J/ApJ/896/77ivo://CDS.VizieR/J/ApJ/896/77doi:10.26093/cds/vizier.18960077CDSHsyu T.Cooke R.J.Prochaska J.X.Bolte M.2022-03-10T07:25:59Z2021-11-19T13:41:27ZCDS support team

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

cds-question@unistra.frgalaxiesspectroscopyinfrared-astronomyvisible-astronomychemical-abundancesh-ii-regionsWe present Keck NIRSPEC and Keck NIRES spectroscopy of sixteen metal-poor galaxies that have pre-existing optical observations. The near-infrared (NIR) spectroscopy specifically targets the HeI{lambda}10830{AA} emission line, due to its sensitivity to the physical conditions of the gas in HII regions. We use these NIR observations, combined with optical spectroscopy, to determine the helium abundance of sixteen galaxies across a metallicity range 12+log_10_(O/H)=7.13-8.00. This data set is combined with two other samples where metallicity and helium abundance measurements can be secured: star-forming galaxies selected from the Sloan Digital Sky Survey spectroscopic database, and existing low-metallicity systems in the literature. We calculate a linear fit to these measurements, accounting for intrinsic scatter, and report a new determination of the primordial helium number abundance, y_P_=0.0805_-0.0017_^+0.0017^, which corresponds to a primordial helium mass fraction Y_P_=0.2436_-0.0040_^+0.0039^. Using our determination of the primordial helium abundance in combination with the latest primordial deuterium measurement, (D/H)_P_x10^5^=2.527+/-0.030, we place a bound on the baryon density {Omega}_b_h^2^=0.0215_-0.0005_^+0.0005^ and the effective number of neutrino species N_eff_=2.85_-0.25_^+0.28^. These values are in 1.3{sigma} agreement with those deduced from the Planck satellite observations of the temperature fluctuations imprinted on the cosmic microwave background.2020ApJ...896...77Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/896/77CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)J/ApJ/602/200 : HII regions abundances in blue compact gal. (Izotov+, 2004)J/A+A/448/955 : Abundances of emission galaxies in SDSS-DR3 (Izotov+, 2006)J/ApJ/662/15 : Abundances in extragalactic HII regions (Izotov+, 2007)J/A+A/522/A26 : Fe Abundances in metal-poor stars (Sbordone+ 2010)J/ApJ/734/82 : NIR spectroscopy of five dwarf galaxies (Izotov+, 2011)J/MNRAS/448/2687 : Blue diffuse dwarf galaxies spectroscopy (James+, 2015)J/A+A/582/A74 : WISE J072543.88-235119.7 line abundances (Spite+, 2015)J/ApJ/819/73 : Metallicity evolution of COSMOS BCD sample (Lian+, 2016)J/MNRAS/465/3977 : Blue diffuse dwarf galaxies (James+, 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 gal. (Hsyu+, 2018)http://www.sdss.org/ : SDSS home pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/896/77https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/896/77http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/896/77https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/896/77https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/896/77http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/896/77GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/896/77/abund (Best recovered parameters from MCMC analysis (Table 4) and ionic and total abundances of oxygen and helium (Table 5))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/896/77/abund?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/896/77/abund?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/896/77/abund?GETtext/xml+votable180.050000true19.666698935.21583810.005555555555555556Cone search capability for table J/ApJ/896/77/table2 (Near-infrared emission line fluxes of HII regions in our Primordial Helium Legacy Experiment with Keck (PHLEK))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/896/77/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/896/77/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/896/77/table2?GETtext/xml+votable180.050000true4.74715523.76120390.0055555555555555566/1 2275 4378 4417 4464 4732 4749 4806 4824 4917 5083 5203 5381 5408 5419 5556-5557 5644 5737 5764 5862 6005 6011 6075 6085 6128 6385 6630 6977 7243 7251 7266 7281 7371 7374 7381 7472 7497-7498 7532 7878 8418 8713 8727 9054 9332 9510 9923 10211 10237 10332 10472 10689 10700 10769 10775 10818 10821 10834 10965 10970 11006 11020-11021 11101 11111 11137 11140 11168 11239 11241 11593 11825 12615 17260 17502 17751 17758 17771 18002 18077 18235 18750 18767 18881 19028 19828 19902 20002 20416 21853 22719 25594 