Linking quasars to their dark matter environments provides critical insights into the formation and early growth of supermassive black holes (SMBHs). We present JWST observations of the environments surrounding two high-redshift quasars, J0252-0503 at z = 7.0 and J1007+2115 at z = 7.5, which enable the first constraints on quasar-galaxy clustering at z similar or equal to 7.3. Galaxies in the vicinity of the quasars were selected through ground-based and JWST/NIRCam imaging and were then spectroscopically confirmed with JWST/NIRSpec using the multi-shutter assembly (MSA). Over both fields, we identified 51 z > 5 galaxies, of which eight are found within a Delta v(LOS) = +/- 1500 km s(-1) line-of-sight velocity window from the quasars and another eight in the background. The galaxy J0252_8713, located just 7 pkpc and Delta v(LOS) approximate to 360 km s(-1) from quasar J0252-0503, emerges as a compelling candidate for one of the most distant quasar-galaxy mergers. Combining the galaxy discoveries over the two fields, we measured the quasar-galaxy cross-correlation and obtain a correlation length of r(0)(QG) approximate to 7.6(-1.6)(+1.7) h(-1) cMpc, based on a power-law model with a fixed slope of gamma(QG) = 2.0. Under the assumption that quasars and galaxies trace the same underlying dark matter density fluctuations, we infer a minimum dark matter halo mass for z similar or equal to 7.3 quasars of log(10)(M-halo,M-min/M-circle dot) = 11.6(-0.7)(+0.6) in a halo model framework. Compared to measurements from EIGER at < z > = 6.25 and ASPIRE at < z > = 6.7 (where log(10)(M-halo,M- min/M-circle dot)greater than or similar to 12.1), our clustering results provide tentative evidence for a nonmonotonic redshift evolution of quasar clustering properties. We further estimate a quasar duty cycle of f(duty) approximate to 0.05%, consistent with constraints from quasar proximity zones and intergalactic medium (IGM) damping wings. However, this implies very short phases of quasar activity, exacerbating the challenge to build billion solar mass SMBHs in only 700 Myr of cosmic time.

Little Red Dots (LRDs) are a population of compact red sources discovered by the James Webb Space Telescope (JWST). Imaging and spectroscopy have shown that LRDs exhibit a complex spectrum with a “V-shaped" continuum, broad Balmer emission lines, and in some cases Balmer absorption. While the physical origin of these components remains debated, recent studies propose that they arise from a compact central engine likely hosting a rapidly growing black hole embedded within a more extended host galaxy. We test this central engine + host galaxy model using JWST/NIRSpec integral field unit (IFU) spectroscopy to spectrally decompose the observed continuum, narrow and broad emission lines, and absorption. We spatially map each component for five broad Ha-selected LRDs at z 5 observed with both the prism and high-resolution G395H grating. We find that the blue continuum emission is co-spatial with the narrow emission line region, while the red continuum arises from a compact core co-spatial with the broad Balmer emission and absorption. Spatial maps of the [OIII] equivalent width reveal a pronounced decrease in the central core. Our work provides further evidence that the LRD emission is produced by at least two distinct physical components arising from a red central engine embedded within a blue host galaxy.

The abundant population of little red dots (LRDs), compact objects with red UV to optical colors and broad Balmer lines at high redshift, is revealing new insights into the properties of early active galactic nuclei (AGN). Perhaps the most surprising features of this population are the presence of Balmer absorption and ubiquitous strong Balmer breaks. Recent models link these features to an active supermassive black hole (SMBH) cocooned in very dense gas ( N H ∼ 10 24 cm −2 ). We present a stringent test of such models using VLT/MUSE observations of A2744-45924, the most luminous LRD known to date ( L H α ≈ 10 44 erg s −1 ), located behind the Abell-2744 lensing cluster at z = 4.464 ( μ = 1.8). We detect a moderately extended Ly α nebula ( h ≈ 5.7 pkpc), spatially offset from the point-like H α seen by JWST by ≈1.6 pkpc. The Ly α emission is narrow (FWHM = 270 ± 15 km s −1 ), and faint (Ly α = 0.07H α ) compared to Ly α nebulae typically observed around quasars of similar luminosity. We detect compact N IV ] λ 1486 emission, spatially aligned with H α , and a spatial shift in the far-UV continuum matching the Ly α offset. We discuss that H α and Ly α have distinct physical origins: H α originates from the AGN, while Ly α is powered by star formation. In the environment of A2744-45924, we identified four extended Ly α halos (Δ z < 0.02, Δ r < 100 pkpc). Their Ly α luminosities match the expectations based on H α emission, and show no evidence for radiation from A2744-45924 affecting its surroundings. The lack of strong, compact, and broad Ly α and the absence of a luminous extended halo, suggest that the UV AGN light is obscured by dense gas cloaking the SMBH with a covering factor close to unity.

