The spectral energy distributions of narrow line seyfert 1 galaxies
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The Spectral Energy Distributions of Narrow-line Seyfert 1 Galaxies. Karen M. Leighly The University of Oklahoma. Summary. The spectral energy distribution, as either the origin or the consequence , is key for understanding Narrow-line Seyfert 1 galaxies. ASCA Observations of NLS1s.

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The Spectral Energy Distributions of Narrow-line Seyfert 1 Galaxies

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The spectral energy distributions of narrow line seyfert 1 galaxies

The Spectral Energy Distributions of Narrow-line Seyfert 1 Galaxies

Karen M. Leighly

The University of Oklahoma


Summary

Summary

  • The spectral energy distribution, as either the origin or the consequence, is key for understanding Narrow-line Seyfert 1 galaxies.


Asca observations of nls1s

ASCA Observations of NLS1s

Leighly 1999

Emission region size

~black hole mass

Absolute accretion rate


Variance soft excess correlation

Variance / Soft Excess Correlation

Leighly 1999

1H 0707-495

Ton S180

Alphaxx is a measure of the strength of the soft excess


1h 0707 495 ton s180

z=0.04

XMM-Newton observation 10/2000

Exposure ~ 40 ks

Boller et al. 2002

Z=0.06

XMM-Newton observation 12/2000

Exposure ~30 ks

Vaughan et al. 2002

1H 0707-495 Ton S180

Andrea Crews, Carnegie Mellon

Chiho Matsumoto, OU


Spectral properties

Prominent soft excess.

Well modeled by a single blackbody

Subtle soft excess

Modeled as two Comptonized spectra by Vaughan et al.

Spectral Properties


Light curves

High variance

Variance roughly independent of energy.

Low variance

Variance roughly independent of energy.

Light Curves


Structure function analysis

2-10 keV structure function appears harder than other bands on short time scales.

3-10 keV structure function appears similar to other bands on short time scales.

Structure Function Analysis


Energy sliced light curves

Hard X-rays mirror soft X-rays loosely.

Hard X-rays show additional short time scale variability

Implication: two physically distinct components

Hard X-rays and soft X-rays show nearly identical variability.

Implication: components are not distinct. Perhaps a distribution of optical depths and temperatures.

Energy-sliced Light Curves


Chandra observation of 1h 0707 495

Hard X-rays much more variable than soft X-rays.

Qualitatively similar to behavior during XMM-Newton observation.

Also true in I Zw 1, in which a hard flare was observed? (See poster by Luigi Gallo)

Chandra Observation of 1H 0707-495


Optical spectra

Optical Spectra

  • No profound differences between the optical spectra, as expected.

John Moore, OU


Uv spectra

Strong low-ionization lines

High SiIII]/CIII] ratio

Strongly blueshifted, low equivalent width CIV line.

Strong high-ionization lines

Moderate SiIII]/CIII] ratio

Weakly blueshifted, high equivalent width CIV.

UV Spectra


Civ in a sample of nls1s

CIV in a Sample of NLS1s

Ton S180

1H 0707-495

Symmetric line

Blueshifted line


An interpretation

An Interpretation

  • CIV line in some NLS1s is dominated by emission in a wind, resulting in the blueshift (red side is blocked by optically thick accretion disk).

  • What determines the presence of a wind?

  • The answer: the spectral energy distribution.

X-rays relatively strong compared with UV

X-rays relatively weak compared with UV


Resonance line driven winds

Resonance Line Driven Winds

  • What is required for a wind?

  • Resonance scattering of UV photons drives the wind, so the UV should be strong.

  • X-rays can overionize the wind (e.g. Proga et al.), so X-rays should be weak.

  • So steep alphaox should be associated with a wind.


1h 0707 495 and ton s180

1H 0707-495 and Ton S180


Low ionization lines

Low-Ionization Lines

  • Low-ionization lines (FeII, SiII) are strong in windy NLS1s.

  • Filtering continuum through the wind creates a much harder continuum that produces lines characterized by low ionization potential.

  • Many details in Leighly & Moore (ApJ, submitted)

  • Also, next Tuesday-RIKEN, Wednesday-ISAS


Why do some nls1s have blueshifted lines

Why do some NLS1s have blueshifted lines?

  • A blue UV continuum and weak X-ray emission can accelerate a wind without overionizing it. The wind emits blueshifted high-ionization lines (CIV, NV, OVI).

  • The wind filters the continuum before it strikes the intermediate-line emitting region. That region emits rather low-ionization lines (FeII, MgII, SiII).


Why do some nls1s not have blueshifted lines

Why do some NLS1s not have blueshifted lines?

  • Strong X-ray emission ionizes the wind before it can be accelerated.

  • The unfiltered continuum illuminates disk atmosphere producing strong relatively narrow and symmetric high-ionization lines.


Extreme nls1s re 1034 39

Extreme NLS1s: RE 1034+39

  • Simultaneous ASCA, EUVE, FUSE observations

  • A much harder continuum than that of 1H 0707-495

Casebeer & Leighly, in prep.

Darrin Casebeer, OU


The spectral energy distributions of narrow line seyfert 1 galaxies

Emission lines in RE1034+39 can all be modelled with nearly the same profile - no blueshifted emission, as predicted.


Semi empirical sed modeling

Semi-empirical SED modeling

  • Semi-empirical spectral energy distributions parameterized by cutoff temperature


Modeling re1034 39

Modeling RE1034+39

  • Darrin looked for an SED consistent with the lines he measures. He concludes that he very hard spectrum is not only consistent but required to produce the observed equivalent widths and ratios


Phl 1811

PHL 1811

  • Simultaneous HST and Chandra observations

  • Intrinsically X-ray weak - no evidence for significant absorption

Leighly, Halpern & Jenkins in prep.


Intrinsically x ray weak

Factor of 4 variability in 12 days - rules out scattered X-rays.

Nominal NLS1 photon index (2.25) plus black body - rules out absorption

Ratio of the two spectra reveal evidence for spectral variability

Intrinsically X-ray Weak

12/17/01

12/05/01


No evidence for absorption

No clear evidence for intrinsic absorption on CIV - small feature has equivalent width of 0.2 angstroms.

PHL 1811 is very unusual compared with other soft X-ray weak AGNs

No Evidence for Absorption

Galactic


Phl 18111

CIV line is blueshifted, as expected.

NV line may be blueshifted also.

PHL 1811


Strong uv feii in phl 1811

Strong UV FeII in PHL 1811

  • No semiforbidden or forbidden lines.


Very low ionization lines

Very low-ionization lines

  • Strong NaD and CaII H&K lines


X ray outflows in 1h 0707 495

Modeling done by Yair Krongold and Fabrizio Nicastro (CfA).

First component: U=1.14 logNH=21.92 Vout=24,000 km/s

Second component: U=1.47 logNH=22.4 Vout=45,000 km/s

Also Pounds et al.

X-ray Outflows in 1H 0707-495


Summary1

Summary

  • The spectral energy distribution, as either the origin or the consequence, is key for understanding Narrow-line Seyfert 1 galaxies.

  • NLS1 emission lines are a consequence of the SED, both in their excitation and dynamics.

  • Origin of the SED is in the central engine. Dispersion in X-ray spectral and variability properties among NLS1s indicates different conditions, geometries, …

  • And so we attempt to approach a complete picture of NLS1s…


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