Properties of the NLR from Properties of the NLR from Spatially Resolved SpectroscopySpatially Resolved Spectroscopy

Nicola BennertNicola Bennert

University of California RiversideUniversity of California Riverside

Collaborators: Bruno Jungwiert, Stefanie Komossa, Martin Haas, Rolf ChiniCollaborators: Bruno Jungwiert, Stefanie Komossa, Martin Haas, Rolf Chini

The Narrow-Line Region of Active GalaxiesThe Narrow-Line Region of Active Galaxies

Extended enough to be directly accessibleExtended enough to be directly accessibleAffected by ionizing source, presence of torus, jets, … Affected by ionizing source, presence of torus, jets, … Forbidden lines for diagnostics Forbidden lines for diagnostics

[OIII] narrow-band imaging commonly used[OIII] narrow-band imaging commonly used(e.g. Mulchaey et al. 1996, Schmitt et al. 2003)(e.g. Mulchaey et al. 1996, Schmitt et al. 2003)

NLR size-luminosity relationNLR size-luminosity relation

constant product U x nconstant product U x n

5.0][OIIINLR LR

AGNs: same AGNs: same UU, , nn, ionizing SED? (Netzer , ionizing SED? (Netzer 1990)1990)

Bennert et al. Bennert et al. 20022002

Schmitt et al. 2003Schmitt et al. 200333.0

][OIIINLR LR

Strömgren: constant Strömgren: constant density?density?

⇒⇒ ionization mechanism, AGN lifetimes (Martini et al. 2004), BH mass? ionization mechanism, AGN lifetimes (Martini et al. 2004), BH mass?

⇒⇒ Disappearing NLR (Netzer et al. 2004)?Disappearing NLR (Netzer et al. 2004)?

The Narrow-Line Region of Active GalaxiesThe Narrow-Line Region of Active Galaxies

Extended enough to be directly accessibleExtended enough to be directly accessibleAffected by ionizing source, presence of torus, jets, … Affected by ionizing source, presence of torus, jets, … Forbidden lines for diagnostics Forbidden lines for diagnostics

[OIII] narrow-band imaging commonly used [OIII] narrow-band imaging commonly used (e.g. Mulchaey et al. 1996, Schmitt et al. 2003)(e.g. Mulchaey et al. 1996, Schmitt et al. 2003)

But: dependency on sensitivityBut: dependency on sensitivityMulchaey et al. 1996 vs. Schmitt et al. 2003: Mulchaey et al. 1996 vs. Schmitt et al. 2003: 6 times larger NLRs!6 times larger NLRs!

And: emission contaminated by contributions And: emission contaminated by contributions from e.g. star formation/shock-ionized gasfrom e.g. star formation/shock-ionized gas

Answers from SpectroscopyAnswers from Spectroscopy

Correction of stellar contribution: galaxy itself at 18‘‘ distanceCorrection of stellar contribution: galaxy itself at 18‘‘ distance

Reddening correction (dust)Reddening correction (dust)

VLT & NTT observations of 6 Sy1s, 6 Sy2s (Bennert et al. 2006a,b,c)VLT & NTT observations of 6 Sy1s, 6 Sy2s (Bennert et al. 2006a,b,c)

Detailed case study: Seyfert-2 galaxy NGC 1386 (Bennert et al. Detailed case study: Seyfert-2 galaxy NGC 1386 (Bennert et al. 2006a)2006a)

Bennert et al. Bennert et al. 20062006

Bennert et al. Bennert et al. 20062006

Probe AGN photoionization, measure „true“ NLR size (diagnostic diagrams)Probe AGN photoionization, measure „true“ NLR size (diagnostic diagrams)Probe physical parameters (Probe physical parameters (UU, , nn , E_(B-V), T, v, surface brightness) , E_(B-V), T, v, surface brightness)

Spatially resolved diagnosticsSpatially resolved diagnostics

⇒ ⇒ NLR size free of stellar contamination:NLR size free of stellar contamination:r ~ 6‘‘ (here) vs. r ~ 3‘‘ (Schmitt et al. 2003) vs. r ~ 12‘‘ (Fraquelli et al. 2003)r ~ 6‘‘ (here) vs. r ~ 3‘‘ (Schmitt et al. 2003) vs. r ~ 12‘‘ (Fraquelli et al. 2003)

Separation NLR/HII region (2Sy1s, 2Sy2s), confirmed by CLOUDY modelingSeparation NLR/HII region (2Sy1s, 2Sy2s), confirmed by CLOUDY modeling

Electron density and ionization parameterElectron density and ionization parameter

⇒ ⇒ excitation of the NLR due to photoionizationexcitation of the NLR due to photoionization

⇒⇒ No Strömgren behaviour No Strömgren behaviour

Both radially decreasing (1/r) Both radially decreasing (1/r)

Stellar and gaseous kinematicsStellar and gaseous kinematics

curves similar, signs of rotational motion, no difference in HII regioncurves similar, signs of rotational motion, no difference in HII region

⇒ ⇒ torus axis not aligned with galaxy axis, ionization cone lies in disk?torus axis not aligned with galaxy axis, ionization cone lies in disk?

