Photoionization Equilibrium Modeling of Iron L Line Emission

Kallman, T. R.; Liedahl, D. A.; Osterheld, A. L.; Goldstein, W. H.; Kahn, S. M.

doi:10.1086/177485

Cited by 103 publications

(103 citation statements)

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“…We therefore conclude that these features, which are also expected to be emitted in photoionized ADCs (see, e.g., Ko & Kallman 1994 ;Kallman et al 1996), are most probably real and not instrumental e †ects. The values of the parameters corresponding to the bestÐt model are reported in Table 1 (model 3).…”

Section: Observations and Spectral Analysismentioning

confidence: 69%

“…This line could be a result of emission from the L shell of ionized iron (Fe XXIIIÈFe XXIV for plasma densities of D1011 cm~3 ; see Kallman et al 1996) or from the K shell of highly ionized Si or Mg. The emission region of this line could be the outer region of the ADC at high latitude ([15¡), where the coronal density is expected to be around 1011È1012 cm~3 (Vrtilek et al 1993).…”

Section: Discussionmentioning

confidence: 99%

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Partially Absorbed Comptonization Spectrum from the Nearly Edge‐on Source X1822−371

Iaria

Salvo

Burderi

et al. 2001

ApJ

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We report the results of a spectral analysis over the range 0.1È200 keV performed on the dipping source X1822[371 observed by BeppoSAX. We Ðnd the best Ðt to the continuum using a partially covered Comptonization model, representing scattering of soft seed photons by electrons at a temperature of D4.8 keV, without the presence of any soft blackbody emission. The equivalent hydrogen column obtained for the absorbed component is D4.5 ] 1022 cm~2, an order of magnitude larger than the Galactic absorption for this source, and the covering fraction is D71%. Because the inclination angle of X1822[371 to the line of sight is D85¡, this model gives a reasonable scenario for the source : the Comptonized spectrum could come from an extended accretion disk corona (ADC), probably the only region that can be directly observed as a result of the high inclination. The excess matter producing the partial covering could be close to the equatorial plane of the system, above the outer disk, occulting the emission from the inner disk and the inner part of the ADC. An iron emission line is also present at D6.5 keV with an equivalent width of D150 eV. We argue that this strong iron line cannot be explained as reÑection of the Comptonized spectrum by the accretion disk. It is probably produced in the ADC. An emission line at D1.9 keV (with an equivalent width of D54 eV) and an absorption edge at D8.7 keV (with an optical depth of D0.1) are also required to Ðt this spectrum. These features are probably produced by highly ionized iron (Fe XXIV) present in the outer part of the ADC, where the plasma density is D1011È1012 cm~3 and ionized plasma is present.

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Section: Observations and Spectral Analysismentioning

confidence: 69%

Section: Discussionmentioning

confidence: 99%

Partially Absorbed Comptonization Spectrum from the Nearly Edge‐on Source X1822−371

Iaria

Salvo

Burderi

et al. 2001

ApJ

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“…In Pounds et al (2016a,b), we reported the analysis of an extended XMM-Newton observation of PG 1211+143, modelling both hard (2-10 keV) spectra from the EPIC-pn camera (Strüder et al 2001) and higher-resolution soft (< 2 keV) spectra from the Reflection Grating Spectrometer (RGS; den Herder et al 2001) with XSTAR (Kallman et al 1996). We generated a set of self-consistent custom-built XSTAR grids with the correct ionizing continuum for PG 1211+143, based on a spectral energy distribution model described in Lobban et al (2016).…”