Little Red Dots (LRDs) are a population of compact, red sources that have emerged as one of the most puzzling findings of JWST. Variability provides a direct probe of their central engines. Here we present the first joint spectroscopic and photometric time-domain study of LRDs undertaken with the JWST TWINKLE slitless spectroscopy program. Surveying the FRESCO GOODS-North legacy field, TWINKLE monitors a complete, Hα-flux-limited sample of 18 LRDs at z = 3.9-6.8, achieving a rest-frame baseline of ∼140-220 days. We detect no variability in photometry, Hα line flux, or line shape across the sample. If LRDs resembled AGN in reverberation mapping samples – the foundation for black hole mass calibrations and luminosity scaling relations – we would expect >10 sources to show measurable fluctuations. Observing none implies a 5.9σ deficit. The non-detections hold across all broad Hα emitters within TWINKLE's field of view – the 18 V-shaped LRDs as well as 9 non-LRDs. Comparison with simulated light curves disfavors sub-Eddington accretion and is instead consistent with super-Eddington accretion, other mechanisms that suppress variability, or perhaps no AGN whatsoever. If LRDs do harbor black holes, calibrations derived from sub-Eddington systems may not apply, thereby explaining JWST's apparently "overmassive" black holes. These observations provide unique constraints on the physics of one of the most enigmatic populations discovered by JWST.

The population of the little red dots (LRDs) may represent a key phase of supermassive black hole (SMBH) growth. A cocoon of dense excited gas is emerging as a key component to explain the most striking properties of LRDs, such as strong Balmer breaks and Balmer absorption, as well as the weak IR emission. To dissect the structure of LRDs, we analyzed new deep JWST/NIRSpec PRISM and G395H spectra of FRESCO-GN-9771, one of the most luminous known LRDs at z = 5.5. These spectra reveal a strong Balmer break, broad Balmer lines, and very narrow [O III] emission. We revealed a forest of optical [Fe II] lines, which we argue are emerging from a dense (nH = 109 − 10 cm−3) warm layer with electron temperature Te ≈ 7000 K. The broad wings of Hα and Hβ have an exponential profile due to electron scattering in this same layer. The high Hα : Hβ : Hγ flux ratio of ≈10.4 : 1 : 0.14 is an indicator of collisional excitation and resonant scattering dominating the Balmer line emission. A narrow Hγ component, unseen in the other two Balmer lines due to outshining by the broad components, could trace the ISM of a normal host galaxy with a star formation rate of ∼5 M⊙ yr−1. The warm layer is mostly opaque to Balmer transitions, producing a characteristic P Cygni profile in the line centers suggesting outflowing motions. This same layer is responsible for shaping the Balmer break. The broadband spectrum can be reasonably matched by a simple photoionized slab model that dominates the λ > 1500 Å continuum and a low-mass (∼108 M⊙) galaxy that could explain the narrow [O III], with only a subdominant contribution to the UV continuum. Our findings indicate that Balmer lines are not directly tracing the gas kinematics near the SMBH and that the BH mass scale is likely much lower than virial indicators suggest.

