J/A+A/634/A83ivo://CDS.VizieR/J/A+A/634/A83doi:10.26093/cds/vizier.36340083CDSWang Y.Beuther H.Rugel M.R.Soler J.D.Stil J.M.Ott J.Bihr S.,McClure-Griffiths N.M.Anderson L.D.Klessen R.S.Goldsmith P.F.,Roy N.Glover S.C.O.Urquhart J.S.Heyer M.Linz H.Smith R.J.,Bigiel F.Dempsey J.Henning T.2020-02-12T05:17:42Z2020-02-12T06:17:14ZCDS support team

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

cds-question@unistra.frsurveysmilky-way-galaxyradio-sourcesradio-continuum-emissionThe Galactic plane has been observed extensively by a large number of Galactic plane surveys from infrared to radio wavelengths at an angular resolution below 40". However, a 21cm line and continuum survey with comparable spatial resolution is lacking. The first half of THOR data (l=14.0{deg}-37.9{deg}, and l=47.1{deg}-51.2{deg}, |b|<=1.25{deg}) has been published in our data release 1 paper. With this data release 2 paper, we publish all the remaining spectral line data and Stokes I continuum data with high angular resolution (10"-40"), including a new HI dataset for the whole THOR survey region (l=14.0{deg}-67.4{deg} and |b|<=1.25{deg}). As we published the results of OH lines and continuum emission elsewhere, we concentrate on the HI analysis in this paper With the Karl G. Jansky Very Large Array (VLA) in C-configuration, we observed a large portion of the first Galactic quadrant, achieving an angular resolution of 40". At L Band, the WIDAR correlator at the VLA was set to cover the 21cm HI line, four OH transitions, a series of Hn{alpha} radio recombination lines (RRLs; n=151 to 186), and eight 128MHz-wide continuum spectral windows (SPWs), simultaneously. We publish all OH and RRL data from the C-configuration observations, and a new HI dataset combining VLA C+D+GBT (VLA D-configuration and GBT data are from the VLA Galactic Plane Survey) for the whole survey. The HI emission shows clear filamentary substructures at negative velocities with low velocity crowding. The emission at positive velocities is more smeared-out, likely due to higher spatial and velocity crowding of structures at the positive velocities. Compared to the spiral arm model of the Milky Way, the atomic gas follows the Sagittarius and Perseus Arm well, but with significant material in the inter-arm regions. With the C-configuration-only HI+continuum data, we produced a HI optical depth map of the THOR areal coverage from 228 absorption spectra with the nearest-neighbor method. With this map, we corrected the HI emission for optical depth, and the derived column density is 38% higher than the column density with optically thin assumption. The total HI mass with optical depth correction in the survey region is 4.7x10^8^M_{sun}_, 31% more than the mass derived assuming the emission is optically thin. If we applied this 31% correction to the whole Milky Way, the total atomic gas mass would be 9.4-10.5x10^9^M_{sun}_. Comparing the HI with existing CO data, we find a significant increase in the atomic-to-molecular gas ratio from the spiral arms to the inter-arm regions. The high-sensitivity and resolution THOR HI dataset provides an important new window on the physical and kinematic properties of gas in the inner Galaxy. Although the optical depth we derive is a lower limit, our study shows that the optical depth correction is significant for Hi column density and mass estimation. Together with the OH, RRL and continuum emission from the THOR survey, these new HI data provide the basis for high-angular-resolution studies of the interstellar medium (ISM) in different phases.2020A&A...634A..83Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/634/A83CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/580/A112 : THOR. The HI, OH, Recombination Line Survey (Bihr+, 2015)J/A+A/588/A97 : Continuum sources from the THOR survey (Bihr+, 2016)J/A+A/619/A124 : THOR survey in northern Galactic plane (Wang+, 2018)J/A+A/628/A90 : OH maser emission in THOR survey (Beuther+, 2019)http://www2.mpia-hd.mpg.de/thor/DATA/www : THOR Data Accesshttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/634/A83https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/634/A83http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/634/A83https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/634/A83https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/634/A83http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/634/A83GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/634/A83/tablea1 (Optical depth measurements towards the selected continuum sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/634/A83/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/634/A83/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/634/A83/tablea1?GETtext/xml+votable180.050000true274.19427-16.342260.0055555555555555565/3589 7377 7561 7578 7651 6/12971 12975 12987 14337 14340 14343 14352-14353 14355 14365 14400 14406-14409 14412-14413 14415 14419 14425 14427 29115-29116 29118 29162 29457 29460-29461 29504-29505 29507 29513 29517 29520 29522-29523 29528-29529 29531-29533 29535 30217-30219 30222 30256 30258-30259 30262-30263 30269 30317-30319 30331 30405 30416-30418 30420-30421 30423 30429 30592 30594-30595 30601 30603 30616-30618 30622-30623 30640-30641 30644 30689 30691-30692 30694-30695 30701 30706 30712 30715 30717-30719https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/634/A83?format=asciiRadiodefaultJ/A+A/634/A83/tablea1Optical depth measurements towards the selected continuum sourcesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName of the source (GLL.lll+B.bbb)meta.id;meta.maincharTcontBrightness temperature of the continuum sourceKphys.temperature;spect.continuuminte_Tcontrms noise level of the brightness temperatureKstat.errorinttaulimitLower limit of the optical depthphys.absorption.opticalDepthfloatinttauIntegrated optical depth across the velocity range (-128.5<vlsr<170 km/s)km/sspect.line.widthintReffEffective radius of the source (1)phys.size.radiusintNoteNote (2)meta.notechar_GlonPosition from Name (longitude part)degpos.galactic.lon_GlatPosition from Name (latitude part)degpos.galactic.lat_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.decnullableindexed