In this contribution, we achieve the primary goal of the active galactic nucleus (AGN) STORM campaign by recovering velocity–delay maps for the prominent broad emission lines (Ly α , C iv , He ii , and H β ) in the spectrum of NGC 5548. These are the most detailed velocity–delay maps ever obtained for an AGN, providing unprecedented information on the geometry, ionization structure, and kinematics of the broad-line region. Virial envelopes enclosing the emission-line responses show that the reverberating gas is bound to the black hole. A stratified ionization structure is evident. The He ii response inside 5–10 lt-day has a broad single-peaked velocity profile. The Ly α , C iv , and H β responses extend from inside 2 to outside 20 lt-day, with double peaks at ±2500 km s −1 in the 10–20 lt-day delay range. An incomplete ellipse in the velocity–delay plane is evident in H β . We interpret the maps in terms of a Keplerian disk with a well-defined outer rim at R = 20 lt-day. The far-side response is weaker than that from the near side. The line-center delay τ = ( R / c ) ( 1 − sin i ) ≈ 5 days gives the inclination i ≈ 45°. The inferred black hole mass is M BH ≈ 7 × 10 7 M ⊙ . In addition to reverberations, the fit residuals confirm that emission-line fluxes are depressed during the “BLR Holiday” identified in previous work. Moreover, a helical “Barber-Pole” pattern, with stripes moving from red to blue across the C iv and Ly α line profiles, suggests azimuthal structure rotating with a 2 yr period that may represent precession or orbital motion of inner-disk structures casting shadows on the emission-line region farther out.

ABSTRACT We present results of time-series analysis of the first year of the Fairall 9 intensive disc-reverberation campaign. We used Swift and the Las Cumbres Observatory global telescope network to continuously monitor Fairall 9 from X-rays to near-infrared at a daily to subdaily cadence. The cross-correlation function between bands provides evidence for a lag spectrum consistent with the τ ∝ λ4/3 scaling expected for an optically thick, geometrically thin blackbody accretion disc. Decomposing the flux into constant and variable components, the variable component’s spectral energy distribution is slightly steeper than the standard accretion disc prediction. We find evidence at the Balmer edge in both the lag and flux spectra for an additional bound-free continuum contribution that may arise from reprocessing in the broad-line region. The inferred driving light curve suggests two distinct components, a rapidly variable (<4 d) component arising from X-ray reprocessing, and a more slowly varying (>100 d) component with an opposite lag to the reverberation signal.

Luminous z ≥ 7 quasars provide direct probes of the evolution of supermassive black holes (SMBHs) and the intergalactic medium (IGM) during the epoch of reionization (EoR). The Lyα damping wing absorption imprinted by neutral hydrogen in the IGM can be detected in a single EoR quasar spectrum, allowing the measurement of the IGM neutral fraction toward that line of sight. However, damping wing features have only been detected in two z > 7 quasars in previous studies. In this paper, we present new high-quality optical and near-infrared spectroscopy of the z = 7.00 quasar DES J025216.64–050331.8 obtained with Keck/Near-Infrared Echellette Spectrometer and Gemini/GMOS. By using the Mg ii single-epoch virial method, we find that it hosts a SMBH accreting at an Eddington ratio of λEdd = 0.7 ± 0.1, consistent with the values seen in other luminous z ∼ 7 quasars. Furthermore, the Lyα region of the spectrum exhibits a strong damping wing absorption feature. The lack of associated metal absorption in the quasar spectrum indicates that this absorption is imprinted by a neutral IGM. Using a state-of-the-art model developed by Davies et al., we measure a volume-averaged neutral hydrogen fraction at z = 7 of within 68% (95%) confidence intervals when marginalizing over quasar lifetimes of . This is the highest IGM neutral fraction yet measured using reionization-era quasar spectra.

Measurements of the physical properties of accretion disks in active galactic nuclei are important for better understanding the growth and evolution of supermassive black holes. We present the accretion disk sizes of 22 quasars from continuum reverberation mapping with data from the Dark Energy Survey (DES) standard-star fields and the supernova C fields. We construct continuum light curves with the griz photometry that span five seasons of DES observations. These data sample the time variability of the quasars with a cadence as short as 1 day, which corresponds to a rest-frame cadence that is a factor of a few higher than most previous work. We derive time lags between bands with both JAVELIN and the interpolated cross-correlation function method and fit for accretion disk sizes using the JAVELIN thin-disk model. These new measurements include disks around black holes with masses as small as ∼107 M⊙, which have equivalent sizes at 2500 Å as small as ∼0.1 lt-day in the rest frame. We find that most objects have accretion disk sizes consistent with the prediction of the standard thin-disk model when we take disk variability into account. We have also simulated the expected yield of accretion disk measurements under various observational scenarios for the Large Synoptic Survey Telescope Deep Drilling Fields. We find that the number of disk measurements would increase significantly if the default cadence is changed from 3 days to 2 days or 1 day.

