J/ApJ/804/34 Luminous AGNs and early-type SDSS galaxies (Hong+, 2015)
Correlation between galaxy mergers and luminous active galactic nuclei.
Hong J., Im M., Kim M., Ho L.C.
<Astrophys. J., 804, 34 (2015)>
=2015ApJ...804...34H 2015ApJ...804...34H
ADC_Keywords: Active gal. nuclei ; Magnitudes, absolute ; Morphology ;
Galaxies, optical
Keywords: galaxies: active; galaxies: evolution; galaxies: general;
galaxies: interactions; galaxies: nuclei; quasars: general
Abstract:
It is not yet clear what triggers the activity of active galactic
nuclei (AGNs), but galaxy merging has been suspected to be one of the
main mechanisms fueling the activity. Using deep optical images taken
at various ground-based telescopes, we investigate the fraction of
galaxy mergers in 39 luminous AGNs (MR≲-22.6mag) at z≤0.3 (a
median redshift of 0.155), for which the host galaxies are generally
considered as early-type galaxies. Through visual inspection of the
images, we find that 17 of 39 AGN host galaxies (43.6%) show evidence
for current or past mergers like tidal tails, shells, and disturbed
morphology. In order to see if this fraction is abnormally high, we
also examined the merging fraction of normal early-type galaxies in
the Sloan Digital Sky Survey (SDSS) Stripe 82 data (a median redshift
of 0.04), of which the surface-brightness limit is comparable to our
imaging data. To correct for the effects related to the redshift
difference of the two samples, we performed an image simulation by
putting a bright point source as an artificial AGN in the images of
SDSS early-type galaxies and placing them onto the redshifts of AGNs.
The merging fraction in this realistic sample of simulated AGNs is
only ∼5-15% (1/4 to 1/8 of that of real AGNs). Our result strongly
suggests that luminous AGN activity is associated with galaxy merging.
Description:
The base sample comprises 39 luminous type-1 AGNs at z<0.3. In order
to reveal faint, extended merging features around AGNs, we obtained
deep optical images using several facilities. We observed 10 AGNs
using SNUCAM on the 1.5m telescope at the Maidanak observatory in
Uzbekistan from 2010 June to 2011 August, six AGNs using the Camera
for QUasars in EArly uNiverse (CQUEAN) on the 2.1m telescope at the
McDonald observatory in Texas from 2011 February to April, and 21 AGNs
using the SITe2K CCD camera of the 2.5m DuPont telescope at the Las
Campanas observatory from 2008 September to 2009 March.
We look into the merging fraction of AGNs through the presence of a
merging feature in AGN host galaxies. To compare it with the merging
fraction of inactive galaxies, we construct a control sample. The
control sample is restricted to only early-type galaxies.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 92 39 AGN sample
table3.dat 101 317 Control sample of early-type galaxies from
SDSS Stripe 82
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See also:
VII/258 : Quasars and Active Galactic Nuclei (13th Ed.) (Veron+ 2010)
J/AJ/148/137 : Merging galaxies in COSMOS to z∼1 (Lackner+, 2014)
J/ApJ/766/109 : Color/age/metallicity gradients of E galaxies (Kim+, 2013)
J/ApJS/197/22 : The Carnegie-Irvine Galaxy Survey (GGS). II. (Li+, 2011)
J/ApJS/197/21 : The Carnegie-Irvine Galaxy Survey (CGS). I. (Ho+, 2011)
J/ApJS/196/11 : Bulge+disk decompositions of SDSS galaxies (Simard+, 2011)
J/ApJ/721/98 : Morphology of 70um COSMOS galaxies (Kartaltepe+, 2010)
J/ApJ/709/884 : Starburst-AGN composite role in LIRG mergers (Yuan+, 2010)
J/MNRAS/406/382 : Early-type galaxies in the SDSS Stripe82 (Kaviraj, 2010)
J/ApJ/697/1369 : GOODS Ks-selected multiwavelength compilations (Bundy+, 2009)
J/ApJ/692/511 : Mergers of luminous early-type galaxies (Wen+, 2009)
J/ApJ/640/579 : Near-infrared spectra of 27 SDSS quasars (Glikman+, 2006)
J/AJ/132/2596 : Spectroscopy of Ultraluminous IR galaxies (Darling+, 2006)
J/AJ/130/2647 : Tidal features of 126 nearby red galaxies (van Dokkum+, 2005)
J/ApJ/613/682 : AGN central mass & broad-line region sizes (Peterson+, 2004)
J/ApJ/571/136 : DEEP Groth Strip survey. X. (Im+, 2002)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name AGN name
15- 18 F4.2 --- z [0.05/0.3] Redshift
20- 24 F5.2 mag Vmag [13.8/17.5] Apparent V-band magnitude from
Veron-Cetty+, 2010, VII/258
26- 31 F6.2 mag RMag [-26.1/-22.7] Absolute R-band magnitude (1)
33- 35 F3.1 [Msun] logMbh [7.4/8.9] log Black hole mass
37 A1 --- n_logMbh Method for estimating logMbh (2)
39- 41 A3 --- r_logMbh References for logMbh (3)
43- 48 F6.2 mag Mag.n [-26.1/-18.9] Absolute R-band magnitude of
the AGN nuclear component (4)
50- 55 F6.2 mag Mag.b [-24/-20.9] Absolute R-band magnitude of
the bulge of the AGN (4)
57- 62 F6.2 mag Mag.h [-24.1/-21.3] Absolute R-band magnitude of
the AGN host galaxy (4)
64- 68 F5.3 --- L/Edd [0.01/0.7]? Eddington ratio from Kim et al.
