J/ApJ/688/290ivo://CDS.VizieR/J/ApJ/688/290doi:10.26093/cds/vizier.16880290CDSFord H.A.McClure-Griffiths N.M.Lockman F.J.Bailin J.,Calabretta M.R.Kalberla P.M.W.Murphy T.Pisano D.J.2012-11-13T06:15:05Z2011-01-25T15:38:08ZCDS support team

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

cds-question@unistra.frmolecular-cloudsh-i-line-emissionradio-astronomysurveysinterstellar-mediumWe have detected over 400 HI clouds in the lower halo of the Galaxy within the pilot region of the Galactic All-Sky Survey (GASS), a region of the fourth quadrant that spans 18{deg} in longitude, 40{deg} in latitude, and is centered on the Galactic equator. These clouds have a median peak brightness temperature of 0.6K, a median velocity width of 12.8km/s, and angular sizes <~1{deg}. The motion of these clouds is dominated by Galactic rotation with a random cloud-to-cloud velocity dispersion of 18km/s. A sample of clouds likely to be near tangent points was analyzed in detail. These clouds have radii on the order of 30pc and a median HI mass of 630M_{sun}_. The population has a vertical scale height of 400pc and is concentrated in Galactocentric radius, peaking at R=3.8kpc. This confined structure suggests that the clouds are linked to spiral features, while morphological evidence that many clouds are aligned with loops and filaments is suggestive of a relationship with star formation. The clouds might result from supernovae and stellar winds in the form of fragmenting shells and gas that has been pushed into the halo rather than from a galactic fountain.2008ApJ...688..290Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/688/290CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVIII/75 : HI survey of the sky DE<+25deg (Bajaja+, 2005)VIII/73 : HI Parkes All Sky Survey Catalogue (HIPASS) (Meyer+, 2004)VIII/54 : Atlas of Galactic Neutral Hydrogen (Hartmann+, 1997)J/ApJ/626/887 : HI clouds in Southern Galactic Plane Survey (Kavars+, 2005)J/ApJS/146/125 : O VI in the galactic halo (Savage+, 2003)J/AJ/123/873 : HIPASS high-velocity clouds (Putman+, 2002)J/ApJS/140/331 : High-velocity HI observations at 21cm (Lockman+, 2002)J/A+AS/142/25 : High velocity HI Southern Survey (Morras+, 2000)J/MNRAS/201/495 : HI Survey of Southern Galactic Plane (Strong+ 1982)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/688/290https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/688/290http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/688/290https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/688/290https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/688/290http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/688/290GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/688/290/table1 (HI clouds - Observed properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/688/290/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/688/290/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/688/290/table1?GETtext/xml+votable180.050000true223.2286-44.26780.005555555555555556Cone search capability for table J/ApJ/688/290/table2 (Tangent point HI clouds - Derived properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/688/290/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/688/290/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/688/290/table2?GETtext/xml+votable180.050000true240.3199-58.95630.0055555555555555565/10526 10527 10534 10535 10546 10549 10592 10642 10643 10644 10646 10656 6/41329 41330 41421 41431 41458 41459 41460 41462 41464 41465 41466 41847 41851 41852 41941 41942 41974 41979 41988 41990 42006 42007 42008 42013 42021 42028 42035 42036 42041 42042 42044 42045 42046 42052 42054 42057 42059 42064 42065 42067 42068 42075 42083 42084 42087 42088 42090 42091 42092 42093 42094 42098 42099 42102 42103 42112 42117 42119 42123 42124 42125 42131 42133 42134 42135 42149 42150 42160 42161 42163 42164 42165 42177 42179 42181 42182 42183 42188 42189 42190 42192 42194 42195 42200 42201 42208 42216 42219 42222 42234 42235 42237 42238 42239 42242 42244 42248 42250 42267 42274 42275 42277 42278 42279 42280 42281 42282 42284 42286 42287 42288 42290 42372 42373 42406 42409 42410 42411 42412 42414 42506 42510 42511 42518 42519 42520 42525 42526 42527 42532 42534 42535 42537 42539 42540 42541 42546 42547 42548 42549 42550 42553 42554 42556 42557 42559 42560 42562 42563 42564 42565 42567 42581 42582 42583 42589 42590 42591 42592 42594 42595 42598 42602 42603 42607 42608 42611 42612 42615 42620 42621 42623 42630 42631 42633 42636 42637 42641 42642 42644 42645 42650 42651 42652 42653 42654 42656 42657 42662 42663 42664 42668 42672 42674 42677 42681 42682 42689 42690 42691 42694 42697 42700 42701 42703 42706 42712 42714 42717 42718 42720 42724 42727 42729 42731 42733 42739 42752 42753 42754 42756 42758 42760 42763 42785 42786 42792 42793 42880 42890 42914 44036 44039 44043 44050 44053 47234 47240 47243 47267 47270 47272 47274 47278 47625 47626https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/688/290?format=asciiRadiodefaultJ/ApJ/688/290/table1HI clouds - Observed propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGLONGalactic longitude (1)degpos.galactic.lonGLATGalactic latitude (1)degpos.galactic.latVLSRLocal Standard of Rest velocity (2)km/sphys.veloc;pos.lsrfloate_VLSRUncertainty in VLSRkm/sstat.error;phys.veloc;pos.lsrfloatTpkPeak brightness temperature (3)Kphys.temperature;stat.maxfloatDelVVelocity profile FWHM (4)km/sspect.line.profilefloate_DelVUncertainty in DelVkm/sstat.errorfloatNHIHI column density (5)1e+19cm**-2phys.columnDensityfloate_NHIUncertainty in NHI1e+19cm**-2stat.errorfloataminMinor axis (6)arcminphys.angSize;srcintamajMajor axis (6)arcminphys.angSizeintMHI/D2HI surface density (mass divided by squared distance) (7)solMass.kpc**-2phot.flux.density.sb;em.line.HIfloatNoteDetails of prior detections in literature (8)meta.notechar_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)degpos.eq.decnullableindexedJ/ApJ/688/290/table2Tangent point HI clouds - Derived propertiesVLSRLocal Standard of Rest velocity (2)km/sphys.veloc;pos.lsrfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGLONGalactic longitude (1)degpos.galactic.lonGLATGalactic latitude (1)degpos.galactic.late_VLSRUncertainty in VLSRkm/sstat.error;phys.veloc;pos.lsrfloatVdevDeviation velocity (3)km/sphys.velocfloate_VdevUncertainty in Vdevkm/sstat.errorfloatDistHeliocentric distance (4)kpcpos.distance;pos.heliocentricfloate_DistUncertainty in Distkpcstat.errorfloatRGalactocentric distance (5)kpcpos.distance;pos.galactocentricfloate_RUncertainty in Rkpcstat.errorfloatzHeight from Galactic plane (6)kpcpos.cartesian.z;pos.galacticfloate_zUncertainty in zkpcstat.error;src.redshiftfloatRadRadius of HI cloud (7)pcphys.size.radiusinte_RadUncertainty in Radpcstat.errorintMHIPhysical HI mass (8)solMassphys.massinte_MHIUncertainty in MHIsolMassstat.errorintt1Display the properties of the cloud from Table 1meta.ref.urlchar_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)degpos.eq.decnullableindexed