A disc wind model for blueshifts in quasar broad emission lines

Abstract

Blueshifts - or, more accurately, blue asymmetries - in broad emission lines such as CIV $\lambda$1550 are common in luminous quasars and correlate with fundamental properties such as Eddington ratio and broad absorption line (BAL) characteristics. However, the formation of these blueshifts is still not understood, and neither is their physical connection to the BAL phenomenon or accretion disc. In this work, we present Monte Carlo radiative transfer and photoionization simulations using parametrized biconical disc-wind models. We take advantage of the azimuthal symmetry of a quasar and show that we can reproduce CIV blueshifts provided that (i) the disc-midplane is optically thick out to radii beyond the line formation region, so that the receding wind bicone is obscured; and (ii) the system is viewed from relatively low (that is, more face-on) inclinations ($\lesssim 40^{\circ }$). We show that CIV emission line blueshifts and BALs can form in the same wind structure. The velocity profile of the wind has a significant impact on the location of the line formation region and the resulting line profile, suggesting that the shape of the emission lines can be used as a probe of wind-driving physics. While we are successful at producing blueshifts/blue asymmetries in outflows, we struggle to match the detailed shape or skew of the observed emission line profiles. In addition, our models produce redshifted emission-line asymmetries for certain viewing angles. We discuss our work in the context of the CIV $\lambda$1550 emission blueshift versus equivalent-width space and explore the implications for quasar disc wind physics.

arXiv comment20 pages, 12 figures + 1 appendix. Supplementary material, simulation data and plotting scripts available at: https://github.com/jhmatthews/blueshifts

References in corpus (88)

