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A View of the Narrow-line Region in the Infrared: Active Galactic Nuclei With Resolved Fine-Structure Lines in the Spitzer Archive

Dasyra, K. M. and Ho, L. C. and Netzer, H. and Combes, F. and Trakhtenbrot, B. and Sturm, E. and Armus, L. and Elbaz, D. (2011) A View of the Narrow-line Region in the Infrared: Active Galactic Nuclei With Resolved Fine-Structure Lines in the Spitzer Archive. Astrophysical Journal, 740 (2). Art. No. 94. ISSN 0004-637X.

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We queried the Spitzer archive for high-resolution observations with the Infrared Spectrograph of optically selected active galactic nuclei (AGNs) for the purpose of identifying sources with resolved fine-structure lines that would enable studies of the narrow-line region (NLR) at mid-infrared wavelengths. By combining 298 Spitzer spectra with 6 Infrared Space Observatory spectra, we present kinematic information of the NLR for 81, z ≾ 0.3 AGNs. We used the [Ne v], [O iv], [Ne iii], and [S iv] lines, whose fluxes correlate well with each other, to probe gas photoionized by the AGN. We found that the widths of the lines are, on average, increasing with the ionization potential of the species that emit them. No correlation of the line width with the critical density of the corresponding transition was found. The velocity dispersion of the gas, σ, is systematically higher than that of the stars, σ_∗, in the AGN host galaxy, and it scales with the mass of the central black hole, M_(BH). Further correlations between the line widths and luminosities L, and between L and M_(BH), are suggestive of a three-dimensional plane connecting log(M_(BH)) to a linear combination of log(σ) and log(L). Such a plane can be understood within the context of gas motions that are driven by AGN feedback mechanisms, or virialized gas motions with a power-law dependence of the NLR radius on the AGN luminosity. The M_(BH) estimates obtained for 35 type 2 AGNs from this plane are consistent with those obtained from the M_(BH)–σ_∗ relation.

Item Type:Article
Related URLs:
URLURL TypeDescription
Ho, L. C.0000-0001-6947-5846
Combes, F.0000-0003-2658-7893
Trakhtenbrot, B.0000-0002-3683-7297
Armus, L.0000-0003-3498-2973
Elbaz, D.0000-0002-7631-647X
Additional Information:© 2011 The American Astronomical Society. Received 2011 March 25; accepted 2011 July 18; published 2011 October 4. K.D. acknowledges support by the European Community through a Marie Curie Fellowship (PIEF-GA-2009-235038) awarded under the Seventh Framework Programme (FP7/2007-2013). The authors thank T. Boroson and B. Peterson for providing optical spectra to be compared with the MIR ones, and S. Collin for useful discussions. This work made use of the NASA/IPAC Extragalactic Database, and it was based on archival data obtained with the Spitzer Space Telescope, operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Marie Curie FellowshipPIEF-GA-2009-235038
Subject Keywords:galaxies: active; galaxies: kinematics and dynamics; galaxies: nuclei; galaxies: Seyfert; infrared: galaxies; quasars: emission lines
Issue or Number:2
Record Number:CaltechAUTHORS:20111206-101656096
Persistent URL:
Official Citation:A View of the Narrow-line Region in the Infrared: Active Galactic Nuclei with Resolved Fine-structure Lines in the Spitzer Archive K. M. Dasyra et al. 2011 ApJ 740 94
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:28315
Deposited By: Ruth Sustaita
Deposited On:06 Dec 2011 18:52
Last Modified:03 Oct 2019 03:31

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