The central engines of Little Red Dots (LRDs) may be “black hole stars" (BH*s), early stages of black hole growth characterized by dense gas envelopes. So far, the most direct evidence for BH*s comes from a handful of sources where the host galaxy is completely outshone as suggested by their remarkably steep Balmer breaks. Here we present a novel scheme to disentangle BH*s from their host galaxies assuming that the [OIII]5008Å line arises exclusively from the host. Using a sample of 98 LRDs (z 2-9) with high quality NIRSpec/PRISM spectra, we demonstrate that the host-subtracted median stack displays a Balmer break >2× stronger than massive quiescent galaxies, with the rest-optical continuum resembling a blackbody-like SED (T_eff 4050 K, log(L_bol) 43.9 erg s^-1, R_eff 1300 au). We measure a steep Balmer decrement (Hα/Hβ>10) and numerous density-sensitive features (e.g., FeII, HeI, OI). These are hallmark signatures of dense gas envelopes, providing population-level evidence that BH*s indeed power LRDs. In the median LRD, BH*s account for ∼20% of the UV emission, ∼50% at the Balmer break, and ∼90% at wavelengths longer than Hα with the remainder arising from the host. BH*s preferentially reside in low-mass galaxies (M_⋆ 10^8 M_⊙) undergoing recent starbursts, as evidenced by extreme emission line EWs (e.g., [OIII]5008Å 1100Å, CIII] 12Å), thereby favoring BH* origins linked to star-formation. We show V-shaped LRD selections are biased to high BH*/host fractions (≳60% at 5500Å) – less dominant BH*s may be powering JWST's blue broad-line AGN. We find BH*s are so commonplace and transient (duty cycle ∼1%, lifetime ∼10 Myrs) that every massive black hole may have once shone as a BH*.

Obscured active galactic nuclei (AGN) are often invoked to explain the rapid emergence of young quasars at high redshift and are crucial for building a complete census of AGN activity and black hole growth. The advent of the James Webb Space Telescope (JWST) extends the discovery space for obscured AGN into the mid-infrared (mid-IR) with unprecedented precision through reprocessed dust emission. In this work, we use deep JWST Mid-Infrared Instrument (MIRI) imaging from the MIRI Early Obscured AGN Wide Survey (MEOW), together with existing JWST Near Infrared Camera (NIRCam), spectroscopic, and Hubble Space Telescope imaging data, to identify a previously unrecognized population of obscured AGN out to z 6. Using spectral energy distribution (SED) modeling of the MIRI-detected sources, we identify 883 AGN over an area of 131 arcmin2 and construct the AGN bolometric luminosity function, including both obscured and unobscured sources, across five redshift bins. We find an excess in AGN abundance relative to UV-selected AGN luminosity functions, indicating a substantial obscured population missed by optical/UV surveys, with the inferred obscured fraction increasing with redshift and reaching 98-99

JWST data have enabled the abundant identification of compact broad Balmer line sources nicknamed the Little Red Dots. While they share broad lines with active galactic nuclei, they are unusually X-ray and infrared weak. We investigate the origin of the Balmer line profiles based on an empirical analysis of 18 broad Hα-selected sources with high quality spectra at z≈3-7. The Hα line profiles vary systematically with Balmer break strength: sources with blue UV to optical colors show a narrow core profile, redder sources with Balmer breaks a blue shifted absorption (P Cygni shape), and the reddest sources display absorption-dominated cores. All Hα lines have symmetric exponential wings, which are more dominant and slightly broader in red sources. Balmer absorption is present in ∼60

Luminous quasars at the redshift frontier z > 7 serve as stringent probes of super-massive black hole (SMBH) formation and they are thought to undergo much of their growth obscured by dense gas and dust in their host galaxies. Fully characterizing the symbiotic evolution of SMBHs and hosts requires rest-frame optical observations that span spatial scales from the broad-line region (BLR) to the interstellar and circumgalactic medium (ISM and CGM). The James Webb Space Telescope (JWST) now provides the necessary spatially resolved spectroscopy to do so. However, the physical conditions that regulate the interplay between SMBHs and their hosts at the highest redshifts, especially the nature of early feedback phases, remain unclear. We present JWST/NIRSpec integral field unit (IFU) observations of J0313-1806 at z = 7.64, the most distant luminous quasar known. From the rest-frame optical spectrum of the unresolved quasar, we derived a black hole mass of M-BH = (1.63 +/- 0.10)& times;10(9) M-circle dot based on H beta lambda 4861 (H beta) and an Eddington rate of lambda = L/L-Edd = 0.80 +/- 0.05, consistent with previous Mg II lambda 2800-based estimates. J0313-1806 exhibits no detectable [O III] lambda lambda 4959, 5007 emission on nuclear scales (3 sigma upper limit equivalent width of [O III] lambda 5007 < 1.42 & Aring;). Most remarkably, we did detect an ionized gas shell extending out to similar to 1.8 kpc traced by H beta emission that also lacks any significant [O III] lambda lambda 4959, 5007, with a 3 sigma upper limit on the [O III] lambda 5007 to H beta flux ratio of log(10)(F([O III])/F(H beta)) = -1.15. Through photoionization modeling, we demonstrate that the extended emission is consistent with a thin, clumpy outflowing shell where [O III] is collisionally de-excited by dense gas. We interpret this structure as a fossil remnant of a recent blowout phase, providing evidence for episodic feedback cycles in one of the earliest quasars. These findings suggest that dense ISM phases may play a crucial role in shaping the spectral properties of quasars across cosmic time.

