually connecting LRDs to the bluer LBD regime and motivating the expanded LRD definition.
Figure 6. This figure quantifies both spectroscopic completeness and broad-line yield across optical slope, color, and F444W magnitude, directly supporting the revised βopt threshold and the reported high efficiency of photometric LRD selection.
Figure 7. The continuum-slope distributions show the population-level structure of CEERS broad-line emitters, including the bimodality between red LRDs and the bluest broad-line sources and the minimum near the proposed dividing slope.
Figure 8. This redshift-dependent census places the LRD–LBD connection in evolutionary context by showing that blue non-LRD broad-line sources become increasingly important toward lower redshift and eventually dominate the broad-line population.

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2608.27596v1

Formation of black hole stars via star--black hole collisions

Yanlong Shi, Qingru Hu, Zhenghao Xu, Douglas N. C. Lin, Norman Murray

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Shi et al. model collisions between stellar-mass black holes and a 100-solar-mass main-sequence star using drag-based orbital integrations, 3D GIZMO hydrodynamics, and follow-up MESA evolution. Gas drag generally traps the intruding black hole unless its impact speed exceeds roughly twice the mutual escape speed, but the remnant is controlled chiefly by mass ratio: black holes below about 10 solar masses produce quasi-hydrostatic, extended black-hole stars, whereas those above about 30 solar masses leave shock-heated, dynamically unstable spherical or disk-like envelopes. The simulations and analytic argument converge on a BH-star formation criterion of black-hole mass below about 0.2 times the stellar mass, and MESA finds that the low-mass cases thermally relax rather than entering runaway expansion. This supplies a concrete collision channel for embedded-envelope black-hole growth in dense clusters and AGN disks, with a possible, still speculative connection to JWST little red dots.

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Key figures to inspect

Figure 2. This is the paper's clearest formation map: it identifies the impact-velocity and impact-parameter regimes in which gas drag retains the stellar-mass black hole, separating geometric encounters from successful embedded-BH outcomes.
Figure 3. The imposed-inspiral-heating experiment directly supports the thermal-survival claim by tracking injected energy, stellar expansion, core conditions, and nuclear luminosity during and after the shock-heating interval.
Figure 5. This diagnostic links collision parameters and black-hole mass to the final classification of the remnant as a quasi-spherical BH star, a disk-envelope system, or a bare black hole, making the mass-ratio dependence visually explicit.
Figure 6. The envelope mass, size, and rotational-support evolution provide the central structural comparison across black-hole masses and distinguish the stable extended BH-star branch from disk-like remnants.
Figure 7. The final radial density and mixed hydrogen-abundance profiles show the internal structure left by the collision, connecting the hydrodynamic remnant to the stellar-evolution interpretation of a relaxed black-hole star.

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2609.00437v1

Formation of Heavy Seed Black Holes and Little Red Dots-like Compact Clusters in Metal-enriched Star-forming Regions

Sunmyon Chon, Shingo Hirano, Ke-Jung Chen, Volker Springel

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Using a cosmological radiation-hydrodynamic zoom-in simulation with self-consistent rapidly accreting supermassive-star evolution, Chon et al. connect heavy black-hole seed formation to compact cluster assembly in strongly irradiated, weakly metal-enriched star-forming regions. The first seeds arise once the mass-weighted internal Lyman-Werner field reaches J21~1000, typically from gas at [Z/H]~−3 to −2; every halo above 10^9 Msun in the simulated region hosts a BH exceeding 10^5 Msun. Five of eight clusters above 10^6 Msun produce intrinsically V-shaped, Little Red Dot-like continua, with 6000 K bloated supermassive stars often supplying the red optical component and normal-population Balmer breaks adding to it. The result frames heavy seeds, dense compact clusters, and even off-center LRD-like sources as linked products of clustered, enriched-but-still-low-metallicity environments rather than exclusively pristine direct-collapse sites.