• Astropy: A Community Python Package for Astronomy
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• Energy input from quasars regulates the growth and activity of black holes and their host galaxies
• Observational Evidence of AGN Feedback
• Protoplanetary Disks and Their Evolution
• Dynamics of line-driven disk winds in Active Galactic Nuclei
• The SDSS Quasar Survey: Quasar Luminosity Function from Data Release Three
• Black Holes, Galaxy Formation, and the M_BH-sigma Relation
• A Structure for Quasars
• Quasar feedback revealed by giant molecular outflows
• Quasar Feedback: More Bang for Your Buck
• Dynamics of Line-Driven Disk Winds in Active Galactic Nuclei II: Effects of Disk Radiation
• Unification of Luminous Type 1 Quasars through CIV Emission
• AGN outflows and feedback twenty years on
• Broad Emission Line Shifts in Quasars: An Orientation Measure for Radio-Quiet Quasars?
• Locally Optimally Emitting Clouds and the Origin of Quasar Emission Lines
• Eigenvector 1: An Optimal Correlation Space for Active Galactic Nuclei
• The Frequency and Radio Properties of Broad Absorption Line Quasars
• The origin of the Broad Line Region in Active Galactic Nuclei
• A physical model of the broadband continuum of AGN and its implications for the UV/X relation and optical variability
• CIV 1549 as an Eigenvector 1 Parameter for Active Galactic Nuclei
• A strong redshift dependence of the broad absorption line quasar fraction
• What the Optical Recombination Lines Can Tell Us About the Broad Line Regions of Active Galactic Nuclei
• Feedback from Active Galactic Nuclei: Energy- versus momentum-driving
• The Intrinsic Fraction of Broad Absorption Line Quasars
• The impact of baryons on the matter power spectrum from the Horizon-AGN cosmological hydrodynamical simulation
• Searching for the Physical Drivers of the Eigenvector 1 Correlation Space
• Diverse Broad Line Region Kinematic Signatures From Reverberation Mapping
• The Many Routes to AGN Feedback
• A global view of the inner accretion and ejection flow around super massive black holes: radiation driven accretion disk winds in a physical context
• HST STIS Ultraviolet Spectral Evidence of Outflow in Extreme Narrow-line Seyfert 1 Galaxies: II. Modeling and Interpretation
• Average Quasar Spectra in the Context of Eigenvector 1
• Geometric and Dynamical Models of Reverberation Mapping Data
• Cosmic evolution of stellar quenching by AGN feedback: clues from the Horizon-AGN simulation
• Major contributor to AGN feedback: VLT X-shooter observations of SIV BAL QSO outflows
• Searching For the Physical Drivers of Eigenvector 1: Influence of Black Hole Mass and Eddington Ratio
• Kinematic Linkage Between the Broad and Narrow Line Emitting Gas in AGN
• Radial Velocity Offsets Due to Mass Outflows and Extinction in Active Galactic Nuclei
• Kinematic links and the co-evolution of MHD winds, jets, and inner disks from a high-resolution optical [OI] survey
• CIV Emission Line Properties and Systematic Trends in Quasar Black Hole Mass Estimates
• Modeling the Spectral Signatures of Accretion Disk Winds: A New Monte Carlo Approach
• Monte Carlo transition probabilities
• Monte Carlo transition probabilities. II
• BAL and non-BAL quasars: continuum, emission and absorption properties establish a common parent sample
• Velocity-resolved reverberation mapping of five bright Seyfert 1 galaxies
• Monte Carlo Radiative Transfer
• Evidence that 50% of BALQSO Outflows Are Situated at Least 100 pc from the Central Source
• The spatially resolved broad line region of IRAS 09149-6206
• Line Shifts, Broad-Line Region Inflow, and the Feeding of AGNs
• The Prevalence of Gas Outflows in Type 2 AGNs. II. 3D Biconical Outflow Models
• How Big Can a Black Hole Grow?
• [O III] Equivalent Width and Orientation Effects in Quasars
• Failed radiatively Accelerated Dusty Outflow model of the Broad Line Region in Active Galactic Nuclei. I. Analytical solution
• The dust sublimation radius as an outer envelope to the bulk of the narrow Fe Kalpha line emission in Type 1 AGN
• Testing Quasar Unification: Radiative Transfer in Clumpy Winds
• The Evolution of Disk Winds from a Combined Study of Optical and Infrared Forbidden Lines
• Thermal Winds in Stellar Mass Black Hole and Neutron Star Binary Systems
• A Simple Disk Wind Model for Broad Absorption Line Quasars
• Stratified disc wind models for the AGN broad-line region: ultraviolet, optical and X-ray properties
• What is the True Covering Factor of Absorbing Matter in BALQSOs?
• Testing AGN outflow and accretion models with CIV and HeII emission line demographics in z=2 quasars
• The Intrinsic Fractions and Radio Properties of Low Ionization Broad Absorption Line Quasars
• Thermally driven wind as the origin of warm absorbers in AGN
• VLT/X-Shooter Survey of BAL Quasars: Large Distance Scale and AGN Feedback
• Quasar Rain: the Broad Emission Line Region as Condensations in the Warm Accretion Disk Wind
• Photoionization calculations of the radiation force due to spectral lines in AGNs
• Reverberation Mapping of the Broad Line Region: application to a hydrodynamical line-driven disk wind solution
• Radiation-hydrodynamic simulations of thermally-driven disc winds in X-ray binaries: A direct comparison to GRO J1655-40
• Multi-Wavelength Monitoring and Reverberation Mapping of a Changing Look Event in the Seyfert Galaxy NGC 3516
• 3D Radiation hydrodynamics of a dynamical torus
• Radiation pressure on dust explains the Low Ionized Broad Emission Lines in Active Galactic Nuclei
• MHD Disc Winds and Linewidth Distributions
• High-ionization emission line ratios from quasar broad line regions: metallicity or density?
• Do Reverberation Mapping Analyses Provide an Accurate Picture of the Broad Line Region?
• The reverberation signatures of rotating disc winds in active galactic nuclei
• Monte-Carlo methods for NLTE spectral synthesis of supernovae
• Quasar emission lines as probes of orientation: implications for disc wind geometries and unification
• The Kinematics of Quasar Broad Emission Line Regions Using a Disk-wind Model
• Modelling the X-ray spectra of high velocity outflows from quasars
• Dust-driven wind as a model of Broad Absorption Line quasars
• The case for inflow of the broad-line region of active galactic nuclei
• Using the Properties of Broad Absorption Line Quasars to Illuminate Quasar Structure
• No redshift evolution in the rest-frame UV emission line properties of quasars from z=1.5 to z=4.0
• The general applicability of self-similar solutions for thermal disc winds
• A test of the failed disk wind scenario for the origin of the broad line region in active galactic nuclei
• On Synthetic Absorption Line Profiles of Thermally Driven Winds from Active Galactic Nuclei
• Magnetohydrodynamic DiscWinds and LineWidth Distributions.II
• Effects of Radiation Field Geometry on Line Driven Disc Winds

Cited by in corpus (10)

• SIROCCO: A Publicly Available Monte Carlo Ionization and Radiative Transfer Code for Astrophysical Outflows
• [OIII] emission in z=2 quasars with and without Broad Absorption Lines
• HYPERION. Shedding light on the first luminous quasars: A correlation between UV disc winds and X-ray continuum
• X-ray selected broad absorption line quasars in SDSS-V: BALs and non-BALs span the same range of X-ray properties
• Accretion disc winds in X-ray binaries
• Radio Scrutiny of the X-ray-Weak Tail of Low-Mass Active Galactic Nuclei: A Novel Signature of High-Eddington Accretion?
• A Tentative Detection of Molecular Hydrogen (H${}_2$) Emission Lines at Cosmic Dawn
• Exploring the quasar disc-wind-jet connection with LoTSS and SDSS
• A Diagnostic Kit for Optical Emission Lines Shaped by Accretion Disc Winds
• Flux-Averaged Force Multipliers