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 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:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 87 85 List of properties of the composite AGNs from SDSS
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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
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Bytes Format Units Label Explanations
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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 4000Å break (2)
59- 64 F6.3 0.1nm HdA Equivalent width of the Hδ absorption
66- 69 F4.2 10-35W LHa Hα 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]λ5007
line in 1040erg/s (3)
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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 1999ApJ...527...54B;
Bruzual, 1983ApJ...273..105B 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.
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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 2009ApJ...696..741W
Wang J. & Wei J.Y. Paper III. 2010ApJ...719.1157W 2010ApJ...719.1157W
(End) Emmanuelle Perret [CDS] 22-Sep-2010