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Key figures to inspect

Figure 1. Maps the simulated metal-enriched, FUV-irradiated star-forming environment and locates the eight massive SMS-hosting clusters, directly visualizing the spatial setting proposed to unite heavy-seed formation with LRD-like compact systems.
Figure 3. Shows that SMS formation occupies the overlap of strong external Lyman-Werner irradiation and low, but nonzero, stellar metallicity, making the paper's departure from a strictly pristine direct-collapse picture concrete.
Figure 6. Quantifies the halo occupation fraction of heavy seed BHs and underpins the headline result that all halos above 10^9 Msun in the zoom-in region contain BHs more massive than 10^5 Msun.
Figure 10. Presents the full spectral decomposition of all eight massive clusters into normal-star and SMS light, establishing how frequently the simulated systems generate the red optical excess associated with LRD-like V-shaped continua.
Figure 13. Places the simulated UV and optical slopes against the empirical V-shaped LRD selection region, providing the clearest population-level diagnostic for the claimed LRD-like spectral resemblance and the effect of dust attenuation.

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2609.00033v1

Lynx2030 Science Analysis Group: Final Report

Lynx2030 Science Analysis Group, Simon R. Bandler, Laura W. Brenneman, Nico Cappelluti, Daniel Castro, Steven R. Ehlert, W. Peter Maksym, Fabio Pacucci, Scott W. Randall, Grant R. Tremblay, John ZuHone, Steven W. Allen, Antara R. Basu-Zych, Akos Bogdan, Joel N. Bregman, Tamta Burduli, Thomas Connor, Sanskriti Das, Casey DeRoo, Stephen DiKerby, Paul A. Draghis, Martin Elvis, Giuseppina Fabbiano, Ralf K. Heilmann, Jimmy A. Irwin, Amruta Jaodand, Margarita Karovska, Vinay L. Kashyap, Anthony A. Kerr, Caroline Kilbourne, Ralph Kraft, Jiangtao Li, Labani Mallick, Herman L. Marshall, Michael L. McCollough, Anna Ogorzałek, Frederik Paerels, Daniel Patnaude, Paul Plucinsky, David Pooley, Frederick S. Porter, Daniele Rogantini, Roger Romani, Helen R. Russell, Kazuhiro Sakai, Mark Schattenburg, Dan A. Schwartz, Malgorzata Sobolewska, Paolo Soffitta, Alexey Vikhlinin, Daniel R. Wilkins, Scott Wolk, Ka-Wah Wong, Irina Zhuravleva

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This Lynx2030 Science Analysis Group report re-evaluates the Lynx flagship X-ray concept against the science and facility landscape expected in the 2030s, testing gains from sharper imaging, wider bandpass, enhanced microcalorimetry, new observing modes, and larger fields of view. For little red dots, the central argument is that their compact, broad-Balmer-line, apparently X-ray-weak black holes require deep, subarcsecond X-ray imaging spectroscopy to distinguish super-Eddington accretion from Compton-thick obscuration or reprocessing in ionized cocoons. The report concludes that modest extensions to the original Lynx design could be transformative while retaining its core architecture, positioning a Lynx-class observatory as the X-ray complement to JWST, Roman, Rubin, SKA, ngVLA, LISA, and NewAthena.

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Figure 1. This Chandra-to-Lynx simulation makes the report’s angular-resolution case visually immediate: cluster cavities that disappear after cosmological dimming in a Chandra-like view remain detectable with 0.3-arcsec Lynx imaging. It illustrates why subarcsecond resolution is treated as a core, rather than optional, capability.
Figure 3. This synthesis figure connects resolved Bondi radii, the accessible nearby-SMBH population, and competing RIAF density profiles. It shows that substantially finer spatial sampling is needed to discriminate accretion-flow models rather than merely detect hot gas near the Bondi scale.
Figure 7. The simulated microcalorimeter observation demonstrates a conclusion-driving spectral diagnostic: narrow O VII, O VIII, and Fe XVII features separate redshifted circumgalactic emission from the Milky Way foreground. It clearly motivates the report’s emphasis on high-resolution imaging spectroscopy and an expanded microcalorimeter capability.

