X-ray dips in the Seyfert Galaxy Fairall 9: Compton-thick "comets" or a failed radio galaxy?

Abstract

We investigate the spectral variability of the Seyfert galaxy Fairall 9 using almost 6 years of monitoring with the Rossi X-ray Timing Explorer (RXTE) with an approximate time resolution of 4 days. We discover the existence of pronounced and sharp dips in the X-ray flux, with a rapid decline of the 2--20 keV flux of a factor 2 or more followed by a recovery to pre-dip fluxes after ~10 days . These dips skew the flux distribution away from the commonly observed log-normal distribution. Dips may result from the eclipse of the central X-ray source by broad line region (BLR) clouds, as has recently been found in NGC 1365 and Mrk 766. Unlike these other examples, however, the clouds in Fairall 9 would need to be Compton-thick, and the non-dip state is remarkably free of any absorption features. A particularly intriguing alternative is that the accretion disk is undergoing the same cycle of disruption/ejection as seen in the accretion disks of broad line radio galaxies (BLRGs) such as 3C120 but, for some reason, fails to create a relativistic jet. This suggests that a detailed comparison of Fairall 9 and 3C120 with future high-quality data may hold the key to understanding the formation of relativistic jets in AGN.

5 pages, 4 figures, accepted to ApJ Letters

References in corpus (11)

• An XMM-Newton survey of broad iron lines in Seyfert galaxies
• Simultaneous X-ray/optical/UV snapshots of active galactic nuclei from XMM-Newton: spectral energy distributions for the reverberation mapped sample
• X-ray absorption by Broad Line Region Clouds in Mrk 766
• "Comets" orbiting a black hole
• Variability of Active Galactic Nuclei from the Optical to X-ray Regions
• Suzaku Studies of Wide-Band Spectral Variability of the Bright Type I Seyfert Galaxy Markarian 509
• A Distinctive Disk-Jet Coupling in the Seyfert-1 AGN NGC 4051
• Spectral Survey of X-Ray Bright Active Galactic Nuclei from the Rossi X-ray Timing Explorer
• An XMM-Newton view of the `bare' nucleus of Fairall 9
• Multi-wavelength Variability of the Broad Line Radio Galaxy 3C 120
• Jets from the faintest black holes

Cited by in corpus (11)

• Measuring Black Hole Spin using X-ray Reflection Spectroscopy
• First X-ray-Based Statistical Tests for Clumpy-Torus Models: Eclipse Events from 230 Years of Monitoring of Seyfert AGN
• The Black Hole Spin and Soft X-ray Excess of the Luminous Seyfert Galaxy Fairall 9
• A Suzaku, NuSTAR, and XMM-Newton view on variable absorption and relativistic reflection in NGC 4151
• The rhythm of Fairall 9 -- I: Observing the spectral variability with XMM-Newton and NuSTAR
• Correlated X-ray/UV/optical variability and the nature of accretion disc in the bare Seyfert 1 galaxy Fairall~9
• A Variable-Density Absorption Event in NGC 3227 mapped with Suzaku and Swift
• Transient obscuration event captured in NGC~3227 II. Warm absorbers and obscuration events in archival XMM-Newton and NuSTAR observations
• No Signatures of Black-Hole Spin in the X-ray Spectrum of the Seyfert 1 Galaxy Fairall 9
• The fast UV variability of the active galactic nucleus in Fairall 9
• Stellar transits in active galactic nuclei