J/ApJ/911/55ivo://CDS.VizieR/J/ApJ/911/55doi:10.26093/cds/vizier.19110055CDSShull J.M.Danforth C.W.Anderson K.L.2022-11-16T06:18:58Z2022-11-09T10:37:31ZCDS support team

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

cds-question@unistra.frob-starsultraviolet-astronomysurveysmilky-way-galaxyextinctionmolecular-physicsinterstellar-mediumh-i-line-emissionWe report results from a Far Ultraviolet Spectrographic Explorer (FUSE) survey of interstellar molecular hydrogen (H_2_) in the Galactic disk toward 139 O-type and early B-type stars at Galactic latitudes |b|<=10{deg}, with updated photometric and parallax distances. H_2_ absorption is measured using the far-UV Lyman and Werner bands, including strong R(0), R(1), and P(1) lines from rotational levels J=0 and J=1 and excited states up to J=5 (sometimes J=6 and 7). For each sight line, we report column densities N_H2_, N_HI_, N(J), and N_H_=N_HI_+2N_H2_ and the molecular fraction f_H2_=2N_H2_/N_H_. Our survey extends the 1977 Copernicus H_2_ survey up to N_H_~5x10^21^cm^-2^. The lowest rotational states have excitation temperatures and rms dispersions <T_01_>=88+/-20K and <T_02_>=77+/-18K, suggesting that J=0, 1, 2 are coupled to the gas kinetic temperature. Populations of higher-J states exhibit mean excitation temperatures <T_24_>=237+/-91K and <T_35_>=304+/-108K, produced primarily by UV radiative pumping. Correlations of f_H2_ with E(B-V) and N_H_ show a transition to f_H2_>=0.1 at N_H_>~10^21^cm^-2^ and E(B-V)>~0.2, interpreted with an analytic model of H_2_ formation-dissociation equilibrium and attenuation of the far-UV radiation field by self-shielding and dust opacity. Results of this disk survey are compared to previous FUSE studies of H_2_ in translucent clouds, at high Galactic latitudes, and in the Magellanic Clouds. Using updated distances to the target stars, we find average sight-line values <f_H2_>=0.20 and <N_H_/E(B-V)>=6.07x10^21^cm^-2^/mag.2021ApJ...911...55Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/911/55CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIII/274 : Galactic O-Star Spectroscopic Survey (GOSSS) (Sota+, 2014)V/116 : Galactic O star catalog (Maiz-apellaniz+, 2004)J/ApJS/93/211 : IUE survey of H I Ly{alpha} absorption. I. (Diplas+ 1994)J/ApJS/163/282 : Molecular hydrogen column densities (Wakker+, 2006)J/ApJS/176/59 : FUSE survey of OVI in the disk of the Milky Way (Bowen+, 2008)J/ApJ/711/1236 : Equivalent width of H_2_ from FUSE (Jensen+, 2010)J/ApJ/734/65 : CI radial velocities with HST/STIS (Jenkins+, 2011)J/A+A/613/A9 : Extinction towards Galactic O stars (Maiz Apellaniz+, 2018)J/ApJ/872/55 : OI, GeII, KrI & H abundances from HST UV sp. (Jenkins, 2019)J/ApJ/906/73 : Extinction & emission PostPlanck Era (Hensley+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/911/55https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/911/55http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/911/55https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/911/55https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/911/55http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/911/55GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/911/55/table1 (Stellar parameters and distances)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/911/55/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/911/55/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/911/55/table1?GETtext/xml+votable180.050000true311.554135.54280.0055555555555555566/1332 