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2608.30459v1

Broad-band host measurements of little red dots and similar compact nuclei require source-conditioned polychromatic PSFs

Sergio Bonaque-González

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Bonaque-González shows that broad-band nucleus–host decompositions of little red dots can be systematically biased when empirical PSFs built from field stars are applied to LRDs with very different in-band spectral shapes. Reanalysing the Zhang et al. 217-object stacking framework with synthetic point-only LRDs, the paper finds that chromatic PSF mismatch alone can be absorbed by a compact Sérsic component, reaching 18.73% of the flux in F444W despite no input host. A source-conditioned polychromatic PSF, either computed from the nuclear spectrum or flexibly represented with LRD-derived diffraction modes, removes this false extended-light allocation while recovering injected hosts. The result puts rest-frame-optical host sizes, luminosities, and stellar masses inferred from stellar-PSF subtraction on a spectrum-dependent footing, with a provisional correction lowering the aggregate F444W host fraction from 11.8% to 4.6%.

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Figure 1. This is the paper's central demonstration: a simulated LRD containing only an unresolved nucleus leaves wavelength-dependent residuals when fit with a stellar polychromatic PSF, and the decomposition assigns those residuals to a Sérsic host. The enclosed-energy comparison makes clear that small chromatic changes in the point-source light distribution grow toward F444W and can be amplified into an apparent rest-frame-optical host component.

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2608.29727v1

Primordial Black Hole Seeds for Little Red Dots in $f(R)$ Gravity

Saeed Fakhry

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Fakhry presents a hybrid early-black-hole assembly scenario in which clustered primordial black holes undergo hierarchical gravitational-wave-capture mergers in Hu–Sawicki f(R) gravity before their remnants grow through galactic gas accretion. The screened fifth force boosts the early merger kernel and hence the intermediate-mass seed population, while chameleon screening regulates the enhancement; because later accretion scales with seed mass, the model lowers the time-averaged Eddington ratios needed to reach little-red-dot black-hole masses by z≈6. The predicted active mass functions can reproduce the reported LRD space densities with a small clustered PBH fraction and an AGN duty cycle of 10^-2, while the paper proposes remnant-spin states, an SGWB cutoff, and a scale-dependent PBH-clustering inversion as ways to distinguish modified gravity from denser PBH clusters.

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Figure 1. This establishes the central assembly claim directly: Hu–Sawicki gravity raises the maximum black-hole mass relative to GR during the merger-plus-accretion epoch, reducing the Eddington ratio needed to enter the observed LRD mass range by z≈6.
Figure 5. This is the main population-level test of the model, comparing active black-hole mass functions at z≈5.5 and z≈6.5 against LRD mass-distribution information and other observational constraints while varying PBH fraction and f(R) strength.
Figure 6. This figure presents one of the paper’s proposed degeneracy-breaking observables: the stochastic gravitational-wave background and its observer-frame ISCO cutoff, which encode the merger-built PBH seed population.
Figure 8. This captures the other distinctive large-scale diagnostic emphasized by the paper, showing how the PBH real-space correlation function at z=6 differs between GR and screened f(R) models.

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2608.29011v1

Can Little Red Dots Contribute To The Early Universe Cosmic Dust Budget?

Chris Ashall, Rohan P. Naidu, Alberto Torralba, Irene Shivaei, John Chisholm, Hanpu Liu, Zhaoran Liu, Jorryt Matthee, Kyle Medler, Tyco Mera, Takashi J. Moriya, Devesh Nandal, Robert A. Simcoe, Wendy Q. Sun

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Ashall et al. ask whether Little Red Dots can be an early-Universe dust-production channel, motivated by their proposed physical kinship with efficiently dust-forming Type IIn supernovae. Modeling the infrared SEDs of two low-redshift LRD analogs with a pseudo-photosphere plus optically thin dust yields inferred reservoirs of roughly 10^2–10^3 solar masses; narrow Balmer ratios near Case B and metal-poor narrow-line environments argue against diffuse host-ISM dust as the dominant origin. Their population model spans negligible to dominant contributions, with favorable assumptions allowing LRDs to rival or exceed the lower core-collapse-supernova dust contribution above z≈5, making LRD outflows plausible dust factories or seed-grain sources, although photometry alone cannot rule out pre-existing dust.