Close quasar pairs are rare products of galaxy mergers in which both supermassive black holes (SMBHs) are actively accreting, offering strong constraints on merger-driven active galactic nuclei evolution. Identifying close quasar pairs at z greater than or similar to 4 is challenging due to the declining quasar number density in the early Universe. Here we report the confirmation of a close quasar pair at z = 5.7, J2037-4537, utilizing high-resolution Atacama Large Millimeter/submillimeter Array observations. The quasar host galaxies exhibit tidal disturbed features in both the far-infrared continuum emission and the [C ii] line emission, ruling out the doubly imaged lensed quasar scenario. The two quasar hosts are massive (M-dyn greater than or similar to 10(10)M(circle dot)) and star-forming (star formation rate greater than or similar to 500M(circle dot) yr(-1)). The confirmation of J2037-4537 puts a lower limit on the quasar pair fraction at 5.5 < z < 6, F-pair > 1.2%, which is much higher than the quasar pair fraction at z less than or similar to 4. J2037-4537 is expected to form a gravitationally bound SMBH binary within less than or similar to 2 Gyr. The elevated quasar pair fraction at z > 5.5, as indicated by J2037-4537, likely contributes to the high gravitational-wave background reported by recent pulsar timing array experiments.

We investigate the association between galaxies and neutral O i absorption systems at z similar to 6, which trace metal-enriched gas during the epoch of reionization. We identify 40 galaxies across six quasar fields, residing in 15 overdensities within 300 kpc of the background sight lines. Five O i absorption systems are associated with five of these overdensities, yielding a covering fraction of 0.27-0.10+0.13 within 300 kpc. The absorption occurs beyond typical virial radii, indicating that the gas traces extended overdensity environments rather than individual galaxy halos, unlike the z similar to 0 circumgalactic medium (CGM), which is largely bound to halos. These galaxy-associated absorbers account for similar to 35% of all O i systems seen in blind quasar surveys, implying the remainder arise in lower-mass galaxies below our detection threshold or in dense neutral intergalactic medium pockets. The CGM around these galaxies contains greater than or similar to 2 & times; 106 M circle dot of oxygen, comparable to the interstellar medium oxygen mass of the galaxies themselves, suggesting that the surrounding environment holds as much metal mass as the galaxies. All five galaxy-associated systems show significantly higher log(NCII/NOI) ratios than absorbers lacking galaxy associations. Furthermore, relative abundance ratios ([Si/O], [C/O]) reveal that four of the five exhibit enrichment patterns consistent with Population III nucleosynthesis at the outskirts of galaxy overdensities. These rare systems offer a unique window into the role of first-generation stars in shaping the early metal enrichment of galaxies and their environments.

