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We present a velocity-resolved reverberation mapping analysis of the hypervariable quasar RM160 (SDSS J141041.25+531849.0) at z = 0.359 with 153 spectroscopic epochs of data representing a 10 yr baseline (2013–2023). We split the baseline into two regimes based on the 3× flux increase in the light curve: a “low state” phase during the years 2013–2019 and a “high state” phase during the years 2022–2023. The velocity-resolved lag profiles (VRLPs) indicate that gas with different kinematics dominates the line emission in different states. The H β VRLP begins with a signature of inflow onto the broad-line region (BLR) in the low state, while in the high state it is flatter with less signature of inflow. The H α VRLP begins consistent with a virialized BLR in the low state, while in the high state shows a signature of inflow. The differences in the kinematics between the Balmer lines and between the low state and the high state suggests complex BLR dynamics. We find that the BLR radius and velocity (both FWHM and σ ) do not obey a constant virial product throughout the monitoring period. We find that the BLR lags and continuum luminosity are correlated, consistent with rapid response of the BLR gas to the illuminating continuum. The BLR kinematic profile changes in unpredictable ways that are not related to continuum changes and reverberation lag. Our observations indicate that nonvirial kinematics can significantly contribute to observed line profiles, suggesting caution for black hole mass estimation in luminous and highly varying quasars like RM160.

Time-domain studies of active galactic nuclei (AGNs) offer a powerful tool for understanding black hole accretion physics. Prior to the optical outburst on 2017 December 23, 1ES 1927+654 was classified as a “true” type 2 AGN, an unobscured source intrinsically devoid of broad-line emission in polarized spectra. Through our 3 yr monitoring campaign spanning X-ray to ultraviolet/optical wavelengths, we analyze the post-outburst evolution of the spectral energy distribution (SED) of 1ES 1927+654. Examination of the intrinsic SED and subsequent modeling using different models reveal that the post-outburst spectrum is best described by a combination of a disk, blackbody, and corona components. We detect systematic SED variability and identify four distinct stages in the evolution of these components. During the event the accretion rate is typically above the Eddington limit. The correlation between ultraviolet luminosity and optical to X-ray slope ( α _OX ) resembles that seen in previous studies of type 1 AGNs, yet exhibits two distinct branches with opposite slopes. The optical bolometric correction factor ( κ _5100 ) is ∼10 times higher than typical AGNs, again displaying two distinct branches. Correlations among the corona optical depth, disk surface density, and α _OX provide compelling evidence of a disk–corona connection. The X-ray corona showcases systematic variation in the compactness-temperature plot. Between 200 and 650 days, the corona is “hotter when brighter,” whereas after 650 days, it becomes “cooler when brighter.” This bimodal behavior, in conjunction with the bifurcated branches of α _OX and κ _5100 , offers strong evidence of a transition from a slim disk to a thin disk ∼650 days after the outburst.

The properties of slim accretion disks, while crucial for our understanding of black hole growth, have yet to be studied extensively observationally. We analyze the multiepoch broadband spectral energy distribution of the changing-look active galactic nucleus 1ES 1927+654 to derive the properties of its complex, time-dependent accretion flow. The accretion rate decays as $\dot{M}\propto {t}^{-1.53}$ , consistent with the tidal disruption of a 1.1 M _⊙ star. Three components contribute to the spectral energy distribution: a central overheated zone resembling a slim disk, an outer truncated thin disk, and a hot corona. Photon trapping in the slim disk triggered by the high initial $\dot{M}$ was characterized by a low radiation efficiency (3%), which later more than doubled (8%) after $\dot{M}$ dropped sufficiently low for the disk to transition to a geometrically thin state. The blackbody temperature profile T ∝ R ^−0.60 for the inner overheated zone matches the theoretical expectations of a slim disk, while the effective temperature profile of T ∝ R ^−0.69 for the outer zone is consistent with the predictions of a thin disk. Both profiles flatten toward the inner boundary of the disk as a result of Compton cooling in the corona. Our work presents compelling observational evidence for the existence of slim accretion disks and elucidates the key parameters governing their behavior, paving the way for further exploration in this area.