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Key figures to inspect

Figure 1. This schematic establishes the paper’s physical proposal: a fast inner wind interacts with a dense, hydrogen-rich outer flow, while cooling and shielding in the extended outflow or compressed layer enable warm-to-cool dust formation. It is the clearest visual guide to why LRDs can resemble long-lived, dust-forming Type IIn-like environments without requiring their optical pseudo-photospheres to be strongly extinguished.
Figure 2. The SED fits for J0129+0628 and J0829+1312 provide the central empirical evidence for substantial infrared-emitting dust reservoirs in low-redshift LRD analogs. Showing both graphite-silicate and all-graphite solutions makes the key caveat explicit: composition is not uniquely constrained by broadband photometry, but both viable model families require a large dust component.
Figure 3. This is the conclusion-driving population comparison between LRD and core-collapse-supernova comoving dust-production-rate densities. Its parameter rescaling directly shows the paper’s main conditional result: LRDs can be a minor source or become competitive with, even exceed, the lower CCSN contribution depending on event multiplicity, dust survival, and the fraction of LRDs that form dust.

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2608.28745v1

Super-Eddington Little Blue Dots May Reionize Helium Too Early

Christopher Cain, Brent Smith, Gibson B. Bowling, Yongda Zhu, Lily Whitler, Rafael Ortiz, Anson D'Aloisio, Rogier Windhorst

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Cain et al. test whether the blue, broad-line JWST AGN population dubbed Little Blue Dots can predominantly host the EUV-bright, X-ray-weak super-Eddington accretion flows proposed in orientation-based unification pictures of LBDs and Little Red Dots. Using the observed faint broad-line AGN UV luminosity function, super-Eddington spectral models, and a He II reionization calculation, they find that completing helium reionization no earlier than z≈3 limits the fiducial highly super-Eddington fraction to ≲10% if LBDs comprise 5% of MUV<-18 galaxies and have a 15% ionizing escape fraction. A majority-super-Eddington interpretation would instead require He II-ionizing escape fractions ≲1.5% or a substantially rarer LBD population, with the constraint importantly dependent on the uncertain EUV spectral shape of super-Eddington black holes.

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Figure 1. This establishes the empirical population normalization: a roughly 5% broad-line AGN fraction among galaxies down to the adopted UV-magnitude cutoff is consistent with the measured UV luminosity functions, setting the LBD abundance used in the reionization calculation.
Figure 2. This is the physical linchpin of the paper, showing why low-mass soft-state super-Eddington black holes can produce He II-ionizing photons much more efficiently than a conventional quasar power-law SED while remaining X-ray weak.
Figure 3. The reionization histories directly connect the assumed super-Eddington SEDs to the observational timing constraint, illustrating how efficient EUV production can drive He II reionization to finish too early unless the super-Eddington contribution is restricted.
Figure 4. This is the headline constraint figure: it maps the combinations of super-Eddington LBD fraction and ionizing escape fraction disfavored by the requirement that He II reionization not complete before z≈3, including the fiducial ≲10% result.
Figure 5. This comparison tests whether the conclusion survives alternative EUV-bright accretion prescriptions, showing that the exclusion strength depends materially on the assumed black-hole mass and spectral state rather than on a single soft-state model.

