Weekly issue

Week 19, 2026

May 4–10, 2026

Week 19, 2026 includes 7 curated papers, centered on spectroscopy, LRD, JWST AGN.

2605.04685v1

Compact, AGN-hosting Dwarf Galaxies with "Little Red Dots"-like SEDs in the Local Universe

Lulu Bao, Chao-Wei Tsai, Jingwen Wu, Jialai Wang

Theme match 5/5

Digest

Using a compiled sample of 1,204 local AGN-hosting dwarf galaxies with luminosities comparable to JWST Little Red Dots, Bao et al. cluster rest-frame SED shapes and sizes into four groups that trace changes in UV-optical slope, metallicity, star formation, and dust emission. Roughly half of the local dwarf AGN sample falls into classes with the same broad hallmarks that define LRDs, namely compact morphologies and "V-shaped" UV-to-optical SEDs. But the main comparison goes the other way: these local compact, V-shaped systems are systematically larger and show different ionization states than high-redshift LRDs, indicating that they are more evolved rather than straightforward nearby twins. The paper argues that local compact dwarf AGN are therefore useful comparison objects, but likely follow a different black hole-galaxy growth pathway from the z > 5 LRD population.

Open paper page arXiv abstract arXiv PDF Highlighted PDF

Key figures to inspect

Figure 2. This is the clearest entry point for the paper’s selection logic. It places local AGN-hosting dwarf galaxies and published LRDs in the same UV-slope versus optical-slope plane, shows the Kocevski et al. "V-shaped" selection window explicitly, and makes it easy to see how much of the local sample genuinely overlaps the LRD-like SED locus.
Figure 3. This is the core results figure for the clustering analysis. The stacked SEDs define what each of the four K-means groups actually looks like, while the effective-radius distributions show which groups are truly compact versus diffuse, directly connecting SED class to the size comparison that drives the paper’s main conclusion.
Figure 8. This figure is central for the paper’s claim that local compact V-shaped systems are not simple LRD analogs. By putting the "Compact & V-shape" sample on the [N ii]-based BPT diagram and coloring points by similarity to the LRD template, it tests whether the most LRD-like local dwarfs also share the same ionization regime as comparison LRD-like systems.
Figure 11. This is the best late-paper synthesis figure. The correlation matrices tie UV slope, optical slope, effective radius, [O iii]/Hβ, metallicity, and WISE colors together for the full sample and for the compact V-shaped subset, showing which physical parameters are most tightly linked to the SED sequence and which trends remain important inside the most LRD-like local class.

Tags

2605.07976v1

Testing the BH$^*$ Model: a UV-to-Optical Spectral Fitting of The Cliff

Rosa M. Mérida, Marcin Sawicki, Gaia Gaspar, Chris J. Willott, Kartheik G. Iyer

Theme match 4/5

Digest

This paper performs a full UV-to-optical Bagpipes fit to the JWST/NIRSpec PRISM spectrum of The Cliff at z=3.55, explicitly allowing stellar, nebular, AGN, and blackbody components to test the BH* picture on one of the canonical little red dots. The fit naturally lands on a BH*-like solution, with a low-mass, star-forming, metal-poor host of log Mstar/Msun about 7.7 and moderate attenuation around Av about 0.5 mag, while the host had already assembled roughly log Mstar/Msun about 7 some 200 Myr earlier. That makes this a strong end-to-end demonstration that the BH* framework can reproduce the full V-shaped SED of a benchmark LRD rather than only its optical continuum. The main remaining ambiguity is in the UV, where weak AGN leakage is allowed but not required, and in the high inferred BH-to-stellar-mass ratio relative to standard BH-host scaling relations.