2619 3011 3050 3214 3245 3247 3249 3256 3307 3585 6891 13001 13255 13273 13289 14173 14179 14197 14236 14240 14249 14435 14459 14628 14630 14636 14643 14805 14810 15369 15478-15479 15580 15631 15662-15663 15682-15683 15748 21531 22246 22249 22264 23780 23851 23982 28687 28759 28774 28796 28890-28891 28915 29025 29036 29040 29091 29095 29304 29459 29463 29513 29602 29828 29839 29876 30709 37140 37209 37212 37331-37334 37339 37870 37893 37897 37900 37914 37926 37930 37938 37948 37963 38016 38024 38074 39238 39281 39374 39775 39803-39804 39873 40480 40609 41103 41528 41598 41655 41696 41700 41903 42126 42303 42335 42394 42417 42421 42470 43040https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/911/55?format=asciiUVRadiodefaultJ/ApJ/911/55/table1Stellar parameters and distancesSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/139] Internal target numbermeta.idintprimaryNameTarget identifiermeta.id;meta.maincharGLON[2.26/355.36] Galactic longitudedegpos.galactic.lonGLAT[-23.23/13.5] Galactic latitudedegpos.galactic.latBmag[5.3/10.61] Apparent B band magnitudemagphot.mag;em.opt.BfloatVmag[5/10.7] Apparent V band magnitudemagphot.mag;em.opt.VfloatE(B-V)[0.02/1.1] The(B-V) color excessmagphot.color.excessfloatSpTypeSpectral typesrc.spTypeDphot[0.2/9.9] Photometric distance (1)kpcpos.distancefloatf_Dphot[b] Flag on Dphot (2)meta.codecharl_DGaiaLimit flag on DGaiameta.code.errorchar_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.decnullableindexedf_DGaiaFlag on DGaia (4)meta.codecharDGaia[0.28/14]? Parallax distance (3)kpcpos.distancefloatnullablee_DGaia[0.27/7.7]? Lower limit on DGaiakpcstat.errorfloatnullableE_DGaia[0.29/20.1]? Upper limit on DGaiakpcstat.error;stat.maxfloatnullableFUSEFUSE program identifiermeta.id;obscharTexp[0.059/31.6] FUSE spectroscopic exposure timekstime.expofloatJ/ApJ/911/55/table2HI column density measurementsSeq[1/139] Internal target numbermeta.idintprimaryr_logNHI-OReference for logNHI-O (3)meta.ref;pos.framecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameTarget identifiermeta.id;meta.maincharE(B-V)[0.02/1.1] The(B-V) color excess (1)magphot.color.excessfloatlogNHI-A[20.5/21.7] Adopted log HI column density (2)log(cm**-2)phys.columnDensityfloatlogNHI-S[20.9/21.5]? log HI column density from Shull & Van Steenberg 1985ApJ...294..599Slog(cm**-2)phys.columnDensityfloatnullablee_logNHI-S[0.05/0.15]? Uncertainty in logNHI-Slog(cm**-2)stat.errorfloatnullablelogNHI-D[20.56/21.65]? log HI column density from Diplas & Savage, 1994, J/ApJS/93/211log(cm**-2)phys.columnDensityfloatnullablee_logNHI-D[0.06/0.23]? Uncertainty in logNHI-Dlog(cm**-2)stat.errorfloatnullablelogNHI-J[20.55/21.5]? log HI column density from Jenkins 2019, J/ApJ/872/55log(cm**-2)phys.columnDensityfloatnullableE_logNHI-J[0.03/0.1]? Upper uncertainty in logNHI-Jlog(cm**-2)stat.error;stat.maxfloatnullablee_logNHI-J[0.02/0.13]? Lower uncertainty in logNHI-Jlog(cm**-2)stat.errorfloatnullablelogNHI-O[20.8/21.6]? Other log HI column densitylog(cm**-2)phys.columnDensityfloatnullablee_logNHI-O[0.05/0.3]? Uncertainty in logNHI-Olog(cm**-2)stat.errorfloatnullableJ/ApJ/911/55/table3Column densities and Doppler parametersf_Target[bc] Flag on Target (1)meta.codecharE_b[0.3/4.4]? Upper uncertainty in bkm/sstat.error;stat.maxfloatnullableb[2.8/20]? Doppler