J/ApJ/961/173ivo://CDS.VizieR/J/ApJ/961/173CDSZou HuSui J.Saintonge A.Scholte D.Moustakas J.Siudek M.Dey A.,Juneau S.Guo W.Canning R.Aguilar J.Ahlen S.Brooks D.,Claybaugh T.Dawson K.de la Macorra A.Doel P.Forero-Romero J.E.,Gontcho Gontcho S. AHonscheid K.Landriau M.Le Guillou L.,Manera M.Meisner A.Miquel R.Nie J.Poppett C.Rezaie M.Rossi G.,Sanchez E.Schubnell M.Seo H.Tarle G.Zhou Z.Zou S.2026-05-27T10:48:25Z2026-05-27T11:27:51ZCDS support team

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

cds-question@unistra.frdwarf-galaxiesvisible-astronomyspectroscopychemical-abundancesline-intensitiesredshiftedsurveysExtremely metal-poor galaxies (XMPGs) at relatively low redshift are excellent laboratories for studying galaxy formation and evolution in the early universe. Much effort has been spent on identifying them from large-scale spectroscopic surveys or spectroscopic follow-up observations. Previous work has identified a few hundred XMPGs. In this work, we obtain a large sample of 223 XMPGs at z<1 from the early data of the Dark Energy Spectroscopic Instrument (DESI). The oxygen abundance is determined using the direct Te method based on the detection of the [OIII]{lambda}4363 line. The sample includes 95 confirmed XMPGs based on the oxygen abundance uncertainty; the remaining 128 galaxies are regarded as XMPG candidates. These XMPGs are only 0.01% of the total DESI observed galaxies. Their coordinates and other properties are provided in the paper. The most XMPGs have an oxygen abundance of ~1/34 Z_{sun}_, a stellar mass of about 1.5x10^7^M_{sun}_, and a star formation rate of 0.22M_{sun}_/yr. The two most XMPGs present distinct morphologies suggesting different formation mechanisms. The local environmental investigation shows that XMPGs preferentially reside in relatively low-density regions. Many of them fall below the stellar mass-metallicity relations (MZRs) of normal star-forming galaxies. From a comparison of the MZR with theoretical simulations, it appears that XMPGs are good analogs to high-redshift star-forming galaxies. The nature of these XMPG populations will be further investigated in detail with larger and more complete samples from the ongoing DESI survey.2024ApJ...961..173Zhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/961/173CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVI/141 : Nebular [OIII] collision strengths - SSB (Storey+, 2014)VII/292 : DESI Legacy Imaging Surveys DR8 photometric redshifts (Duncan, 2022)V/161 : DESI DR1 redshift catalog (DESI Col.+ 2025)J/ApJS/132/37 : Spectroscopy of Southern warm IR galaxies (Kewley+, 2001)J/ApJ/602/200 : HII regions abund. in blue compact galaxies (Izotov+, 2004)J/ApJS/190/233 : Spectroscopy & abundances of SINGS galaxies (Moustakas+, 2010)J/ApJS/188/32 : Breit-Pauli transition probabilities for SII (Tayal+, 2010)J/ApJ/743/77 : Extremely metal-poor galaxies in SDSS (Morales-Luis+, 2011)J/ApJ/765/140 : Stacked spectra of SDSS star forming galaxies (Andrews+, 2013)J/A+A/568/L8 : VUDS emission line 0.2<~z<~0.9 galaxies (Amorin+, 2014)J/ApJ/819/110 : EMP galaxies in SDSS. II. (Sanchez Almeida+ 2016)J/other/RAA/17.41 : LAMOST metal-poor galaxies sample (Gao+, 2017)J/ApJ/847/38 : Extreme emission line galaxies at z<~0.05 (Yang+, 2017)J/ApJ/863/134 : SDSS low-metallicity blue compact dwarf galaxies (Hsyu+, 2018)J/ApJ/896/77 : The PHLEK survey: oxygen & helium abundances (Hsyu+, 2020)J/ApJS/258/11 : The COSMOS2020 catalog (Weaver+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/961/173https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/961/173http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/961/173https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/961/173https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/961/173http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/961/173GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/961/173/table2 (Properties of our confirmed extremely metal-poor galaxies (XMPGs))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/961/173/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/961/173/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/961/173/table2?GETtext/xml+votable180.050000true226.3995631.777630.005555555555555556Cone search capability for table J/ApJ/961/173/table3 (Properties of our candidate