Open paper page arXiv abstract arXiv PDF Highlighted PDF

Key figures to inspect

Figure 1. Recommend the figure that shows the full JWST/NIRSpec PRISM spectrum and the multi-component fit decomposition. This is the single best visual summary of the paper because it demonstrates that a model with stellar, nebular, AGN, and blackbody terms can reproduce The Cliff across the full UV-to-optical range, which is the central test of the BH* scenario.
Figure 2. Recommend the figure that presents the inferred star-formation history or continuum-driven host constraints. It matters because the paper argues that the host is not an arbitrarily hidden massive galaxy but a low-mass system that had already built about 10^7 solar masses roughly 200 Myr before the observed epoch, which sharpens the physical interpretation of the UV side of the SED.
Figure 4. Recommend the figure comparing dust-law assumptions or posterior host-property shifts under different attenuation prescriptions. This carries one of the paper's main modeling caveats by showing how the preferred host remains low-mass and dusty, yet the inferred stellar mass and Av move upward when the attenuation law is changed.
Figure 6. Recommend the figure contrasting host-dominated UV and AGN-plus-host UV solutions. This figure is important because it directly addresses the paper's main unresolved point: modest AGN UV leakage is consistently allowed by the fit, but it is weak and not robustly constrained, leaving statistically similar UV interpretations on the table.
Figure 7. Recommend the later synthesis figure that places The Cliff in BH-to-host context or tracks the inferred BH-to-Mstar tension. This is the conclusion-driving comparison because it shows that the inferred BH is overmassive relative to the host compared with standard scaling relations, motivating either revised BH estimates or non-coeval BH and galaxy growth.

Tags

2605.05074v1

Little red dots as obscured little blue dots: relative abundances, luminosities, and black-hole masses

Piero Madau, Roberto Maiolino

Theme match 4/5

Digest

Madau and Maiolino test whether little red dots are simply the dust-reddened, high-inclination counterparts of compact broad-line AGN with bluer continua, which they frame as little blue dots. Starting from the observed z>4 BLAGN UV luminosity function, they forward-model anisotropic super-Eddington emission, orientation, and clumpy circumnuclear dust and show that this setup reproduces the observed LRD luminosity function over the JWST-constrained range. The preferred solutions imply modest obscuration, with a characteristic per-cloud extinction of about A_V=2.8 mag and a mean dust covering factor of about 0.23, while predicting an LRD fraction that rises toward fainter UV magnitudes and becomes even larger at rest-frame optical wavelengths. In this unification picture, UV-selected LRDs should appear to host systematically more massive black holes than unobscured little blue dots because dust preferentially removes lower-mass obscured systems from the observed UV sample, making the LRD luminosity function a direct demographic test of rapid early black-hole growth.

Open paper page arXiv abstract arXiv PDF Highlighted PDF

Key figures to inspect

Figure 1. Use Figure 1 as the anchor figure because it directly tests the paper’s central claim: whether the observed LRD UV luminosity function can be recovered from the parent compact BLAGN luminosity function through orientation-dependent emission plus dust obscuration. The upper panel shows the empirical setup and the best-fitting forward model together, while the lower panel translates that fit into the luminosity-dependent apparent LRD fraction. This is the cleanest single figure for showing that LRDs can emerge as a minority, dust-intercepted subset of the same parent population rather than requiring a distinct class.
Figure 2. Use Figure 2 to capture the paper’s main physical diagnostic and caveat. The confidence contours show the degeneracy between per-cloud extinction and the mean dust covering factor, making clear that the data favor a trade-off rather than a uniquely fixed obscuration geometry. This figure matters because it tells the reader what is actually constrained by the luminosity-function fit and why the inferred obscuration parameters carry asymmetric uncertainties.
Figure 3. Use Figure 3 because it visualizes one of the paper’s most important predictions beyond the luminosity-function fit: UV-selected LRDs should be biased toward higher inferred black-hole masses than unobscured little blue dots. The top panel compares the mass distributions of unobscured sightlines, all dust-intercepted systems, and the subset that would be classified photometrically as LRDs, while the bottom panel connects the model to an implied black-hole mass function and an observational comparison set. This figure is essential for showing that the mass offset is a selection effect within a unified parent population, not evidence for a separate LRD black-hole population.

