J/A+A/707/A152 Bar morphologies of HSC-SSP disc galaxies (La Marca+, 2026)
Galactic bars and active galactic nucleus fuelling in the second half of cosmic
history.
La Marca A., Nardone M.T., Wang L., Margalef-Bentabol B., Kruk S.,
Trager S.C.
<Astron. Astrophys. 707, A152 (2026)>
=2026A&A...707A.152L 2026A&A...707A.152L (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, interacting ; Active gal. nuclei ; Positional data ;
Photometry, infrared ; Galaxies, radius ; Morphology
Keywords: galaxies: active - galaxies: evolution - galaxies: spiral -
galaxies: structure
Abstract:
We investigate the role of galactic bars in fuelling and triggering
Active Galactic Nucleus (AGN) in disc galaxies up to z∼0.8. We
utilise a Deep Learning model, fine-tuned on Galaxy Zoo volunteer
classifications, to identify (strongly and weakly) barred and unbarred
disc galaxies in Hyper Suprime-Cam Subaru Strategic Program i-band
images. We select AGN using three independent diagnostics:
mid-infrared colours, X-ray detections, and spectral energy
distribution (SED) fitting. The SED analysis, performed using CIGALE,
quantifies the relative AGN contribution to the total galaxy
luminosity (fAGN) and the AGN luminosity (Ldisc). We assess the
impact of bars by comparing AGN incidence and properties in barred
galaxies against carefully constructed redshift-, stellar mass-, and
colour-matched unbarred control samples. Our binary AGN classification
experiment demonstrates that barred disc galaxies host a higher
fraction of AGN compared to their unbarred counterparts, though the
significance depends on the AGN selection method, with a more modest
excess for SED AGN, and control sample size. This suggests a
contributing role for bars in the global AGN budget. The contribution
of bars to AGN fuelling appears confined to systems where the AGN has
a lower relative contribution to the host galaxy's emission
(fAGN<0.75). Crucially, we find a significant dearth of barred disc
galaxies hosting AGN with fAGN>0.75, independent of bar strength.
Consistent with this, the fraction of barred galaxies among AGN hosts
decreases with increasing Ldisc. Combined with previous results, we
suggest that bars may contribute to fuelling the population of
low-to-moderate luminosity AGN, but major mergers are the principal
mechanism for triggering the most powerful and dominant accretion
events.
Description:
Morphological information for 5579 disc galaxies in the NW-2 field,
with rich multi-wavelength data, retrievable from the catalogue
presented in La Marca et al. (2024A&A...690A.326L 2024A&A...690A.326L, Cat.
J/A+A/690/A326) (Merger-AGN connection in the NW-2 field). The parent
catalogue contains all data necessary to characterise galaxy
properties and AGN selections, as well as extensive photometry and a
galaxy merger classification. Here we present a refined morphological
classification of galaxies, meant for identifying strong and weak bars
in disc-like galaxies of the KiDS-NW-2 sky area. The dataset in
catalog.dat includes source coordinates, and morphological class
probabilities obtained with the Zoobot software, trained on HSC-SSP
DR3 galaxy cutouts. The classes included are: Strong bar, Weak bar,
Unbarred disc, Smooth galaxy, Edge-on. The final class label, selected
as detailed in the paper, is reported in the Label column. In
addition, the catalogue reports the Kron radius measured by the
HSC-SSP collaboration in the i-band. This radius was used make galaxy
cutouts. Note that the catalogue is limited only to the disc galaxies
analysed in this work.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
catalog.dat 184 5579 Master catalogue of N-W2 selected disc galaxies
classified with Zoobot algorithm
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See also:
J/A+A/690/A326 : Merger-AGN connection in the NW-2 field (La Marca+, 2024)
J/A+A/661/A1 : The eFEDS X-ray catalogs (V7.4) (Brunner+, 2022)
J/A+A/661/A3 : eFEDS counterparts to point-like sources (Salvato+, 2022)
J/A+A/632/A34 : KiDS+VIKING-450 opt+NIR dataset (Wright+, 2019)
J/A+A/622/A103 : Python Code Investigating GALaxy Emission (Boquien+, 2019)
J/A+A/598/A32 : 2D decomposition of CALIFA galaxies (Mendez-Abreu+, 2017)
J/MNRAS/509/3966 : Galaxy Zoo DR1&2, DR5 and DeepL version (Walmsley+, 2022)
J/MNRAS/473/4731 : Barred galaxies structural decomposition (Kruk+, 2018)
J/MNRAS/462/3146 : Herschel-ATLAS DR1 (HATLAS) (Valiante+, 2016)
J/MNRAS/461/3663 : Galaxy Zoo 2: new classification (Hart+, 2016)
J/MNRAS/435/2835 : Morphological types from Galaxy Zoo 2 (Willett+, 2013)
J/MNRAS/419/687 : Morphology of luminous radio-loud AGN (Ramos Almeida+, 2012)
J/MNRAS/413/971 : Galaxy And Mass Assembly (GAMA) DR1 (Driver+, 2011)
J/ApJ/739/57 : Ultra hard X-ray AGNs in the Swift/BAT survey (Koss+, 2011)
J/ApJS/186/427 : Detailed morphology of SDSS galaxies (Nair+, 2010)
II/329 : VIKING catalogue data release 1 (Edge+, 2013)
II/388 : Euclid final merged catalog. Q1 data release
(Euclid Coll., 2025)
Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 I17 --- ID ?=999999 HSC-SSP survey id (id)
19- 34 F16.12 deg RAdeg Right Ascension (J2000) (ra)
36- 53 F18.15 deg DEdeg Declination (J2000) (dec)
55- 62 F8.6 --- Krad Kron radius in the HSC i band
(ikronfluxradius)
64- 80 F17.15 --- Pstrong Zoobot Strong bar probability (PStrongbar)
82- 98 F17.15 --- Pweak Zoobot Weak bar probability (PWeakbar)
100-116 F17.15 --- Punbar Zoobot Unbarred disc probability (PUnbardisc)
118-134 F17.15 --- Pell Zoobot Smooth/Elliptical probability
(PElliptical)
136-152 F17.15 --- Pedgon Zoobot Edge-on probability (PEdge-on)
154-170 F17.15 --- Pbar Total Zoobot bar probability (PBar)
172 I1 --- Class Most likely class number (ClassNumber) (1)
174-184 A11 --- Label Most likely class label (Label)
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Note (1): As defined in section SC-SSP imaging and Galaxy Zoo classifications
for bar identification, classes are as follows:
1 = Strong Bar, bar likelihood pbar => 0.5
2 = Weak Bar, bar likelihood 0.2 < pbar < 0.5
3 = Unbar. disc, bar likelihood pbar ≤ 0.2
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Acknowledgements:
Antonio La Marca, antonio.la.marca.astro(at)gmail.com.
This research is part of the project 'Clash of the titans: deciphering
the enigmatic role of cosmic collisions' (with project number
VI.Vidi.193.113) of the research programme Vidi which is (partly)
financed by the Dutch Research Council (NWO).
(End) Luc Trabelsi [CDS] 26-Jan-2026