Section: Spectral Analysismentioning

confidence: 99%

TESTING RELATIVISTIC REFLECTION AND RESOLVING OUTFLOWS IN PG 1211+143 WITH XMM-NEWTON AND NuSTAR

Lobban

Pounds

Vaughan

et al. 2016

ApJ

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We analyze the broad-band X-ray spectrum (0.3-50 keV) of the luminous Seyfert 1 / quasar PG 1211+143 -the archetypal source for high-velocity X-ray outflows -using near-simultaneous XMM-Newton and NuS-TAR observations. We compare pure relativistic reflection models with a model including the strong imprint of photoionized emission and absorption from a high-velocity wind (Pounds et al. 2016a,b), finding a spectral fit that extrapolates well over the higher photon energies covered by NuSTAR. Inclusion of the high S/N XMM-Newton spectrum provides much tighter constraints on the model parameters, with a much harder photon index / lower reflection fraction compared to that from the NuSTAR data alone. We show that pure relativistic reflection models are not able to account for the spectral complexity of PG 1211+143 and that wind absorption models are strongly required to match the data in both the soft X-ray and Fe K spectral regions. In confirming the significance of previously reported ionized absorption features, the new analysis provides a further demonstration of the power of combining the high throughput and resolution of long-look XMM-Newton observations with the unprecedented spectral coverage of NuSTAR.

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“…5 We therefore added a further component to the spectral model of 2M1049+5837 to represent line emission from ionized gas, modeled by an XSTAR grid (Kallman et al 1996). Here the free parameters were the ionization parameter and emission measure, while the metal abundances (C-Fe) were initially fixed at their solar values.…”

Section: The Soft X-ray Emissionmentioning

confidence: 99%

XMM‐NewtonObservations of the Red Type 1.8 Quasar 2M1049+5837: Reflection from Cold and Warm (Ionized) Matter

Wilkes

Pounds

Schmidt

2008

ApJ

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Chandra observations of the type 1.8, low-redshift (z ¼ 0:115), red (J À K S $ 2) quasar 2MASSJ 104943+583750 (2M1049+5837) indicated an unusually hard X-ray spectrum (HR $ 0:6), suggesting obscuration of N H $ 4 ; 10 22 cm À2 and a flat À $ 0:4 power-law slope. A higher signal-to-noise ratio XMM-Newton observation reported here reveals a more complex spectrum, being extremely hard above $2 keV, À $ À0:6, with a well-defined soft excess similar to the bright, nearby Seyfert 2 galaxy Mrk 3. Such extremely hard quasar spectra cannot be a dominant contributor to the cosmic X-ray background (CXRB; À $ 1:4). Modeling of 2M1049+5837 shows the observed 2-10 keV spectrum to be the sum of a strongly absorbed ''normal'' À $ 1:8 underlying quasar X-ray continuum, and a cold reflection component (R $ 2). The strong attenuation of the intrinsic X-ray continuum by a sub-Compton-thick line-of-sight column, N H $ 3:4 ; 10 23 cm À2 , reveals a soft X-ray emission component whose spectrum indicates reprocessing / emission from, possibly extended, photoionized gas. The luminosity of the soft X-ray component is similar to Seyfert 2 galaxies, an order of magnitude less than comparable type 1 AGNs, suggesting partial obscuration of core-bright emission. The optical emission is complex, with distinct red and blue scattered light components believed to originate in two extended regions visible in HST imaging data. The unusual combination of properties: optical and X-ray obscuration of the nuclear emission, partially obscured broad but unobscured narrow emission lines, and partially obscured soft X-ray excess, implies an intermediate viewing angle, over or through the edge of an obscuring disk + wind or torus. 2M1049+5837 again demonstrates both the ambiguity of low signal-to-noise X-ray spectra/hardness ratios and the potential of 2MASS-selected red sources for exploring the complex obscuration and geometry of the nuclear regions in AGNs.

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Photoionization Equilibrium Modeling of Iron L Line Emission

Cited by 103 publications

References 0 publications

Partially Absorbed Comptonization Spectrum from the Nearly Edge‐on Source X1822−371

Partially Absorbed Comptonization Spectrum from the Nearly Edge‐on Source X1822−371

TESTING RELATIVISTIC REFLECTION AND RESOLVING OUTFLOWS IN PG 1211+143 WITH XMM-NEWTON AND NuSTAR

XMM‐NewtonObservations of the Red Type 1.8 Quasar 2M1049+5837: Reflection from Cold and Warm (Ionized) Matter

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