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Abstract We present the first results from a program searching for extended Lyαhalos around high-redshift (z ≳ 6.5) quasars using the red channel of the Keck Cosmic Web Imager (KCWI). Our observations reveal a Lyαhalo extending to ≃11 pkpc around thez= 6.64 broad absorption line quasar J0910−0414. The Lyαvelocity field displays a rotation-like gradient, and the gas velocity dispersion is consistent with gravitationally dominated motion (σ_Lyα < 300 km s⁻¹). Comparison with the [Cii] kinematics of the host galaxy core from Atacama Large Millimeter/submillimeter Array observations shows that the Lyα-emitting gas extends over a much larger region, shows distinct kinematics, and has a smaller velocity dispersion (σ_Lyα ≃ 0.6σ_{[C II]}). The Lyαspectral region of the quasar is largely obscured by a deep Nvabsorption trough, and as a result, roughly 55% of the total Lyαflux is from the extended halo. These observations demonstrate the potential of KCWI for probing the cool gas reservoir that fuels the growth of quasars and their hosts in the epoch of reionization. 

Abstract The virial coefficient (f), which is meant to encapsulate broad-line region (BLR) geometry and kinematics, remains one of the largest sources of systematic uncertainty in black hole mass estimates for active galactic nuclei (AGNs). While the use of a sample average 〈f〉 enables black hole mass estimates across large samples and cosmological distances, individual AGNs may deviate from this average due to differences in BLR structure and viewing angle. In previous work, we reported marginal evidence for a correlation betweenfand the shape of the broad Hβemission line, ${\log }_{10}(\mathrm{FWHM}/\sigma )$ . In this work, we update our sample to include 10 new sources withCARAMELBLR dynamical modeling, increasing both the black hole mass range and statistical power of our analysis. We find marginal evidence for a correlation betweenfand ${\log }_{10}(\mathrm{FWHM}/\sigma )$ , with a slope and intrinsic scatter consistent with previous results. The confirmation of this trend across a larger sample further supports the idea that line profile shape may reflect BLR properties in a way that directly impactsf. If confirmed with future BLR dynamical modeling of sources within a wider range of ${\log }_{10}(\mathrm{FWHM}/\sigma )$ , this relationship could enable empirical estimates of the virial coefficient and improve single-epoch black hole mass estimates across cosmic time. 

Abstract In this work, we present deep NIRSpec/PRISM and NIRSpec/G395M observations of J0910M0414-BHAE-1, a broad-line active galactic nucleus atz = 4.910 ± 0.003 initially discovered with NIRCam/WFSS. We detect rest-frame UV (e.g., Lyα, C iv, C iii], Mg ii) and optical (Hγ, Hβ, Hα, and [O iii]) lines. By modeling the Hαline, we measure FWHM = 3351 ± 66 km s⁻¹, implying a supermassive black hole with $\log (M_{\mathrm{BH}}/M_{\odot })=8.14\pm 0.02$ . The bolometric luminosity (from the broad Hα) is (2.23 ± 0.09) × 10⁴⁵ erg s⁻¹with an Eddington ratio of 0.11 ± 0.01. The errors do not include the ∼0.3–0.5 dex systematic uncertainty of the single-epoch virial method. Comparing the object’s spectral energy distribution to those of quasars and Little Red Dots suggests that the object bridges the gap between these classes. 

Abstract Reverberation mapping (RM) determines the mass of black holes (BHs) in active galactic nuclei (AGNs) by resolving the BH gravitational sphere of influence in the time domain. Recent RM campaigns have yielded direct BH masses through dynamical modeling for a sample of 32 objects, spanning a wide range of AGN luminosities and BH masses. In addition, accurate BH masses have been determined by spatially resolving the broad-line region with GRAVITY for a handful of AGNs. Here, we present a detailed analysis of Hubble Space Telescope images using surface-brightness profile fitting with state-of-the-art programs. We derive AGN luminosity and host-galaxy properties, such as radii and luminosities for the spheroid, disk, and bar (if present). The spheroid effective radii are used to measure stellar velocity dispersion from integral-field spectroscopy. Since the BH masses of our sample do not depend on any assumption of the virial factor needed in single-epoch spectroscopic mass estimates, we can show that the resulting scaling relations between the mass of the supermassive BHs and their host galaxies match those of quiescent galaxies, naturally extending to lower masses in these (predominantly) spiral galaxies. We find that the inner AGN orientation, as traced by the broad-line region inclination angle, is uncorrelated with the host-galaxy disk. Our sample has the most direct and accurateM_BH measurements of any AGN sample and provides a fundamental local benchmark for studies of the evolution of massive BHs and their host galaxies across cosmic time. 

