J/MNRAS/483/1829 Host galaxies of luminous type 2 AGNs (Urbano-Mayorgas+, 2019)
The host galaxies of luminous type 2 AGNs at z ∼ 0.3-0.4.
Urbano-Mayorgas J.J., Villar Martin M., Buitrago F., Piqueras Lopez J.,
Rodriguez del Pino B., Koekemoer A.M., Huertas-Company M.,
Dominguez-Tenreiro R., Carrera F.J., Tadhunter C.
<Mon. Not. R. Astron. Soc., 483, 1829-1849 (2019)>
=2019MNRAS.483.1829U 2019MNRAS.483.1829U (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; QSOs ; Galaxies, Seyfert
Keywords: galaxies: active - galaxies: evolution - quasars: general
Abstract:
We study the morphological and structural properties of the host
galaxies associated with 57 optically selected luminous type 2 active
galactic nuclei (AGNs) at z∼0.3-0.4: 16 high-luminosity Seyfert 2
[HLSy2, 8.0=<log(L[OIII]/L☉)<8.3] and 41 obscured [QSO2,
log(L[OIII]/L☉)≥8.3] quasars. With this work, the total
number of QSO2s at z<1 with parametrized galaxies increases from ∼35
to 76. Our analysis is based on Hubble Space Telescope WFPC2 and ACS
images that we fit with galfit. HLSy2s and QSO2s show a wide diversity
of galaxy hosts. The main difference lies in the higher incidence of
highly disturbed systems among QSO2s. This is consistent with a
scenario in which galaxy interactions are the dominant mechanism
triggering nuclear activity at the highest AGN power. There is a
strong dependence of galaxy properties with AGN power (assuming
L[OIII] is an adequate proxy). The relative contribution of the
spheroidal component to the total galaxy light (B/T) increases with
L[OIII]. While systems dominated by the spheroidal component spread
across the total range of L[OIII], most disc-dominated galaxies
concentrate at log(L[OIII]/L☉)<8.6. This is expected if more
powerful AGNs are powered by more massive black holes which are hosted
by more massive bulges or spheroids. The average galaxy sizes (<re>)
are 5.0±1.5kpc for HLSy2s and 3.9±0.6kpc for HLSy2s and QSO2s,
respectively. These are significantly smaller than those found for
QSO1s and narrow-line radio galaxies at similar z. We put the results
of our work in the context of related studies of AGNs with quasar-like
luminosities.
Description:
The sample studied here consists of 57 luminous
(lO3=log(L[OIII]/L☉)≥8.0) type 2 AGNs at 0.3<z<0.4 from
Zakamska et al. (2003AJ....126.2125Z 2003AJ....126.2125Z, Cat. J/AJ/126/2125) and Reyes et
al. (2008AJ....136.2373R 2008AJ....136.2373R, Cat. J/AJ/136/2373) catalogues of Sloan
Digital Sky Survey (SDSS) luminous type 2 AGNs.
Zakamska et al. (2003AJ....126.2125Z 2003AJ....126.2125Z, Cat. J/AJ/126/2125) selected 291
luminous type 2 AGNs (lO3>7.3), at z<0.83, from SDSS on the basis of
their optical emission-line properties: narrow emission lines (full
width at half-maximum, FWHM < 2000km/s) without underlying broad
components and optical line ratios typical of active galaxies,
consistent with non-stellar ionizing radiation. Reyes et al.
(2008AJ....136.2373R 2008AJ....136.2373R, Cat. J/AJ/136/2373) updated this catalogue based
on ∼3 times as much SDSS data. Their catalogue contains 887 luminous
type 2 AGNs (lO3>7.9), recovering >90 per cent of objects in Zakamska
et al. (2003AJ....126.2125Z 2003AJ....126.2125Z, Cat. J/AJ/126/2125) in the same
luminosity range. The spectra of the objects they missed tend to have
low S/N or ambiguous classification. About 744 (84 per cent) objects
in Reyes et al. (2008AJ....136.2373R 2008AJ....136.2373R, Cat. J/AJ/136/2373) have
lO3≥8.3 and are, therefore, QSO2s. This threshold ensures the
selection of objects with AGN luminosities in the quasar regime. Using
L[OIII] as a proxy for AGN power (Heckman et al.
2004ApJ...613..109H 2004ApJ...613..109H), the implied bolometric luminosities are above
the classical Seyfert/quasar separation of Lbol ∼1045erg/s. Only ∼15
per cent ±5 per cent QSO2s are expected to be radio-loud (Lal & Ho
2010AJ....139.1089L 2010AJ....139.1089L).
