Probing the Disk-Jet Connection of the Radio Galaxy 3C120 Observed With Suzaku

Journal Article · Wed Jan 03 00:00:00 EST 2007 · Submitted to Publ.Astron.Soc.Jap.

DOI:https://doi.org/10.1093/pasj/59.2.279· OSTI ID:896943

Kataoka, Jun; Reeves, James N; Iwasawa, Kazushi; Markowitz, Alex G; Mushotzky, Richard F; Arimoto, Makoto; Takahashi, Tadayuki; Tsubuku, Yoshihiro; Ushio, Masayoshi; Watanabe, Shin; Gallo, Luigi C; Madejski, Greg M; Terashima, Yuichi; Isobe, Naoki; Tashiro, Makoto S; Kohmura, Takayoshi

Broad line radio galaxies (BLRGs) are a rare type of radio-loud AGN, in which the broad optical permitted emission lines have been detected in addition to the extended jet emission. Here we report on deep (40ksec x 4) observations of the bright BLRG 3C 120 using Suzaku. The observations were spaced a week apart, and sample a range of continuum fluxes. An excellent broadband spectrum was obtained over two decades of frequency (0.6 to 50 keV) within each 40 ksec exposure. We clearly resolved the iron K emission line complex, finding that it consists of a narrow K{sub {alpha}} core ({sigma} {approx_equal} 110 eV or an EW of 60 eV), a 6.9 keV line, and an underlying broad iron line. Our confirmation of the broad line contrasts with the XMM-Newton observation in 2003, where the broad line was not required. The most natural interpretation of the broad line is iron K line emission from a face-on accretion disk which is truncated at {approx} 10 r{sub g}. Above 10 keV, a relatively weak Compton hump was detected (reflection fraction of R {approx_equal} 0.6), superposed on the primary X-ray continuum of {Lambda} {approx_equal} 1.75. Thanks to the good photon statistics and low background of the Suzaku data, we clearly confirm the spectral evolution of 3C 120, whereby the variability amplitude decreases with increasing energy. More strikingly, we discovered that the variability is caused by a steep power-law component of {Lambda} {approx_equal} 2.7, possibly related to the non-thermal jet emission. We discuss our findings in the context of similarities and differences between radio-loud/quiet objects.

• Research Organization: Stanford Linear Accelerator Center (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 896943
• Report Number(s): SLAC-PUB-12211; astro-ph/0612754
• Journal Information: Submitted to Publ.Astron.Soc.Jap., Journal Name: Submitted to Publ.Astron.Soc.Jap.
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ACCRETION DISKS
AMPLITUDES
Astrophysics
ASTRO
IRON
PHOTONS
RADIO GALAXIES
REFLECTION
STATISTICS