Tags

2605.05301v1

An X-ray and optical spectral study of the changing-look narrow-line Seyfert 1 2MASX J0413-0050

A. Vietri, A. Tortosa, D. Ilić, S. Ciroi, M. Berton, E. Järvelä, C. Ricci, E. Sani, L. Crepaldi, B. Dalla Barba, S. Chen, E. Congiu, P. Condò, I. Varglund, G. Rodighiero

Theme match 3/5

Digest

Using four optical spectra from 6dF, NTT/EFOSC2, NOT/ALFOSC, and VLT/UT1 FORS2 between April 2004 and September 2023, plus eROSITA and Swift/XRT coverage from 2020 to 2023, this paper follows 2MASX J0413-0050 from its original NLS1 classification into a clear changing-look phase. The standout result is that Hbeta disappears completely in the 2021 spectra even though the source still shows a blue continuum and a relatively high inferred Eddington ratio of about 0.19 in January 2021; by September 2023, both broad and narrow Balmer components and Fe II have returned, giving an intermediate Seyfert 1.8 state. In X-rays the source varies only at the factor-of-few level, with a roughly factor-3 drop between the two Swift epochs and no strong change in photon index, but the data cannot constrain intrinsic NH. The authors therefore favor repeated changing-state switch-on and switch-off episodes over simple changing obscuration, strengthening the case that even high-accretion NLS1s can undergo CL behavior. ([arxiv.org](https://arxiv.org/pdf/2605.05301))

Open paper page arXiv abstract arXiv PDF Highlighted PDF

Key figures to inspect

Figure 1. This is the baseline 2004 decomposition that establishes why the source was originally treated as an NLS1: broad and narrow Balmer lines, Fe II multiplets, and broad He I are all present in the host-subtracted fit. It is the essential starting-point figure for understanding how dramatic the later loss of Hbeta and Fe II really is. ([arxiv.org](https://arxiv.org/pdf/2605.05301))
Figure 6. This zoom on the 2021-12 Hbeta-[O III] region is the sharpest visual proof of the paper's central anomaly, because the authors explicitly show an attempted Hbeta fit despite there being no real line at that position. It matters because the source still has narrow oxygen emission and a high inferred accretion state, so the near-total absence of Hbeta is what makes the 2021 phase physically puzzling. ([arxiv.org](https://arxiv.org/pdf/2605.05301))
Figure 8. This 2023-09 Hbeta zoom is the cleanest evidence that the line came back: the spectrum is decomposed into broad and narrow Hbeta, with the narrow component tied to [O III]lambda5007. Use this figure to see the re-emergence of BLR emission that drives the paper's later Seyfert 1.8 classification and seals the changing-look interpretation. ([arxiv.org](https://arxiv.org/pdf/2605.05301))
Figure 10. This X-ray comparison condenses the eROSITA 2020 and Swift/XRT 2022 and 2023 data into the paper's main high-energy constraint: the flux changes by factors of a few while the spectral slope remains consistent within uncertainties, and the low-count spectra cannot deliver a useful intrinsic NH measurement. It is the key caveat figure because it shows why a pure changing-obscuration explanation cannot be demonstrated from the available X-ray data. ([arxiv.org](https://arxiv.org/pdf/2605.05301))
Figure 11. This multi-epoch optical comparison is the best single summary figure in the paper, because it places all host-subtracted spectra on the same footing and shows Hbeta present in 2004 and 2023 but absent in both 2021 observations, together with the evolution in Halpha and continuum shape. If LRDigest runs only one synthesis panel, this is the one that most directly captures the paper's full switch-on and switch-off narrative over two decades. ([arxiv.org](https://arxiv.org/pdf/2605.05301))

Tags

2605.03016v1

Resolving the Multiphase Outflow, Shock Signatures, and PAHs in the AGN-Starburst Composite ULIRG F10565+2448 with JWST MIRI/MRS

Kylie Yui Dan, Jerome Seebeck, Sylvain Veilleux, David Rupke, Eduardo Gonzalez-Alfonso, Ismael Garcia-Bernete, Weizhe Liu, Dieter Lutz, Marcio Melendez, Miguel Pereira Santaella, Eckhard Sturm, Francesco Tombesi

Theme match 3/5

Digest

Using JWST/MIRI MRS integral-field spectroscopy, this paper maps warm molecular gas, ionized gas, and PAH emission in the nearby ULIRG F10565+2448, a system long suspected to host both starburst and AGN activity. The main result is a scale-dependent multiphase outflow: a compact nuclear outflow appears in both ionized gas and warm H2, while the resolved kpc-scale outflow is seen primarily in warm molecular gas and is only modestly faster than the rotating disk, likely remaining below the escape speed. H2 excitation analysis further shows that the outflow is warmer than the disk, with hotter and lower-column-density patches that, together with elevated [Fe II] 5.34 μm/Pfα, point to localized shock activity. The PAH ratios change non-monotonically with radius, strengthening the case that both star formation and AGN-powered processes are needed to explain the observed energetics and mid-infrared diagnostics.