We present geometric and dynamical modeling of the broad line region (BLR) for the multi-wavelength reverberation mapping campaign focused on NGC 5548 in 2014. The data set includes photometric and spectroscopic monitoring in the optical and ultraviolet, covering the H beta, Civ, and Ly alpha broad emission lines. We find an extended disk-like H beta BLR with a mixture of near-circular and outflowing gas trajectories, while the Civand Ly alpha BLRs are much less extended and resemble shell-like structures. There is clear radial structure in the BLR, with Civand Ly alpha emission arising at smaller radii than the H beta emission. Using the three lines, we make three independent black hole mass measurements, all of which are consistent. Combining these results gives a joint inference of log(10) (M-BH/M-circle dot) = 7.64(-0.18)(+0.21). We examine the effect of using the V band instead of the UV continuum light curve on the results and find a size difference that is consistent with the measured UV-optical time lag, but the other structural and kinematic parameters remain unchanged, suggesting that theVband is a suitable proxy for the ionizing continuum when exploring the BLR structure and kinematics. Finally, we compare the H beta results to similar models of data obtained in 2008 when the active galactic nucleus was at a lower luminosity state. We find that the size of the emitting region increased during this time period, but the geometry and black hole mass remained unchanged, which confirms that the BLR kinematics suitably gauge the gravitational field of the central black hole.

ABSTRACT We present a description of the Australian Dark Energy Survey (OzDES) and summarize the results from its 6 years of operations. Using the 2dF fibre positioner and AAOmega spectrograph on the 3.9-m Anglo-Australian Telescope, OzDES has monitored 771 active galactic nuclei, classified hundreds of supernovae, and obtained redshifts for thousands of galaxies that hosted a transient within the 10 deep fields of the Dark Energy Survey. We also present the second OzDES data release, containing the redshifts of almost 30 000 sources, some as faint as rAB = 24 mag, and 375 000 individual spectra. These data, in combination with the time-series photometry from the Dark Energy Survey, will be used to measure the expansion history of the Universe out to z ∼ 1.2 and the masses of hundreds of black holes out to z ∼ 4. OzDES is a template for future surveys that combine simultaneous monitoring of targets with wide-field imaging cameras and wide-field multi-object spectrographs.

We model the ultraviolet spectra of the Seyfert 1 galaxy NGC~5548 obtained with the Hubble Space Telescope during the 6-month reverberation-mapping campaign in 2014. Our model of the emission from NGC 5548 corrects for overlying absorption and deblends the individual emission lines. Using the modeled spectra, we measure the response to continuum variations for the deblended and absorption-corrected individual broad emission lines, the velocity-dependent profiles of Ly$\alpha$ and C IV, and the narrow and broad intrinsic absorption features. We find that the time lags for the corrected emission lines are comparable to those for the original data. The velocity-binned lag profiles of Ly$\alpha$ and C IV have a double-peaked structure indicative of a truncated Keplerian disk. The narrow absorption lines show delayed response to continuum variations corresponding to recombination in gas with a density of $\sim 10^5~\rm cm^{-3}$. The high-ionization narrow absorption lines decorrelate from continuum variations during the same period as the broad emission lines. Analyzing the response of these absorption lines during this period shows that the ionizing flux is diminished in strength relative to the far-ultraviolet continuum. The broad absorption lines associated with the X-ray obscurer decrease in strength during this same time interval. The appearance of X-ray obscuration in $\sim\,2012$ corresponds with an increase in the luminosity of NGC 5548 following an extended low state. We suggest that the obscurer is a disk wind triggered by the brightening of NGC 5548 following the decrease in size of the broad-line region during the preceding low-luminosity state.

Black hole mass measurements outside the local Universe are critically important to derive the growth of supermassive black holes over cosmic time, and to study the interplay between black hole growth and galaxy evolution. In this paper, we present two measurements of supermassive black hole masses from reverberation mapping (RM) of the broad C iv emission line. These measurements are based on multiyear photometry and spectroscopy from the Dark Energy Survey Supernova Program (DES-SN) and the Australian Dark Energy Survey (OzDES), which together constitute the OzDES RM Program. The observed reverberation lag between the DES continuum photometry and the OzDES emission line fluxes is measured to be $358^{+126}_{-123}$ and $343^{+58}_{-84}$ d for two quasars at redshifts of 1.905 and 2.593, respectively. The corresponding masses of the two supermassive black holes are 4.4 × 109 and 3.3 × 109 M⊙, which are among the highest redshift and highest mass black holes measured to date with RM studies. We use these new measurements to better determine the C iv radius−luminosity relationship for high-luminosity quasars, which is fundamental to many quasar black hole mass estimates and demographic studies.

Swift intensive accretion disk reverberation mapping of four AGN yielded light curves sampled $\sim$200-350 times in 0.3-10 keV X-ray and six UV/optical bands. Uniform reduction and cross-correlation analysis of these datasets yields three main results: 1) The X-ray/UV correlations are much weaker than those within the UV/optical, posing severe problems for the lamp-post reprocessing model in which variations in a central X-ray corona drive and power those in the surrounding accretion disk. 2) The UV/optical interband lags are generally consistent with $ \tau \propto \lambda^{4/3} $ as predicted by the centrally illuminated thin accretion disk model. While the average interband lags are somewhat larger than predicted, these results alone are not inconsistent with the thin disk model given the large systematic uncertainties involved. 3) The one exception is the U band lags, which are on average a factor of $\sim$2.2 larger than predicted from the surrounding band data and fits. This excess appears due to diffuse continuum emission from the broad-line region (BLR). The precise mixing of disk and BLR components cannot be determined from these data alone. The lags in different AGN appear to scale with mass or luminosity. We also find that there are systematic differences between the uncertainties derived by javelin vs. more standard lag measurement techniques, with javelin reporting smaller uncertainties by a factor of 2.5 on average. In order to be conservative only standard techniques were used in the analyses reported herein.