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2608.27571v1

Dust and PAHs in late-stage galaxy evolution: Imprints of TP-AGB dust injection, grain growth and AGN feedback in high-z quiescent galaxies with JWST and ALMA

D. Donevski, A. Nanni, K. E. Whitaker, A. W. S. Man, A. Faisst, A. Lapi, I. García-Bernete, M. Romano, T. Petrushevska, G. Gururajan, G. Lorenzon, D. Narayanan

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Donevski et al. introduce UNDUST, a one-zone semi-analytic model for the coupled post-quenching evolution of cold gas, dust, grain sizes, and PAHs in high-redshift quiescent galaxies. For galaxies with comparable stellar mass, stellar-population age, and cold-gas fraction, the models produce a broad range of dust fractions and dust-to-gas ratios, from star-forming-like values to strongly dust-depleted states. Delayed TP-AGB dust injection and grain growth can maintain enrichment for up to several Gyr after quenching, while AGN-driven heating and outflows accelerate depletion; meanwhile, small carbonaceous grains can preserve appreciable PAH fractions after the cold-dust reservoir becomes ALMA-faint. The paper therefore frames JWST/MIRI PAH emission as a complementary diagnostic of chemically enriched post-quenching ISM phases that dust-continuum surveys may miss.

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Figure 2. This is the core population-level result: it shows how post-quenching dust fraction and dust-to-gas ratio diverge across destruction regimes, with and without AGN feedback, and places the tracks against existing CO and dust-continuum constraints on quiescent galaxies.
Figure 4. This figure isolates the physical origin of the total dust evolution by separating inherited dust, delayed TP-AGB injection, and ISM grain growth. It directly demonstrates why replenishment channels can prolong dust survival even as the pre-quenching reservoir is being destroyed.
Figure 7. The PAH-fraction diagnostic connects the model's grain-processing physics to an observable population plane. It shows that PAH-rich small carbonaceous-grain reservoirs can persist through multiple post-quenching stages and respond differently to AGN feedback and destruction strength.
Figure 8. This is the paper's main observational forecast, translating the PAH evolution into JWST/MIRI fluxes and identifying the regime where quiescent galaxies remain MIRI-detectable after falling below representative ALMA dust-continuum limits.

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2609.01711v1

JWST Reveals a Candidate Supermassive Black Hole Binary at z=4.3 in the Brightest Sub-millimeter Galaxy in COSMOS-Web

Jed McKinney, Ansh Gupta, Julian B. Munoz, John Chisholm, Caitlin M. Casey, Stephanie M. Urbano Stawinski, Olivia Cooper, Erini Lambrides, Hollis Akins, Maximilien Franco, Archana Aravindan, Seiji Fujimoto, Kohei Inayoshi, Andreas L. Faisst, Jeyhan S. Kartaltepe, Michael Boylan-Kolchin

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McKinney et al. present JWST/NIRSpec PRISM and G395M spectroscopy of AzTEC-1, the exceptionally bright sub-mm galaxy at z=4.34, finding a dust-attenuated 100–400 Myr-old stellar population and narrow-line BPT ratios consistent with an AGN. The central result is a broad Hα component with FWHM of about 2500 km s⁻¹ that is blueshifted by 1245 km s⁻¹ relative to the narrow systemic emission, with the resolved G395M fit strongly favoring an offset broad-line region rather than systemic broad Hα. The authors argue that AzTEC-1's smooth, post-starburst-like morphology and dense, unstable gas disk make a merger-delivered SMBH companion and stalled binary evolution plausible, while the lack of extended signatures across NIRSpec, NIRCam, and resolved ALMA data disfavors an ionized outflow interpretation. If confirmed, the system would offer a rare view of an obscured, high-redshift SMBH binary in the evolutionary regime relevant to low-frequency gravitational-wave sources.

