Weekly issue

Week 7, 2026

Feb 9–15, 2026

Week 7, 2026 includes 3 curated papers, centered on spectroscopy, LRD, QSO.

2602.12325v1

Direct pathway to the Early Supermassive Black Holes: A Red Super-Eddington Quasar in a Massive Starburst Host at $z=7.2$

Qinyue Fei, Seiji Fujimoto, Gabriel Brammer, Ruancun Li, Luis C. Ho, Volker Bromm, Javier Álvarez-Márquez, Yoshihisa Asada, Guillermo Barro, Luis Colina, Pratika Dayal, Steven L. Finkelstein, Johan P. U. Fynbo, Michele Ginolfi, Kohei Inayoshi, Vasily Kokorev, Gene C. K. Leung, Jorryt Matthee, Romain A. Meyer, Rohan P. Naidu, Masafusa Onoue, Pablo G. Pérez-González, Charles L. Steinhardt, Francesco Valentino, Fabian Walter, Mengyuan Xiao, Haowen Zhang

Theme match 5/5

Digest

GNz7q at z=7.1899 is panchromatically dissected with JWST (NIRCam/NIRSpec/MIRI) plus NOEMA, revealing an X-ray‑weak, rapidly growing red quasar embedded in a dusty starburst. Deep NIRSpec/G395M shows clear broad Balmer lines (FWHM 2221±20 km s^-1), implying a super‑Eddington SMBH (λEdd=2.7±0.4) with log(MBH/M⊙)=7.55±0.34 from accretion‑rate–corrected virial estimates. PSF‑subtracted imaging recovers a massive, actively star‑forming host with log(M*/M⊙)=10.5±0.4 and SFR=330±97 M⊙ yr^-1, placing GNz7q on the local MBH–M* relation (MBH/M*≈0.001). Unlike many little red dots with weak/undetected SF, GNz7q looks like a rare transitional phase en route to the massive z~6 quasar locus, outlining a direct pathway to early SMBHs.

Open paper page arXiv abstract arXiv PDF Highlighted PDF

Key figures to inspect

Fig. 1 (NIRSpec spectrum and model): Verify the continuum+Fe II decomposition and the broad Balmer fit that drives the λEdd and MBH inference; check residuals for missed absorption or template mismatches.
Fig. 2 (Zoom on Balmer lines): Inspect the Hβ/Hγ profiles and the two-component BLR (including the redshifted rBLR) that underpins the super‑Eddington interpretation and the precise FWHM measurement.
Fig. 3 (MIRI MRS Paα map and spectrum): Confirm a compact, nuclear recombination line and evaluate residuals; use the spatial concentration and line strength to gauge embeddedness/extinction consistent with an X‑ray‑weak red quasar.
Fig. 4 (Multi-band AGN–host decomposition): Assess PSF subtraction across filters, host morphology/extent, and residual structure that set the stellar mass and imply a dusty starburst (driving the quoted SFR).

The Structure and Evolution of LRDs: Insights from JWST NIRSpec Medium and High Resolution Spectroscopy at $z\sim4$

Yuxuan Pang, Xin Wang, Cheng Cheng, Shengzhe Wang, Hang Zhou, Qianqiao Zhou, Xue-Bing Wu, Karl Glazebrook

Theme match 4/5

Digest

Medium/high-resolution NIRSpec spectra of 11 z≈4 LRDs enable clean decomposition of Balmer lines and a direct tie between lines and continua. Broad Hα luminosity tracks the rest‑optical continuum while [O III] tracks the UV, pointing to a common AGN origin for the optical continuum and BLR, with the UV-linked narrow-line region responding differently. Broad‑Hα–based virial masses of ~10^6–10^8 M⊙ at high λ_Edd≈0.6 imply rapid growth on ~10^5–10^7 yr timescales and an evolutionary path toward NLS1s, with intrinsically weak optical Fe II. A “Clumpy Envelope” of tens of light‑days is proposed to power the optical continuum and its diversity via temperature gradients and self‑absorption.