Thus far, Lyman-alpha damping wings towards quasars have been used to probe the global ionization state of the foreground intergalactic medium (IGM). A new parametrization has demonstrated that the damping wing signature also carries local information about the distribution of neutral hydrogen (HI) in front of the quasar before it started shining. Leveraging a recently introduced Bayesian JAX-based Hamiltonian Monte Carlo inference framework, we derive constraints on the Lorentzian-weighted HI column density N-H I(DW), the quasar's distance r(patch) to the first neutral patch, and its lifetime t(Q) based on James Webb Space Telescope (JWST) Near Infrared Spectrograph (NIRSpec) spectra of the two z similar to 7.5 quasars J1007+2115 and J1342+0928. After folding in model-dependent topology information, we find that J1007+2115 (and J1342+0928) is most likely to reside in a < x(HI)> = 0.32(-0.23)(+0.23)(0.58(-0.23)(+0.23)) neutral IGM while shining for a remarkably short lifetime of log(10) t(Q)/yr = 4.14(-0.18)(+0.74) (an intermediate lifetime of 5.64(-0.43)(+0.25)) along a sightline with log(10) N-HI(DW) /cm(-2) = 19.70(-0.86)(+0.35) (20.24(-0.22)(+0. 25) ) and r(patch) = 28.9(-14.4)(+54.0) cMpc (10.9(-5.9)(+5.6) cMpc). In light of the potential presence of local absorbers in the foreground of J1342+0928 as has been recently suggested, we also demonstrate how the Lorentzian-weighted column density N-HI(DW) provides a natural means for quantifying their contribution to the observed damping wing signal.

We present a systematic study of the environments of 25 luminous quasars at z > 6.5 from the ASPIRE program. Using JWST/NIRCam wide-field slitless spectroscopy data, we identified 487 galaxies at 5.3 less than or similar to z less than or similar to 7.0 exhibiting [O III] emission. Among these, 122 [O III] emitters lie within divided by Delta v(los)divided by < 1000 km s(-1) of the quasars, corresponding to a similar to 9.4-fold enhancement relative to the average galaxy density at other redshifts. Furthermore, we identified 16 [C II]-emitting galaxies at the quasar redshifts from Atacama Large Millimeter/submillimeter Array (ALMA) mosaic observations. A cross-correlation function analysis between quasars and [O III]+[C II] emitters yields a cross-correlation length of r(0)(QG) = 8.68 (+ 0.51)(-0.55) h(-1) cMpc and an autocorrelation of r(0)(QQ )= 15.7 6(- 2.70 )(+2.48) h(-1 )cMpc , indicating that z similar to 7 quasars reside in dark matter halos with M-halo = 10(12.27) (-0.26) (+0.21) M circle dot and have a quasar lifetime of t(Q) = 10 (7.05 )(-1.01) (+0.95 )yr . Notably, the number of [O III]-emitting galaxies at quasar redshifts varies significantly from field to field, ranging from 0 to 20, highlighting a diverse quasar environment. Remarkably, seven quasars trace significant galaxy overdensities (i.e., protoclusters), with delta(gal) > 5 within a volume of V similar to 500 cMpc(3). We also find that divided by Delta v(los)divided by increases rapidly toward smaller galaxy-quasar separations in protocluster fields, consistent with galaxy kinematics around extremely massive halos in cosmological simulations. By combining JWST and ALMA data, we reveal the complex and diverse environments of these early quasars, providing robust evidence that the earliest luminous quasars are effective tracers of galaxy overdensities, albeit with substantial field-to-field variation.

In the nearby universe, quasars are well known to exhibit variability in their brightness over time, offering a powerful tool to probe the physics of accretion onto the supermassive black hole (SMBH) and directly measure the mass of the SMBH. However, detecting variability in early quasars remains challenging. Here we report the detection of multiwavelength infrared and X-ray variability in a quasar observed just 850 million years after the Big Bang. The infrared variability spans five filters, tracing rest-frame ultraviolet and optical emission from the accretion disk, while the X-ray variability probes the corona. The variable spectrum reveals that the accretion disk has a geometrically thin, optically thick structure. This provides observational constraints on the accretion disk structure at early times, when quasars are accreting at high Eddington ratios and reside in extreme environments. Our findings demonstrate the feasibility of characterizing accretion physics using variability in the early universe, laying the groundwork for studies exploiting upcoming facilities such as the Rubin Observatory and Roman Space Telescope. These facilities will discover large samples of variable high-redshift quasars, enabling population-level variability studies of accretion physics and black hole masses, filling key missing ingredients in understanding early SMBH growth.

