J/A+A/708/A152ivo://CDS.VizieR/J/A+A/708/A152CDSLlerena M.Pentericci L.Amorin R.Ferrara A.Dickinson M.,Arevalo-Gonzalez F.Calabro A.Napolitano L.Mascia S.Arrabal Haro P.,Begley R.Cleri N.J.Davis K.Hu W.Kartaltepe J.S.Koekemoer A.M.,Lucas R.A.McGrath E.McLeod D.J.Papovich C.Stanton T.M.Taylor A.J.,Tripodi R.Wang X.Yung L.Y.A.2026-04-03T10:38:32Z2026-04-03T11:37:55ZCDS support team

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

cds-question@unistra.frgalaxiesredshiftedinfrared-photometryline-intensitiesWe investigate the properties of extreme emission line galaxies (EELGs) at z=4-9 and their role in reionization. Compact, low-mass galaxies with intense optical emission lines are linked to elevated specific star formation rates (sSFRs) and recent bursts of star formation. Feedback in these systems may enable the leakage of ionizing radiation into the intergalactic medium. Using JWST/NIRSpec spectroscopy from the CAPERS, CEERS, and RUBIES surveys, we compile 160 NIRCam-selected EELGs in the EGS field. These galaxies show extreme rest-frame equivalent widths (EWs), with a median EW([OIII/Hbeta])=1616{AA} and EW(Halpha)=763{AA}. They are low-mass (median log(M*/M_{sun}_)=8.26) with high sSFRs (median 43Gyr^-1^), above the z~6 main sequence. UV slopes are diverse, with a median value of beta=-2.0, and only 7% have extremely blue continua (beta<-2.6). Emission-line diagnostics suggest stellar populations as the primary ionizing source, although an AGN fraction of 14% {cannot be entirely ruled out. These galaxies are efficient ionizing photon producers, with median log(xi_ion_[Hz/erg])={25.37}, exceeding typical values at similar redshifts. Escape fractions, however, are heterogeneous: 16% of EELGs at z<7 show escape fractions >5% for both Lyalpha and LyC photons, while 82% lack detectable Lya emission. The median inferred LyC escape fraction is modest (5%) but enhanced in compact super-Eddington systems with sSFR>25Gyr^-1^. These results indicate that EELGs contribute approximately 16-40% of the total ionizing emissivity required to sustain hydrogen reionization. EELGs are extremely compact, with a median effective radius of 0.49kpc, and exhibit a recent star-formation burst. Our analysis indicates that sSFR and star-formation rate surface density are the primary drivers of their extreme emission line strengths.2026A&A...708A.152Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/708/A152CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/691/A59 : Extreme emission-line galaxies at z~4-9 (Llerena+, 2024)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/708/A152https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/708/A152http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/708/A152https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/708/A152https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/708/A152http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/708/A152GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/708/A152/tablea1 (Informations about the galaxies in the sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/708/A152/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/708/A152/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/708/A152/tablea1?GETtext/xml+votable180.050000true214.88352.840420.0055555555555555566/11425https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/708/A152?format=asciiInfrareddefaultJ/A+A/708/A152/tablea1Informations about the galaxies in the samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintE(B-V)E(B-V) from SED fittingmagphot.color.excessfloatl_logsSFRLimit flag on logsSFRmeta.code.errorcharlogsSFRlog Specific star-formation ratelog(Gyr**-1)phys.SFRfloate_logsSFR? log Specific star-formation ratelog(Gyr**-1)stat.errorfloatnullablebetaUV? UV beta slopemeta.crypticfloatnullableE_betaUV? UV beta slope error (upper value)stat.error;stat.maxfloatnullablee_betaUV? UV beta slope error (lower value)stat.errorfloatnullableUVMAG? UV absolute magnitudemagphys.magAbsfloatnullableroptkpc? Rest-frame optical effective radiuskpcphys.size.radiusfloatnullablee_roptkpc? Rest-frame optical effective radius errorkpcstat.errorfloatnullablelogfescLyC? Infered LyC escape fractionstat.fit.paramfloatnullableFlagClassification flag (1)meta.code.errorcharIDID from CEERS photometric catalogmeta.id;meta.mainintSpecIDSpectroscopic IDmeta.idintRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainSurveySurvey and disperser abbreviations (2)meta.notecharzspecSpectroscopic redshiftsrc.redshiftfloatl_EWHbLimit flag on EWHbmeta.code.errorcharEWHb? Hbeta equivalent width0.1nmspect.line.eqWidthintnullablee_EWHb? Hbeta equivalent width error0.1nmstat.errorintnullableEW[OIII]? [OIII]5007 equivalent width0.1nmspect.line.eqWidthintnullablee_EW[OIII]? [OIII]5007 equivalent width error0.1nmstat.error;spect.line.eqWidthintnullableEWHa? Halpha equivalent width0.1nmspect.line.eqWidthintnullablee_EWHa? Halpha equivalent width0.1nmstat.errorintnullable