J/ApJ/756/171ivo://CDS.VizieR/J/ApJ/756/171doi:10.26093/cds/vizier.17560171CDSFrance K.Schindhelm E.Herczeg G.J.Brown A.Abgrall H.,Alexander R.D.Bergin E.A.Brown J.M.Linsky J.L.Roueff E.Yang H.2021-08-04T12:44:10Z2014-06-23T09:38:17ZCDS support team

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

cds-question@unistra.fryoung-stellar-objectsspectroscopyultraviolet-astronomystellar-agesThe formation timescale and final architecture of exoplanetary systems are closely related to the properties of the molecular disks from which they form. Observations of the spatial distribution and lifetime of the molecular gas at planet-forming radii (a<10AU) are important for understanding the formation and evolution of exoplanetary systems. Toward this end, we present the largest spectrally resolved survey of H_2_ emission around low-mass pre-main-sequence stars compiled to date. We use a combination of new and archival far-ultraviolet spectra from the Cosmic Origins Spectrograph and Space Telescope Imaging Spectrograph instruments on the Hubble Space Telescope to sample 34 T Tauri stars (27 actively accreting Classical T Tauri Stars and 7 non-accreting Weak-lined T Tauri Stars) with ages ranging from ~1 to 10Myr. We observe fluorescent H_2_emission, excited by Ly{alpha} photons, in 100% of the accreting sources, including all of the transitional disks in our sample (CS Cha, DM Tau, GM Aur, UX Tau A, LkCa 15, HD 135344B, and TW Hya). The spatial distribution of the emitting gas is inferred from spectrally resolved H_2_ line profiles. Some of the emitting gas is produced in outflowing material, but the majority of H_2_ emission appears to originate in a rotating disk. For the disk-dominated targets, the H_2_ emission originates predominately at a<~3AU. The emission line widths and inner molecular radii are found to be roughly consistent with those measured from mid-IR CO spectra.2012ApJ...756..171Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/756/171CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/hst : HST Archived Exposures Catalog (STScI, 2007)J/ApJ/744/121 : Far-UV spectroscopy of T Tau stars (Yang+, 2012)J/AJ/139/1338 : UV-selected stars in Tau and Upper Sco (Findeisen+, 2010)J/ApJ/704/531 : The coevality of young binary systems (Kraus+, 2009)J/A+A/409/1037 : AK Sco ubvy & Geneva differential photometry (Alencar+, 2003)J/ApJS/147/305 : IUE atlas of pre-main-sequence stars (Valenti+, 2003)J/AJ/119/3026 : Circumstellar disk candidates in Orion (Rebull+, 2000)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/756/171https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/756/171http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/756/171https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/756/171https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/756/171http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/756/171GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/756/171/table1 (HST target list)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/756/171/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/756/171/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/756/171/table1?GETtext/xml+votable180.050000true68.730926124.48139940.0055555555555555566/1029 1048 1050 1073 1074 1081 1083 1111 1114 1115 1170 1171 23549 23551 24201 24300 28746 36956 36957 37012 38363 38382 38687 41472 42429 42611 42704 44049https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/756/171?format=asciiUVdefaultJ/ApJ/756/171/table1HST target listSimbadNameSimbad column added by the CDSmeta.idcharNameTarget name (1)meta.id;meta.maincharprimaryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintm_NameMultiplicity index on Namemeta.code.multipcharFmeta.ref.urlcharAv[0/3.2] Extinction (2)phys.absorptionfloatlogAge[5.82/7.24] Age (2)log(yr)time.agefloate_logAge[0/0.53] logAge uncertainty (2)log(yr)stat.error;time.agefloatM*[0.19/2.5] Stellar mass (2)solMassphys.massfloatf_M*[+] +: V4046 Sgr also has 0.69Msun valuemeta.codechardM/dt[0.01/17.7]? Mass accretion rate (3)1e-08solMass.yr**-1phys.mass.lossfloatnullablel_incLimit flag on incmeta.code.errorcharinc[4/85]? Inclination (4)degsrc.orbital.inclinationintnullablePID[8041/12361] HST Proposal IDmeta.id;obsintf_PID[S] S: STIS observation was usedmeta.codecharRefReference(s) (see refs.dat file)meta.ref;pos.framechar_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/756/171/table3Reddening corrected H_2_ progression fluxes for the Classical T Tauri Star (CTTS) samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameTarget namemeta.id;meta.maincharF3-13? F_[3,13]_ (1213.36{AA}) flux (1)1e-17W.m**-2phot.fluxfloatnullablee_F3-13? Uncertainty in F3-13 (1)1e-17W.m**-2stat.errorfloatnullableF4-13? F_[4,13]_ (1213.68{AA}) flux (1)1e-17W.m**-2phot.fluxfloatnullablee_F4-13? Uncertainty in F4-13 (1)1e-17W.m**-2stat.errorfloatnullableF3-16? F_[3,16]_ (1214.47{AA}) flux (1)1e-17W.m**-2phot.fluxfloatnullablee_F3-16? Uncertainty in F3-16 (1)1e-17W.m**-2stat.errorfloatnullableF4-4? F_[4,4]_ (1214.78{AA}) flux (1)1e-17W.m**-2phot.fluxfloatnullablee_F4-4? Uncertainty in F4-4 (1)1e-17W.m**-2stat.errorfloatnullableF1-7[2.3/8138] F_[1,7]_ (1215.73{AA}) flux (1)1e-17W.m**-2phot.fluxfloate_F1-7[0.1/777] Uncertainty in F1-7 (1)1e-17W.m**-2stat.errorfloatF1-4F_[1,4]_ (1216.07{AA}) flux (1)1e-17W.m**-2phot.fluxdoublee_F1-4Uncertainty in F1-4 (1)1e-17W.m**-2stat.errorfloatF3-0? F_[3,0]_ (1217.04{AA}) flux (1)1e-17W.m**-2phot.fluxfloatnullablee_F3-0? Uncertainty in F3-0 (1)1e-17W.m**-2stat.errorfloatnullableF0-1? F_[0,1]_ (1217.21{AA}) flux (1)1e-17W.m**-2phot.fluxfloatnullablee_F0-1? Uncertainty in F0-1 (1)1e-17W.m**-2stat.errorfloatnullableF0-2F_[0,2]_ (1217.64{AA}) flux (1)1e-17W.m**-2phot.fluxdoublee_F0-2Uncertainty in F0-2 (1)1e-17W.m**-2stat.errorfloatF2-12? F_[2,12]_ (1217.90{AA}) flux (1)1e-17W.m**-2phot.fluxfloatnullablee_F2-12? Uncertainty in F2-12 (1)1e-17W.m**-2stat.errorfloatnullableF2-15? F_[2,15]_ (1218.52{AA}) flux (1)1e-17W.m**-2phot.fluxfloatnullablee_F2-15? Uncertainty in F2-15 (1)1e-17W.m**-2stat.errorfloatnullableF0-3? F_[0,3]_ (1219.09{AA}) flux (1)1e-17W.m**-2phot.fluxfloatnullablee_F0-3? Uncertainty in F0-3 (1)1e-17W.m**-2stat.errorfloatnullableJ/ApJ/756/171/refsReferencesAutAuthor's name(s)meta.bib.authorcharBibCodeBibcodemeta.bib.bibcodecharCommCommentmeta.notecharnullableRefReference codemeta.noteintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint