TY - JOUR

T1 - Diskjet connection in the radio galaxy 3C 120

AU - Chatterjee, Ritaban

AU - Marscher, Alan P.

AU - Jorstad, Svetlana G.

AU - Olmstead, Alice R.

AU - Mchardy, Ian M.

AU - Aller, Margo F.

AU - Aller, Hugh D.

AU - Lähteenmäki, Anne

AU - Tornikoski, Merja

AU - Hovatta, Talvikki

AU - Marshall, Kevin

AU - Miller, H. Richard

AU - Ryle, Wesley T.

AU - Chicka, Benjamin

AU - Benker, A. J.

AU - Bottorff, Mark C.

AU - Brokofsky, David

AU - Campbell, Jeffrey S.

AU - Chonis, Taylor S.

AU - Gaskell, C. Martin

AU - Gaynullina, Evelina R.

AU - Grankin, Konstantin N.

AU - Hedrick, Cecelia H.

AU - Ibrahimov, Mansur A.

AU - Klimek, Elizabeth S.

AU - Kruse, Amanda K.

AU - Masatoshi, Shoji

AU - Miller, Thomas R.

AU - Pan, Hong Jian

AU - Petersen, Eric A.

AU - Peterson, Bradley W.

AU - Shen, Zhiqiang

AU - Strel'nikov, Dmitriy V.

AU - Tao, Jun

AU - Watkins, Aaron E.

AU - Wheeler, Kathleen

PY - 2009

Y1 - 2009

N2 - 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.

AB - 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.

KW - Active - galaxies

KW - Galaxies

KW - Galaxies - X-rays

KW - Individual (3C 120) - galaxies

KW - Jets - radio continuum

UR - http://www.scopus.com/inward/record.url?scp=70549098821&partnerID=8YFLogxK

U2 - 10.1088/0004-637X/704/2/1689

DO - 10.1088/0004-637X/704/2/1689

M3 - Article

AN - SCOPUS:70549098821

VL - 704

SP - 1689

EP - 1703

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2

ER -