We present the third catalog release of the wide-area (31.3 deg ^2 ) Stripe 82 X-ray survey. This catalog combines previously published X-ray source properties with multiwavelength counterparts and photometric redshifts, presents 343 new spectroscopic redshifts, and provides black hole masses for 1297 Type 1 active galactic nuclei (AGN). With spectroscopic redshifts for 3457 out of 6181 Stripe 82X sources, the survey has a spectroscopic completeness of 56%. This completeness rises to 90% when considering the contiguous portions of the Stripe 82X survey with homogeneous X-ray coverage at an optical magnitude limit of r < 22. Within that portion of the survey, 23% of AGN can be considered obscured by being either a Type 2 AGN, reddened ( R − K > 4, Vega), or X-ray obscured with a column density of N _H > 10 ^22 cm ^−2 . Unlike other surveys, there is only an 18% overlap between Type 2 and X-ray obscured AGN. We calculated black hole masses for Type 1 AGN that have Sloan Digital Sky Survey spectra using virial mass estimators calibrated on the H β , Mg ii , H α , and C iv emission lines. We find wide scatter in these black hole mass estimates, indicating that statistical analyses should use black hole masses calculated from the same formula to minimize bias. We find that the AGN with the highest X-ray luminosities are accreting at the highest Eddington ratios, consistent with the picture that most black hole mass accretion happens in the phase when the AGN is luminous ( L _2−10keV > 10 ^45 erg s ^−1 ).

Low-luminosity active galactic nuclei (AGNs) with low-mass black holes (BHs) in the early universe are fundamental to understanding the BH growth and their coevolution with the host galaxies. Utilizing JWST NIRCam Wide Field Slitless Spectroscopy, we perform a systematic search for broad-line H α emitters (BHAEs) at z ≈ 4–5 in 25 fields of the A SPectroscopic survey of biased halos In the Reionization Era (ASPIRE) project, covering a total area of 275 arcmin ^2 . We identify 16 BHAEs with FWHM of the broad components spanning from ∼1000 to 3000 km s ^−1 . Assuming that the broad line widths arise as a result of Doppler broadening around BHs, the implied BH masses range from 10 ^7 to 10 ^8 M _⊙ , with broad H α -converted bolometric luminosities of 10 ^44.5 –10 ^45.5 erg s ^−1 and Eddington ratios of 0.07–0.47. The spatially extended structure of the F200W stacked image may trace the stellar light from the host galaxies. The H α luminosity function indicates an increasing AGN fraction toward the higher H α luminosities. We find possible evidence for clustering of BHAEs: two sources are at the same redshift with a projected separation of 519 kpc; one BHAE appears as a composite system residing in an overdense region with three close companion H α emitters. Three BHAEs exhibit blueshifted absorption troughs indicative of the presence of high column density gas. We find that the broad-line-selected and photometrically selected BHAE samples exhibit different distributions in the optical continuum slopes, which can be attributed to their different selection methods. The ASPIRE broad-line H α sample provides a good database for future studies of faint AGN populations at high redshift.