XMPGs)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/961/173/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/961/173/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/961/173/table3?GETtext/xml+votable180.050000true210.9358548.765990.0055555555555555565/6814 6/940 4958-4959 4975 4984 5023 5043 5058 5068 5230 5237 5278 5314 5316 5322 5636 5638 5663 5942 5964 5975 6255 6398 6415 6441 6742 6854 6856 7018 7020 7022 7034 7105 7563 7585 7940 8239 8276 8325 8452 8468 8520 8536 8548 8573 8607 8768 8771 8840 8963 9063 9067 9118 9133 9147 9150 9153 9156 9210 9223 9245 9337 9339 9341 9380 9511 9590 9630 9668 9721 9738 9750 9822-9823 9829 9879 9923 10030 10090 10157 10234 10237 10377 10382 10400 10406 10431 10442 10449 10489 10500 10513 10537 10727 10739 10741 10749 10809 10884 11177-11178 11185 11189 11226 11230 11252 11323 11400 11424 11520 11605-11607 12400 13363 15088 15341-15342 16003 17692-17693 17697 17710 18862 18989 19171-19172 20298 21075 21080 22487 22489 25469 25599 25801 25817 25851 25916 25918 25934 25952 25955 25963 25967 25978 25980 26004 26010 26064 26083 26086 26126 26139 26155 26179 26272 26278 26280-26282 26284 26460 26497 26951 26964 26967 27205 27245 27250 27262 27344 28115-28116 28118-28119 28126 28149-28151 28529 28532 28537 28540 28640 31356 31434 31442 31450 31453 31518 31557 31561 31613 31641 31679 32287 32410 32485 32682 32714 38777 45004 45017 45052https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/961/173?format=asciiOpticaldefaultJ/ApJ/961/173/table2Properties of our confirmed extremely metal-poor galaxies (XMPGs)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/95] Sequential identifiermeta.idintDESIExtremely metal-poor galaxy (XMPG) name (JHHMMSS.ss+DDMMSSs)meta.id;meta.maincharTargetID[234520901058560/39633461119550747] DESI target identifiermeta.idRAJ2000[30.46/324.3] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-27.3/66.7] Declination (J2000)degpos.eq.dec;meta.mainzspec[0.003/0.9] Spectroscopic redshiftsrc.redshiftfloatrmag[17.2/25.4] DESI r-band magnitudemagphot.mag;em.opt.RfloatEBV[0/0.43] Reddening, E(B-V)magphot.color.excessfloatEWOIII[1.6/3.24] Equivalent width of [OIII]5007{AA}, in Angstroms0.1nmspect.line.eqWidth;em.line.OIIIfloatNe[100/1064] Electron volume densitycm**-3phys.density;phys.electronfloate_Ne[0/1156] Uncertainty in Necm**-3stat.error;phys.density;phys.electronfloatTe[17632/23394] Electron temperature for [OIII]Kphys.temperature;phys.electronfloate_Te[594/3542] Uncertainty in TeKstat.error;phys.temperature;phys.electronfloatlogOH[7.16/7.62] Oxygen abundance, 12+log(O/H)phys.abundfloate_logOH[0.03/0.2] Uncertainty in logOHstat.error;phys.abundfloatlogMs[4.36/10.1] Log of stellar masslog(solMass)phys.massfloate_logMs[0.04/0.5] Uncertainty in logMslog(solMass)stat.error;phys.massfloatlogSFR[-3.8/1.6] Log of star formation ratelog(solMass.yr**-1)phys.SFRfloate_logSFR[0.1/0.14] Uncertainty in logSFRlog(solMass.yr**-1)stat.error;phys.SFRfloatDR8Display data from the DESI DR8 (VII/292) within 0.5"meta.ref.urlintnullableJ/ApJ/961/173/table3Properties of our candidate XMPGsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/128] Sequential identifiermeta.idintDESIExtremely metal-poor galaxy (XMPG) name (JHHMMSS.ss+DDMMSSs)meta.id;meta.maincharTargetID[234514848677892/39633478710462243] DESI target identifiermeta.idRAJ2000[3.98/339.6] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-20.15/68.7] Declination (J2000)degpos.eq.dec;meta.mainzspec[0.002/0.96] Spectroscopic redshiftsrc.redshiftfloatrmag[16.39/24.93] DESI r-band magnitudemagphot.mag;em.opt.RfloatEBV[0/0.35] Reddening, E(B-V)magphot.color.excessfloatEWOIII[1.8/3.84]? Equivalent Width of [OIII]5007{AA}, in Angstroms0.1nmspect.line.eqWidth;em.line.OIIIfloatnullableNe[76/1648] Electron volume densitycm**-3phys.density;phys.electronfloate_Ne[0/1323] Uncertainty in Necm**-3stat.error;phys.density;phys.electronfloatTe[16529/20709] Electron temperature for [OIII]Kphys.temperature;phys.electronfloate_Te[480/3499] Uncertainty in TeKstat.error;phys.temperature;phys.electronfloatlogOH[7.5/7.7] Oxygen abundance, 12+log (O/H)phys.abundfloate_logOH[0.03/0.3] Uncertainty in OHstat.error;phys.abundfloatlogMs[5.77/9.7] Log of stellar masslog(solMass)phys.massfloate_logMs[0.04/0.76] Uncertainty in logMslog(solMass)stat.error;phys.massfloatlogSFR[-2.4/1.6] Log of Star formation ratelog(solMass.yr**-1)phys.SFRfloate_logSFR[0.13/0.14] Uncertainty in logSFRlog(solMass.yr**-1)stat.error;phys.SFRfloatDR8Display data from the DESI DR8 (VII/292) within 0.5"meta.ref.urlintnullable