J/ApJ/737/101 AGN pairs from SDSS-DR7. I. (Liu+, 2011)
Active galactic nucleus pairs from the Sloan Digital Sky Survey.
I. The frequency on ∼5-100 kpc scales.
Liu X., Shen Y., Strauss M.A., Hao L.
<Astrophys. J., 737, 101 (2011)>
=2011ApJ...737..101L 2011ApJ...737..101L
ADC_Keywords: Active gal. nuclei ; Redshifts ; Spectroscopy ; Photometry, SDSS ;
QSOs ; Galaxies, Seyfert
Keywords: black hole physics - galaxies: active - galaxies: interactions -
galaxies: nuclei - quasars: general
Abstract:
Galaxy-galaxy mergers and close interactions have long been regarded
as a viable mechanism for channeling gas toward the central
supermassive black holes (SMBHs) of galaxies which are triggered as
active galactic nuclei (AGNs). AGN pairs, in which the central SMBHs
of a galaxy merger are both active, are expected to be common from
such events. We conduct a systematic study of 1286 AGN pairs at
{bar}z∼0.1 with line-of-sight velocity offsets Δv<600km/s and
projected separations rp<100h-170kpc, selected from the Seventh
Data Release of the Sloan Digital Sky Survey (SDSS, Cat. II/294). This
AGN pair sample was drawn from 138070 AGNs optically identified based
on diagnostic emission line ratios and/or line widths. The fraction of
AGN pairs with 5h-170kpc≲rp<100h-170kpc among all
spectroscopically selected AGNs at 0.02<z<0.16 is 3.6% after
correcting for SDSS spectroscopic incompleteness; ∼30% of these pairs
show morphological tidal features in their SDSS images, and the
fraction becomes ≳80% for pairs with the brightest nuclei.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 66 2618 SDSS AGN Pairs (from SDSS-DR7)
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See also:
VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
J/AJ/142/122 : SDSS DR7 galaxy/QSOs pairs (Cherinka+, 2011)
J/ApJ/708/427 : Type 2 AGNs with double-peaked [OIII] lines (Liu+, 2010)
J/AJ/136/2373 : Type 2 quasars from SDSS (Reyes+, 2008)
J/ApJ/658/99 : Pairs of QSO in SDSS-DR4 (Myers+, 2007)
J/AJ/126/2125 : SDSS candidate type II quasars (Zakamska+, 2003)
J/ApJS/112/315 : Spectroscopic parameters of Seyfert nuclei (Ho+ 1997)
http://www.sdss.org/ : SDSS home page
http://www.mpa-garching.mpg.de/SDSS/DR7/ : The MPA-JHU DR7 release of
spectrum measurements
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 of observation
36- 41 F6.4 --- z [0.02/0.27] Redshift
43- 47 F5.1 arcsec sep [1.5/232] Angular separation Δθ
49- 52 F4.1 kpc rp Transverse proper separation rp (h70-1kpc)
54- 56 I3 km/s dV Line-of-sight velocity offset ΔV
58- 62 F5.2 mag rmag [12.47/20.38] SDSS r-band model magnitude
corrected for Galactic extinction
64 I1 --- FAGN [0/5] Sub-population flag (1)
66 I1 --- FTid [0/3]? Tidal flag (2)
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Note (1): Flag for sub-populations in the parent AGN sample:
* "0" through "2" are for narrow-line AGNs contained in the MPA-JHU DR7
catalog, where "0" stands for Seyferts, "1" for LINERs, and "2" for
composites, respectively, according to the Kewley et al.
(2001ApJ...556..121K 2001ApJ...556..121K) and Kauffmann et al. (2003MNRAS.346.1055K 2003MNRAS.346.1055K)
criteria for separating AGNs and composites from HII regions, and
the Ho et al. (1997, Cat. J/ApJS/112/315) criterion for separating
Seyferts from LINERS (Figure 4).
* "3" for narrow-line quasars in the Reyes et al. (2008,
Cat. J/AJ/136/2373) sample but not in the MPA-JHU DR7 catalog;
* "4" for broad-line quasars, and "5" for broad-line AGNs according
to the Hao et al. (2005AJ....129.1783H 2005AJ....129.1783H) selection.
Note (2): Flag from visual identification of tidal features as follows :
0 = non-interaction,
1 = ambiguous,
2 = tidal,
3 = "dumbbell" systems.
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History:
From electronic version of the journal
References:
Liu et al. Paper II. 2012ApJ...745...94L 2012ApJ...745...94L
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 10-Jan-2013