High-redshift active galactic nuclei (AGN) serve as powerful probes of early black-hole growth, galaxy formation, and the evolving intergalactic medium (IGM). In this work, we use Lumina, a cosmological radiation-hydrodynamic simulation spanning the epochs of hydrogen and helium reionization, which combines a large (500 cMpc)^3 volume with 2× 6000^3 resolution elements, to explore high-redshift AGN. The simulation self-consistently follows hundreds of millions of galaxies and supermassive black holes (SMBHs), together with their impact on the ionization and thermal state of the IGM. We exploit this uniquely large dynamic range to predict multi-band AGN luminosity functions (LFs) at z ≥ 3, from hard X-rays to the mid-infrared. These predictions encompass both moderately luminous quasars and the faint “Little Red Dots” (LRDs) uncovered by JWST. We develop an empirical model that maps simulated SMBHs onto observed AGN using bolometric and extinction/absorption corrections for canonical AGN and LRDs, and in which SMBHs with M_ BH≤ 10 M_ seed∼ 10^7 M_⊙ stay in the LRD phase with a duty cycle of 30%. This simple framework reproduces the observed LFs and clustering of LRDs. Meanwhile, the pre-JWST quasar LF constraints are recovered, although we find that a ∼ 0.3 dex log-normal scatter in bolometric luminosity is required to reproduce the bright end. We place the simulated AGN population in the cosmological context by quantifying the redshift evolution of AGN and LRD number densities, and their contributions to the integrated BH mass densities. The same AGN population is the dominant driver for the HeII reionization modelled self-consistently in Lumina. This empirical AGN model paves the way for general population-synthesis models of high-redshift AGN, including LRDs, in a unified cosmological framework.

The abundant population of little red dots (LRDs), compact objects with red UV to optical colors and broad Balmer lines at high redshift, is revealing new insights into the properties of early active galactic nuclei (AGN). Perhaps the most surprising features of this population are the presence of Balmer absorption and ubiquitous strong Balmer breaks. Recent models link these features to an active supermassive black hole (SMBH) cocooned in very dense gas (N-H similar to 10(24) cm(-2)). We present a stringent test of such models using VLT/MUSE observations of A2744-45924, the most luminous LRD known to date (L-H alpha approximate to 10(44) erg s(-1)), located behind the Abell-2744 lensing cluster at z = 4.464 (mu = 1.8). We detect a moderately extended Ly alpha nebula (h approximate to 5.7 pkpc), spatially offset from the point-like H alpha seen by JWST by approximate to 1.6 pkpc. The Ly alpha emission is narrow (FWHM = 270 +/- 15 km s(-1)), and faint (Ly alpha = 0.07H alpha) compared to Ly alpha nebulae typically observed around quasars of similar luminosity. We detect compact N IV]lambda 1486 emission, spatially aligned with H alpha, and a spatial shift in the far-UV continuum matching the Ly alpha offset. We discuss that H alpha and Ly alpha have distinct physical origins: H alpha originates from the AGN, while Ly alpha is powered by star formation. In the environment of A2744-45924, we identified four extended Ly alpha halos (Delta z < 0.02, Delta r < 100 pkpc). Their Ly alpha luminosities match the expectations based on H alpha emission, and show no evidence for radiation from A2744-45924 affecting its surroundings. The lack of strong, compact, and broad Ly alpha and the absence of a luminous extended halo, suggest that the UV AGN light is obscured by dense gas cloaking the SMBH with a covering factor close to unity.

The existence of abundant post-starburst and quiescent galaxies just about 1-2 Gyr after the Big Bang challenges our current model of galaxy evolution1-3. Cosmological simulations suggest that quasar feedback is likely the most promising mechanism responsible for this rapid quenching4-6. Here we report a high detection rate (6/27) of exceptionally fast and powerful galaxy-scale outflows traced by [O III] emission in z ≈ 5-6 luminous quasars as shown by the James Webb Space Telescope, with velocity up to about 8,400 km s-1 and order-of-magnitude kinetic energy outflow rates up to around 260% of the observed quasar bolometric luminosities. This fraction is >3.9 and 8.8 times that in comparison samples at z ≈ 1.5-3.5 and z < 1, respectively. These extreme outflows are comparable to or even faster than the most rapid [O III] outflows reported at z ≲ 3, and could reach the circumgalactic medium or even the intergalactic medium. The average kinetic energy outflow rate of our sample is more than 2 dex higher than that of the lower-redshift comparison samples. The substantially higher frequency of outflows with energetics well above the threshold for negative feedback in our sample strongly suggests that quasar feedback plays an important part in efficiently quenching and regulating early massive galaxies.

