Galactic bars and active galactic nucleus fuelling in the second half of cosmic history

Abstract

We investigate the role of galactic bars in fuelling and triggering Active Galactic Nucleus (AGN) in disc galaxies up to $z\sim 0.8$. 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 ($f_{\mathrm{AGN}}$) and the AGN luminosity ($L_{\mathrm{disc}}$). 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 ($f_{\mathrm{AGN}}<0.75$). Crucially, we find a significant dearth of barred disc galaxies hosting AGN with $f_{\mathrm{AGN}}>0.75$, independent of bar strength. Consistent with this, the fraction of barred galaxies among AGN hosts decreases with increasing $L_{\mathrm{disc}}$. 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.

17 pages (3 pages appendix), 19 figures. Accepted for publication in A&A. Catalogue of Galaxy Bar Classification submitted to CDS and available at https://zenodo.org/records/18299075

References in corpus (34)

• A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies: I. Galaxy Mergers & Quasar Activity
• The Co-Evolution of Galaxies and Supermassive Black Holes: Insights from Surveys of the Contemporary Universe
• The eROSITA X-ray telescope on SRG
• Euclid. I. Overview of the Euclid mission
• A Near-Infrared Study of 2MASS Bars in Local Galaxies: An Anchor for High Redshift Studies
• Third Data Release of the Hyper Suprime-Cam Subaru Strategic Program
• The eROSITA Final Equatorial Depth Survey (eFEDS): The X-ray catalog
• The population of barred galaxies in the local universe I. Detection and characterisation of bars
• The fourth data release of the Kilo-Degree Survey: ugri imaging and nine-band optical-IR photometry over 1000 square degrees
• X-CIGALE: fitting AGN/galaxy SEDs from X-ray to infrared
• Bars in Disk-Dominated and Bulge-Dominated Galaxies at z~0: New Insights from ~3600 SDSS Galaxies
• The Herschel-ATLAS Data Release 1 Paper I: Maps, Catalogues and Number Counts
• Galaxy Zoo DECaLS: Detailed Visual Morphology Measurements from Volunteers and Deep Learning for 314,000 Galaxies
• Fitting AGN/galaxy X-ray-to-radio SEDs with CIGALE and improvement of the code
• The Dependence of Bar Frequency on Galaxy Mass, Colour, and Gas Content -- and Angular Resolution -- in the Local Universe
• Two-dimensional multi-component photometric decomposition of CALIFA galaxies
• Galaxy Zoo: comparing the demographics of spiral arm number and a new method for correcting redshift bias
• The eROSITA Final Equatorial-Depth Survey (eFEDS): Identification and characterization of the counterparts to the point-like sources
• Galaxy Zoo: Secular evolution of barred galaxies from structural decomposition of multi-band images
• Galaxy Zoo: Morphological Classifications for 120,000 Galaxies in HST Legacy Imaging
• Galaxy Zoo: the effect of bar-driven fueling on the presence of an active galactic nucleus in disc galaxies
• Galaxy Zoo: Are Bars Responsible for the Feeding of Active Galactic Nuclei at 0.2 < z < 1.0?
• A JWST investigation into the bar fraction at redshifts 1 < z < 3
• Galaxy Zoo: Stronger bars facilitate quenching in star forming galaxies
• The EDGE-CALIFA survey: The role of spiral arms and bars in driving central molecular gas concentrations
• The role of bars in AGN fueling in disk galaxies over the last seven billion years
• Revisiting the role of bars in AGN fuelling with propensity score sample matching
• A new method for age-dating the formation of bars in disc galaxies: The TIMER view on NGC1433's old bar and the inside-out growth of its nuclear disc
• Dust and Power: Unravelling the merger - active galactic nucleus connection in the second half of cosmic history
• Bar ages derived for the first time in nearby galaxies: Insights on secular evolution from the TIMER sample
• Evidence for non-merger co-evolution of galaxies and their supermassive black holes
• The most luminous, merger-free AGN show only marginal correlation with bar presence
• Unraveling Joint Evolution of Bars, Star Formation, and Active Galactic Nuclei of Disk Galaxies
• Euclid Quick Data Release (Q1). First Euclid statistical study of galaxy mergers and their connection to active galactic nuclei