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Key figures to inspect

Figure 4. The resolved NIRSpec/G395M Hα+[N II] fit is the paper's core observational evidence: it shows that allowing the broad Hα component to have an independent velocity is statistically preferred over a systemic broad-line model.
Figure 5. The two-dimensional G395M analysis tests whether the unusual broad and narrow profiles are spatially distinct or extended. Its unresolved, point-source-like line emission is central to the argument against a galaxy-scale ionized outflow.
Figure 8. This BPT comparison establishes that AzTEC-1's narrow-line ratios lie in the general AGN domain, providing the excitation diagnostic needed to interpret the offset broad Hα feature as connected to accreting black-hole activity.
Figure 10. This synthesis plot places AzTEC-1's broad Hα velocity offset and width against known outflows and binary-SMBH candidates. It makes clear both why an extreme outflow remains a comparison case and why the absence of spatially extended emission is decisive for the binary interpretation.
Figure 12. The black-hole-to-stellar-mass comparison translates the candidate-binary scenario into host-galaxy evolution, showing how the inferred companion or total binary mass would compare with local scaling relations and JWST AGN populations.

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2609.01421v1

Extreme AGN Variability in WISE: Powerful Flares and Candidate Tidal Disruption Events in AGN

Satya Teja Anuraag Upadhyayula, Daniel Stern, Kishalay De, Christos Panagiotou, Matthew J. Graham, K. E. Saavik Ford, Barry McKernan, Murray Brightman, J. A. Acevedo Barroso, Daniel H. McIntosh

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Using the 15-year, six-month-cadence WISE/NEOWISE baseline, the authors search the high-reliability WISE R90 AGN catalog for extreme mid-infrared color variability and isolate two powerful flares, J2244+0816 and J2150−1132. J2244+0816 has a near-simultaneous optical flare and persistent broadened Hα, whereas J2150−1132 is optically quiet and its initially broadened Hα subsequently weakens and narrows; both show dust-echo-like mid-infrared evolution and are argued to be candidate TDEs embedded in AGN. The unusually rapid optical decay of J2244+0816 relative to the canonical t^-5/3 expectation points to a partial disruption or a disruption by an intermediate-mass black hole in an AGN disk, while illustrating how mid-infrared selection can recover dust-obscured TDEs and constrain their bolometric energetics.

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Key figures to inspect

Figure 3. This is the core discovery figure: it places the W1/W2 flare histories, optical behavior, color evolution, and spectroscopic epochs of J2244+0816 and J2150−1132 side by side, making the optical counterpart in only one source immediately clear.
Figure 5. The two-epoch spectra of J2150−1132 provide the key temporal line diagnostic for the obscured candidate: Hα weakens and narrows while narrow [O III] and [N II] remain strong, supporting a fading transient contribution rather than a static broad-line component.
Figure 7. The monotonic W1/W2-derived cooling of J2150−1132 over roughly 900 days is direct physical evidence for a dust echo, linking the extreme mid-infrared flare to progressively more distant reprocessing material.
Figure 10. This population-level phase-space comparison shows where the two WISE AGN flares fall in peak rest-frame 3.4 μm luminosity and decline timescale relative to optically selected TDEs, Type IIn supernovae, changing-look AGN, and prior mid-infrared TDE candidates.

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2608.30914v1

Measuring peculiar velocity and tomographic redshift dipole with DESI DR1 catalogs

Yi-Wen Wu, Jun-Qing Xia

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Wu and Xia use the DESI DR1 redshift-dipole estimator to measure the Solar System’s peculiar velocity tomographically with BGS, LRG, ELG, and QSO samples spanning 0.1<z<2.1. The high-redshift QSO catalog yields v=357.95^{+55.05}_{-48.47} km s^-1, consistent with the CMB-dipole value of 369.82±0.11 km s^-1, supporting a standard kinematic origin for the dipole on the largest DESI scales. In contrast, conventional number counts give an enhanced dipole that the authors associate with large-scale-power leakage and incomplete DESI footprint coverage, positioning redshift dipoles as the cleaner rest-frame diagnostic.

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Figure 1. This Mollweide map establishes the four DESI DR1 tracer footprints and marks the CMB-dipole direction in the QSO panel. It is essential context for the paper’s central methodological claim, because the substantial sky incompleteness and resulting survey window are the proposed explanation for the inflated number-count dipole relative to the redshift-dipole result.