26014 26174 26204 26222 26232 26362 26423 26480 26483 26992 27396 27431 27499 27741 27796 27810 28089 28208 28324 28441 28460 28491 28612 31316 31462 31640-31641 31720 36766 48855 48990 49011 49016https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/896/77?format=asciiOpticalInfrareddefaultJ/ApJ/896/77/abundBest recovered parameters from MCMC analysis (Table 4) and ionic and total abundances of oxygen and helium (Table 5)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNIRDisplay data from Keck NIR observations (link to Table 2)meta.ref.urlintnullableIDGalaxy identifiermeta.id;meta.mainchary+[0.07/0.097] Singly ionized helium abundancephys.abund.YdoubleE_y+[0.0007/0.011] Upper uncertainty in y+stat.error;stat.maxdoublee_y+[0.00079/0.015] Lower uncertainty in y+stat.error;pos.cartesian.ydoubleTe[10370/17900] Electron temperatureKphys.temperature.electron;phys.electronintE_Te[440/2400] Upper uncertainty in TeKstat.error;stat.maxinte_Te[270/2400] Lower uncertainty in TeKstat.errorintlogNe[0.4/2.8] log electron densitylog(cm**-3)phys.density;phys.electronfloatE_logNe[0.083/1.1] Upper uncertainty in logNelog(cm**-3)stat.error;stat.maxfloate_logNe[0.087/1.5] Lower uncertainty in logNelog(cm**-3)stat.errorfloatcHb[0.004/0.48] H{beta} reddening parameterphot.color.excessfloatE_cHb[0.0065/0.14] Upper uncertainty in cHbstat.error;stat.maxfloate_cHb[0.003/0.14] Lower uncertainty in cHbstat.errorfloataH[0.27/7] Underlying hydrogen stellar absorption0.1nmphys.absorptionfloatE_aH[0.3/2.1] Upper uncertainty in aH0.1nmstat.error;stat.maxfloate_aH[0.2/1.9] Lower uncertainty in aH0.1nmstat.errorfloataHe[0.1/1.16] Underlying helium stellar absorption0.1nmphys.absorptionfloatE_aHe[0.06/0.6] Upper uncertainty in aHe0.1nmstat.error;stat.maxfloate_aHe[0.063/0.5] Lower uncertainty in aHe0.1nmstat.errorfloattauHe[0.29/3.8] Helium optical depth parameterphys.absorption.opticalDepthfloatE_tauHe[0.29/1.8] Upper uncertainty in tauHestat.error;stat.maxfloate_tauHe[0.21/1.7] Lower uncertainty in tauHestat.errorfloatlogxi[-4.71/-1] log ratio of neutral to singly ionized hydrogen densityphys.density;arith.ratiofloatE_logxi[0.65/2] Upper uncertainty in logxistat.error;stat.maxfloate_logxi[0.87/2.97] Lower uncertainty in logxistat.errorfloatO+/H+[0.43/7.5] Singly ionized Oxygen abundancephys.abundfloatE_O+/H+[0.05/1.4] Upper uncertainty in O+/H+stat.error;stat.maxfloate_O+/H+[0.04/1.2] Lower uncertainty in O+/H+stat.error;phys.abundfloatO++/H+[0.6/15.7] Doubly ionized Oxygen abundancephys.abundfloatE_O++/H+[0.26/4.8] Upper uncertainty in O++/H+stat.error;stat.maxfloate_O++/H+[0.15/4] Lower uncertainty in O++/H+stat.error;phys.abundfloatO/H[1.73/18.3] Total Oxygen abundancephys.abundfloatE_O/H[0.39/4.8] Upper uncertainty in O/Hstat.error;stat.maxfloate_O/H[0.25/4] Lower uncertainty in O/Hstat.error;phys.abundfloaty++[0/0.003] Doubly ionized Helium abundancephys.abund.YfloatE_y++[0/0.0009] Upper uncertainty in y++stat.error;stat.maxfloate_y++[0/0.0008] Lower uncertainty in y++stat.error;pos.cartesian.yfloaty[0.07/0.097] Total Helium abundancephys.abund.YdoubleE_y[0.00072/0.011] Upper uncertainty in ystat.error;stat.maxdoublee_y[0.00079/0.015] Lower uncertainty in ystat.error;pos.cartesian.ydoubleH18Display data from Hsyu+, 2018, J/ApJ/863/134 within 5"meta.ref.urlintnullableSloanDisplay the online SDSS data for the nearest objectmeta.ref.urlcharSpInteractive spectrum from SDSSmeta.ref.urlcharSimbadNameSimbad column added by the CDSmeta.idcharnullableNEDNED column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/ApJ/896/77/table2Near-infrared emission line fluxes of HII regions in our Primordial Helium Legacy Experiment with Keck (PHLEK)NameGalaxy namemeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintyDisplay oxygen and helium abundances if any (link to Tables 4+5 )meta.ref.urlintnullableFHeI[8.3/380] HeI{lambda}10830 flux in 10^-17^erg/s/cm^2^ (1)1e-20W.m**-2phot.flux;em.IRfloate_FHeI[0.38/14] FHeI uncertainty1e-20W.m**-2stat.errorfloatFPgam[2.3/190] P{gamma} flux in 10^-17^erg/s/cm^2^ (1)1e-20W.m**-2phot.flux;em.IRfloate_FPgam[0.67/10] FPgam uncertainty1e-20W.m**-2stat.errorfloatHeI/Pgam[1.8/4.7] FHeI to FPgam ratiophot.flux;arith.ratiofloate_HeI/Pgam[0.046/0.46] HeI/Pgam uncertaintystat.errorfloatH18Display data from Hsyu+, 2018, J/ApJ/863/134 within 5"meta.ref.urlintnullableSimbadNameSimbad column added by the CDSmeta.idcharnullableNEDNED column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main