Broad Band X-Ray Observations of the Narrow Line X-Ray Galaxy NGC 5506

Abstract

We present a detailed analysis of broad band X-ray data of the Seyfert 2 galaxy NGC5506. 2-10 keV band are detected during a 1-day ASCA observation, while no significant change in the 2-10 keV continuum shape is found. The ASCA spectrum consists of an absorbed power-law, a 'soft excess' below 2 keV, and an Fe K$\alpha$ emission line at 6.4 keV. The 'soft excess' can be well described by either thermal emission from very low abundance material at a temperature kT$\simeq$0.8 keV, or scattered/leaking flux from the primary power-law plus a small amount of thermal emission. Analysis of ROSAT HRI data reveals that the soft X-ray emission is extended on kpc scales in this object, and the extended component may account for most of the soft X-ray excess observed by the ASCA. The result suggests that in this type 2 AGN, the 'soft excess' at least partly comes from an extended region, imposing serious problem for the model in which the source is partially covered. Fe K$\alpha$ profile is complex and can not be satisfactorily modeled by a single gaussian. Models of either double gaussians, or a narrow gaussian plus a line from a relativistic accretion disk viewed at an inclination of about 40$\pm 10^{\circ }$ provide good fits to the data. However, the inclination of the disk can be substantially larger if there is a small amount of excessive Fe K edge absorption. The intermediate inclinations for NLXGs are consistent with the ideas that the inner accretion disk is aligned with the outer obscuring torus.

8 pages, 5 postscript figures. to appear in Astrophy. J., 1999, April 20

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• Broadening of the Iron emission line in MCG-6-30-15 by Comptonization
• Detecting Compton Reflection and a Broad Iron Line in MCG-5-23-16 with the Rossi X-ray Timing Explorer
• ASCA PV observations of the Seyfert 2 galaxy NGC 4388: the obscured nucleus and its X-ray emission
• Are the Nuclei of Seyfert 2 Galaxies Viewed Face-On?
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Cited by in corpus (13)

• A NuSTAR census of coronal parameters in Seyfert galaxies
• The hard X-ray spectrum of NGC 5506 as seen by NuSTAR
• Ionized iron Kαlines in AGN X-ray spectra
• The recent X-ray history of NGC 5506
• Discovery of Water Maser Emission in Five AGN and a Possible Correlation Between Water Maser and Nuclear 2-10 keV Luminosities
• The complex iron line of NGC 5506
• RXTE observations of the Seyfert galaxy NGC 5506: evidence for reflection from disk and torus
• The broad Fe K line profile in NGC 4151
• Multi-epoch analysis of the X-ray spectrum of the active galactic nucleus in NGC 5506
• Direct measurement of the jet geometry in Seyfert galaxies
• The optical-ultraviolet continuum of Seyfert 2 galaxies
• The final verdict by XMM-Newton: the X-ray obscured Seyfert galaxy NGC5506 has a broad Fe K-alpha line
• Testing The Lamp-Post and Wind Reverberation Models with XMM-Newton Observations of NGC 5506