Are X-ray emitting coronae around supermassive black holes outflowing?

Journal Article · Mon Mar 10 00:00:00 EDT 2014 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/783/2/106· OSTI ID:22351566

Liu, Teng; Wang, Jun-Xian; Yang, Huan; Zhu, Fei-Fan; Zhou, You-Yuan ^[1]

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1. CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Hefei, Anhui 230026 (China)

Hard X-ray emission in radio-quiet active galactic nuclei (AGNs) is believed to be produced via inverse Compton scattering by hot and compact coronae near the supermassive black hole. However, the origin and physical properties of the coronae, including geometry, kinematics, and dynamics, remain poorly known. In this work, taking [O IV] 25.89 μm emission line as an isotropic indicator of AGNs' intrinsic luminosity, we compare the intrinsic corona X-ray emission between Seyfert 1 and Compton-thin Seyfert 2 galaxies, which are viewed at different inclinations according to the unification scheme. We compile a sample of 130 Compton-thin Seyfert galaxies with both [O IV] 25.89 μm line luminosities measured with the Spitzer Infrared Spectrometer and X-ray spectra observed by XMM-Newton, Chandra, Suzaku, or Swift. Known radio-loud sources are excluded. We fit the X-ray spectra to obtain the absorption-corrected 2-10 keV continuum luminosities. We find that Seyfert 1 galaxies are intrinsically brighter in intrinsic 2-10 keV emission by a factor of 2.8{sub −0.4}{sup +0.5} (2.2{sub −0.3}{sup +0.9} in Swift Burst Alert Telescope 14-195 keV emission), compared with Compton-thin Seyfert 2 galaxies. The Seyfert 1 and Compton-thin Seyfert 2 galaxies follow a statistically identical correlation between the absorption-corrected 2-10 keV luminosity and the 14-195 keV luminosity, indicating that our absorption correction to the 2-10 keV flux is sufficient. The difference in X-ray emission between the two populations is thus unlikely to be due to X-ray absorption, and instead implies an intrinsic anisotropy in the corona X-ray emission. This striking anisotropy of X-ray emission can be explained by a bipolar outflowing corona with a bulk velocity of ∼0.3-0.5c. This would provide a natural link between the so-called coronae and weak jets in these systems. Other consequences of outflowing coronae are also discussed.

• OSTI ID: 22351566
• Journal Information: Astrophysical Journal, Vol. 783, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ABSORPTION
ANISOTROPY
BLACK HOLES
COMPARATIVE EVALUATIONS
COMPTON EFFECT
CORRELATIONS
EMISSION
GALAXY NUCLEI
HARD X RADIATION
INFRARED SPECTROMETERS
LUMINOSITY
RELATIVISTIC RANGE
SCATTERING
SEYFERT GALAXIES
STELLAR CORONAE
TELESCOPES
VELOCITY
X-RAY GALAXIES
X-RAY SPECTRA