We present optical continuum lags for two Seyfert 1 galaxies, MCG+08-11-011 and NGC 2617, using monitoring data from a reverberation mapping campaign carried out in 2014. Our light curves span the ugriz filters over four months, with median cadences of 1.0 and 0.6 days for MCG+08-11-011 and NGC 2617, respectively, combined with roughly daily X-ray and near-UV data from Swift for NGC 2617. We find lags consistent with geometrically thin accretion-disk models that predict a lag-wavelength relation of τ∝λ^4/3. However, the observed lags are larger than predictions based on standard thin-disk theory by factors of 3.3 for MCG+08-11-011 and 2.3 for NGC 2617. These differences can be explained if the mass accretion rates are larger than inferred from the optical luminosity by a factor of 4.3 in MCG+08-11-011 and a factor of 1.3 in NGC 2617, although uncertainty in the SMBH masses determines the significance of this result. While the X-ray variability in NGC 2617 precedes the UV/optical variability, the long 2.6 day lag is problematic for coronal reprocessing models.

We present accretion disk size measurements for 15 luminous quasars at 0.7 ≤ z ≤ 1.9 derived from griz light curves from the Dark Energy Survey. We measure the disk sizes with continuum reverberation mapping using two methods, both of which are derived from the expectation that accretion disks have a radial temperature gradient and the continuum emission at a given radius is well described by a single blackbody. In the first method we measure the relative lags between the multiband light curves, which provides the relative time lag between shorter and longer wavelength variations. From this, we are only able to constrain upper limits on disk sizes, as many are consistent with no lag the 2σ level. The second method fits the model parameters for the canonical thin disk directly rather than solving for the individual time lags between the light curves. Our measurements demonstrate good agreement with the sizes predicted by this model for accretion rates between 0.3 and 1 times the Eddington rate. Given our large uncertainties, our measurements are also consistent with disk size measurements from gravitational microlensing studies of strongly lensed quasars, as well as other photometric reverberation mapping results, that find disk sizes that are a factor of a few (∼3) larger than predictions.

We present the first results from a reverberation-mapping campaign undertaken during the first half of 2012, with additional data on one AGN (NGC 3227) from a 2014 campaign. Our main goals are (1) to determine the black hole masses from continuum-Hbeta reverberation signatures, and (2) to look for velocity-dependent time delays that might be indicators of the gross kinematics of the broad-line region. We successfully measure Hbeta time delays and black hole masses for five AGNs, four of which have previous reverberation mass measurements. The values measured here are in agreement with earlier estimates, though there is some intrinsic scatter beyond the formal measurement errors. We observe velocity dependent Hbeta lags in each case, and find that the patterns have changed in the intervening five years for three AGNs that were also observed in 2007.

We describe the derivation and validation of redshift distribution estimates and their uncertainties for the populations of galaxies used as weak-lensing sources in the Dark Energy Survey (DES) Year 1 cosmological analyses. The Bayesian Photometric Redshift (BPZ) code is used to assign galaxies to four redshift bins between z approximate to 0.2 and approximate to 1.3, and to produce initial estimates of the lensing-weighted redshift distributions n(PZ)(i)(z) proportional to d(n)(i)/dz for members of bin i. Accurate determination of cosmological parameters depends critically on knowledge of n(i), but is insensitive to bin assignments or redshift errors for individual galaxies. The cosmological analyses allow for shifts n(i)(z) = n(PZ)(i)(z - Delta z(i)) to correct the mean redshift of n(i)(z) for biases in n(PZ)(i). The Delta z(i) are constrained by comparison of independently estimated 30-band photometric redshifts of galaxies in the Cosmic Evolution Survey (COSMOS) field to BPZ estimates made from the DES griz fluxes, for a sample matched in fluxes, pre-seeing size, and lensing weight to the DES weak-lensing sources. In companion papers, the Delta z(i) of the three lowest redshift bins are further constrained by the angular clustering of the source galaxies around red galaxies with secure photometric redshifts at 0.15 < z < 0.9. This paper details the BPZ and COSMOS procedures, and demonstrates that the cosmological inference is insensitive to details of the n(i)(z) beyond the choice of Delta z(i). The clustering and COSMOS validation methods produce consistent estimates of Delta z(i) in the bins where both can be applied, with combined uncertainties of sigma(i)(Delta z) = 0.015, 0.013, 0.011, and 0.022 in the four bins. Repeating the photo-z procedure instead using the Directional Neighbourhood Fitting algorithm, or using the n(i)(z) estimated from the matched sample in COSMOS, yields no discernible difference in cosmological inferences.