(2008ApJ...687..767K 2008ApJ...687..767K)
70 A1 --- n_mu Filter (V, R, i or r)
72- 76 I5 s Exp [640/14400] Integrated exposure time
78- 82 F5.2 mag/arcsec2 mu [25/28] Surface-brightness limit (5)
84- 87 F4.2 arcsec See [0.7/2.6] Seeing FWHM
89- 90 A2 --- Tel Telescope (6)
92 A1 --- Cl Merging type (7)
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Note (1): Converted from absolute B-band magnitude.
Note (2): Method as follows:
R = reverberation mapping;
S = single-epoch method
Note (3): Reference as follows:
Kim = Kim et al. (2008ApJ...687..767K 2008ApJ...687..767K); Kim et al. 2015, in preparation (K15);
VP = Vestergaard & Peterson (2006ApJ...641..689V 2006ApJ...641..689V)
Note (4): See Section 2.3 for how we derived Mbh and absolute magnitudes of
components. Bulge magnitudes come from an SB fitting of the images
from D or C in column "Tel" and from the black hole mass for Ma or Mc
in column "Tel".
Note (5): Surface-brightness limit, averaged over a 1"x1" area at 1σ
per pixel in the observed band.
Note (6): Telescope as follows:
D = 2.5m DuPont telescope in Las Campanas,
C = CFHT,
Ma = 1.5m telescope in Maidanak observatory,
Mc = 2.1m telescope in McDonald observatory
Note (7): Merging type as follows:
T = tidal tail;
S = shell structures;
I = interaction;
N = no merging feature
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq [2/3726] ID from Kaviraj 2010, J/MNRAS/406/382
6- 23 I18 --- objID SDSS-DR7 object identifier
25- 34 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
36- 44 F9.6 deg DEdeg Declination in decimal degrees (J2000)
46- 50 F5.3 --- z [0.01/0.05] Redshift
52- 57 F6.3 mag Rmag [12.2/16.1] Apparent R band magnitude
59- 63 F5.3 mag e_Rmag [0.002/0.005] Error in Rmag
65- 69 F5.3 --- B/T [0.1/1] Bulge-to-Total ratio
71- 77 F7.3 --- e_B/T [0/0.3]?=-99.99 Error in B/T (1)
79- 85 F7.3 mag RMag [-23.2/-18.8] Absolute bulge component
R band magnitude
87- 91 F5.3 mag e_RMag [0/0.7] Error in RMag
93- 97 F5.3 [Msun] logMbh [6.8/9.1] Log Black Hole mass
99 I1 --- TT0 Kaviraj 2010 (J/MNRAS/406/382) morphological
type (2)
101 A1 --- TT [INST] Morphological type from this work (3)
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Note (1): A -99.99 indicates that the SB model does not have a disk component.
Note (2): Morphological type as follows:
1 = Relaxed;
2 = Tidal feature;
3 = Dust feature;
4 = Tidal and dust feature;
5 = Interacting;
7 = Spheroids with faint disk.
Note (3): Morphological type as follows:
I = interaction
N = Relaxed;
T = tidal feature;
S = Shell-type.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 05-Aug-2015