Abstract The nature of ‘little red dots’ and their relation to other forms of accreting supermassive black holes remain an open question. Here we report the discovery of a little red dot atz = 7.3. It is attenuated by moderate amounts of dust,A_V = 2.79 mag, and has an intrinsic bolometric luminosity of 10^46.6 erg s⁻¹and a supermassive black hole mass of 5 × 10⁸ M_⊙. Most notably, this object is embedded in an overdensity of eight nearby galaxies, allowing us to calculate a spectroscopic estimate of the clustering of galaxies around little red dots. We find a little red dot versus galaxy cross-correlation length ofr₀ = 8 ± 2 h⁻¹ cMpc, comparable to that ofz ≈ 6 ultraviolet-luminous quasars. The resulting estimate of their minimum dark matter halo mass$$\log_{10}({M}_{{\rm{halo}},\min }/{{{M}}}_{\odot })=12.{0}_{-1.0}^{+0.8}$$ ${\log }_{10}\left(M_{\mathrm{halo},\min }/M_{\odot }\right)=12.0_{-1.0}^{+0.8}$ indicates that nearly all haloes above this mass must host actively accreting supermassive black holes atz ≈ 7, in strong contrast with the far smaller duty cycle of luminous quasars (<1%). Our results, taken at face value, motivate a picture in which supermassive black holes in little red dot phases could serve as the obscured precursors of ultraviolet-luminous quasars, which provides a natural explanation for the short ultraviolet-luminous lifetimes inferred from both quasar clustering and quasar proximity zones. 

Abstract We present optical integral-field spectroscopic data of ten nearby (0.02 ≤z≤ 0.05) Seyfert 1 galaxies taken with the Keck Cosmic Web Imager. We map the spatially resolved kinematics of the [Oiii] gas and stars, and investigate the alignments between their global kinematic position angles (PAs). Large-scale gas motions are primarily dominated by rotation and are kinematically aligned with the stars (ΔPA ≤ 30°). However, eight galaxies exhibit nonrotational kinematic signatures (e.g., kinematic twists, possible outflows) in their ionized gas velocity fields near the nucleus. We compare aperture-wide measurements of the gas and stellar velocity dispersions (σ_gasandσ_⋆) to test the use of the width of the [Oiii] line core as a surrogate forσ_⋆. Direct comparisons betweenσ_gasandσ_⋆show thatσ_gastends to underestimateσ_⋆, and thus is not a reliable tracer ofσ_⋆for our selected galaxies. We measure the extent of the narrow-line region (NLR) using several definitions, resulting in sizes of ∼0.1–10 kpc. For a given [Oiii] luminosity, our NLR sizes derived from the [Oiii]/Hβflux ratio or an [Oiii] isophotal radius are an order of magnitude larger than those measured from past imaging data. 

The origin of the tight scaling relation between the mass of supermassive black holes (SMBHs; MBH) and their host-galaxy properties remains unclear. Active galactic nuclei (AGNs) probe phases of ongoing SMBH growth and offer the only opportunity to measure MBH beyond the local Universe. However, determining an AGN's host galaxy's stellar velocity dispersion, σå, and its galaxy dynamical mass, Mdyn, is complicated by AGN contamination, aperture effects, and different host-galaxy morphologies. We select a sample of AGNs for which MBH has been independently determined to high accuracy by state-of-the-art techniques: dynamical modeling of the reverberation signal and spatially resolving the broad-line region with the Very Large Telescope Interferometer/GRAVITY. Using integral-field spectroscopic observations, we spatially map the host-galaxy stellar kinematics across the galaxy and bulge effective radii. We find that the dynamically hot component of galaxy disks correlates with MBH; however, the correlations are tightest for aperture-integrated σå measured across the bulge. Accounting for the different MBH distributions, we demonstrate—for the first time—that AGNs follow the same MBH–σ and MBH–M_bulge,dyn relations as quiescent galaxies. We confirm that the classical approach of determining the virial factor as a sample average, yielding log f = 0.65 +/- 0.18, is consistent with the average f from individual measurements. The similarity between the underlying scaling relations of AGNs and quiescent galaxies implies that the current AGN phase is too short to have altered black hole masses on a population level. These results strengthen the local calibration of f for measuring single-epoch MBH in the distant Universe. 