Open paper page arXiv abstract arXiv PDF Highlighted PDF

Key figures to inspect

Figure 4. Use this figure to anchor the compact ionized-outflow claim. The fitted [Ne II], [Ne III], and [Ne V] profiles isolate blueshifted broad components in the nucleus and show that the highest-ionization emission is dominated by the outflowing component, which is central to the paper’s AGN-linked nuclear interpretation.
Figure 6. This is the clearest map-level view of the resolved warm-molecular outflow. The H2 S(1) and S(3) flux, v50, and W80 maps separate the low-velocity disk from the asymmetric blueshifted second component and show where the kpc-scale molecular flow emerges relative to the nucleus.
Figure 11. This figure carries the paper’s main physical interpretation of the resolved H2 outflow. The temperature and column-density maps show that the outflowing warm molecular gas is hotter than the disk and identify hotter, lower-column-density regions along the flow edges, which is the key evidence motivating a shock-front scenario.
Figure 12. Include this figure for the PAH result because it captures the radial behavior emphasized in the abstract, not just an integrated diagnostic point. The distance-coded PAH ratio planes show how inferred ionization and grain-size trends change from the center to several kiloparsecs, supporting the composite AGN plus star-forming picture.
Figure 14. This is the paper’s most direct shock-diagnostic figure. The [Fe II] 5.34 μm/Pfα map highlights candidate shocked regions south and northwest of the nucleus that line up with the hotter, less dense edges of the warm-H2 outflow, tying the line-ratio evidence directly to the outflow structure.

Tags

2605.02663v1

Jet-driven shocks and turbulence in radio-loud Active Galactic Nuclei observed with JWST MIRI/MRS

Rogemar A. Riffel, Gabriel L. Souza-Oliveira, Luis Colina, Almudena Alonso-Herrero, Marina Bianchin, Kalliopi M. Dasyra, Lorenzo Evangelista, Kameron Goold, Pierre Guillard, Rogério Riffel, Anil Seth, Thaisa Storchi-Bergmann, Nadia Zakamska, Samile Araujo-Santos, Anelise Audibert, Enrica Bellocchi, Steph Campbell, Françoise Combes, Guilherme S. Couto, José Henrique Costa-Souza, Richard I. Davies, Maitê S. Z. de Mellos, Tanio Díaz-Santos, Fergus R. Donnan, Ismael García-Bernete, Santiago García-Burillo, Laura Hermosa Muñoz, Erin K. S. Hicks, Alvaro Labiano, Enrique Lopez-Rodriguez, Vincenzo Mainieri, Christopher Packham, Miguel Pereira Santaella, Cristina Ramos Almeida, Claudio Ricci, Lucas Ramos Vieira, Vivian U

Theme match 3/5

Digest

This paper uses JWST MIRI/MRS integral-field spectroscopy of seven nearby radio-loud AGN, including 3C 293, 3C 305, Centaurus A, Cygnus A, IC 5063, NGC 1052, and M87, to test how radio jets heat and stir the multiphase ISM on nuclear and circumnuclear scales. Spatially resolved H2 S(3)/PAH 11.3, H2 excitation temperatures, and ionized-gas diagnostics such as [Fe II]/PAH and [Ne III]/[Ne II] show that enhanced turbulence and shock signatures appear not just along the radio axis but also perpendicular to it. The central result is that H2 excess and hotter molecular gas correlate strongly with shock-sensitive tracers, supporting jet-driven shocks as the dominant excitation mechanism for the warm H2 rotational lines in most of the sample. That makes this a clean JWST view of radio jets coupling to both molecular and ionized gas beyond the narrow jet channel itself.

