J/ApJ/916/11ivo://CDS.VizieR/J/ApJ/916/11doi:10.26093/cds/vizier.19160011CDSIndahl B.Zeimann G.Hill G.J.Bowman W.P.Ciardullo R.Drory N.,Gawiser E.Hopp U.Janowiecki S.Boylan-Kolchin M.Mentuch Cooper E.,Davis D.Farrow D.Finkelstein S.Gronwall C.Kelz A.McQuinn K.B.W.,Schneider D.Tuttle S.E.2023-01-24T14:12:28Z2023-01-19T14:18:46ZCDS support team

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

cds-question@unistra.frgalaxiesspectroscopyredshiftedline-intensitiesultraviolet-photometryinfrared-photometryvisible-astronomybroad-band-photometryWe assemble a sample of 17 low-metallicity (7.45<log(O/H)+12<8.12) galaxies with z<=0.1 found spectroscopically, without photometric preselection, in early data from the Hobby-Eberly Telescope Dark Energy Experiment. Star-forming galaxies that occupy the lowest-mass and lowest-metallicity end of the mass-metallicity relation tend to be undersampled in continuum-based surveys as their spectra are typically dominated by emission from newly forming stars. We search for galaxies with high [OIII]{lambda}5007/[OII]{lambda}3727, implying highly ionized nebular emission often indicative of low-metallicity systems. With the Second Generation Low Resolution Spectrograph on the Hobby-Eberly Telescope we acquired follow-up spectra, with higher resolution and broader wavelength coverage, of each low-metallicity candidate in order to confirm the redshift, measure the H{alpha} and [NII] line strengths, and, in many cases, obtain deeper spectra of the blue lines. We find our galaxies are consistent with the mass-metallicity relation of typical low-mass galaxies. However, galaxies in our sample tend to have similar specific star formation rates as the incredibly rare "blueberry" galaxies found by Yang+ (2017, J/ApJ/847/38). We illustrate the power of spectroscopic surveys for finding low-mass and low-metallicity galaxies and reveal that we find a sample of galaxies that are a hybrid between the properties of typical dwarf galaxies and the more extreme blueberry galaxies.2021ApJ...916...11Ihttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/916/11CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)II/371 : The Dark Energy Survey (DES): Data Release 2 (Abbott+, 2021)VII/292 : DESI Legacy Imaging Surveys DR8 (Duncan, 2022)J/A+AS/120/323 : Long-slit spectroscopy of UCM galaxies (Gallego+ 1996)J/A+AS/141/371 : Low-mass stars evolutionary tracks (Girardi+, 2000)J/A+A/448/955 : Abundances of emission galaxies in SDSS-DR3 (Izotov+, 2006)J/A+A/459/85 : O/H and gas densities in star-forming galaxies (Nagao+, 2006)J/ApJ/668/853 : Sp. of UltraStrong Emission Line galaxies (Kakazu+, 2007)J/ApJS/178/247 : H{alpha} and [NII] survey in local 11 Mpc (Kennicutt+, 2008)J/ApJ/703/517 : The Spitzer Local Volume Legacy: IR photometry (Dale+, 2009)J/ApJ/703/1672 : Far-IR and H{alpha} fluxes in galaxies (Kennicutt+, 2009)J/ApJS/192/5 : Emission-line galaxies from HETDEX pilot survey (Adams+, 2011)J/ApJ/765/140 : Stacked spectra of SDSS star forming galaxies (Andrews+, 2013)J/ApJ/777/18 : Stellar mass functions of galaxies to z=4 (Muzzin+, 2013)J/ApJ/817/10 : Star-forming galaxy metallicities (Grasshorn Gebhardt+, 2016)J/ApJ/819/73 : Metallicity evolution of COSMOS BCD sample (Lian+, 2016)J/A+A/599/A71 : SDSS star-forming galaxies aperture-free (Duarte+, 2017)J/ApJ/847/38 : Extreme emission line galaxies at z<~0.05 (Yang+, 2017)J/ApJ/865/L1 : LAEs discovered with ultra-deep MUSE in UDF (Maseda+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/916/11https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/916/11http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/916/11https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/916/11https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/916/11http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/916/11GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/916/11/table1 (*Basic properties of objects in the sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/916/11/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/916/11/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/916/11/table1?GETtext/xml+votable180.050000true31.0511-0.22860.0055555555555555566/5625 5957 5963 10742 11059 11061 11081 17811 17813-17814 18025 18067 18070 180747.447298006782415e-19 1.4134638842407062e-18https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/916/11?format=asciiUVOpticalInfrareddefaultJ/ApJ/916/11/table1*Basic properties of objects in the samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDIdentifiermeta.id;meta.maincharprimaryRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainz[0.027/0.096] Spectroscopic redshiftsrc.redshiftfloatO2-3727[2/708] The [O II] 3727 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_O2-3727[0.5/80] Uncertainty in O2-37271e-17mW.m**-2stat.errorfloatNe3-3869[0.4/457] The [Ne III] 3869 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_Ne3-3869[0.3/16] Uncertainty in Ne3-38691e-17mW.m**-2stat.errorfloatH8[-3/253] The H8 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_H8[0.4/12] Uncertainty in H81e-17mW.m**-2stat.errorfloatNe3-3968[-0.95/287] The [Ne III]+H7 3968 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_Ne3-3968[0.6/63] Uncertainty in Ne3-39681e-17mW.m**-2stat.errorfloatHd[-0.6/281] The H{delta} flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_Hd[0.3/14] Uncertainty in Hd1e-17mW.m**-2stat.errorfloatHg[1.8/527] The H{gamma} flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_Hg[0.2/59] Uncertainty in Hg1e-17mW.m**-2stat.errorfloatO3-4363[-0.93/135] The [O III] 4363 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_O3-4363[0.14/14] Uncertainty in O3-43631e-17mW.m**-2stat.errorfloatHe1-4471[-3.8/35.5] The He I 4471 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_He1-4471[0.3/4] Uncertainty in He1-44711e-17mW.m**-2stat.errorfloatHe2-4686[-3.2/23] The He II 4686 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_He2-4686[0.19/6] Uncertainty in He2-46861e-17mW.m**-2stat.errorfloatHb[3.3/952] The H{beta} flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_Hb[0.4/74] Uncertainty in Hb1e-17mW.m**-2stat.errorfloatO3-4959[2.9/1297] The [O III] 4959 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_O3-4959[0.6/150] Uncertainty in O3-49591e-17mW.m**-2stat.errorfloatO3-5007[11/4403] The [O III] 5007 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_O3-5007[0.8/195] Uncertainty in O3-50071e-17mW.m**-2stat.errorfloatDESDisplay data from DES DR2 (II/371) within 1"meta.ref.urlcharDESIDisplay data from DESI DR8 (VII/292) within 1.5"meta.ref.urlcharJ/ApJ/916/11/table3*Photometry from all surveysIDIdentifiermeta.id;meta.maincharprimarye_FUVFlux[0.2/10]? Uncertainty in FUVFluxuJystat.errorfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintgLSmag[17.47/21.9] Apparent DESI LS g band magnitudemagphot.mag;em.opt.BfloatgLSFlux[1.7/102.5] LS g band flux densityuJyphot.flux.density;em.opt.Bfloate_gLSFlux[0.08/0.4] Uncertainty in gLSFluxuJystat.errorfloatrLSFlux[1.7/74] LS r band flux densityuJyphot.flux.density;em.opt.Rfloate_rLSFlux[0.09/0.5] Uncertainty in rLSFluxuJystat.errorfloatzLSFlux[0.9/54] LS z band flux densityuJyphot.mag;em.opt.Ifloate_zLSFlux[0.2/0.9] Uncertainty in zLSFluxuJystat.errorfloatW1LSFlux[0.06/32]? LS WISE 3.4 um band flux