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. The spectral energy distribution, as either the origin or the consequence, is key for understanding Narrow-line Seyfert 1 galaxies. ASCA Observations of NLS1s Absolute accretion rate Emission region size ~black hole mass Leighly 1999 Variance / Soft Excess Correlation 1H Ton S180 Leighly 1999 Alpha xx is a measure of the strength of the soft excess 1H Ton S180 z=0.04 z=0.04 XMM-Newton observation 10/2000 XMM-Newton observation 10/2000 Exposure ~ 40 ks Exposure ~ 40 ks Boller et al Boller et al Z=0.06 XMM-Newton observation 12/2000 Exposure ~30 ks Vaughan et al Andrea Crews, Carnegie Mellon Chiho Matsumoto, OU Spectral Properties Prominent soft excess. Prominent soft excess. Well modeled by a single blackbody Well modeled by a single blackbody Subtle soft excess Modeled as two Comptonized spectra by Vaughan et al. Light Curves High variance High variance Variance roughly independent of energy. Variance roughly independent of energy. Low variance Variance roughly independent of energy. Structure Function Analysis 2-10 keV structure function appears harder than other bands on short time scales keV structure function appears harder than other bands on short time scales keV structure function appears similar to other bands on short time scales. Energy-sliced Light Curves Hard X-rays mirror soft X-rays loosely. Hard X-rays mirror soft X-rays loosely. Hard X-rays show additional short time scale variability Hard X-rays show additional short time scale variability Implication: two physically distinct components 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. Chandra Observation of 1H 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) Optical Spectra No profound differences between the optical spectra, as expected. No profound differences between the optical spectra, as expected. John Moore, OU UV Spectra Strong low-ionization lines Strong low-ionization lines High SiIII]/CIII] ratio High SiIII]/CIII] ratio Strongly blueshifted, low equivalent width CIV line. Strongly blueshifted, low equivalent width CIV line. Strong high-ionization lines Moderate SiIII]/CIII] ratio Weakly blueshifted, high equivalent width CIV. CIV in a Sample of NLS1s Ton S180 1H Blueshifted line Symmetric line 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). 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? What determines the presence of a wind? The answer: the spectral energy distribution. The answer: the spectral energy distribution. X-rays relatively strong compared with UV X-rays relatively weak compared with UV Resonance Line Driven Winds What is required for a wind? What is required for a wind? Resonance scattering of UV photons drives the wind, so the UV should be strong. 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. X-rays can overionize the wind (e.g. Proga et al.), so X-rays should be weak. So steep alpha ox should be associated with a wind. So steep alpha ox should be associated with a wind. 1H and Ton S180 Low-Ionization Lines Low-ionization lines (FeII, SiII) are strong in windy NLS1s. 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. 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) Many details in Leighly & Moore (ApJ, submitted) Also, next Tuesday- RIKEN, Wednesday- ISAS Also, next Tuesday- RIKEN, Wednesday- ISAS 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? 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 Simultaneous ASCA, EUVE, FUSE observations Simultaneous ASCA, EUVE, FUSE observations A much harder continuum than that of 1H A much harder continuum than that of 1H Casebeer & Leighly, in prep. Darrin Casebeer, OU Emission lines in RE can all be modelled with nearly the same profile - no blueshifted emission, as predicted. Semi-empirical SED modeling Semi-empirical spectral energy distributions parameterized by cutoff temperature Semi-empirical spectral energy distributions parameterized by cutoff temperature Modeling RE 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 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 Simultaneous HST and Chandra observations Simultaneous HST and Chandra observations Intrinsically X- ray weak - no evidence for significant absorption 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. Factor of 4 variability in 12 days - rules out scattered X-rays. Nominal NLS1 photon index (2.25) plus black body - rules out absorption Nominal NLS1 photon index (2.25) plus black body - rules out absorption Ratio of the two spectra reveal evidence for spectral variability 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. 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 Galactic PHL 1811 CIV line is blueshifted, as expected. CIV line is blueshifted, as expected. NV line may be blueshifted also. Strong UV FeII in PHL 1811 No semiforbidden or forbidden lines. No semiforbidden or forbidden lines. Very low-ionization lines Strong NaD and CaII H&K lines Strong NaD and CaII H&K lines X-ray Outflows in 1H Modeling done by Yair Krongold and Fabrizio Nicastro (CfA). Modeling done by Yair Krongold and Fabrizio Nicastro (CfA). First component: U=1.14 logNH=21.92 Vout=24,000 km/s 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 Second component: U=1.47 logNH=22.4 Vout=45,000 km/s Also Pounds et al. Also Pounds et al. Summary The spectral energy distribution, as either the origin or the consequence, is key for understanding Narrow-line Seyfert 1 galaxies. 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. 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, 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 And so we attempt to approach a complete picture of NLS1s