DISK-JET CONNECTION IN THE RADIO GALAXY 3C 120
- Institute for Astrophysical Research, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States)
- Department of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom)
- Astronomy Department, University of Michigan, 830 Dennison, 501 East University Street, Ann Arbor, MI 48109-1042 (United States)
- Metsaehovi Radio Observatory, Helsinki University of Technology TKK, Metsaehovintie 114, FIN-02540 Kylmaelae (Finland)
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303 (United States)
- Department of Physics and Astronomy, University of Nebraska, Lincoln, NE 68588-0111 (United States)
We present the results of extensive multi-frequency monitoring of the radio galaxy 3C 120 between 2002 and 2007 at X-ray (2-10 keV), optical (R and V bands), and radio (14.5 and 37 GHz) wave bands, as well as imaging with the Very Long Baseline Array (VLBA) at 43 GHz. Over the 5 yr of observation, significant dips in the X-ray light curve are followed by ejections of bright superluminal knots in the VLBA images. Consistent with this, the X-ray flux and 37 GHz flux are anti-correlated with X-ray leading the radio variations. Furthermore, the total radiative output of a radio flare is related to the equivalent width of the corresponding X-ray dip. This implies that, in this radio galaxy, the radiative state of accretion disk plus corona system, where the X-rays are produced, has a direct effect on the events in the jet, where the radio emission originates. The X-ray power spectral density of 3C 120 shows a break, with steeper slope at shorter timescale and the break timescale is commensurate with the mass of the central black hole (BH) based on observations of Seyfert galaxies and black hole X-ray binaries (BHXRBs). These findings provide support for the paradigm that BHXRBs and both radio-loud and radio-quiet active galactic nuclei are fundamentally similar systems, with characteristic time and size scales linearly proportional to the mass of the central BH. The X-ray and optical variations are strongly correlated in 3C 120, which implies that the optical emission in this object arises from the same general region as the X-rays, i.e., in the accretion disk-corona system. We numerically model multi-wavelength light curves of 3C 120 from such a system with the optical-UV emission produced in the disk and the X-rays generated by scattering of thermal photons by hot electrons in the corona. From the comparison of the temporal properties of the model light curves to that of the observed variability, we constrain the physical size of the corona and the distances of the emitting regions from the central BH. In addition, we discuss physical scenarios for the disk-jet connection that are consistent with our observations.
- OSTI ID:
- 21367323
- Journal Information:
- Astrophysical Journal, Vol. 704, Issue 2; Other Information: DOI: 10.1088/0004-637X/704/2/1689; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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SIX YEARS OF FERMI-LAT AND MULTI-WAVELENGTH MONITORING OF THE BROAD-LINE RADIO GALAXY 3C 120: JET DISSIPATION AT SUB-PARSEC SCALES FROM THE CENTRAL ENGINE
SIX YEARS OF FERMI-LAT AND MULTI-WAVELENGTH MONITORING OF THE BROAD-LINE RADIO GALAXY 3C 120: JET DISSIPATION AT SUB-PARSEC SCALES FROM THE CENTRAL ENGINE
Related Subjects
COSMOLOGY AND ASTRONOMY
ACCRETION DISKS
BLACK HOLES
DISTANCE
ELECTRONS
GALAXY NUCLEI
GHZ RANGE 01-100
MASS
PHOTON EMISSION
RADIO GALAXIES
SCATTERING
SEYFERT GALAXIES
SPECTRAL DENSITY
X-RAY GALAXIES
COSMIC RADIO SOURCES
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
ELEMENTARY PARTICLES
EMISSION
FERMIONS
FREQUENCY RANGE
FUNCTIONS
GALAXIES
GHZ RANGE
LEPTONS
SPECTRAL FUNCTIONS