parameterkm/sspect.dopplerParamfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/139] Internal target numbermeta.idintprimaryE_logN6[0.04/0.2]? Upper uncertainty in logN6log(cm**-2)stat.error;stat.maxfloatnullableTargetTarget identifiermeta.idcharlogN0[16.8/21.1]? log J=0 rotational state column density (2)log(cm**-2)phys.columnDensityfloatnullableE_logN0[0.05/0.15]? Upper uncertainty in logN0log(cm**-2)stat.error;stat.maxfloatnullablee_logN0[0.05/0.15]? Lower uncertainty in logN0log(cm**-2)stat.errorfloatnullablelogN1[17.3/20.8]? log J=1 rotational state column density (2)log(cm**-2)phys.columnDensityfloatnullableE_logN1[0.05/0.15]? Upper uncertainty in logN1log(cm**-2)stat.error;stat.maxfloatnullablee_logN1[0.05/0.15]? Lower uncertainty in logN1log(cm**-2)stat.errorfloatnullablelogN2[14.36/19.64]? log J=2 rotational state column density (2)log(cm**-2)phys.columnDensityfloatnullableE_logN2[0.03/1.5]? Upper uncertainty in logN2log(cm**-2)stat.error;stat.maxfloatnullablee_logN2[0.04/0.5]? Lower uncertainty in logN2log(cm**-2)stat.errorfloatnullablelogN3[14.93/18.24]? log J=3 rotational state column density (2)log(cm**-2)physfloatnullableE_logN3[0.04/1.9]? Upper uncertainty in logN3log(cm**-2)stat.error;stat.maxfloatnullablee_logN3[0.04/0.8]? Lower uncertainty in logN3log(cm**-2)stat.errorfloatnullablelogN4[13.95/16.93] log J=4 rotational state column density (2)log(cm**-2)phys.columnDensityfloatE_logN4[0.02/1.9]? Upper uncertainty in logN4log(cm**-2)stat.error;stat.maxfloatnullablee_logN4[0.02/0.7]? Lower uncertainty in logN4log(cm**-2)stat.errorfloatnullablel_logN5Limit flag on logN5meta.code.errorcharlogN5[13.88/16.68]? log J=5 rotational state column density (2)log(cm**-2)phys.columnDensityfloatnullableE_logN5[0.03/1.4]? Upper uncertainty in logN5log(cm**-2)stat.error;stat.maxfloatnullablee_logN5[0.02/0.3]? Lower uncertainty in logN5log(cm**-2)stat.errorfloatnullablel_logN6Limit flag on logN6meta.code.errorcharlogN6[13.53/15.71]? log J=6 rotational state column density (2)log(cm**-2)phys.columnDensityfloatnullablee_logN6[0.04/0.2]? Lower uncertainty in logN6log(cm**-2)stat.errorfloatnullablee_b[0.4/3.7]? Lower uncertainty in bkm/sstat.errorfloatnullableJ/ApJ/911/55/table4Column densities and rotational temperaturesSeq[1/139] Internal target numbermeta.idintprimaryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlogNH2[17.48/21.17] log H2 column density (1)log(cm**-2)phys.columnDensityfloatT01[40/159] Rotational excitation temperature from N1/N0 ratio (2)Kphys.atmol.excitation;phys.mol.rotationintT02[44/331]? Rotational excitation temperature from N2/N0 ratio (2)Kphys.atmol.excitation;phys.mol.rotationintnullablefH2[0.0017/0.747] Molecular fraction (4)phys.columnDensity;arith.difffloatT24[118/582]? Rotational excitation temperature from N4/N2 ratio (2)Kphys.atmol.excitation;phys.mol.rotationintnullableT35[171/1358]? Rotational excitation temperature from N5/N3 ratio (2)Kphys.atmol.excitation;phys.mol.rotationintnullablelogNHI[20.55/21.65] log HI column density (1)log(cm**-2)phys.columnDensityfloatf_logNHI[*] Flag on logNHI (3)meta.codecharlogNH[20.55/21.74] log H column density (1)log(cm**-2)phys.columnDensityfloatDphot[0.21/9.85] Photometric distancekpcpos.distancefloatnH[0.02/3.9] Mean total hydrogen density along sight linecm**-3phys.densityfloatNote[1/3] S/N ratio level (5)meta.codeintTargetTarget identifiermeta.idchar