J/A+A/695/A106ivo://CDS.VizieR/J/A+A/695/A106doi:10.26093/cds/vizier/bc-nq/lbagCDSThuruthipilly H.JunaisKoda J.Pollo A.Yagi M.Yamanoi H.,Komiyama Y.Romano M.Malek K.Donevski D.2026-07-03T06:36:26Z2025-03-17T09:08:56ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgalaxiesphotometryvisible-astronomysurveysgalaxy-classification-systemsLow surface brightness galaxies (LSBGs) are important for understanding galaxy evolution and cosmological models. The upcoming large-scale surveys are expected to uncover a large number of LSBGs, requiring accurate automated or machine learning-based methods for their detection. We study the scope of transfer learning for the identification of LSBGs. We used transformer models trained on Dark Energy Survey (DES) data to identify LSBGs from dedicated Hyper Suprime-Cam (HSC) observations of the Abell 194 cluster, which are two magnitudes deeper than DES. A new sample of LSBGs and ultra-diffuse galaxies (UDGs) around Abell 194 was compiled, and their properties were investigated. We used eight models, divided into two categories: LSBG Detection Transformer (LSBG DETR) and LSBG Vision Transformer (LSBG ViT). The data from DES and HSC were standardised based on the pixel-level surface brightness. We used an ensemble of four LSBG DETR models and another ensemble of four LSBG ViT models to detect LSBGs. This was followed by a singlecomponent Sersic model fit and a final visual inspection to filter out potential false positives and improve sample purity. We present a sample of 171 LSBGs in the Abell 194 cluster using HSC data, including 87 new discoveries. Of these, 159 were identified using transformer models, and 12 additional LSBGs were found through visual inspection. The transformer model achieves a true positive rate of 93% in HSC data without any fine-tuning. Among the LSBGs, 28 were classified as UDGs. The number of UDGs and the radial UDG number density suggests a linear relationship between UDG numbers and cluster mass on a log scale. The UDGs share similar Sersic parameters with dwarf galaxies and occupy the extended end of the Reff-Mg plane, suggesting they might be an extended sub-population of dwarf galaxies. We also found that LSBGs and UDGs near the cluster centre are brighter and redder than those in outer regions. We have demonstrated that transformer models trained on shallower surveys can be successfully applied to deeper surveys with appropriate data normalisation. This approach allows us to use existing data and apply the knowledge to upcoming and ongoing surveys, such as the Rubin Observatory Legacy Survey of Space and Time (LSST) and Euclid.2025A&A...695A.106Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/695/A106CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/695/A106https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/695/A106http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/695/A106https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/695/A106https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/695/A106http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/695/A106GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/695/A106/catalog (Abell 194 LSBS catalog (table B1))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/695/A106/catalog?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/695/A106/catalog?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/695/A106/catalog?GETtext/xml+votable180.050000true20.63166-1.624860.0055555555555555566/17657 17659-17660 17662 18001 18004https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/695/A106?format=asciiOpticaldefaultJ/A+A/695/A106/catalogAbell 194 LSBS catalog (table B1)nSersic index (n)stat.fit.paramfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName of the LSBG based on the coordinated of the sources (JHH:MM:SS.sss-DD:MM:SS.sss)meta.id;meta.maincharRAJ2000Right Ascension (J2000) from galfit (RA)degpos.eq.ra;meta.mainDEJ2000Declination (J2000) from galfit (DEC)degpos.eq.dec;meta.mainb/aAxis ratio (q)phys.angSize;arith.ratiofloatPA[] Position angle (PA)degpos.posAngfloatlog(Sigma*)Stellar mass surface density in log scalelog(solMass.kpc**-2)phys.densityfloatlog(M*)Stellar mass in log scalelog(solMass)phys.massfloatreff-gHalf-light radius, g-bandarcsecphys.angSize;srcfloatEgExtinction corrected g-band magnitudemagphys.absorptionfloatmumean-gg-band mean surface brightnessmag.arcsec**-2phot.mag.sbfloatreff-rHalf-light radius, r-bandarcsecphys.angSize;srcfloatErExtinction corrected r-band magnitudemagphys.absorptionfloatmumean-rr-band mean surface brightnessmag.arcsec**-2phot.mag.sb;em.opt.Rfloatl_NUVLimit flag on NUVmeta.code.errorcharNUVExtinction corrected NUV magnitudemagphot.mag;em.UVfloate_NUV? NUV magnitude errormagstat.errorfloatnullablel_FUVLimit flag on FUVmeta.code.errorcharFUVExtinction corrected FUV magnitudemagphot.mag;em.UV.100-200nmfloate_FUV? FUV magnitude errormagstat.errorfloatnullableDES[0/1] If it has been reported in DES (0 for no and 1 for yes)meta.code