The optical-ultraviolet continuum of Seyfert 2 galaxies

Abstract

This paper aims to understand the continuum of Seyfert 2 galaxies. By fitting the single galaxies in the sample of Heckman et al. (1995) with composite models (shock+ photoionization from the active center), we show that five main components characterize the SED of the continuum. Shocks play an important role since they produce a high temperature zone where soft X-rays are emitted. We show that in the optical-UV range, the slope of the NLR emission reproduces the observed values, and may be the main component of the featureless continuum. The presence of star forming regions cannot be excluded in the circumnuclear region of various Seyfert galaxies. An attempt is made to find their fingerprints in the observed AGN spectra. Finally, it is demonstrated that multi-cloud models are necessary to interpret the spectra of single objects, even in the global investigation of a sample of galaxies.

arXiv comment26 pages, LaTeX (including 5 Tables) + 17 PostScript figures. To appear in "The Astrophysical Journal"

References in corpus (5)

• Starbursts and Star Clusters in the Ultraviolet
• The Stellar Content of Active Galaxies
• ASCA Observations of the Seyfert 2 Galaxy NGC 7582: An Obscured and Scattered View of the Hidden Nucleus
• Gas and Dust Emission from the Nuclear Region of the Circinus Galaxy
• Broad Band X-Ray Observations of the Narrow Line X-Ray Galaxy NGC 5506

Cited by in corpus (13)

• A grid of composite models for the simulation of the emission-line spectra from the NLR of active galaxies
• X-ray binary accretion states in Active Galactic Nuclei? Sensing the accretion disc of supermassive black holes with mid-infrared nebular lines
• The Infrared Continuum of Active Galaxies
• The complex structure of low luminosity AGN : NGC 4579
• Dust-to-gas ratios in the starburst regions of luminous infrared galaxies
• The Narrow Line Region of Ark 564
• The signature of high velocity gas in the spectra of NGC 4151
• The interpretation of the emission spectra of the Seyfert 2 galaxy NGC 7130. Determination of the AGN and starburst contributions
• Dust-to-gas ratios in the Kepler supernova remnant
• 2-D spectroscopy and modeling of the biconical ionized gas in NGC 4388
• The Infrared-X-ray continuum correlation in Active Galactic Nuclei
• The IR spectral energy distribution of the Seyfert 2 prototype NGC 5252
• Comparison of dust-to-gas ratios in luminous, ultraluminous, and hyperluminous infrared galaxies