[PPT] - Quan%fying the diffuse con%nuum contribu%on from BLR gas: a PowerPoint Presentation

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Atlanta , USA 2017 Mike Goad

Quan%fying the diffuse con%nuum contribu%on from BLR gas: a modeling approach

Mike Goad, Daniel Lawther, Kirk Korista, Otho Ulrich, Marianne Vestergaard

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Atlanta 2017 Mike Goad

Our approach:

q Build a model BLR match the intensi:es (variability 9mescale/amplitude)

f strongest UV/op%cal emission lines in NGC 5548

(For objects of interest, no such thing as a steady-state model)

q Compute wavelength-dependent (UV-op%cal-IR) flux and variability %mescale of DC arising from the same gas q Scale delays according to the frac%onal flux contribu%on

DC/(INCIDENT + DC)

q Drive with model con%nuum light-curves

es%mate sta%s%cally likely delays (CCF/JAVELIN)

+ dependence on characteris9c %mescale & variability amplitude

f driving con%nuum (MC approach)

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Atlanta 2017 Mike Goad

Types of model:

q Pressure law model : Rees, Netzer and Ferland 1989, Goad, O’Brien, Gondhalekar 1993 Kaspi and Netzer 1999 Netzer 2000 q Local Op1mally emi4ng Clouds : Baldwin, Ferland, Korista, Verner 1995, Korista and Goad 2000, 2001, 2004.

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Atlanta 2017 Mike Goad

(1) Pressure Law models :

Lawther, Goad, Korista, Ulrich, Vestergaard 2017, in prep

Run of physical condi%ons with radius specified by simple radial pressure law P(r) ∝ r−s

nH(r) ∝ r−s

U(r) ∝ rs−2

Ac(r) ∝ R2

c ∝ r2s/3

dC(r) ∝ Ac(r)nc(r)dr ∝ r2s/3−3/2dr

L = 4⇡ Z rout

rin

✏(r)Ac(r)nc(r)r2dr

Assume mass conserva%on + spherical clouds Differen%al covering frac%on Line luminosity

Ncol(r) ∝ RcnH ∝ r−2s/3

const Temp

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Atlanta 2017 Mike Goad

Normaliza%on condi%on : specify

ΦH, nH, Ncol at some r

+ inner and outer radius, and total covering frac%on Ctot Choose line radia%on pagern – we assume clouds are spherical

✏(r, ✓) = ✏totl[1 − (2F(r) − 1) cos ✓] F(r) = ✏inwd/✏totl

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Atlanta 2017 Mike Goad

−2 2 4 6

log[Energy / 1Ryd]

40 41 42 43 44 45

log[λLλ /1 erg s−1]

Two cases: s=0 , constant density nh, constant column density Nh + s=2 , constant ioniza%on parameter U

Mehdipour et al. 2015

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Atlanta 2017 Mike Goad

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Atlanta 2017 Mike Goad

7 8 9 10 11 12 13 14

log(nH/1cm−3)

20 40 60 80 100 120 140 160 180

r (lightdays) Ly-α C IV Hα Hβ He II 4686 He II 1640 log(ncol) = 22.5

emissivity-weighted radii can include effects of anisotropy/responsivity tends to increase delays further R=14.8 lt-days R=148 lt-days R=1.48 lt-days

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Atlanta 2017 Mike Goad

Similarly – constant U models

−2.0 −1.5 −1.0 −0.5 0.0 0.5

log(U)

1040 1041 1042 1043 1044

Lline (erg s−1)

Ly-α C IV Hβ He II 4686

Broad range in ioniza%on for which we can exceed the measured line luminosi%es

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Atlanta 2017 Mike Goad

2000 4000 6000 8000 10000

Wavelength [ ˚ A]

1042 1043 1044

Continuum νLν [erg s−1]

Diffuse continuum Ionizing continuum Total continuum

Model 1 (s =0,log(nH) = 10.75)

2000 4000 6000 8000 10000

Wavelength[ ˚ A]

0.0 0.2 0.4 0.6 0.8 1.0

Diffuse continuum fraction, Fdiff

Model 1

2000 4000 6000 8000 10000

Wavelength [ ˚ A]

10 20 30 40 50 60 70 80

Centroid [lightdays]

r rη τ (anisotropic) τη (anisotropic)

Model 1 (s =0,log(nH) = 10.75)

2000 4000 6000 8000 10000

Wavelength [ ˚ A]

10 20 30 40 50 60 70 80

Lag (days)

CCF Peak CCF Centroid

Model 1 (s =0,log(nH) = 10.75)

2000 4000 6000 8000 10000

Wavelength [ ˚ A]

2 4 6 8 10 12 14

Diluted lag (days)

CCF Peak × Fdiff CCF Centroid × Fdiff

Model 1

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Atlanta 2017 Mike Goad

2000 4000 6000 8000 10000

Wavelength [ ˚ A]

10 20 30 40 50 60 70 80

Centroid [lightdays]

r rη τ (anisotropic) τη (anisotropic)

Model 2 (s =2,log(U) = −1.23)

2000 4000 6000 8000 10000

Wavelength [ ˚ A]

2 4 6 8 10 12 14

Diluted lag (days)

CCF Peak × Fdiff CCF Centroid × Fdiff

Model 2 (s =2,log(U) = −1.23)

2000 4000 6000 8000 10000

Wavelength [ ˚ A]

10 20 30 40 50 60 70 80

Lag (days)

CCF Peak CCF Centroid

Model 2 (s =2,log(U) = −1.23)

2000 4000 6000 8000 10000

Wavelength[ ˚ A]

0.0 0.2 0.4 0.6 0.8 1.0

Diffuse continuum fraction, Fdiff

Model 2 (s =2,log(U) = −1.23)

2000 4000 6000 8000 10000

Wavelength [ ˚ A]

1042 1043 1044

Continuum νLν [erg s−1]

Diffuse continuum Ionizing continuum Total continuum

Model 2 (s =2,log(U) = −1.23)

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Atlanta 2017 Mike Goad

2000 4000 6000 8000 10000

Wavelength[ ˚ A]

0.5 0.6 0.7 0.8 0.9

Anisotropy, F = in(λ)/tot(λ)

Model 1 (s =0,log(nH) = 10.75)

2000 4000 6000 8000 10000

Wavelength[ ˚ A]

0.4 0.5 0.6 0.7 0.8 0.9 1.0

Anisotropy, F = in(λ)/tot(λ)

Model 2 (s =2,log(U) = −1.23)

Inward frac%ons

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Atlanta 2017 Mike Goad Density dependence - constant density models

10 20 30 40 50 60 τCCF,cent. [days] 10 20 30 40 50 60 τCCF,cent. [days] 10 20 30 40 50 60 τCCF,cent. [days] 10 20 30 40 50 60 τCCF,cent. [days] 10 20 30 40 50 60 τCCF,cent. [days] 10 20 30 40 50 60 τCCF,cent. [days] 2000 4000 6000 8000 10000 Wavelength [ ˚ A] 10 20 30 40 50 60 τCCF,cent. [days] 2 4 6 8 10 12 14 τCCF,cent × Fdiff.

log(nH) = 8