Open paper page arXiv abstract arXiv PDF Highlighted PDF

Key figures to inspect

Figure 1: Inspect Hα fits to see the separation and significance of broad vs. narrow components and the range of BLR FWHM across the 11 LRDs.
Figure 2: Examine Hβ+[O III] decompositions to gauge [O III] strength and kinematics relative to Balmer components, checking for offsets or width differences that inform the UV‑linked narrow-line region.
Figure 3: Read the correlation panels to verify that broad Hα scales with optical (not UV) while [O III] scales with UV (not optical), noting the plotted slopes and Spearman coefficients/p‑values.
Figure 4: Place the sample on the M_BH–λ_Edd plane versus SDSS/DESI/NLS1 contours and follow the dashed 20 Myr tracks to visualize the proposed growth/evolution pathway.

J-PAS: Semi-Supervised Sim-to-Obs Transfer for Robust Star--Galaxy--Quasar Classification

Daniel López-Cano, L. Raul Abramo, L. Nakazono, I. Pérez-Ràfols, G. Martínez-Solaeche, J. Chaves-Montero, Matthew M. Pieri, Jailson Alcaniz, Narciso Benitez, Silvia Bonoli, Saulo Carneiro, Javier Cenarro, David Cristóbal-Hornillos, Simone Daflon, Renato Dupke, Alessandro Ederoclite, Rosa González Delgado, Antonio Hernán-Caballero, Carlos Hernández-Monteagudo, Jifeng Liu, Carlos López-Sanjuan, Antonio Marín-Franch, Claudia Mendes de Oliveira, Mariano Moles, Fernando Roig, Laerte Sodré, Keith Taylor, Jesús Varela, Héctor Vázquez Ramió, Jose Vilchez, Javier Zaragoza-Cardiel

Theme match 2/5

Digest

Presents a semi-supervised domain adaptation pipeline that transfers a four-class spectral classifier (stars, galaxies, low‑z QSOs, high‑z QSOs) from DESI→J‑PAS mocks to real J‑PAS using a small labeled target set. On held‑out J‑PAS data it attains macro‑F1=0.82 and TPR=0.89, outperforming a J‑PAS‑only baseline (0.79/0.85) and a mocks‑only model (0.73/0.87), with the largest gains for high‑z quasars (F1=0.66 vs 0.55/0.37). The approach yields better‑calibrated quasar candidate lists for spectroscopic follow‑up (e.g., WEAVE‑QSO) and AGN searches when target labels are scarce. Results indicate efficient sim‑to‑obs transfer that boosts quasar purity at low FPR while keeping galaxy/star performance saturated.

Open paper page arXiv abstract arXiv PDF Highlighted PDF

Key figures to inspect

Figure 1: Inspect SED pairs (real J‑PAS solid vs DESI→J‑PAS mock dashed) per class to see band‑by‑band systematics and missing‑band behavior that drive domain shift.
Figure 2: Check per‑magnitude class balance differences between the full mock catalog and the labeled J‑PAS subset to understand label scarcity and potential magnitude‑dependent bias.
Figure 3: Compare the four confusion matrices to pinpoint which misclassifications are fixed by SSDA—especially leakage between high‑z QSO and galaxies—and read off per‑class TPR/PPV/F1.
Figure 4: Use the radar plot and per‑class ROC curves to quantify that SSDA primarily lifts both AUC and F1 for the quasar subclasses while leaving GALAXY/STAR essentially saturated in performance.

Week 7, 2026

Direct pathway to the Early Supermassive Black Holes: A Red Super-Eddington Quasar in a Massive Starburst Host at $z=7.2$

Digest

Key figures to inspect

Tags

The Structure and Evolution of LRDs: Insights from JWST NIRSpec Medium and High Resolution Spectroscopy at $z\sim4$

Digest

Key figures to inspect

Tags

J-PAS: Semi-Supervised Sim-to-Obs Transfer for Robust Star--Galaxy--Quasar Classification

Digest

Key figures to inspect

Tags