J/ApJ/983/2ivo://CDS.VizieR/J/ApJ/983/2doi:10.26093/cds/vizier.19830002CDSDey S.Jones M.G.Sand D.J.Mazziotti N.Janowiecki S.Zeimann G.R.,Bennet P.2025-08-11T20:15:15Z2025-04-30T07:29:17ZCDS support team

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

cds-question@unistra.frsurveysgalaxy-clusterschemical-abundancesultraviolet-astronomyphotometryWe present a catalog of 34 new candidate (13 high confidence) isolated, young stellar systems within the Virgo galaxy cluster identified through a citizen science search of public optical and ultraviolet imaging. "Blue blobs" are a class of blue, faint, isolated, extremely low stellar mass, and metal-rich star-forming clouds embedded in the hot intracluster medium of the Virgo cluster. Only six blue blobs were known previously and here we confirm an additional six of our candidates through velocity and metallicity measurements from follow-up optical spectroscopy on the Hobby-Eberly Telescope (HET). Our 13 high confidence candidates (including the six confirmed) have properties consistent with prior known blue blobs and are inconsistent with being low-mass galaxies. Most candidates are concentrated in relatively dense regions, roughly following filamentary structures within the cluster, but avoiding its center. Three of our candidates are likely the stellar counterparts of known "optically dark" clouds of neutral hydrogen in the cluster, while a further four are widely separated extensions to previously known blue blobs. The properties of our new candidates are consistent with previous conclusions that blue blobs likely originated from ram pressure stripping events, however, their locations in velocity-projected cluster-centric radius phase space imply that their parent galaxies are not on their first infall into the cluster. Through our ongoing follow-up program with HET we aim to confirm additional candidates, however, detailed understanding of the stellar populations and star formation histories of blue blobs will require JWST observations.2025ApJ...983....2Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/983/2CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/983/2https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/983/2http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/983/2https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/983/2https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/983/2http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/983/2GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/983/2/table1 (All Rank 1 and Rank 2 Blue Blobs Found in the Virgo Cluster)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/983/2/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/983/2/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/983/2/table1?GETtext/xml+votable180.050000true185.47541713.4602780.005555555555555556Cone search capability for table J/ApJ/983/2/table2 (All Jellyfish Candidates Found in the Main Virgo Cluster through the Citizen Science Search)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/983/2/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/983/2/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/983/2/table2?GETtext/xml+votable180.050000true183.213.996670.0055555555555555565/6932 6935 6941 6/26351 26361-26363 26366 27712 27716 27718-27719 27723 27725 27735-27737 27739 27748-27749 27762-27763 27768 27771 27773-27775 27845 27857 27859 27861-27862 27904 27906-27907 27909 27911 27914-27915 27918 27929-27930 27937 27939 27944 27946-27947 27951 27955 28033 28036 28038https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/983/2?format=asciiUVdefaultJ/ApJ/983/2/table1All Rank 1 and Rank 2 Blue Blobs Found in the Virgo ClusterrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName of the blue blob, BCHHMM+DDMMmeta.id;meta.maincharNoteNote (1)meta.notecharBCNameShort BC name for easier reference within the papermeta.idcharONameName within a major catalogmeta.idcharRank[1/2] Rank of the blue blobmeta.code.qualintRAJ2000Right Ascension (J2000) of blue blobpos.eq.ra;meta.mainDEJ2000Declination (J2000) of blue blobpos.eq.dec;meta.mainimagApparent magnitude in i bandmagphot.mag;em.opt.Ifloate_imagUncertainty of apparent magnitude in i bandmagstat.error;phot.magfloatgmagApparent magnitude in g bandmagphot.mag;em.opt.Bfloate_gmagUncertainty of apparent magnitude in g bandmagstat.error;phot.magfloatNUVmag? Apparent magnitude in NUV bandmagphot.mag;em.UVfloatnullablee_NUVmag? Uncertainty of apparent magnitude in NUV bandmagstat.error;phot.magfloatnullablelogMstarBlue blob stellar masslog(solMass)phys.massfloate_logMstarUncertainty of blue blob stellar masslog(solMass)stat.errorfloatlogSFRNUV? Blue blob NUV star formation ratelog(solMass.yr**-1)phys.SFRfloatnullablee_logSFRNUV? Uncertainty of blue blob NUV star formation ratelog(solMass.yr**-1)stat.errorfloatnullablel_logMHI[<] Lower limit flag on blue blob HI massmeta.code.errorcharlogMHIBlue blob HI masslog(solMass)phys.massfloatHRV-HI? Blue blob HI velocitykm/sphys.veloc;pos.heliocentricintnullableHRV-Ha? blob Halpha velocitykm/sphys.veloc;pos.heliocentricintnullablen_HRV-Ha[No_Ha] No_Ha for No H{alpha}meta.notechar[O/H]? Blue blob metallicityphys.abundfloatnullablee_[O/H]? Uncertainty in blue blob metallicitystat.error;phys.abundfloatnullableBibCodePapers referenced bibcodemeta.bib.bibcodecharJ/ApJ/983/2/table2All Jellyfish Candidates Found in the Main Virgo Cluster through the Citizen Science SearchrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameJellyfish candidate name, BCHHMM+DDMMmeta.id;meta.maincharAGC? UGC/AGC identifiermeta.idintnullableONameName in a major catalogmeta.idcharRAJ2000Right Ascension (J2000) of Jellyfish candidatepos.eq.ra;meta.mainDEJ2000Declination (J2000) of Jellyfish candidatepos.eq.dec;meta.mainSimbadNameSimbad column added by the CDSmeta.idcharnullable