J/ApJS/256/40 HST imaging survey of low-z Swift-BAT AGNs (Kim+, 2021)
A Hubble Space Telescope imaging survey of low-redshift Swift-BAT active
galaxies.
Kim M., Barth A.J., Ho L.C., Son S.
<Astrophys. J. Suppl. Ser., 256, 40 (2021)>
=2021ApJS..256...40K 2021ApJS..256...40K
ADC_Keywords: Active gal. nuclei; Gamma rays; Photometry, HST; Optical;
Redshifts; Morphology
Keywords: Active galaxies
Abstract:
We present initial results from a Hubble Space Telescope snapshot
imaging survey of the host galaxies of Swift-BAT active galactic
nuclei (AGN) at z<0.1. The hard X-ray selection makes this sample
relatively unbiased in terms of obscuration, compared to optical AGN
selection methods. The high-resolution images of 154 target AGN enable
us to investigate the detailed photometric structure of the host
galaxies, such as the Hubble type and merging features. We find 48%
and 44% of the sample to be hosted by early-type and late-type
galaxies, respectively. The host galaxies of the remaining 8% of the
sample are classified as peculiar galaxies because they are heavily
disturbed. Only a minor fraction of host galaxies (18%-25%) exhibit
merging features (e.g., tidal tails, shells, or major disturbance).
The merging fraction increases strongly as a function of bolometric
AGN luminosity, revealing that merging plays an important role in
triggering luminous AGN in this sample. However, the merging fraction
is weakly correlated with the Eddington ratio, suggesting that merging
does not necessarily lead to an enhanced Eddington ratio. Type 1 and
Type 2 AGN are almost indistinguishable in terms of their Hubble type
distribution and merging fraction. However, the merging fraction of
Type 2 AGN peaks at a lower bolometric luminosity compared with those
of Type 1 AGN. This result may imply that the triggering mechanism and
evolutionary stages of Type 1 and Type 2 AGN are not identical.
Description:
Observations for HST program 15444 began in 2018 March and are ongoing
(at a low rate) during the first half of 2021. This paper includes
data taken through 2021 June. We used ACS/WFC with the F814W filter,
which is approximately equivalent to the I band.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 135 154 The sample
table2.dat 41 154 Morphology of host galaxies
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See also:
B/hst : HST Archived Exposures Catalog (STScI, 2007)
J/ApJS/147/1 : Classification of nearby galaxies (Conselice+, 2003)
J/AJ/128/163 : Galaxy morphological classification (Lotz+, 2004)
J/AJ/132/321 : Morphology of narrow-line Seyfert 1 galaxies (Deo+, 2006)
J/ApJ/739/57 : Ultra hard X-ray AGNs in the Swift/BAT survey (Koss+, 2011)
J/ApJ/746/L22 : Dual AGNs in the nearby Universe (Koss+, 2012)
J/ApJS/207/19 : Hard X-ray survey from Swift-BAT 2004-2010 (Baumgartner+, 2013)
J/ApJS/206/1 : Mid-IR properties of GOALS nearby LIRGs (Stierwalt+, 2013)
J/ApJ/804/34 : Luminous AGNs and early-type SDSS galaxies (Hong+, 2015)
J/ApJ/806/129 : Space telescope RM project. II. Swift data (Edelson+, 2015)
J/ApJ/850/74 : Swift/BAT AGN Spectroscopic Survey. I. (Koss+, 2017)
J/ApJS/233/17 : Swift/BAT AGN spectroscopic survey. V. X-ray (Ricci+, 2017)
J/ApJ/856/6 : SEAMBHs IX. 10 new Hβ light curves (Du+, 2018)
J/ApJS/244/34 : The CGS. VIII. R-band images of disk galaxies (Gao+, 2019)
J/A+A/639/A5 : X-ray absorption in INTEGRAL AGN (Malizia+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [SWIFT]
7- 19 A13 --- SWIFT Source name (JHHMM.m+DDMMA)
21- 44 A24 --- AName Alternate name
46- 53 F8.4 deg RAdeg Right Ascension (J2000)
55- 62 F8.4 deg DEdeg [-84.4/82.1] Declination (J2000)
64- 68 F5.3 mag Av [0.016/9.4] Galactic V band extinction
70- 75 F6.4 --- z [0.0063/0.0992] Spectroscopic redshift
77- 77 I1 --- Type [1/2] AGN type based on the optical
spectrum
79- 88 A10 "Y/M/D" Obs Observation date
90- 94 F5.2 [10-7W] logLbol [43.2/45.7]? log bolometric luminosity;
erg/s (1)
96- 99 F4.2 [Msun] logMBH [5.5/9.5] log black hole mass
101-108 A8 --- n_logMBH Method for determining logMBH (2)
110-114 F5.2 [-] loglam [-3.8/1.3]? log Eddington ratio;
λ=Lbol/LEdd
116-119 F4.2 --- b/a [0.22/0.99] Axis ratio
121-125 F5.2 [cm-2] logNH [20/24.42]?=-9 log HI column density (3)
127-130 F4.2 [cm-2] E_logNH [0.01/1.9]?=0 Upper uncertainty in logNH
132-135 F4.2 [cm-2] e_logNH [0.01/2.6]?=0 Lower uncertainty in logNH
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Note (1): Inferred from the intrinsic X-ray luminosity, assuming a bolometric
correction of 8 (Ricci+ 2017, J/ApJS/233/17).
Note (2): Method as follows:
Hα = virial method with the broad Hα;
Hβ = virial method with the broad Hβ;
σ* = MBH-σ* relation;
M* = MBH-M* relation.
Note (3): Drived from the hard X-ray spectrum (Ricci+ 2017, J/ApJS/233/17).
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [SWIFT]
7- 19 A13 --- SWIFT Source Name (JHHMM.m+DDMMA)
21- 24 A4 --- Morph Morphological classification (1)
26- 27 A2 --- MorphB Bulge dominance morphological classification (2)
29- 29 A1 --- T/S Perturbed structure (T=tidal tail or
S=Shell structure)
31- 35 A5 --- Maj/Min Merging feature ("Major" or "Minor" merger)
37- 38 A2 --- Merge Merging stage (3)
40- 41 A2 --- Nnuc Number of nuclei (4)
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Note (1): Morphological classification as follows:
E = Elliptical (30 occurrences)
E/S0 = 13 occurrences
S0 = 17 occurrences
SB0 = 14 occurrences
SA = 27 occurrences
SB = 40 occurrences
pec. = peculiar (13 occurrences)
Note (2): Morphological classification based on the bulge dominance as follows:
Sa = 57 occurrences
Sb = 32 occurrences
Sc = 16 occurrences
Note (3): Merging stage as follows:
m1 = a companion galaxy with very faint (or no) sign of interaction
(23 occurrences);
m2 = a sign of interaction (tail and shell) but no major disturbance in
the host galaxy (11 occurrences);
m3 = major disturbance in the host galaxy but the companion galaxy
is not yet merged (7 occurrences).
m4 = two galaxies share the common envelope (latest stage of the merger;
10 occurrences).
Note (4): Number of nuclei as follows:
s = single nucleus (147 occurrences);
d = double nuclei in a single host (3 occurrences);
dd = double nuclei in separate hosts (4 occurrences).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 14-Feb-2022