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J/ApJ/679/86    AGN-host connection in partially obscured AGNs. I. (Wang+, 2008)

Understanding the AGN-host connection in partially obscured active galactic nuclei. I. The nature of AGN+H II composites. Wang J., Wei J.Y. <Astrophys. J., 679, 86-100 (2008)> =2008ApJ...679...86W
ADC_Keywords: Active gal. nuclei ; Equivalent widths ; Line Profiles ; Redshifts ; Spectroscopy Keywords: galaxies: active - galaxies: evolution - galaxies: nuclei Abstract: The goal of our serial papers is to examine the evolutionary connection between an active galactic nucleus (AGN) and star formation in the AGN's host galaxy for partially obscured AGNs (i.e., Seyfert 1.8 and 1.9 galaxies). Taking advantage of these galaxies, the properties of both components can be studied together by direct measurements. In this paper, we focus on broad-line composite galaxies (composite AGNs), which are located between the theoretical and empirical separation lines in the [NII]/Hα versus [OIII]/Hβ diagram. These galaxies are selected from the composite galaxies provided by the SDSS DR4 MPA/JHU catalogs. After we reanalyze the spectra, we perform a fine classification for the 85 composite AGNs in terms of Baldwin-Phillips-Terlevich (BPT) diagrams. All objects located below the three theoretical separation lines are associated with a young stellar population (<1Gyr), while either a young or old stellar population is identified in the individual multiply classified objects. The multiply classified objects with very old stellar populations are located in the LINER region in the [OI]/Hα versus [OIII]/Hβ diagram. We then consider the connection between AGNs and star formation to derive the key results. The Eddington ratio inferred from the broad Hα emission, the age of the stellar population of the AGN's host as assessed by Dn(4000), and the line ratio [OI]/Hα are found to be related to each other. Description: We select a sample of composite AGNs from the SDSS Data Release 4 MPA/JHU catalogs. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 87 85 List of properties of the composite AGNs from SDSS
See also: II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009) J/A+AS/135/437 : AGNs with composite spectra. II. (Goncalves+ 1999) http://www.mpa-garching.mpg.de/SDSS : Home page for MPA/JHU data http://www.sdss.org/ : SDSS home page Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 4 A4 --- --- [SDSS] 6- 24 A19 --- SDSS SDSS name (JHHMMSS.ss+DDMMSS.s) 25 A1 --- f_SDSS [ab] Flag on SDSS J095030.53+011313.7 (1) 27- 31 F5.3 --- z SDSS redshift 33- 36 F4.2 --- NII/Ha Line ratio of [NII]/Hα 38- 41 F4.2 --- SII/Ha ?=- [SII]/Hα line ratio 43- 47 F5.3 --- OI/Ha ?=- [OI]/Hα line ratio 49- 52 F4.2 --- OIII/Hb Line ratio of [OIII]/Hβ 54- 57 F4.2 --- Dn4000 4000AA break (2) 59- 64 F6.3 0.1nm HdA Equivalent width of the Hδ absorption 66- 69 F4.2 10-35W LHa Halpha broad component intrinsic luminosity in 1042erg/s (3) 71- 74 F4.2 [solMass] logM ?=- Logarithm of Mass 76- 80 F5.3 --- L/LEdd ?=- Eddington ratio 82- 87 F6.2 10-33W LOIII Intrinsic luminosity of the [OIII]lambda5007 line in 1040erg/s (3)
Note (1): Flag as follows: a = The spectra ID is spSpec51608-0267-405, given by the SDSS. b = The spectra ID is spSpec51989-0480-120, given by the SDSS. Note (2): The 4000Å break is a strong discontinuity in the optical spectrum of a galaxy. The break is mainly caused by the absorption features of ionized metal lines blueward of 4000Å. The popular definition of Dn(4000) is (Balogh et al., 1999ApJ...527...54B; Bruzual, 1983ApJ...273..105B). See sect. 3.2 for further details. Note (3): Luminosities are corrected for local extinction. The extinction is inferred from the narrow-line ratio Hα/Hβ for each object, assuming the Balmer decrement for standard case B recombination and a Galactic extinction curve with RV=3.1.
History: From electronic version of the journal References: Wang J. & Wei J.Y. Understanding the AGN-Host Connection in Broad Mg II Emission-Selected AGN-Host Hybrid Quasars. 2009ApJ...696..741W Wang J. & Wei J.Y. Paper III. 2010ApJ...719.1157W
(End) Emmanuelle Perret [CDS] 22-Sep-2010
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