J/A+A/699/A232ivo://CDS.VizieR/J/A+A/699/A232doi:10.26093/cds/vizier.36990232CDSHeesters N.Chemaly D.Mueller O.Sola E.Fabbro S.Ferreira A.,McConnachie A.W.Magnier E.Hudson M.J.Chambers K.Hammer F.,Sanchez-Janssen R.2025-08-01T20:03:13Z2025-07-14T17:00:51ZCDS support team

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

cds-question@unistra.frgalaxiesvisible-astronomycatalogssurveysThe detection of low surface brightness galaxies beyond the Local Group poses significant observational challenges, yet these faint systems are fundamental to our understanding of dark matter, hierarchical galaxy formation, and cosmic structure. Their abundance and distribution provide crucial tests for cosmological models, particularly regarding the small-scale predictions of LambdaCDM. We present a systematic detection and classification framework for unresolved dwarf galaxy candidates in the large-scale Ultraviolet Near Infrared Optical Northern Survey (UNIONS) imaging data. The main survey region covers 4861deg^2^. Our pipeline preprocesses UNIONS data in three (gri) of the five bands (ugriz), including binning, artifact removal, and stellar masking before employing the software MTObjects (MTO) to detect low surface brightness objects. After parameter cuts using known dwarf galaxies from the literature and cross-matching between the three bands, we are left with an average of ~360 candidates per deg^2. With ~4000deg^2^ in g, r and i, this amounts to ~1.5 million candidates that form our GOBLIN (Galaxies OBserved as Low-luminosity Identified Nebulae) catalog. For the final classification of these candidates, we fine-tuned the deep learning model Zoobot, which was pre- trained based on labels from the Galaxy Zoo project. We created our training dataset by visually inspecting dwarf galaxy candidates from existing literature catalogs within our survey area and assigning probability labels based on averaged expert assessments. This approach captures both consensus and uncertainty among experts. Applied to all detected MTO objects, our method identifies 42965 dwarf galaxy candidates with probability scores >0.8, of which 23072 have probabilities exceeding 0.9. The spatial distribution of high-probability candidates reveals a correlation with the locations of massive galaxies (log(M*/M_{sun}_)>=10) within 120Mpc. While some of these objects may have been previously identified in other surveys, we present this extensive catalog of candidates, including their positions, structural parameter estimates, and classification probabilities, as a resource for the community to enable studies of galaxy formation, evolution, and the distribution of dwarf galaxies in different environments.2025A&A...699A.232Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/699/A232CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/933/47 : The ELVES survey photometric results (Carlsten+, 2022)J/MNRAS/506/5494 : MATLAS dwarfs structure and morphology (Poulain+, 2021)J/ApJS/267/27 : SMUDGes V. The complete catalog of UDGs from DR9J/ApJ/907/85 : The SAGA Survey. II. Satellite systems around galaxiesJ/ApJS/265/57 : Early-type dwarf galaxies in the local universehttps://www.skysurvey.cc : UNIONS survey websitehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/699/A232https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/699/A232http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/699/A232https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/699/A232https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/699/A232http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/699/A232GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/699/A232/table3 (GOBLIN catalog: dwarf galaxy candidates in UNIONS)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/699/A232/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/699/A232/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/699/A232/table3?GETtext/xml+votable180.050000true164.875229.2550.0055555555555555562/37-39 