Open paper page arXiv abstract arXiv PDF Highlighted PDF

Key figures to inspect

Figure 1. Use this as the setup figure because it places the sample in the broader H2-excess context. The comparison between Spitzer subsamples and JWST spaxel-by-spaxel measurements shows that these radio-loud AGN occupy the regime of elevated H2 S(3)/PAH 11.3, establishing why resolved jet-driven heating is the central question of the paper.
Figure 3. This is the compact synthesis figure for the paper’s main diagnostic logic. By summarizing which correlations are statistically significant between H2 S(3)/PAH 11.3, H2 temperature, [Fe II]/PAH, and [Ne III]/[Ne II], separately along and perpendicular to the jet, it makes clear that shock-linked trends are the recurring result across the sample rather than a single-galaxy anecdote.
Figure 4. This figure is especially useful for the digest because it distills the directional result at the galaxy-by-galaxy level. The paired along-jet and perpendicular measurements, together with the Spitzer BAT AGN and radio-selected comparison densities and the radio-luminosity color coding, show how the H2 excess, shock tracers, and ionization diagnostics shift with geometry and where the radio-loud sample sits relative to other AGN populations.
Figure 5. Choose this for the kinematic bottom line. The mean W80 measurements for H2 S(3), [Fe II], and [Ne III] directly show that the jets are associated with broadened molecular and ionized gas profiles, and the separation into along-jet, perpendicular, nuclear, and all-spaxel measurements makes the claim about turbulence extending beyond the collimated jet channel much more concrete.

Tags

2605.07965v1

A Changing-Look Seyfert Discovered by eROSITA Reveals a Two-Component Broad-Line Region

Alex Markowitz, Mirko Krumpe, David Homan, Bożena Czerny, Mariusz Gromazdki, Hartmut Winkler, Joern Wilms, Steven Hämmerich, Georg Lamer, Tathagata Saha, David A. H. Buckley, Malte Schramm, Daniel E. Reichart, Mara Salvato, Pietro Baldini

Theme match 2/5

Digest

This paper follows the Seyfert HE 1237-2252 after eROSITA caught its soft X-ray flux dropping by a factor of 17 in 18 months, and the follow-up campaign then tracked the recovery as the inferred accretion rate relative to Eddington rose by about a factor of 7 over 3 years. During that evolution, the source moved from subtype 1.0-1.2 in 2002 to subtype 1.8 near the dip and then back to subtype 1.0 within 3 months, with broad Hbeta flux changing by factors of 4-6. The broad Balmer lines are best described with two BLR components: a virialized broad Gaussian at 27 +/- 3 light-days and a double-peaked diskline originating at more than roughly 5 light-days, with the diskline contribution growing as the continuum brightens. Because the X-ray spectra do not show strong obscuration and the IR continuum also dipped, the paper argues this was an intrinsic accretion-rate pause rather than line-of-sight hiding, offering a rare look at BLR structure responding in real time to a changing accretion flow.

Open paper page arXiv abstract arXiv PDF Highlighted PDF

Key figures to inspect

Figure 1. This is the event-definition figure. It puts the eROSITA/XMM/Swift X-ray history, the UV-optical continuum, the NEOWISE IR behavior, and the broad Balmer line-flux changes on one timeline, making the changing-look nature of HE 1237-2252 and the coordinated multi-band recovery immediately clear.
Figure 3. Use this as the multiwavelength synthesis figure. The optical/UV/X-ray SED fits across XM1-XM3 show how the continuum shape and modeled accretion flow changed during recovery, which is where the paper ties together the rising accretion rate, the corona-disk components, and the case against a simple obscuration-driven explanation.
Figure 6. This is the clearest single-spectrum demonstration of the paper's main spectroscopic result. The decomposition explicitly separates the Balmer diskline and broad Gaussian components while also fitting Fe II, host-galaxy light, and narrow-line structure, so readers can see why the authors infer a genuinely two-component BLR rather than a single evolving broad profile.
Figure 8. This is the key physical diagnostic for the paper's BLR interpretation. By showing that the diskline fraction in both Halpha and Hbeta increases with UV flux density, it directly links continuum brightening to the growing prominence of the disk-like BLR component and supports the idea that the illuminating geometry changes as the accretion state recovers.
Figure 9. This figure is the best quantitative summary of the changing-look classification itself. The time series of subtype indicators shows the source crossing the Seyfert subtype boundaries from roughly 1.0-1.2 to 1.8 and then back to 1.0, turning the narrative of the transition into a measured spectral sequence.