We report the identification of 15 galaxy candidates at z ≥ 9 using the initial COSMOS-Web JWST observations over 77 arcmin ^2 through four Near Infrared Camera filters (F115W, F150W, F277W, and F444W) with an overlap with the Mid-Infrared Imager (F770W) of 8.7 arcmin ^2 . We fit the sample using several publicly available spectral energy distribution (SED) fitting and photometric redshift codes and determine their redshifts between z = 9.3 and z = 10.9 (〈 z 〉 = 10.0), UV magnitudes between M _UV = −21.2 and −19.5 (with 〈 M _UV 〉 = −20.2), and rest-frame UV slopes (〈 β 〉 = −2.4). These galaxies are, on average, more luminous than most z ≥ 9 candidates discovered by JWST so far in the literature, while exhibiting similar blue colors in their rest-frame UV. The rest-frame UV slopes derived from SED fitting are blue ( β ∼ [−2.0, −2.7]) without reaching extremely blue values as reported in other recent studies at these redshifts. The blue color is consistent with models that suggest the underlying stellar population is not yet fully enriched in metals like similarly luminous galaxies in the lower-redshift Universe. The derived stellar masses with $\langle {\mathrm{log}}_{10}($ M _⋆ / M _⊙ )〉 ≈ 8–9 are not in tension with the standard Lambda cold dark matter (ΛCDM) model, and our measurement of the volume density of such UV-luminous galaxies aligns well with previously measured values presented in the literature at z ∼ 9–10. Our sample of galaxies, although compact, is significantly resolved.

“Changing-look” active galactic nuclei (CL-AGNs) challenge our basic ideas about the physics of accretion flows and circumnuclear gas around supermassive black holes. Using first-year Sloan Digital Sky Survey V (SDSS-V) repeated spectroscopy of nearly 29,000 previously known active galactic nuclei (AGNs), combined with dedicated follow-up spectroscopy, and publicly available optical light curves, we have identified 116 CL-AGNs where (at least) one broad emission line has essentially (dis-)appeared, as well as 88 other extremely variable systems. Our CL-AGN sample, with 107 newly identified cases, is the largest reported to date, and includes ∼0.4% of the AGNs reobserved in first-year SDSS-V operations. Among our CL-AGNs, 67% exhibit dimming while 33% exhibit brightening. Our sample probes extreme AGN spectral variability on months to decades timescales, including some cases of recurring transitions on surprisingly short timescales (≲2 months in the rest frame). We find that CL events are preferentially found in lower-Eddington-ratio ( f _Edd ) systems: Our CL-AGNs have a f _Edd distribution that significantly differs from that of a carefully constructed, redshift- and luminosity-matched control sample (Anderson–Darling test yielding p _AD ≈ 6 × 10 ^−5 ; median f _Edd ≈ 0.025 versus 0.043). This preference for low f _Edd strengthens previous findings of higher CL-AGN incidence at lower f _Edd , found in smaller samples. Finally, we show that the broad Mg ii emission line in our CL-AGN sample tends to vary significantly less than the broad H β emission line. Our large CL-AGN sample demonstrates the advantages and challenges in using multi-epoch spectroscopy from large surveys to study extreme AGN variability and physics.

This work studies the relationship between accretion-disk size and quasar properties, using a sample of 95 quasars from the Sloan Digital Sky Survey Reverberation Mapping Project with measured lags between the g and i photometric bands. Our sample includes disk lags that are both longer and shorter than predicted by the Shakura and Sunyaev model, requiring explanations that satisfy both cases. Although our quasars each have one lag measurement, we explore the wavelength-dependent effects of diffuse broad-line region (BLR) contamination through our sample’s broad redshift range, 0.1 < z < 1.2. We do not find significant evidence of variable diffuse Fe ii and Balmer nebular emission in the rms spectra, nor from Anderson–Darling tests of quasars in redshift ranges with and without diffuse nebular emission falling in the observed-frame filters. Contrary to previous work, we do not detect a significant correlation between the measured continuum and BLR lags in our luminous quasar sample, similarly suggesting that our continuum lags are not dominated by diffuse nebular emission. Similar to other studies, we find that quasars with larger-than-expected continuum lags have lower 3000 Å luminosities, and we additionally find longer continuum lags with lower X-ray luminosities and black hole masses. Our lack of evidence for diffuse BLR contribution to the lags indicates that the anticorrelation between continuum lag and luminosity is not likely to be due to the Baldwin effect. Instead, these anticorrelations favor models in which the continuum lag increases in lower-luminosity active galactic nuclei, including scenarios featuring magnetic coupling between the accretion disk and X-ray corona, and/or ripples or rims in the disk.