42 44-45 3/84 86 88-90 92 101-103 112 114 124 143 147 164-165 172-173 184-185 187-188 447 4/317-319 327 331 333-335 340-342 364-366 372 376 401 403 433 436-437 439 465-467 479-480 482-483 485-487 489 492-493 500 502 567 571 583 587 647 651-652 654-655 667 669-671 696-697 745-747 756 760-761 942-943 954-955 958-959 1002-1003 1006 1783 1787 2043 2046-2047 5/1237 1239 1245-1247 1261-1263 1265-1267 1301-1303 1305 1307 1317-1319 1321-1323 1330-1331 1372-1373 1375 1392 1394 1400 1402 1496-1498 1508-1510 1512-1513 1516 1533 1535 1591 1597 1601-1603 1608-1609 1611 1728-1729 1741 1752-1753 1755 1781 1808 1810-1811 1816 1842-1843 1848 1854-1855 1859 1877 1879-1880 1882 1892-1893 1895 1898-1899 1901-1904 1906 1911-1912 1914-1915 1924 1926-1927 1937-1939 1952-1953 1955 2004-2006 2016-2018 2261-2263 2265-2267 2277-2279 2281-2283 2325-2327 2329-2331 2341-2343 2345-2347 2581-2583 2585-2587 2597-2599 2601-2603 2612 2665-2667 2673-2675 2792-2793 2796-2797 2800-2802 2813-2815 2977-2979 3028-3030 3032-3034 3048-3050 3052 3056 3752 3754-3755 3757-3759 4002 4028 4030-4031 4074 7125-7127 7129-7131 7141-7143 7145-7147 8165-8167 8169-8171 8178-8179 8182 6/4607 4947 4953 4973-4975 4977-4979 5021-5023 5037-5039 5041-5043 5057-5059 5198-5199 5203 5219 5224-5225 5227 5263 5267 5283 5312 5314-5317 5319 5496-5498 5572-5574 5589 5591 5604 5606 5612 5614-5615 5872-5874 5876-5877 5879-5880 5978 5996-5998 6000 6044 6046 6056-6057 6060-6061 6068 6075-6076 6078-6081 6131 6137 6139 6237 6239 6261 6357-6359 6361-6363 6384-6385 6387 6396-6397 6399 6401-6403 6441-6443 6741 6921 6924-6925 6927 6960-6961 6973 7016-7017 7120-7121 7236 7238-7239 7256 7258 7268-7270 7272-7274 7287 7293 7362 7396 7400-7402 7407 7411 7414-7415 7431 7435 7490 7496 7498-7499 7505 7507 7540-7541 7543 7549 7551 7553 7556-7557 7559 7577 7586 7601-7603 7620 7622 7628 7630 7637 7639 7643 7652 7655 7700-7702 7747 7816-7817 7857 7860-7861 7904-7905 7908-7909 7920-7921 7924-7925 8028 8048 8050 8056 8076-8078 8080-8082 8085 8096-8097 8128-8129 8703 8959 9023 9037 9039 9043 9059 9103 9107 9123 9279 9293 9295 9298-9299 9313 9315 9359 9361-9363 9377-9379 10303 10319 10323 10339 10382-10383 10387 10401-10403 10452-10454 10456-10458 10640-10641 10644 10653-10655 10657-10659 10689-10691 11176-11178 11180-11181 11192-11193 11196 11212-11214 11216-11218 11229-11234 11247 11251 11905-11907 12124-12126 12140-12142 12144-12146 12204 12212 12232 15014-15015 15026-15027 15070-15071 15242-15243 15246-15247 15258-15259 15262-15263 15306-15307 15310-15311 15322-15323 15325-15327 16013-16015 16024 16026-16027 16029-16031 16072 16074-16075 16078-16079 16090 16116 16118-16119 16300 16302 28159 28413 28415 28478-28479 28495 28499 28513 28515 28558-28559 28563 28577 28579 32509 32511 32653 32655 32657 32659 32675 32706-32707 32710 32734-32735https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/699/A232?format=asciiOpticaldefaultJ/A+A/699/A232/table3GOBLIN catalog: dwarf galaxy candidates in UNIONSrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintb/ar? Axis ratio (B/A) in r-bandphys.abund;arith.ratiofloatnullablePAi? Position angle in i-band (3)degpos.posAngfloatnullableRAJ2000Right ascension (J2000)degphys.angSize;srcindexedDEJ2000Declination (J2000)degpos.eq.dec;meta.mainindexedTileUNIONS tile identifierobs.fieldcharIDlitIdentifier from literature catalog if previously knownmeta.idcharSourceSource catalog of the previously known dwarf galaxy (1)meta.bibcharpmodelProbability of being a dwarf galaxy from ML modelstat.fit.goodnessfloatplabel[0/1]? Visual classification label from training set (2)meta.code.classfloatnullablePAr? Position angle in r-band (3)degpos.posAngfloatnullableFluxr? Total flux in r-band (in ADU unit) (4)phot.flux.density;em.opt.Rdoublenullablemumaxr? Maximum pixel value