J/ApJ/708/427 Type 2 AGNs with double-peaked [OIII] lines (Liu+, 2010)
Type 2 active galactic nuclei with double-peaked [O III] lines: narrow-line
region kinematics or merging supermassive black hole pairs?
Liu X., Shen Y., Strauss M.A., Greene J.E.
<Astrophys. J., 708, 427-434 (2010)>
=2010ApJ...708..427L 2010ApJ...708..427L
ADC_Keywords: Redshifts ; Galaxies, spectra ; Active gal. nuclei
Keywords: black hole physics - cosmology: observations - galaxies: active -
quasars: general - surveys
Abstract:
We present a sample of 167 type 2 active galactic nuclei (AGNs) with
double-peaked [OIII]4959,5007 narrow emission lines, selected from the
Seventh Data Release of the Sloan Digital Sky Survey. The
double-peaked profiles can be well modeled by two velocity components,
blueshifted and redshifted from the systemic velocity. Half of these
objects have a more prominent redshifted component. In cases where the
Hβ emission line is strong, it also shows two velocity components
whose line-of-sight (LOS) velocity offsets are consistent with those
of [OIII]. The relative LOS velocity offset between the two components
is typically a few hundred km/s, larger by a factor of ∼1.5 than the
line full width at half maximum of each component. The offset
correlates with the host stellar velocity dispersion σ*. The
host galaxies of this sample show systematically larger σ*,
stellar masses, and concentrations, and older luminosity-weighted mean
stellar ages than a regular type 2 AGN sample matched in redshift,
[OIII]5007 equivalent width, and luminosity; they show no significant
difference in radio properties. These double-peaked features could be
due to narrow-line region kinematics, or binary black holes.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 73 167 The sample of type-2 AGNs
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See also:
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
J/A+A/534/A110 : Type-2 AGN from XMM-COSMOS bolometric output (Lusso+,
2011)
J/A+A/510/A56 : zCOSMOS type-2 AGN (Bongiorno, 2010)
J/MNRAS/399/1206 : SWIRE/SDSS quasars. II. Type 2 AGN (Hatziminaoglou+,
2009)
J/ApJ/705/L76 : AGNs with double-peaked [OIII] lines (Wang+, 2009)
J/AJ/136/2373 : Type 2 quasars from SDSS (Reyes+, 2008)
J/ApJ/549/155 : [OIII] emission in a sample of AGNs (Nagao+, 2001)
http://www.sdss.org/ : SDSS home page
http://www.mpa-garching.mpg.de/SDSS/ : MPA-JHU SDSS DR7 home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- SDSS SDSS designation (JHHMMSS.ss+DDMMSS.s)
21- 24 I4 --- Plate Spectroscopic plate number
26- 28 I3 --- Fiber Fiber identification
30- 34 I5 d MJD Modified Julian Date
35 A1 --- f_SDSS [f] Flag on SDSS J130128.76-005804.3 (1)
37- 42 F6.4 --- z Redshift from the specBS pipeline (2)
44- 46 I3 km/s sigma ?=0 Host stellar velocity dispersion (3)
48- 50 I3 km/s FWHM1 ?=0 Blueshifted [OIII] component FWHM (4)
52- 54 I3 km/s FWHM2 ?=0 Redshifted [OIII] component FWHM (4)
56- 59 I4 km/s VOIII1 ?=0 Blueshifted [OIII] component velocity
offset (5)
61- 63 I3 km/s VOIII2 ?=0 Redshifted [OIII] component velocity
offset (5)
65- 68 I4 km/s VHb1 ?=0 Blueshifted Hβ component velocity
offset (6)
70- 73 I4 km/s VHb2 ?=0 Redshifted Hβ component velocity
offset (6)
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Note (1): The plate-MJD-fiber found in the SDSS-DR7 for this object is:
293-51994-016 and not 293-51689-007 as found in the paper; table
corrected at CDS.
Note (2): Our parent sample is the MPA-JHU SDSS DR7 galaxy sample drawn from
the SDSS DR7 spectroscopic database (Abazajian et al. 2009,
Cat. II/294); those include objects spectrally classified as galaxies
by the specBS pipeline (Adelman-McCarthy et al. 2008, Cat. II/282) or
quasars that are targeted as galaxies (Strauss et al.
2002AJ....124.1810S 2002AJ....124.1810S; Eisenstein et al. 2001AJ....122.2267E 2001AJ....122.2267E) and have
redshifts z<0.7. We adopt redshifts z and stellar velocity dispersions
σ* from the specBS pipeline. We have checked the accuracy of
the redshift by refitting the stellar continuum with galaxy templates
(Liu et al. 2009ApJ...702.1098L 2009ApJ...702.1098L), as well as comparing multiple epoch
spectra of the same objects. See section 2.1 for further details.
Note (3): The typical uncertainty is ∼15km/s. A zero is given if the quantity is
unmeasurable.
Note (4): The typical statistical error is ∼10km/s. A zero is given if the
quantity is unmeasurable.
Note (5): The typical statistical error is ∼5km/s. A zero is given if the
quantity is unmeasurable.
Note (6): The typical statistical error is generally a few times larger than in
[OIII] since Hβ is weaker than [OIII]. A zero is given if the
quantity is unmeasurable.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 01-Feb-2012