The 57 AGNs studied here are the sample of objects observed for the
HST programme 10880, with principal investigator Henrique Schmitt. HST
imaging observations for other programmes exist for several more
QSO2s, but in general they have been done with different filters
and/or the targets are at different z than our sample. Since the
statistics will not improve significantly, these are not considered in
our study.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 104 57 List of objects observed for the HST programme
10880
table3.dat 49 42 Comparison between the total magnitude and the
half-radius calculated with SExtractor and the
effective radius inferred with the task ellipse
applied to the GALFIT 2D model image
table5.dat 111 42 List of the 42/57 objects that could be fitted
with GALFIT and results of the best fits
table6.dat 106 57 Results of the visual and parametric
classification
tablea1.dat 82 15 Test performed for several normal galaxies in
the fields of three AGNs of our WFPC2 sub-sample
to investigate the impact of the PSF
undersampling
tablea2.dat 99 12 Test performed for 4 random AGN hosts of our
sample to investigate the impact of the PSF
undersampling
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 24 A24 --- Name Object name (SDSS JHHMMSS.ss+DDMMSS.s)
26- 30 F5.3 --- z Redshift
32- 35 F4.2 kpc/arcsec Scale kpc/arcsec conversion
37- 40 F4.2 [Lsun] logLO3 OIII line luminosity
42- 46 A5 --- Instr HST instrument (ACS or WFPC2)
48- 52 A5 --- Filter HST filter (F775W or F814W)
54- 63 A10 "date" Date Date of observation
65- 69 A5 --- AGNtype AGN classification (QSO2s or HLSy2s) (1)
71-104 A34 --- Emlines Emission lines contaminating the filter
--------------------------------------------------------------------------------
Note (1): AGN classification as follows:
QSO2 = Type 2 obscured QSOs (LO3>8.3) (41 objects)
HLSy2 = High-luminosity Seyfert 2 (8<LO3<8.3) (16 objects)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 24 A24 --- Name Object name (SDSS JHHMMSS.ss+DDMMSS.s)
26- 29 F4.2 [Lsun] logLO3 OIII line luminosity
31- 34 F4.1 mag magS Total magnitude calculated with SExtractor (1)
36- 39 F4.1 mag magG Integrated magnitude inferred with the task
ELLIPSE applied to the GALFIT 2D model image (2)
41- 44 F4.1 kpc HrS Half-radius calculated with SExtractor (1)
46- 49 F4.1 kpc ReffG Effective radius inferred with the task ELLIPSE
applied to the GALFIT 2D model image (2)
--------------------------------------------------------------------------------
Note (1): The SExtractor values were obtained by applying the code to the HST
data
Note (2): The galfit mag and Reff values were measured in the best-fitting
model image
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 24 A24 --- Name Object name (SDSS JHHMMSS.ss+DDMMSS.s)
26- 27 A2 --- Method Method to obtain the best fit (1)
29- 32 F4.1 mag magG Total magnitude of the GALFIT galaxy model
34- 37 F4.1 kpc ReffG Effective radius of the GALFIT galaxy model
39- 42 F4.1 mag magPS ? Magnitude of the point source
44- 48 F5.2 --- lfracPS ? Relative contribution (light fraction) to
the total galaxy luminosity of the point
source
50- 53 F4.1 mag magFPC Magnitude of the first component identified
with GALFIT
55- 60 F6.2 --- lfracFPC Light fraction of the first component
identified with GALFIT
62- 65 F4.1 kpc ReffFPC Effective radius of the first component
identified with GALFIT
67- 69 F3.1 --- nFPC Sersic index of the first component identified
with GALFIT
71- 74 F4.2 --- b/aFPC Axial ratio of the first component identified
with GALFIT
76- 80 F5.1 deg PAFPC Position angle of the first component
identified with GALFIT
82- 85 F4.1 mag magSPC ? Magnitude of the second component identified
with GALFIT
87- 91 F5.2 --- lfracSPC ? Light fraction of the second component
identified with GALFIT
93- 96 F4.1 kpc ReffSPC ? Effective radius of the second component
identified with GALFIT
98-100 F3.1 --- nSPC ? Sersic index of the second component
identified with GALFIT
102-105 F4.2 --- b/aSPC ? Axial ratio of the second component
identified with GALFIT
107-111 F5.1 deg PASPC ? Position angle of the second component
identified with GALFIT
--------------------------------------------------------------------------------
Note (1): Method as follows:
1 = Single Sersic
2A = Sersic + disc
2B = PS + Sersic
2C = PS + disc + Sersic
2D = Other
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 24 A24 --- Name Object name (SDSS JHHMMSS.ss+DDMMSS.s)
26- 29 F4.2 [Lsun] logLO3 OIII line luminosity
31- 37 A7 --- VisI Galaxy morphological type based on Method
Vis-I (1)
39- 41 A3 --- VisII Type of merger based on Method Vis-II (2)
43- 55 A13 --- VisIII Nature of the peculiar features based on
Method Vis-III (3)
57- 59 A3 --- ParamMet Classification based on the parametric
method (4)
61- 75 A15 --- Details Type of profile according to the dominant
structural component (5)
77-106 A30 --- visparam Comparison between the visual and parametric
classifications
--------------------------------------------------------------------------------
Note (1): Galaxy morphological type as follows:
El = Elliptical
Sp = Spiral
disc = Disc galaxy with no obvious spiral arms
HD = Highly disturbed: when 2 or more components are interacting and make
the classification in the previous groups difficult
Note (2): Type of merger following Rodriguez Zaurin et al. (2011A&A...527A..60R 2011A&A...527A..60R)
and Veilleux et al. (2002ApJS..143..315V 2002ApJS..143..315V, Cat. J/ApJS/143/315)
as follows:
0 = Isolated undisturbed galaxy
0* = Isolated disturbed galaxy
1 = Two nuclei with projected separation >1.5kpc
2 = Two nuclei with projected separation =<1.5 or single nucleus with
signatures of a post-coalescence phase
Note (3): Nature of the peculiar features following Ramos-Almeida et al.
