SHORT-TERM VARIABILITY AND POWER SPECTRAL DENSITY ANALYSIS OF THE RADIO-LOUD ACTIVE GALACTIC NUCLEUS 3C 390.3

Journal Article · Sun Sep 20 04:00:00 EDT 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/703/1/1021· OSTI ID:21371941

Gliozzi, Mario ^[1]; Papadakis, Iossif E ^[2]; Eracleous, Michael ^[3]; Sambruna, Rita M ^[4]; Ballantyne, David R ^[5]; Braito, Valentina ^[6]; Reeves, James N ^[7]

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1. George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States)
2. Physics Department, University of Crete (Greece)
3. Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States)
4. NASA's Goddard Space Flight Center, Code 661, Greenbelt, MD 20771 (United States)
5. Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, 837 State Street, Atlanta, GA 30032 (United States)
6. Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom)
7. Astrophysics Group, School of Physical and Geographical Sciences, Keele University, Keele, Staffordshire (United Kingdom)

We investigate the short-term variability properties and the power spectral density (PSD) of the broad-line radio galaxy (BLRG) 3C 390.3 using observations made by XMM-Newton, RXTE, and Suzaku on several occasions between 2004 October and 2006 December. The main aim of this work is to derive model-independent constraints on the origin of the X-ray emission and on the nature of the central engine in 3C 390.3. On timescales of the order of few hours, probed by uninterrupted XMM-Newton light curves, the flux of 3C 390.3 is consistent with being constant in all energy bands. On longer timescales, probed by the 2-day RXTE and Suzaku observations, the flux variability becomes significant. The latter observation confirms that the spectral variability behavior of 3C 390.3 is consistent with the spectral evolution observed in (radio-quiet) Seyfert galaxies: the spectrum softens as the source brightens. The correlated variability between soft and hard X-rays, observed during the Suzaku exposure and between the two XMM-Newton pointings, taken 1 week apart, argues against scenarios characterized by the presence of two distinct variable components in the 0.5-10 keV X-ray band. A detailed PSD analysis carried out over five decades in frequency suggests the presence of a break at T{sub br} = 43{sup +34}{sub -25} days at a 92% confidence level. This is the second tentative detection of a PSD break in a radio-loud, non-jet dominated active galactic nucleus (AGN), after the BLRG 3C 120, and appears to be in general agreement with the relation between T{sub br}, M{sub BH}, and L{sub bol}, followed by Seyfert galaxies. Our results indicate that the X-ray variability properties of 3C 390.3 are broadly consistent with those of radio-quiet AGN, suggesting that the X-ray emission mechanism in 3C 390.3 is similar to that of nearby Seyfert galaxies without any significant contribution from a jet component.

• OSTI ID: 21371941
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 703; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COSMIC RADIO SOURCES
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
ELECTROMAGNETIC RADIATION
EMISSION
FUNCTIONS
GALAXIES
GALAXY NUCLEI
HARD X RADIATION
IONIZING RADIATIONS
PHOTON EMISSION
RADIATIONS
RADIO GALAXIES
SEYFERT GALAXIES
SPECTRAL DENSITY
SPECTRAL FUNCTIONS
X RADIATION
X-RAY GALAXIES