in r-band (in ADU unit)stat.value;instr.pixeldoublenullablemumedr? Median pixel value in r-band (in ADU unit)stat.value;instr.pixelfloatnullablemumeanr? Mean pixel value in r-band (in ADU unit)stat.value;instr.pixelfloatnullableRer? Effective radius in r-band (in ADU unit)arcsecphys.angSize;srcfloatnullableRFWHMr? FWHM radius in r-bandarcsecphys.angSize;srcfloatnullableR10r? Radius enclosing 10% of light in r-bandarcsecphys.angSize;srcfloatnullableR25r? Radius enclosing 25% of light in r-bandarcsecphys.angSize;srcfloatnullableR75r? Radius enclosing 75% of light in r-bandarcsecphys.angSize;srcfloatnullableR90r? Radius enclosing 90% of light in r-bandarcsecphys.angSize;srcfloatnullableR100r? Radius enclosing 100% of light in r-band (6)arcsecphys.angSize;srcfloatnullablear? Major axis in r-bandarcsecphys.angSizefloatnullablebr? Minor axis in r-bandarcsecphys.angSize;srcfloatnullablermag? Apparent magnitude in r-bandmagphot.mag;em.opt.Rfloatnullablermagcor? Corrected apparent magnitude in r-band (5)magphot.mag;em.opt.RfloatnullableSuBrer? Mean effective surface brightness in r-bandmag.arcsec**-2phot.mag.sb;em.opt.RfloatnullablePAg? Position angle in g-band (3)degpos.posAngfloatnullableFluxg? Total flux in g-band (in ADU unit) (4)phot.flux.density;em.opt.Bdoublenullablemumaxg? Maximum pixel value in g-band (in ADU unit)stat.value;instr.pixelfloatnullablemumedg? Median pixel value in g-band (in ADU unit)stat.value;instr.pixelfloatnullablemumeang? Mean pixel value in g-band (in ADU unit)stat.value;instr.pixelfloatnullableReg? Effective radius in g-bandarcsecphys.angSize;srcfloatnullableRFWHMg? FWHM radius in g-bandarcsecphys.angSize;srcfloatnullableR10g? Radius enclosing 10% of light in g-bandarcsecphys.angSize;srcfloatnullableR25g? Radius enclosing 25% of light in g-bandarcsecphys.angSize;srcfloatnullableR75g? Radius enclosing 75% of light in g-bandarcsecphys.angSize;srcfloatnullableR90g? Radius enclosing 90% of light in g-bandarcsecphys.angSize;srcfloatnullableR100g? Radius enclosing 100% of light in g-band (6)arcsecphys.angSize;srcfloatnullableag? Major axis in g-bandarcsecphys.angSizefloatnullablebg? Minor axis in g-bandarcsecphys.angSize;srcfloatnullableb/ag? Axis ratio (B/A) in g-bandphys.abund;arith.ratiofloatnullablegmag? Apparent magnitude in g-bandmagphot.mag;em.opt.Bfloatnullablegmagcor? Corrected apparent magnitude in g-band (5)magphot.mag;em.opt.BfloatnullableSuBreg? Mean effective surface brightness in g-bandmag.arcsec**-2phot.mag.sb;em.opt.BfloatnullableFluxi? Total flux in i-band (in ADU unit) (4)phot.flux.density;em.opt.Idoublenullablemumaxi? Maximum pixel value in i-band (in ADU unit)stat.value;instr.pixeldoublenullablemumedi? Median pixel value in i-band (in ADU unit)stat.value;instr.pixelfloatnullablemumeani? Mean pixel value in i-band (in ADU unit)stat.value;instr.pixelfloatnullableRei? Effective radius in i-bandarcsecphys.angSize;srcfloatnullableRFWHMi? FWHM radius in i-bandarcsecphys.angSize;srcfloatnullableR10i? Radius enclosing 10% of light in i-bandarcsecphys.angSize;srcfloatnullableR25i? Radius enclosing 25% of light in i-bandarcsecphys.angSize;srcfloatnullableR75i? Radius enclosing 75% of light in i-bandarcsecphys.angSize;srcfloatnullableR90i? Radius enclosing 90% of light in i-bandarcsecphys.angSize;srcfloatnullableR100i? Radius enclosing 100% of light in i-band (6)arcsecphys.angSize;srcfloatnullableai? Major axis in i-bandarcsecphys.angSizefloatnullablebi? Minor axis in i-bandarcsecphys.angSize;srcfloatnullableb/ai? Axis ratio (B/A) in i-bandphys.abund;arith.ratiofloatnullableimag? Apparent magnitude in i-bandmagphot.mag;em.opt.IfloatnullableSuBrei? Mean effective surface brightness in i-bandmag.arcsec**-2phot.mag.sb;em.opt.IfloatnullableTrain[0/1] Flag indicating if object was used to train the model (7)meta.codeintNameGOBLIN source designation (GOBLIN JHHMMSS.s+DDMMSS; J2000)meta.id;meta.mainchar