J/A+A/711/A187ivo://CDS.VizieR/J/A+A/711/A187CDSThuruthipilly H.Lisiecki K.JunaisMalek K.Pollo A.Pearson W.J.,Vanzanella A.Pal S.Figueira M.Dabhade P.Durkalec A.Cotter A.P.,Sureshkumar U.Hazra N.Matera P.Dey S.Vrabel M.Dutta A.,Willems H.Principi Cavaterra N.Dobrowolska N.Knop W.2026-07-14T16:33:42Z2026-07-14T17:26:48ZCDS support team

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

cds-question@unistra.frsurveysgalaxiesphotometrysurface-photometryvisible-astronomyLow-surface-brightness galaxies (LSBGs) are vital for understanding galaxy formation, but their diffuse nature makes them challenging to detect. Upcoming large-scale surveys are expected to uncover a large number of LSBGs, which require robust automated methods to identify them across heterogeneous datasets. As a precursor to the Legacy Survey of Space and Time (LSST) and Euclid, we explore domain adaptation techniques to build homogeneous LSBG catalogues across current surveys. We investigate the use of computer vision models and domain adaptation for cross-survey LSBG identification. Using models trained on the Dark Energy Survey (DES), we search for LSBGs in the Kilo-Degree Survey Data Release 5 (KiDS DR5). We then examine their structural and stellar population properties to pave the way for large-scale LSBG studies with LSST and Euclid. We used an ensemble consisting of one convolutional neural network (CNN) and two transformer models trained on DES cutouts and applied to KiDS DR5 imaging with surface-brightness normalisation. Structural parameters were estimated with galfitm, and the sample was further refined through visual inspection to produce the final candidate sample. Photometric redshift and stellar population properties were estimated through spectral energy distribution (SED) fitting with CIGALE. We identify 20180 LSBGs and 434 Ultra-diffuse galaxies (UDGs) in KiDS DR5. Their structural parameters are similar to the known LSBGs from DES and Hyper Suprime-Cam SSP Survey (HSC-SSP). The KiDS-LSBGs follow a continuous size-luminosity relation connecting classical dwarf galaxies and UDGs, and their colours are bimodal (~73% blue, ~27% red). Cross-matching with spectroscopic and cluster catalogues provides redshifts for 4 913 systems, enabling a systematic characterisation of the star-forming main sequence of LSBGs. Photometric redshifts derived via SED fitting are mildly overestimated (=~0.024), leading to systematic offsets in stellar mass and star formation rate estimates. However, these biases induce only small shifts (~0.13-0.22dex) in specific star formation rate, thereby preserving the structure of the star-forming main sequence. Strong environmental trends are also evident, with cluster LSBGs and UDGs exhibiting redder colours and reduced star formation compared to non-cluster systems. This indicates efficient quenching driven by environmental processes. We demonstrate that, with domain adaptation, cross-survey LSBG identification can be achieved with deep learning models. Thus, the methodology presented here provides a powerful and scalable pathway for constructing homogeneous LSBG catalogues across surveys. This framework is well-suited for the era of LSST and Euclid, where millions of diffuse galaxies will be discovered, and consistent cross-survey classification will become essential.2026A&A...711A.187Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/711/A187CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/383 : The ESO KiDS-DR5 multi-band source catalog (Wright+ 2024)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/711/A187https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/711/A187http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/711/A187https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/711/A187https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/711/A187http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/711/A187GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/711/A187/lsbs (Final visually confirmed KiDS-LSBGs catalogue (table F1))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/711/A187/lsbs?