Testing Super-Eddington Accretion onto a Supermassive Black Hole: Reverberation Mapping of PG 1119+120

Abstract

We measure the black hole mass and investigate the accretion flow around the local ($z=0.0502$) quasar PG 1119+120. Spectroscopic monitoring with Calar Alto provides H$\beta$ lags and linewidths from which we estimate a black hole mass of $\log \left(M_{\bullet }/{\mathrm{M}}_{\odot }\right)=7.0$, uncertain by $\sim 0.4$ dex. High cadence photometric monitoring over two years with the Las Cumbres Observatory provides lightcurves in 7 optical bands suitable for intensive continuum reverberation mapping. We identify variability on two timescales. Slower variations on a 100-day timescale exhibit excess flux and increased lag in the $u^{\prime }$ band and are thus attributable to diffuse bound-free continuum emission from the broad line region. Faster variations that we attribute to accretion disc reprocessing lack a $u^{\prime }$-band excess and have flux and delay spectra consistent with either $\tau \propto {\lambda }^{4/3}$, as expected for a temperature structure of $T(R)\propto R^{-3/4}$ for a thin accretion disc, or $\tau \propto {\lambda }^2$ expected for a slim disc. Decomposing the flux into variable (disc) and constant (host galaxy) components, we find the disc SED to be flatter than expected with $f_{\nu }\sim \mathrm{const}$. Modelling the SED predicts an Eddington ratio of ${\lambda }_{\mathrm{Edd}}>1$, where the flat spectrum can be reproduced by a slim disc with little dust extinction or a thin disc which requires more dust extinction. While this accretion is super-Eddington, the geometry is still unclear, however a slim disc is expected due to the high radiation pressure at these accretion rates, and is entirely consistent with our observations.

arXiv comment23 pages, 16 figures, 10 tables. Accepted for publication in MNRAS

References in corpus (61)

• Astropy: A Community Python Package for Astronomy
• emcee: The MCMC Hammer
• Planck 2015 results. XIII. Cosmological parameters
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies
• Correcting for the Effects of Interstellar Extinction
• Overview of the DESI Legacy Imaging Surveys
• Methods and results of an automatic analysis of a complete sample of Swift-XRT observations of GRBs
• A Quantitative Comparison of SMC, LMC, and Milky Way UV to NIR Extinction Curves
• Revisiting the Unified Model of Active Galactic Nuclei
• The Low-Luminosity End of the Radius-Luminosity Relationship for Active Galactic Nuclei
• The Relationship Between Luminosity and Broad-Line Region Size in Active Galactic Nuclei
• The Relation Between Optical Extinction and Hydrogen Column Density in the Galaxy
• The Pan-STARRS1 Database and Data Products
• On Uncertainties in Cross-Correlation Lags and the Reality of Wavelength-Dependent Continuum Lags in Active Galactic Nuclei
• The diversity of Type II supernova versus the similarity in their progenitors
• An Alternative Approach To Measuring Reverberation Lags in Active Galactic Nuclei
• The Radiative Efficiency of Accretion Flows in Individual AGN
• Space Telescope and Optical Reverberation Mapping Project. III. Optical Continuum Emission and Broad-Band Time Delays in NGC 5548
• Testing thermal reprocessing in AGN accretion discs
• The black hole mass - stellar velocity dispersion relation of narrow-line Seyfert 1 galaxies
• A physical model of the broadband continuum of AGN and its implications for the UV/X relation and optical variability
• An Atlas of Galaxy Spectral Energy Distributions from the Ultraviolet to the Mid-Infrared
• Supermassive black holes with high accretion rates in active galactic nuclei: I. First results from a new reverberation mapping campaign
• On the use of C-stat in testing models for X-ray spectra
• Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. IV. H$\beta$ Time Lags and Implications for Super-Eddington Accretion
• Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. IX 10 New Observations of Reverberation Mapping and Shortened H$\beta$ Lags
• The First Swift Intensive AGN Accretion Disk Reverberation Mapping Survey
• The Radius-Luminosity Relationship Depends on Optical Spectra in Active Galactic Nuclei
• Bolometric correction factors for Active Galactic Nuclei
• Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. V. A New Size-Luminosity Scaling Relation for the Broad-Line Region
• Swift monitoring of NGC 4151: Evidence for a Second X-ray/UV Reprocessing
• The Structure of the Broad-Line Region In Active Galactic Nuclei. II. Dynamical Modeling of Data from the AGN10 Reverberation Mapping Campaign
• General relativistic modelling of the negative reverberation X-ray time delays in AGN
• Self-shadowing Effects of Slim Accretion Disks in Active Galactic Nuclei: Diverse Appearance of the Broad-line Region
• Super-Eddington accreting massive black holes as long-lived cosmological standards
• Super-Eddington Accretion and Feedback from the First Massive Seed Black Holes
• Quantifying the impact of variable BLR diffuse continuum contributions on measured continuum inter-band delays
• Intensive disc-reverberation mapping of Fairall 9: 1st year of Swift & LCO monitoring
• Space Telescope and Optical Reverberation Mapping Project VI: reverberating Disk Models for NGC 5548
• Quantifying the Diffuse Continuum Contribution of BLR Clouds to AGN Continuum Inter-band Delays
• Supermassive black holes with high accretion rates in active galactic nuclei. XI. Accretion disk reverberation mapping of Mrk 142
• Modeling the UV/optical continuum time-lags in AGN
• Accretion Disc Time Lag Distributions: Applying CREAM to Simulated AGN Light Curves
• UV/optical disk thermal reverberation in AGN: an in-depth study with an analytic prescription for the time-lag spectra
• Conditions for Optimal Growth of Black Hole Seeds
• The Sloan Digital Sky Survey Reverberation Mapping Project: The H$\beta$ Radius-Luminosity Relation
• The Fundamental Plane of the Broad-line Region in Active Galactic Nuclei
• Optical/Near-Infrared Imaging of Infrared-Excess Palomar-Green QSOs
• On the multi-wavelength variability of Mrk 110: Two components acting at different timescales
• Modelling the spectral energy distribution of super-Eddington quasars
• Testing broad line region models with Reverberation Mapping
• An ALMA CO(2-1) Survey of Nearby Palomar-Green Quasars
• Evidence that most type 1 AGN are reddened by dust in the host ISM
• Frequency-resolved lags in UV/optical continuum reverberation mapping
• Accretion Disk Size Measurements of Active Galactic Nuclei Monitored by the Zwicky Transient Facility
• The Spectral Energy Distributions of Active Galactic Nuclei
• The Spectral Energy Distributions of Active Galactic Nuclei
• Bayesian Analysis of Quasar Lightcurves with a Running Optimal Average: New Time Delay Measurements of COSMOGRAIL Gravitationally Lensed Quasars
• Testing the X-ray reverberation model KYNREFREV in a sample of Seyfert 1 Active Galactic Nuclei
• Twisted quasar light curves: implications for continuum reverberation mapping of accretion disks

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