densityuJyphot.mag;em.IR.3-4umfloatnullablee_W1LSFlux[1.5/3]? Uncertainty in W1LSFluxuJystat.errorfloatnullableW2LSFlux[3/41]? LS WISE 4.6 um band flux densityuJyphot.mag;em.IR.4-8umfloatnullablee_W2LSFlux[3/6]? Uncertainty in W2LSFluxuJystat.errorfloatnullableW3LSFlux[27/465]? LS WISE 12.1 um band flux densityuJyphot.flux.density;em.IR.8-15umfloatnullablee_W3LSFlux[80/185]? Uncertainty in W3LSFluxuJystat.errorfloatnullableW4LSFlux[333/14004]? LS WISE 22.2 um band flux densityuJyphot.flux.density;em.IR.15-30umdoublenullablee_W4LSFlux[797/1290]? Uncertainty in W4LSFluxuJystat.errorfloatnullablegDESFlux[1.9/23.5]? DES g band flux densityuJyphot.mag;em.opt.Bfloatnullablee_gDESFlux[0.14/0.3]? Uncertainty in gDESFluxuJystat.errorfloatnullablerDESFlux[1.5/31.4]? DES r band flux densityuJyphot.flux.density;em.opt.Rfloatnullablee_rDESFlux[0.2/0.6]? Uncertainty in rDESFluxuJystat.errorfloatnullableiDESFlux[1.6/39.1]? DES g band flux densityuJyphot.mag;em.opt.Ifloatnullablee_iDESFlux[0.3/0.7]? Uncertainty in iDESFluxuJystat.errorfloatnullablezDESFlux[0.2/39]? DES z band flux densityuJyphot.mag;em.opt.Ifloatnullablee_zDESFlux[0.6/1.2]? Uncertainty in zDESFluxuJystat.errorfloatnullableYDESFlux[0.8/45.6]? DES Y band flux densityuJyphot.mag;em.IR.Jfloatnullablee_YDESFlux[2.28/4]? Uncertainty in YDESFluxuJystat.errorfloatnullableFUVFlux[0.7/57]? GALEX FUV band flux densityuJyphot.flux;em.UVfloatnullableNUVFlux[1.13/56]? GALEX NUV band flux densityuJyphot.flux;em.UVfloatnullablee_NUVFlux[0.4/6]? Uncertainty in NUVFluxuJystat.errorfloatnullableJ/ApJ/916/11/table5*LRS2 flux measurements for lines measured in LRS2 spectrae_O3-5007[1/1147]? Uncertainty in O3-50071e-17mW.m**-2stat.errorfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintO2-3727[-2.8/370.4] The [O II] 3727 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_O2-3727[1.2/92]? Uncertainty in O2-37271e-17mW.m**-2stat.errorfloatnullableNe3-3869[-13/290] The [Ne III] 3869 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_Ne3-3869[0.8/61]? Uncertainty in Ne3-38691e-17mW.m**-2stat.errorfloatnullableH8[-24/131] The H8 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_H8[0.5/30]? Uncertainty in H81e-17mW.m**-2stat.errorfloatnullableNe3-3968[-11.5/135] The [Ne III]+H7 3968 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_Ne3-3968[0.5/59]? Uncertainty in Ne3-39681e-17mW.m**-2stat.errorfloatnullableHd[-11.5/216] The H{delta} flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_Hd[1/41]? Uncertainty in Hd1e-17mW.m**-2stat.errorfloatnullableHg[-9.2/462] The H{gamma} flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_Hg[1.8/177]? Uncertainty in Hg1e-17mW.m**-2stat.errorfloatnullableO3-4363[-5.4/130.3] The [O III] 4363 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_O3-4363[0.8/44]? Uncertainty in O3-43631e-17mW.m**-2stat.errorfloatnullableHe1-4471[-7.7/33.4] The He I 4471 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_He1-4471[1/13.4]? Uncertainty in He1-44711e-17mW.m**-2stat.errorfloatnullableHe2-4686[-11.2/25] The He II 4686 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_He2-4686[0.7/7]? Uncertainty in He2-46861e-17mW.m**-2stat.errorfloatnullableHb[0/992] The H{beta} flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_Hb[0.6/237]? Uncertainty in Hb1e-17mW.m**-2stat.errorfloatnullableO3-4959[0/1576] The [O III] 4959 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_O3-4959[0.5/373]? Uncertainty in O3-49591e-17mW.m**-2stat.errorfloatnullableO3-5007[0/4781] The [O III] 5007 flux (1)1e-17mW.m**-2phot.flux;spect.linefloatHe1-5876[-0.6/84.4] The He I 5876 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_He1-5876[0.6/18.5]? Uncertainty in