simulating the spectra of quasars: a simple disk-wind model for balqsos
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Simulating the spectra of Quasars: A simple disk-wind model for BALQSOs. Nick Higginbottom (Southampton University) Christian Knigge (Southampton University ) Knox Long ( STScI ) Stuart Sim (Queens University - Belfast) James Matthews (Southampton University) - PowerPoint PPT PresentationTRANSCRIPT
School of Physics & Astronomy
Simulating the spectra of Quasars:A simple disk-wind model for BALQSOs
Nick Higginbottom (Southampton University)Christian Knigge (Southampton University)Knox Long (STScI) Stuart Sim (Queens University - Belfast)James Matthews (Southampton University)
Naples 21st May 2013
School of Physics & AstronomyOverview
• The problem – BALQSOs, outflows and QSO unification
• A benchmark disk-wind model• Physical state and synthetic spectra for
benchmark model• X-ray results and sensitivity• Summary and the future
Nick Higginbottom Modelling the spectra of (BAL)QSOs
School of Physics & Astronomy
Elvis (2000) Gibson+ (2009)
BALQSOs• Blue shifted absorption features imply outflows at
velocities of ≥ 0.1c (Weymann+ 1981)
• Continuum / emission features similar to other QSO types• Common underlying structure? • Disk-winds?
• BALQSO clearest indicator
Reichard+ (2003)
Nick Higginbottom Modelling the spectra of (BAL)QSOs
School of Physics & AstronomyBALQSOs – Evolution vs Orientation
• About 20% of the population of QSOs exhibit BAL properties (e.g. Knigge+ [2008] and Hewett & Foltz [2003])
• Evolution:• All QSOs spend 20% of the time as BALs
• Orientation• BAL Outflows cover 20% of viewing angles
• Our Aims: • Turn qualitative models into quantitative predictions using Monte Carlo
radiative transfer code - PYTHON (Long & Knigge [2003], Higginbottom et al. [2013 in prep])
• Produce something that looks like a BALQSO from some directions• Can such models look like other types of QSO from other directions?• Can the X-ray properties of such models be made to agree with
observations?Nick Higginbottom Modelling the spectra of (BAL)QSOs
School of Physics & AstronomyPYTHON – a 3D ionization and radiative
transfer code.• Arbitrary 3D wind geometry• Kinematic models• Hydrodynamic simulations
• Monte Carlo radiative transfer• Fast ionization calculations
• Modified Saha approximation• Thermal / Radiative equilibrium
• heating/cooling: free free, line, Comptonphotoionzation, recombination
Nick Higginbottom Modelling the spectra of (BAL)QSOs
Validation of PYTHON (dots) vs CLOUDY (lines)
School of Physics & AstronomyA benchmark wind model
Geometry based on Shlosman and Vitello (1993)Nick Higginbottom Modelling the spectra of (BAL)QSOs
• INPUT SPECTRUMMBH = 109MMacc = 5Myr-1 Lx = 1043ergs s-1
• WIND PARAMETERSRmin = 300RGRmax = 600RGθmin = 70°θmax = 82°Mwind= 5Myr-1
V∞ = Vescape
School of Physics & Astronomy
Nick Higginbottom Modelling the spectra of (BAL)QSOs
Properties of benchmark model
School of Physics & Astronomy
Nick Higginbottom Modelling the spectra of (BAL)QSOs
Properties of benchmark model
School of Physics & Astronomy
Nick Higginbottom Modelling the spectra of (BAL)QSOs
Properties of benchmark model
School of Physics & Astronomy
Nick Higginbottom Modelling the spectra of (BAL)QSOs
Properties of benchmark model
School of Physics & AstronomyProperties of benchmark model
School of Physics & AstronomyPredicted Spectra – 40°
Nick Higginbottom Modelling the spectra of (BAL)QSOs
• (Weak) thermal / scattering emission lines• Slight continuum enhancement due to electron
scattering Continuum without windDisk-wind spectrum
School of Physics & AstronomyPredicted Spectra – 75°
Nick Higginbottom Modelling the spectra of (BAL)QSOs
• Sightline into wind cone• Strong BAL features
Continuum without windDisk-wind spectrumAttenuated continuum
School of Physics & AstronomyPredicted Spectra – 85°
Nick Higginbottom Modelling the spectra of (BAL)QSOs
• Sightline through base of wind• Emission lines appear brighter due to attenuated
continuum Continuum without windDisk-wind spectrumAttenuated continuum
School of Physics & AstronomyX-ray properties of benchmark
model
Benchmark model
Figure from Saez+ 2011
Nick Higginbottom Modelling the spectra of (BAL)QSOs
40
75
85
School of Physics & AstronomyIncreasing LX
1. Increasing X-ray luminosity destroys the BAL
Mass loss rate through wind
X-ray luminosity
Nick Higginbottom Modelling the spectra of (BAL)QSOs
Subplot scales
-3x109 velocity (cms-1) +3x109
flux
School of Physics & Astronomy
1. Increasing X-ray luminosity destroys the BAL
2. Increasing the mass loss rate gets it back!
Mass loss rate through wind
X-ray luminosity
Nick Higginbottom Modelling the spectra of (BAL)QSOs
Subplot scales
-3x109 velocity (cms-1) +3x109
flux
Increasing LX and Mwind
School of Physics & Astronomy
1. Increasing X-ray luminosity destroys the BAL
2. Increasing the mass loss rate gets it back!
3. For Lx = 2x1044ergs s-1 need Mwind=20Myr -1
4. Mwind=4Macc OK??
Mass loss rate through wind
X-ray luminosity
Nick Higginbottom Modelling the spectra of (BAL)QSOs
Subplot scales
-3x109 velocity (cms-1) +3x109
flux
Increasing LX and Mwind
.
..
School of Physics & AstronomyX-ray properties of high Lx Mwind
model Figure from Saez+ 2011
Nick Higginbottom Modelling the spectra of (BAL)QSOs
Benchmark modelObservable values for L2-10keV=2e44ergs s-1, 25 solar mass per year mass loss
40
75
85
8540
75
School of Physics & AstronomySummary and plans for the
future• We have produced a simple disk-wind BAL model
Higginbottom et al. (2013 in prep)
• Correct ionization state• Strong BAL features• X-ray weak• Weak line emission
• The next steps• Explore parameter space• Uniqueness? X-rays? Emission?
• Investigate hydro-models - Higginbottom, Proga et al. (2013 in prep)
Nick Higginbottom Modelling the spectra of (BAL)QSOs
Data from Proga & Kallman 04
School of Physics & AstronomyThanks!
Nick Higginbottom Modelling the spectra of (BAL)QSOs
School of Physics & AstronomyMaking CIV in the wind – lessons
learntPhotoionization absorption in the root of the wind
attenuates UV
School of Physics & AstronomyMaking CIV in the wind – lessons
learntEasier to make CIV with a larger BH:
School of Physics & AstronomyVarying X-rays
Fiducial model is X-ray weakInput αOX varies from -2.4 (pole on) to -1.8 (edge
on)Emergent αOX much lower due to X-ray absorption
in the wind for BAL sightlines