(2012MNRAS.419..687R 2012MNRAS.419..687R, Cat. J/MNRAS/419/687) as follows:
T = Tidal tail
F = Fan
B = Bridge
S = Shell
D = Dust feature
2N = Double nucleus
A = Amorphous halo
I = Irregular feature
IC = Interacting companion
2N* = Two nuclei with relative distance greater than 1.5kpc
PC = Projected companion, that is, there is an object close to the target in
projection with no clear physical relation
K = Knot
tt = Streams
? = Indicates uncertain classification or identification
Note (4): Method as follows:
1 = Single Sersic
2A = Sersic + disc
2B = PS + Sersic
2C = PS + disc + Sersic
2D = Other
N/A = Object that could not be fitted with GALFIT
Note (5): Type of profile as follows:
HD = Highly disturbed objects that could not be fitted with
GALFIT
Point source = System dominated by a spatially unresolved source
Disc-dominated = System dominated by a disc or disc-like component
Bulge-dominated = System dominated by a spheroidal component
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Name 5 random normal galaxies in the fields of three
AGNs of our WFPC2 sub-sample
10 A1 --- Image Host galaxy image used for the GALFIT
fitting (1)
12- 15 F4.1 mag magG Total magnitude of the GALFIT galaxy model
17- 20 F4.1 mag magPS ? Magnitude of the point source
22- 26 F5.2 --- lfracPS ? Relative contribution (light fraction) to the
total galaxy luminosity of the point source
28- 31 F4.1 mag magS1 Magnitude of first Sersic component
33- 38 F6.2 --- lfracS1 Relative contribution (light fraction) to the
total galaxy luminosity of first Sersic
component
40- 42 F3.1 kpc ReffS1 Effective radius of first Sersic component
44- 46 F3.1 --- nS1 Sersic index of first Sersic component
48- 51 F4.1 mag magS2 ? Magnitude of second Sersic component
53- 57 F5.2 --- lfracS2 ? Relative contribution (light fraction) to the
total galaxy luminosity of second Sersic
component
59- 61 F3.1 kpc ReffS2 ? Effective radius of second Sersic component
63- 65 F3.1 --- nS2 ? Sersic index of second Sersic component
67- 82 A16 --- Class Galaxy classification
--------------------------------------------------------------------------------
Note (1): Galaxy image as follows:
a = Hubble Legacy Archive (HLA) image using combined field stars to produce
the PSF
b = Original, unrotated calibrated image using also combined field stars for
the PSF
c = Original, unrotated calibrated image convolved with a Gaussian whose
FWHM ensures achieving Nyquist sampling
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 24 A24 --- Name Object name (SDSS JHHMMSS.ss+DDMMSS.s)
26 A1 --- Image Host galaxy image used for the GALFIT
fitting (1)
28- 31 F4.1 mag magG Total magnitude of the GALFIT galaxy model
33- 36 F4.1 mag magPS ? Magnitude of the point source
38- 42 F5.2 --- lfracPS ? Relative contribution (light fraction) to the
total galaxy luminosity of the point source
44- 47 F4.1 mag magS1 Magnitude of first Sersic component
49- 54 F6.2 --- lfracS1 Relative contribution (light fraction) to the
total galaxy luminosity of first Sersic
component
56- 59 F4.1 kpc ReffS1 Effective radius of first Sersic component
61- 63 F3.1 --- nS1 Sersic index of first Sersic component
65- 68 F4.1 mag magS2 ? Magnitude of second Sersic component
70- 74 F5.2 --- lfracS2 ? Relative contribution (light fraction) to the
total galaxy luminosity of second Sersic
component
76- 78 F3.1 kpc ReffS2 ? Effective radius of second Sersic component
80- 82 F3.1 --- nS2 ? Sersic index of second Sersic component
84- 99 A16 --- Class Galaxy classification
--------------------------------------------------------------------------------
Note (1): Galaxy image as follows:
a = Hubble Legacy Archive (HLA) image using combined field stars to produce
the PSF
b = Original, unrotated calibrated image using also combined field stars for
the PSF
c = Original, unrotated calibrated image convolved with a Gaussian whose
FWHM ensures achieving Nyquist sampling
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 18-Jul-2022