Central AGN and galaxy randomly orientated? (e.g. Kinney et al. Central AGN and galaxy randomly orientated? (e.g. Kinney et al. 2000)2000)

⇒⇒ NLR gas distributed in a disk rather than a sphereNLR gas distributed in a disk rather than a sphere

The Narrow-Line Region of Active GalaxiesThe Narrow-Line Region of Active Galaxies

NLR size free of stellar NLR size free of stellar contaminationcontamination

NLR photoionizedNLR photoionized

NLR gas in a diskNLR gas in a diskTorus axis in galaxy disk?Torus axis in galaxy disk?

Unified model supportedUnified model supported

BLR size from literature („reverberation mapping“; Kaspi et al. 2000)BLR size from literature („reverberation mapping“; Kaspi et al. 2000)

⇒ ⇒ determine BH massesdetermine BH masses

MMBH BH = (10= (105.22 5.22 MM⊙⊙) ) vv3000300022 RRNLR,1NLR,1

0.880.88 MMBH BH = (10= (108.83 8.83 MM⊙⊙) ) vv3000300022 LL44,[OIII]44,[OIII]

0.480.48

NLR size versus BLR sizeNLR size versus BLR size

Bennert et al. 2004Bennert et al. 2004

Modeling: NLR size and luminosityModeling: NLR size and luminosity

⇒ ⇒ Different slopes for type 1/2Different slopes for type 1/2

flatter thanflatter than

Unified model (Antonucci 1993)Unified model (Antonucci 1993) & „receding“ torus (Lawrence & „receding“ torus (Lawrence 1991)1991)

)cos(][

.

150

UVOIII

UV

LLLh

50.UVLh

determined fromdetermined from

HHαα/H/Hββ continuum slope continuum slope

ReddeningReddening

⇒ ⇒ locally varying amount of dust intrinsic to the NLR? (true for all objects)locally varying amount of dust intrinsic to the NLR? (true for all objects)

Comparison of type-1 and type-2Comparison of type-1 and type-2

Seyfert 1sSeyfert 1s

[OIII] 4363, [FeVII], [FeX] higher [OIII] 4363, [FeVII], [FeX] higher

Ionization parameter higher, Ionization parameter higher, decreases faster decreases faster Higher temperatures Higher temperatures

Seyfert 2sSeyfert 2s

Reddening of nuclear spectrum Reddening of nuclear spectrum higher higher

Electron densities comparableElectron densities comparable (decrease faster in Sy1s)(decrease faster in Sy1s)

In agreement with statistics:In agreement with statistics:high-ionization lines & high-critical-density lines stronger in Sy1shigh-ionization lines & high-critical-density lines stronger in Sy1s

⇒⇒ Highly-ionized gas clouds are located close to nucleus and can be hiddenHighly-ionized gas clouds are located close to nucleus and can be hidden by torus (e.g. Nagao et al. 2000)by torus (e.g. Nagao et al. 2000)

Solid line 1: ionization parameter (log Solid line 1: ionization parameter (log U U = -4.0 … -1.5 steps of 0.5, from bottom to top; = -4.0 … -1.5 steps of 0.5, from bottom to top; n n = 800, 400, 200 cm= 800, 400, 200 cm-3-3; ; r r = 50, 100, 250 pc, from right to left)= 50, 100, 250 pc, from right to left)

Dotted lines 2&3: metal abundances (Z = 3…0.05 solar, from right to left; log U = -2.8 Dotted lines 2&3: metal abundances (Z = 3…0.05 solar, from right to left; log U = -2.8 for line 2; log U = -3.7 for line 3)for line 2; log U = -3.7 for line 3)

Dash-dotted lines 4&5: N & S abundances (Dash-dotted lines 4&5: N & S abundances (ZZ, , UU dito 2&3) dito 2&3)

Dashed line 6: high density (Dashed line 6: high density (n n = 1000000 cm= 1000000 cm-3-3; ; U U dito 1)dito 1)

CLOUDY modelingCLOUDY modeling

⇒ ⇒ transition in first and transition in first and third diagnostic diagram: third diagnostic diagram: decreasing ionization decreasing ionization parameter & metallicityparameter & metallicity

But not for second But not for second diagnostic diagramdiagnostic diagram