From thin to thick: The impact of X-ray irradiation on accretion disks in active galactic nuclei

Philip Chang; Eliot Quataert; Norman Murray

doi:10.1086/517960

From thin to thick: The impact of X-ray irradiation on accretion disks in active galactic nuclei

Philip Chang, Eliot Quataert, Norman Murray

Research output: Contribution to journal › Article › peer-review

15 Scopus citations

Abstract

We argue that the X-ray and UV flux illuminating the parsec-scale accretion disk around luminous active galactic nuclei (AGNs) is super-Eddington with respect to the local far-infrared dust opacity. The far-infrared opacity may be larger than in the interstellar medium of the Milky Way due to a combination of supersolar metallicity and the growth of dust grains in the dense accretion disk. Because of the irradiating flux, the outer accretion disk puffs up with a vertical thickness h ∼ R. This provides a mechanism for generating a geometrically thick obscuring region from an intrinsically thin disk. We find obscuring columns ∼10²²-10²³ cm^-2, in reasonable agreement with observations.

Original language	English (US)
Pages (from-to)	94-101
Number of pages	8
Journal	Astrophysical Journal
Volume	662
Issue number	1 I
DOIs	https://doi.org/10.1086/517960
State	Published - Jun 10 2007
Externally published	Yes

All Science Journal Classification (ASJC) codes

Astronomy and Astrophysics
Space and Planetary Science

Keywords

Accretion, accretion disks
Dust, extinction
Galaxies: Seyfert
Galaxies: active
Galaxies: nuclei

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10.1086/517960

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title = "From thin to thick: The impact of X-ray irradiation on accretion disks in active galactic nuclei",

abstract = "We argue that the X-ray and UV flux illuminating the parsec-scale accretion disk around luminous active galactic nuclei (AGNs) is super-Eddington with respect to the local far-infrared dust opacity. The far-infrared opacity may be larger than in the interstellar medium of the Milky Way due to a combination of supersolar metallicity and the growth of dust grains in the dense accretion disk. Because of the irradiating flux, the outer accretion disk puffs up with a vertical thickness h ∼ R. This provides a mechanism for generating a geometrically thick obscuring region from an intrinsically thin disk. We find obscuring columns ∼1022-1023 cm-2, in reasonable agreement with observations.",

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language = "English (US)",

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TY - JOUR

T1 - From thin to thick

T2 - The impact of X-ray irradiation on accretion disks in active galactic nuclei

AU - Chang, Philip

AU - Quataert, Eliot

AU - Murray, Norman

PY - 2007/6/10

Y1 - 2007/6/10

N2 - We argue that the X-ray and UV flux illuminating the parsec-scale accretion disk around luminous active galactic nuclei (AGNs) is super-Eddington with respect to the local far-infrared dust opacity. The far-infrared opacity may be larger than in the interstellar medium of the Milky Way due to a combination of supersolar metallicity and the growth of dust grains in the dense accretion disk. Because of the irradiating flux, the outer accretion disk puffs up with a vertical thickness h ∼ R. This provides a mechanism for generating a geometrically thick obscuring region from an intrinsically thin disk. We find obscuring columns ∼1022-1023 cm-2, in reasonable agreement with observations.

AB - We argue that the X-ray and UV flux illuminating the parsec-scale accretion disk around luminous active galactic nuclei (AGNs) is super-Eddington with respect to the local far-infrared dust opacity. The far-infrared opacity may be larger than in the interstellar medium of the Milky Way due to a combination of supersolar metallicity and the growth of dust grains in the dense accretion disk. Because of the irradiating flux, the outer accretion disk puffs up with a vertical thickness h ∼ R. This provides a mechanism for generating a geometrically thick obscuring region from an intrinsically thin disk. We find obscuring columns ∼1022-1023 cm-2, in reasonable agreement with observations.

KW - Accretion, accretion disks

KW - Dust, extinction

KW - Galaxies: Seyfert

KW - Galaxies: active

KW - Galaxies: nuclei

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JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 1 I

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From thin to thick: The impact of X-ray irradiation on accretion disks in active galactic nuclei

Abstract

All Science Journal Classification (ASJC) codes

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