AGN STORM 2: II. Ultraviolet Observations of Mrk817 with the Cosmic Origins Spectrograph on the Hubble Space Telescope

Abstract

We present reverberation mapping measurements for the prominent ultraviolet broad emission lines of the active galactic nucleus Mrk817 using 165 spectra obtained with the Cosmic Origins Spectrograph on the Hubble Space Telescope. Our ultraviolet observations are accompanied by X-ray, optical, and near-infrared observations as part of the AGN Space Telescope and Optical Reverberation Mapping Program 2 (AGN STORM 2). Using the cross-correlation lag analysis method, we find significant correlated variations in the continuum and emission-line light curves. We measure rest-frame delayed responses between the far-ultraviolet continuum at 1180 A and Ly$\alpha$ $\lambda 1215$ A ($10.4_{-1.4}^{+1.6}$ days), N V $\lambda 1240$ A ($15.5_{-4.8}^{+1.0}$days), SiIV + OIV] $\lambda 1397$ A ($8.2_{-1.4}^{+1.4}$ days), CIV $\lambda 1549$ A ($11.8_{-2.8}^{+3.0}$ days), and HeII $\lambda 1640$ A ($9.0_{-1.9}^{+4.5}$ days) using segments of the emission-line profile that are unaffected by absorption and blending, which results in sampling different velocity ranges for each line. However, we find that the emission-line responses to continuum variations are more complex than a simple smoothed, shifted, and scaled version of the continuum light curve. We also measure velocity-resolved lags for the Ly$\alpha$, and CIV emission lines. The lag profile in the blue wing of Ly$\alpha$ is consistent with virial motion, with longer lags dominating at lower velocities, and shorter lags at higher velocities. The CIV lag profile shows the signature of a thick rotating disk, with the shortest lags in the wings, local peaks at $\pm$ 1500 $\mathrm{km}{\mathrm{s}}^{-1}$, and a local minimum at line center. The other emission lines are dominated by broad absorption lines and blending with adjacent emission lines. These require detailed models, and will be presented in future work.

arXiv commentSubmitted to ApJ. 25 pages, 8 figures, and 6 tables

References in corpus (80)

