NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-04-20 T17:28:51 PDT
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For refcode 2013ApJS..204...23V:
Retrieve 48 NED objects in this reference.
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2013ApJS..204...23V Nuclear Infrared Spectral Energy Distribution of Type II Active Galactic Nuclei Videla, Liza; Lira, Paulina; Andrews, Heather; Alonso-Herrero, Almudena; Alexander, David M.; Ward, Martin Abstract. We present near- and mid-IR observations of a sample of Seyfert II galaxies drawn from the 12 micron Galaxy sample. The sample was observed in the J, H, K, L, M and N bands. Galaxy surface brightness profiles are modeled using nuclear, bulge, bar (when necessary), and disk components. To check the reliability of our findings, the procedure was tested using Spitzer observations of M 31. Nuclear spectral energy distributions (SEDs) are determined for 34 objects, and optical spectra are presented for 38, including analysis of their stellar populations using the STARLIGHT spectral synthesis code. Emission line diagnostic diagrams are used to discriminate between genuine active galactic nuclei (AGNs) and H II nuclei. Combining our observations with those found in the literature, we have a total of 40 SEDs. It is found that about 40% of the SEDs are characterized by an upturn in the near-IR, which we have quantified as a NIR slope {alpha} < 1 for an SED characterized as lambdaf_lambda_vproplambda^{alpha}^. The three objects with an H II nucleus and two Seyfert nuclei with strong contamination from a circumnuclear also show an upturn. For genuine AGNs, this component could be explained as emission from the accretion disk, a jet, or from a very hot dust component leaking from the central region through a clumpy obscuring structure. The presence of a very compact nuclear starburst as the origin for this NIR excess emission is not favored by our spectroscopic data for these objects. Key words: galaxies: active, galaxies: nuclei, galaxies: Seyfert
Retrieve 48 NED objects in this reference.
Please click here for ADS abstract

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