We present near-infrared spectroscopy of 21 quasars at 6.07 < z < 6.90 obtained with JWST/NIRSpec and Subaru/MOIRCS. These targets have absolute ultraviolet magnitudes of -25 < M_1450 < -22 and are drawn from a sample of z>6 quasars identified in the Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) project. These quasars occupy the intermediate-luminosity regime between luminous quasars and the faint high-redshift AGNs uncovered by JWST. We detect broad Balmer emission lines and MgII 2798 with underlying continua from the NIRSpec and MOIRCS targets, respectively. The virial black hole masses of this sample span a wide range of 7.2 < log M_BH/M_sun < 9.4, with Eddington ratios of -1.3 < log L_bol/L_Edd < 0.4. Combining these measurements with our previous mass estimates for other SHELLQs quasars, we construct a sample of 27 quasars with M_BH estimates at 6 < z < 7 and derive the distributions of M_BH and L_bol/L_Edd. When compared with luminosity-matched quasars at z 1.3, we find median offsets of delta log M_BH/M_sun = -0.4 and Delta log L_bol/L_Edd = 0.2 in the high-redshift sample. In addition, 11

We present JWST Cycle 2 NIRCam and NIRSpec observations in a quasar field J0226+0302 at z=6.5412 to probe the direct connections between the intergalactic medium (IGM), galaxies, and AGN during reionization. This field was previously observed by the JWST ASPIRE program and eight [OIII]-emitting galaxies were detected at 5.3<z<6.4 with a single NIRCam pointing. Using new NIRCam and NIRSpec observations, we identify 65 additional line-emitting galaxies at 5.3<z<6.4. The IGM-galaxy cross-correlation function shows a ~2 sigma excess IGM transmission at ~10-40 cMpc from galaxies when compared with the average IGM transmission, suggesting a significant contribution from regions traced by star-forming galaxies to the local ionizing background during reionization. The IGM-galaxy cross-correlation function is consistent with THESAN simulations with an IGM neutral fraction of 5%-7% and an average ionizing photon escape fraction f_esc of 6% from galaxies. Among 49 line-emitting galaxies observed by NIRSpec, we identify four AGN through detection of broad H-alpha emission lines with an AGN fraction of (8+/-4)%. By measuring the IGM effective optical depth around the AGN and the IGM-AGN cross-correlation function, we find that the IGM transmission is higher within 5 cMpc/h of the AGN than around the majority of [OIII] emitters. We interpret the excess IGM transmission as resulting from the local radiation enhancement by the AGN, and estimate f_esc of 50%-100% of the AGN from the IGM-AGN cross-correlation function. Future JWST NIRSpec observations in quasar fields will yield a more constraining IGM-AGN cross-correlation function, providing further insights into the roles of galaxies and AGN in reionization.

Measurements of quasar lifetimes at high redshift indicate that the earliest billion-solar-mass supermassive black holes (SMBHs) have only been active as luminous quasars for less than a million years. Recently, extended Ly alpha nebulae around z similar to 6 quasars have revealed that these short observed lifetimes are unlikely to be a sight-line-dependent effect. However, the interpretation of Ly alpha emission is not straightforward due to its resonant nature. In this work, we use rest-frame optical emission lines, which more directly trace photoionization by the quasar, to unambiguously validate the short line-of-sight quasar lifetimes observed at early cosmic epochs. We use deep James Webb Space Telescope/NIRSpec integral field unit observations of five z similar to 6 quasars with small proximity zones to search for their extended emission line nebulae in H alpha and [O III]5007, and detect extended emission in both emission lines around four quasars in our sample. We then use the light-crossing time of these nebulae to measure quasar lifetimes along transverse sight lines. Using their H alpha nebulae, we also confirm that recombination is likely the dominant emission mechanism behind their previously detected Ly alpha nebulae. Our results confirm the existence of high-redshift quasars with extremely short lifetimes, tQ less than or similar to 105 yr, hosting billion-solar-mass black holes, indicating that rapid or obscured accretion is likely responsible for the assembly of SMBHs in the early Universe.