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Accretion states and radio loudness in active galactic nuclei: analogies with X-ray binaries

Accretion states and radio loudness in active galactic nuclei: analogies with X-ray binaries
Accretion states and radio loudness in active galactic nuclei: analogies with X-ray binaries
Hardness-intensity diagrams (HIDs) have been used with great success to study the accretion states and their connection to radio jets in x-ray binaries (XRBs). The analogy between XRBs and active galactic nuclei (AGN) suggests that similar diagrams may help to understand and identify accretion states in AGN and their connection to radio loudness. We construct "disc-fraction luminosity diagrams" (DFLDs) as a generalization of HIDs, which plot the intensity against the fraction of the disc contribution in the overall spectral energy distribution (SED). Using a sample of 4963 Sloan Digital Sky Survey (SDSS) quasars with ROSAT matches, we show empirically that an AGN is more likely to have a high radio:optical flux ratio when it has a high total luminosity or a large non-thermal contribution to the SED. We find that one has to consider at least two-dimensional diagrams to understand the radio loudness of AGN. To extend our DFLD to lower luminosities we also include a sample of low-luminosity AGN. Using a simulated population of XRBs we show that stellar and supermassive BHs populate similar regions in the DFLD and show similar radio/jet properties. This supports the idea the AGN and XRBs have the same accretion states and associated jet properties.
1365-2966
1366-1378
Koerding, Elmar G.
56c0ead4-2b84-4e51-9b97-9f57c36b7d24
Jester, Sebastian
93678bcc-9003-4330-88d6-4ef630353948
Fender, Rob
c802ddfc-25a3-4c0e-899d-11c405c705d1
Koerding, Elmar G.
56c0ead4-2b84-4e51-9b97-9f57c36b7d24
Jester, Sebastian
93678bcc-9003-4330-88d6-4ef630353948
Fender, Rob
c802ddfc-25a3-4c0e-899d-11c405c705d1

Koerding, Elmar G., Jester, Sebastian and Fender, Rob (2006) Accretion states and radio loudness in active galactic nuclei: analogies with X-ray binaries. Monthly Notices of the Royal Astronomical Society, 372 (3), 1366-1378. (doi:10.1111/j.1365-2966.2006.10954.x).

Record type: Article

Abstract

Hardness-intensity diagrams (HIDs) have been used with great success to study the accretion states and their connection to radio jets in x-ray binaries (XRBs). The analogy between XRBs and active galactic nuclei (AGN) suggests that similar diagrams may help to understand and identify accretion states in AGN and their connection to radio loudness. We construct "disc-fraction luminosity diagrams" (DFLDs) as a generalization of HIDs, which plot the intensity against the fraction of the disc contribution in the overall spectral energy distribution (SED). Using a sample of 4963 Sloan Digital Sky Survey (SDSS) quasars with ROSAT matches, we show empirically that an AGN is more likely to have a high radio:optical flux ratio when it has a high total luminosity or a large non-thermal contribution to the SED. We find that one has to consider at least two-dimensional diagrams to understand the radio loudness of AGN. To extend our DFLD to lower luminosities we also include a sample of low-luminosity AGN. Using a simulated population of XRBs we show that stellar and supermassive BHs populate similar regions in the DFLD and show similar radio/jet properties. This supports the idea the AGN and XRBs have the same accretion states and associated jet properties.

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Published date: March 2006

Identifiers

Local EPrints ID: 45365
URI: http://eprints.soton.ac.uk/id/eprint/45365
ISSN: 1365-2966
PURE UUID: 8f860156-090d-4286-b26f-f02b9ad6fb06

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Date deposited: 22 Mar 2007
Last modified: 15 Mar 2024 09:10

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Contributors

Author: Elmar G. Koerding
Author: Sebastian Jester
Author: Rob Fender

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