ACTIVE GALAXY UNIFICATION IN THE ERA OF X-RAY POLARIMETRY

Journal Article · Wed Mar 10 00:00:00 EST 2010 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/711/2/L112; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21305098

Dorodnitsyn, A; Kallman, T ^[1]

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1. Laboratory for High Energy Astrophysics, NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States)

Active galactic nuclei (AGNs), Seyfert galaxies, and quasars are powered by luminous accretion and often accompanied by winds that are powerful enough to affect the AGN mass budget, and whose observational appearance bears an imprint of processes that are happening within the central parsec around the black hole (BH). One example of such a wind is the partially ionized gas responsible for X-ray and UV absorption (warm absorbers). Here, we show that such gas will have a distinct signature when viewed in polarized X-rays. Observations of such polarization can test models for the geometry of the flow and the gas responsible for launching and collimating it. We present calculations that show that the polarization depends on the hydrodynamics of the flow, the quantum mechanics of resonance-line scattering, and the transfer of polarized X-ray light in the highly ionized moving gas. The results emphasize the three-dimensional nature of the wind for modeling spectra. We show that the polarization in the 0.1-10 keV energy range is dominated by the effects of resonance lines. We predict a 5%-25% X-ray polarization signature of type-2 objects in this energy range. These results are generalized to flows that originate from a cold torus-like structure, located {approx}1 pc from the BH, which wraps the BH and is ultimately responsible for the apparent dichotomy between type 1 and type 2 AGNs. Such signals will be detectable by future dedicated X-ray polarimetry space missions, such as the NASA Gravity and Extreme Magnetism Small Explorer.

• OSTI ID: 21305098
• Journal Information: Astrophysical Journal Letters, Vol. 711, Issue 2; Other Information: DOI: 10.1088/2041-8205/711/2/L112; Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
ABSORPTION
ACCELERATION
BLACK HOLES
GALAXY NUCLEI
GRAVITATION
HYDRODYNAMICS
MAGNETISM
POLARIMETRY
POLARIZATION
QUANTUM MECHANICS
QUASARS
RESONANCE
SCATTERING
SEYFERT GALAXIES
SIMULATION
SPECTRA
THREE-DIMENSIONAL CALCULATIONS
X-RAY GALAXIES