He1-58761e-17mW.m**-2stat.errorfloatnullableO1-6300[-2.9/10.97] The [O I] 6300 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_O1-6300[0.4/2.61]? Uncertainty in O1-63001e-17mW.m**-2stat.errorfloatnullableS3-6312[-1.8/9.85] The [S III] 6312 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_S3-6312[0.48/3.5]? Uncertainty in S3-63121e-17mW.m**-2stat.errorfloatnullableN2-6548[-0.42/9.75] The [N II] 6548 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_N2-6548[0.13/7.15]? Uncertainty in N2-65481e-17mW.m**-2stat.errorfloatnullableHa[11.5/2955] The H{alpha} flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_Ha[1.9/638]? Uncertainty in Ha1e-17mW.m**-2stat.errorfloatnullableN2-6583[-0.3/16.52] The [N II] 6583 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_N2-6583[0.3/4.7]? Uncertainty in N2-65831e-17mW.m**-2stat.errorfloatnullableHe1-6678[-3.5/26.81] The He I 6678 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_He1-6678[0.39/9]? Uncertainty in He1-66781e-17mW.m**-2stat.errorfloatnullableS2-6717[-0.52/47.52] The [S II] 6717 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_S2-6717[0.2/12]? Uncertainty in S2-67171e-17mW.m**-2stat.errorfloatnullableS2-6731[-4.13/29.47] The [S II] 6731 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_S2-6731[0.5/10]? Uncertainty in S2-67311e-17mW.m**-2stat.errorfloatnullableAr3-7136[-2.07/32.36] The [Ar III] 7136 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_Ar3-7136[0.1/7]? Uncertainty in Ar3-71361e-17mW.m**-2stat.errorfloatnullableS3-9069[-25.54/322.86] The [S III] 9069 flux (1)1e-17mW.m**-2phot.flux;spect.linefloate_S3-9069[0.4/255]? Uncertainty in S3-90691e-17mW.m**-2stat.errorfloatnullableIDIdentifiermeta.id;meta.maincharprimaryJ/ApJ/916/11/table6*Properties of the [OIII] emitting galaxies in the samplee_sSFR[0.18/0.4] Lower uncertainty in sSFRyr**-1stat.errorfloatsSFR[-9.6/-7.4] Specific Star Formation Rate (4)yr**-1meta.idfloatf_EWO3Flag on EWO3 (6)meta.codecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDIdentifiermeta.id;meta.maincharprimaryO3/O2[0.7/13.2] VIRUS [O III]/[O II] line ratiospect.line.intensity;arith.ratiofloate_O3/O2[0.1/3.7] Uncertainty in O3/O2stat.error;phys.abundfloatlogO/H[7.5/8.5] Log(O/H)+12 abundance ratio; see Section 4.1phys.abundfloate_logO/H[0.14/0.3] Lower uncertainty in logO/Hstat.error;phys.abundfloatE_logO/H[0.14/0.4] Upper uncertainty in logO/Hstat.error;stat.maxfloatlogO/H*[7.55/7.91]? log(O/H)+12 abundance ratio (1)phys.abundfloatnullablee_logO/H*[0.05/0.3]? Lower uncertainty in logO/H*stat.error;phys.abundfloatnullableE_logO/H*[0.08/0.4]? Upper uncertainty in logO/H*stat.error;stat.maxfloatnullableSFRHa[0/1.3] Star Formation Rate from Halpha (2)solMass/yrphys.SFRfloate_SFRHa[0/0.3] Lower uncertainty in SFRHasolMass/yrstat.errorfloatE_SFRHa[0/0.3] Upper uncertainty in SFRHasolMass/yrstat.error;stat.maxfloatSFR100[0/0.7] Star Formation Rate (3)solMass/yrphys.SFRfloate_SFR100[0/0.4] Lower uncertainty in SFR100solMass/yrstat.errorfloatE_SFR100[0/0.5] Upper uncertainty in SFR100solMass/yrstat.error;stat.maxfloatlogM[6.3/8.8] Log mass (3)log(solMass)phys.massfloate_logM[0.1/0.3] Lower uncertainty in logMlog(solMass)stat.errorfloatE_logM[0.2/0.4] Upper uncertainty in logMlog(solMass)stat.error;stat.maxfloatE_sSFR[0.25/0.5] Upper uncertainty in sSFRyr**-1stat.error;stat.maxfloatE(B-V)[-0.01/0.2] The (B-V) color excessmagphot.color.excessfloate_E(B-V)[0/0.07] Lower uncertainty in E (B-V)magstat.errorfloatE_E(B-V)[0.01/0.07] Upper uncertainty in E (B-V)magstat.error;stat.maxfloatEWO3[35/1272] Equivalent width of [OIII]5007{AA} (5)0.1nmspect.line.eqWidthfloate_EWO3[3/160] Uncertainty in EWO30.1nmstat.errorfloat