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/711/A187/lsbs?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/711/A187/lsbs?GETtext/xml+votable180.050000true0.00329312517-32.86807728120.005555555555555556Cone search capability for table J/A+A/711/A187/nonlsbs (Sources reclassified as non-LSBGs after cosmological surface-brightness dimming correction (table G1))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/711/A187/nonlsbs?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/711/A187/nonlsbs?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/711/A187/nonlsbs?GETtext/xml+votable180.050000true0.31522059637-31.970960926830.0055555555555555563/405 409-410 422 4/1027-1030 1032-1034 1365 1599 1615 1619 1624-1626 1628 1635 1644 1648 1683 1685-1687 1692 1706 1961-1962 2207 2223 2227-2230 2232-2234 2243-2244 2246-2250 2911 2931-2934 2936-2937 5/1024-1026 2048-2050 4103 4107 4124-4126 4140-4142 4144-4146 4160-4162 4224-4226 5459 5468-5469 6391 6395 6455 6459 6471 6475 6508-6510 6516 6520 6535 6539 6580 6584 6596 6711 6716-6717 6719 6727 6731 6737-6739 6772 6776 6805 6819 6828 6830 6848-6849 6851-6852 6912-6914 6920 7823 7834 7843 7852-7854 7856-7858 8635 8823 8827 8887 8891 8903 8907 8924-8926 8940-8942 8944-8946 8967 8971 8982-8983 9004-9005 9008-9010 9012 9088-9090 10239 11259 11262-11263 11639 11643 11719 11723 11740-11742 11753 11756-11758 11760-11762 6/4108 4112 4128 8204 8206-8208 8224-8226 8228 8232 16405-16407 16409-16411 16421-16423 16425-16427 16508 16572 16588 16592 16608 16652 16656 16672 16908 16912 16928 21831 21833 21835 21861 21863 21880-21881 21884 25559 25563 25575 25579 25815 25819 25831 25835 25879 25883 25895 25899 26044-26046 26068 26072 26084 26088 26135 26139 26151 26155 26324 26328 26340 26344 26388 26392 26400-26402 26408 26839 26843 26855 26872-26873 26875 26903 26907 26919 26923 26945-26947 27092 27096 27108 27112 27217 27229 27256 27258-27259 27270 27274-27275 27290 27316 27318-27319 27324 27400-27401 27403 27412 27416 27428 27660-27662 27664-27666 27668 27672 27684 27688 31286-31287 31289-31291 31328 31330-31331 31340 31342-31343 31365-31367 31369-31371 31420 31436 31456 34534 34537-34539 34554 35285-35287 35289-35291 35301-35303 35305-35307 35541-35543 35545-35547 35557-35559 35561-35563 35605-35607 35609-35611 35621-35623 35625-35627 35708 35772 35788 35792 35808 35861 35863 35865-35867 35877-35879 35881-35883 35920 35922-35923 35926 36024-36026 36028 36044-36045 36052 36064 36128-36130 36364 36368 36384 40949 40951 40955 45031 45040 45042-45043 45045 45047 46549-46551 46553-46555 46565-46567 46569-46571 46805-46807 46812-46813 46869-46871 46873-46875 46885-46887 46889-46891 46972 47008-47009 47011 47021 47023 47036 47052 47056 47072 48400https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/711/A187?format=asciiOpticaldefaultJ/A+A/711/A187/lsbsFinal visually confirmed KiDS-LSBGs catalogue (table F1)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDObject identifier, KiDSDR5_JHHMMSS.sss+DDMMSS.ss (ID)meta.id;meta.maincharRAJ2000Right ascension, J2000 (RA)degpos.eq.ra;meta.mainindexedDEJ2000Declination, J2000 (Dec)degpos.eq.dec;meta.mainindexednSersic index (n)stat.fit.paramfloate_nUncertainty in Sersic index (dn)stat.errorfloatqAxis ratio, b/a (q)phys.size.axisRatiofloatPA[] Position angle (PA)degpos.posAngdoublegmag? Sersic g-band magnitude (m_g)magphot.mag;em.opt.Bfloatnullablermag? Sersic r-band magnitude (m_r)magphot.mag;em.opt.Rfloatnullableimag? Sersic i-band magnitude (m_i)magphot.mag;em.opt.IfloatnullablereffgEffective radius in the g band (reff_g)arcsecphys.angSizedoublereffrEffective radius in the r band (reff_r)arcsecphys.angSizedoublereffiEffective radius in the i band (reff_i)arcsecphys.angSizedoublee_reffgUncertainty in reffg (d_reff_g)arcsecstat.errordoublee_reffrUncertainty in reffr (d_reff_r)arcsecstat.errordoublee_reffiUncertainty in reffi (d_reff_i)arcsecstat.errordoublemueffgMean effective surface brightness, g (mu_eff_g)mag.arcsec**-2phot.mag.sbdoublemueffrMean effective surface brightness, r (mu_eff_r)mag.arcsec**-2phot.mag.sbdoublemueffiMean effective surface brightness, i (mu_eff_i)mag.arcsec**-2phot.mag.sbdoublemu0gCentral surface brightness in g band (mu0_g)mag.arcsec**-2phot.mag.sbdoublemu0rCentral surface brightness in r band (mu0_r)mag.arcsec**-2phot.mag.sbdoublemu0iCentral surface brightness in i band (mu0_i)mag.arcsec**-2phot.mag.sbdoublechi2rSerReduced chi-square of the Sersic fit (chi2_red_Ser)stat.fit.param;meta.modelleddoubleBICBayesian Information Criterion (BIC)meta.codedoubleNucleusNucleated-candidate flag (Nucleus) (G1)meta.code.errorintRAPdegRight ascension of PSF component (RA_PSF)degpos.eq.raDEPdegDeclination of PSF component (DEC_PSF)degpos.eq.decgmagPSFPSF-component g-band magnitude (m_g_PSF)magphot.mag;em.opt.BdoublermagPSFPSF-component r-band magnitude (m_r_PSF)magphot.mag;em.opt.RdoubleimagPSFPSF-component i-band magnitude (m_i_PSF)magphot.mag;em.opt.IdoublezAdopted redshift (z)src.redshiftdoubleClusterCluster-association flag (Cluster) (G2)meta.codeintztypeType/source of redshift estimate (z_type)src.classcharMorph? Visual morphology class (Morphology) (G3)meta.code.class;src.morph.typeintnullablemueffrc? Cosmology-corrected mu_eff_r (mu_eff_r_zcorr)mag.arcsec**-2phot.mag.sb;em.opt.RdoublenullableSFRSEDCIGALE star formation rate (SFR_SED)solMass/yrmeta.iddoublee_SFRSEDUncertainty in SFRSED (dSFR_SED)solMass/yrstat.errordoubleMstarCIGALE stellar mass (Mstar)solMassphys.massdoublee_MstarUncertainty in Mstar (dMstar)solMassstat.errordoublechi2SEDReduced chi-square of SED fit (chi2_SED)stat.fit.param;meta.modelleddoubleJ/A+A/711/A187/nonlsbsSources reclassified as non-LSBGs after cosmological surface-brightness dimming correction (table G1)RAJ2000Right ascension, J2000 (RA)degpos.eq.ra;meta.mainDEJ2000Declination, J2000 (Dec)degpos.eq.dec;meta.mainnSersic index (n)stat.fit.paramfloate_nUncertainty in Sersic index (dn)stat.errorfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintqAxis ratio, b/a (q)phys.size.axisRatiofloatPA[] Position angle (PA)degpos.posAngdoublegmagSersic g-band magnitude (m_g)magphot.mag;em.opt.BfloatrmagSersic r-band magnitude (m_r)magphot.mag;em.opt.RfloatimagSersic i-band magnitude (m_i)magphot.mag;em.opt.IfloatreffgEffective radius in the g band (reff_g)arcsecphys.angSizedoublereffrEffective radius in the r band (reff_r)arcsecphys.angSizedoublereffiEffective radius in the i band (reff_i)arcsecphys.angSizedoubler_reffgUncertainty in reff_g (d_reff_g)arcsecmeta.ref;pos.framedoubler_reffrUncertainty in reff_r (d_reff_r)arcsecmeta.ref;pos.framedoubler_reffiUncertainty in reff_i (d_reff_i)arcsecmeta.ref;pos.framedoublemueffgMean effective surface brightness, g (mu_eff_g)mag.arcsec**-2phot.mag.sbdoublemueffrMean effective surface brightness, r (mu_eff_r)mag.arcsec**-2phot.mag.sbdoublemueffiMean effective surface brightness, i (mu_eff_i)mag.arcsec**-2phot.mag.sbdoublemu0gCentral surface brightness in g band (mu0_g)mag.arcsec**-2phot.mag.sbdoublemu0rCentral surface brightness in r band (mu0_r)mag.arcsec**-2phot.mag.sbdoublemu0iCentral surface brightness in i band (mu0_i)mag.arcsec**-2phot.mag.sbdoublechi2rSerReduced chi-square of the Sersic fit (chi2_red_Ser)stat.fit.param;meta.modelleddoubleBICBayesian Information Criterion (BIC)meta.codedoubleNucleusNucleated-candidate flag (Nucleus) (G1)meta.code.errorintRAPdegRight ascension of PSF component (RA_PSF)degpos.eq.raDEPdegDeclination of PSF component (DEC_PSF)degpos.eq.decgmagPSF? PSF-component g-band magnitude (m_g_PSF)magphot.mag;em.opt.BdoublenullablermagPSF? PSF-component r-band magnitude (m_r_PSF)magphot.mag;em.opt.RdoublenullableimagPSF? PSF-component i-band magnitude (m_i_PSF)magphot.mag;em.opt.IdoublenullablezRedshift (z)src.redshiftdoubleClusterCluster-association flag (Cluster) (G2)meta.codeintztypeType/source of redshift estimate (z_type)src.classcharMorphVisual morphology class (Morphology) (G3)meta.code.class;src.morph.typeintmueffrcorz corrected r band surface brightness (mu_eff_r_zcorr)phot.flux.sbdoubleIDObject identifier KiDSDR5_JHHMMSS.sss+DDMMSS.ss (ID)meta.id;meta.mainchar