• A Fundamental Relation Between Supermassive Black Holes and Their Host Galaxies
• The Demography of Massive Dark Objects in Galaxy Centres
• A Relationship Between Nuclear Black Hole Mass and Galaxy Velocity Dispersion
• Energy input from quasars regulates the growth and activity of black holes and their host galaxies
• Central Masses and Broad-Line Region Sizes of Active Galactic Nuclei. II. A Homogeneous Analysis of a Large Reverberation-Mapping Database
• First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole
• A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies: I. Galaxy Mergers & Quasar Activity
• The M-sigma and M-L Relations in Galactic Bulges and Determinations of their Intrinsic Scatter
• Are the Variations in Quasar Optical Flux Driven by Thermal Fluctuations?
• Supermassive Black Holes in Active Galactic Nuclei. II. Calibration of the M-sigma Relationship for AGNs
• The Cosmic Origins Spectrograph
• The Accelerations of Stars Orbiting the Milky Way's Central Black Hole
• First Sagittarius A* Event Horizon Telescope Results. III: Imaging of the Galactic Center Supermassive Black Hole
• The Lick AGN Monitoring Project: Broad-Line Region Radii and Black Hole Masses from Reverberation Mapping of Hbeta
• Stellar Dynamics in the Galactic centre: Proper Motions and Anisotropy
• Reverberation Mapping Measurements of Black Hole Masses in Six Local Seyfert Galaxies
• An Alternative Approach To Measuring Reverberation Lags in Active Galactic Nuclei
• Space Telescope and Optical Reverberation Mapping Project. III. Optical Continuum Emission and Broad-Band Time Delays in NGC 5548
• A Description of Quasar Variability Measured Using Repeated SDSS and POSS Imaging
• Space Telescope and Optical Reverberation Mapping Project. II. Swift and HST Reverberation Mapping of the Accretion Disk of NGC 5548
• Modeling reverberation mapping data II: dynamical modeling of the Lick AGN Monitoring Project 2008 dataset
• Testing thermal reprocessing in AGN accretion discs
• Evidence for Supermassive Black Holes in Active Galactic Nuclei from Emission-Line Reverberation
• Optical Continuum and Emission-Line Variability of Seyfert 1 Galaxies
• Spatially resolved rotation of the broad-line region of a quasar at sub-parsec scale
• Completion of a Survey and Detailed Study of Double-Peaked Emission Lines in Radio-Loud AGNs
• The Lick AGN Monitoring Project: The MBH - sigma Relation For Reverberation-Mapped Active Galaxies
• Double-Peaked Low-Ionization Emission Lines in Active Galactic Nuclei
• The Sloan Digital Sky Survey Reverberation Mapping Project: H$\alpha$ and H$\beta$ Reverberation Measurements From First-year Spectroscopy and Photometry
• Reverberation mapping of Active Galactic Nuclei: from X-ray corona to dusty torus
• On the Reliability of Cross Correlation Function Lag Determinations in Active Galactic Nuclei
• The Lick AGN Monitoring Project 2011: Spectroscopic Campaign and Emission-Line Light Curves
• The Structure of the Broad Line Region in AGN: I. Reconstructed Velocity-Delay Maps
• Diverse Broad Line Region Kinematic Signatures From Reverberation Mapping
• Space Telescope and Optical Reverberation Mapping Project. I. Ultraviolet Observations of the Seyfert 1 Galaxy NGC 5548 with the Cosmic Origins Spectrograph on Hubble Space Telescope
• Swift monitoring of NGC 5548: X-ray reprocessing and short term UV/optical variability
• The Variable Diffuse Continuum Emission of Broad Line Clouds
• The effect of radiation pressure on emission line profiles and black hole mass determination in active galactic nuclei
• Recalibration of the virial factor and M-sigma relation for local active galaxies
• Space Telescope and Optical Reverberation Mapping Project. V. Optical Spectroscopic Campaign and Emission-Line Analysis for NGC 5548
• The Lick AGN Monitoring Project: Velocity-Delay Maps from the Maximum-Entropy Method for Arp 151
• The broad emission-line region: the confluence of the outer accretion disc with the inner edge of the dusty torus
• Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. VI. Velocity-resolved Reverberation Mapping of H$\beta$ Line
• Are Outflows Biasing Single-Epoch CIV Black Hole Mass Estimates?
• Long-Term Profile Variability of Double Peaked Emission Lines in Active Galactic Nuclei
• Double-peaked profiles: ubiquitous signatures of disks in the Broad Emission Lines of Active Galactic Nuclei
• Quantifying the impact of variable BLR diffuse continuum contributions on measured continuum inter-band delays
• The Lick AGN Monitoring Project 2011: Reverberation Mapping of Markarian 50
• Velocity-resolved reverberation mapping of five bright Seyfert 1 galaxies
• The Lick AGN Monitoring Project 2011: Dynamical Modeling of the Broad-Line Region
• Broad-Line Reverberation in the Kepler-Field Seyfert Galaxy Zw 229-015
• Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. VIII. Structure of the Broad-Line Region and Mass of the Central Black Hole in Mrk 142
• Long-Term Profile Variability in Active Galactic Nuclei with Double-Peaked Balmer Emission Lines
• Orientation dependency of broad-line widths in quasars and consequences for black-hole mass estimation
• The central parsec of NGC 3783: a rotating broad emission line region, asymmetric hot dust structure, and compact coronal line region
• Space Telescope and Optical Reverberation Mapping Project. IV. Anomalous behavior of the broad ultraviolet emission lines in NGC 5548
• First Results from the Lick AGN Monitoring Project: The Mass of the Black Hole in Arp 151
• Monitoring AGNs with Hβ Asymmetry. I. First Results: Velocity-resolved Reverberation Mapping
• Space Telescope and Optical Reverberation Mapping Project. IX. Velocity-Delay Maps for Broad Emission Lines in NGC 5548
• Multiwavelength Monitoring of the Narrow-Line Seyfert 1 Galaxy Akn 564. II. Ultraviolet Continuum and Emission-line Variability
• A parallax distance to 3C 273 through spectroastrometry and reverberation mapping
• Clues to Quasar Broad Line Region Geometry and Kinematics
• A wind-based unification model for NGC 5548: spectral holidays, non-disk emission, and implications for changing-look quasars
• Space Telescope and Optical Reverberation Mapping Project. X. Understanding the Absorption-Line Holiday in NGC 5548
• Space Telescope and Optical Reverberation Mapping Project. XII. Broad-Line Region Modeling of NGC 5548
• Space Telescope and Optical Reverberation Mapping Project. VIII. Time Variability of Emission and Absorption in NGC 5548 Based on Modeling the Ultraviolet Spectrum
• Monitoring AGNs with H$\beta$ Asymmetry. III. Long-term Reverberation Mapping Results of 15 Palomar-Green Quasars
• Frequency-resolved lags in UV/optical continuum reverberation mapping
• Space Telescope and Optical Reverberation Mapping Project. VII. Understanding the UV anomaly in NGC 5548 with X-Ray Spectroscopy
• The Lick AGN Monitoring Project 2016: Dynamical Modeling of Velocity-Resolved H\b{eta} Lags in Luminous Seyfert Galaxies
• Oscillatory patterns in the light curves of 5 long-term monitored type 1 AGN
• Gas, dust, and star formation in the positive AGN feedback candidate 4C 41.17 at z=3.8
• Monitoring AGNs with Hβ Asymmetry. II. Reverberation Mapping of Three Seyfert Galaxies Historically Displaying Hβ Profiles with Changing Asymmetry: Mrk 79, NGC 3227, and Mrk 841
• Broad-line Region of the Quasar PG 2130+099 from a Two-Year Reverberation Mapping Campaign with High Cadence
• On the Virialization of Disk Winds: Implications for the Black Hole Mass Estimates in AGN
• Spectroastrometry and Reverberation Mapping: the Mass and Geometric Distance of the Supermassive Black Hole in the Quasar 3C 273
• The Inner Accretion Flow in the Resurgent Seyfert-1.2 AGN Mrk 817
• Periodicity in the continua and broad line curves of a quasar E1821+643
• Anomalous behaviour of the UV-optical continuum bands in NGC 5548
• Weighing black holes from zero to high redshift

Cited by in corpus (4)

• AGN STORM 2. VII. A Frequency-resolved Map of the Accretion Disk in Mrk 817: Simultaneous X-ray Reverberation and UVOIR Disk Reprocessing Time Lags
• Updated Picture of the Active Galactic Nuclei with Dusty/Dust-free Gas Structures and Effects of the Radiation Pressure
• Reverberation Mapping Data of NGC 5548 Imply a Multicomponent Broad-Line Region
• A Convolutional Neural Network for the Recovery of Transfer Functions From Velocity-Resolved Reverberation Mapping Data