ABSTRACT We present optical and near-infrared (NIR) spectroscopic observations for a sample of 45 quasars at $$6.50 < z \le 7.64$$ with absolute magnitudes at 1450 Å in the range $$-28.82 \le M_{1450} \le -24.13$$ and their composite spectrum. The median redshift and $$M_{1450}$$ of the quasars in the sample are $$z_{\rm {median}}=6.71$$ and $$M_{1450,\rm {median}} \simeq -26.1$$, respectively. The NIR spectra are taken with Echelle spectrographs, complemented with additional data from optical long slit instruments, and then reduced consistently using the open-source Python-based spectroscopic data reduction pipeline PypeIt. The median of the mean signal-to-noise ratios per 110 km s$$^{-1}$$ pixel in the J, H, and K band [median $$\langle \rm {SNR}_{\lambda } \rangle$$] is median $$\langle \rm {SNR}_{J} \rangle =9.7$$, median $$\langle \rm {SNR}_{H} \rangle =10.3$$, and median $$\langle \rm {SNR}_{K} \rangle =11.7$$; demonstrating the good data quality. This work presents the largest medium-/moderate-resolution sample of quasars at $z>6.5$ from ground-based instruments. Despite the diversity in instrumental set-ups and spectral quality, the data set is uniformly processed and well-characterized, making it ideally suited for several scientific goals, including the study of the quasar proximity zones and damping wings, the Ly $$\alpha$$ forest, the intergalactic medium’s metal content, as well as other properties such as the distribution of SMBH masses and Eddington ratios. Our composite spectrum is compared to others at both high and low z from the literature, showing differences in the strengths of many emission lines, probably due to differences in luminosity among the samples, but a consistent continuum slope, which proves that the same spectral features are preserved in quasars at different redshift ranges. 

We present 0.22" resolution CO(2–1) observations of the circumnuclear gas disk in the local compact galaxy NGC 384 with the Atacama Large Millimeter/submillimeter Array (ALMA). While the majority of the disk displays regular rotation with projected velocities rising to 370 km/s, the inner ~0.5" exhibits a kinematic twist. We develop warped disk gas-dynamical models to account for this twist, fit those models to the ALMA data cube, and find a stellar mass-to-light ratio in the H-band of M/L_H = 1.34 ± 0.01 [1σ statistical] ±0.02 [systematic] M⊙/L⊙ and a supermassive black hole (BH) mass (M_BH) of M_BH = (7.26_{−0.48}^{+0.43} [1σ statistical]_{-1.00}^{+0.55} [systematic]x10^8 M⊙. In contrast to most previous dynamical M_BH measurements in local compact galaxies, which typically found over-massive BHs compared to the local BH mass−bulge luminosity and BH mass−bulge mass relations, NGC 384 lies within the scatter of those scaling relations. NGC 384 and other local compact galaxies are likely relics of z~2 red nuggets, and over-massive BHs in these relics indicate BH growth may conclude before the host galaxy stars have finished assembly. Our NGC 384 results may challenge this evolutionary picture, suggesting there may be increased scatter in the scaling relations than previously thought. However, this scatter could be inflated by systematic differences between stellar- and gas-dynamical measurement methods, motivating direct comparisons between the methods for NGC 384 and the other compact galaxies in the sample. 

Abstract We present the second iteration of thecaramel-gascode, an empirical model of the broad-line region (BLR) gas density field. Building on the initial development and testing ofcaramel-gas, we expand the meaning of the model parameterα, which initially represented only the power-law index of the dependency of emissivity on radial distance. In this work, we test a more generalized radial power-law index,α, that also includes a description of the effective emitting size(s) of the BLR structure as a function of radial distance. We select a sample of 10 active galactic nuclei (AGN) from three different Lick AGN Monitoring Project campaigns to further validate thecaramel-gascode and test the generalized radial power-law index,α. Our results confirm that thecaramel-gasresults are in general agreement with the published results determined using the originalcaramelcode, further demonstrating that our forward modeling method is robust. We find that a positive radial power-law index is generally favored and propose three possible scenarios: (i) the BLR structure has increasing effective emitting size(s) at larger radial distances from the central source, (ii) emission is concentrated at the outer edges of the BLR, and (iii) stronger theoretical assumptions are needed to break the degeneracies inherent to the interpretation of reverberation mapping data in terms of underlying gas properties.