J/ApJ/887/L7ivo://CDS.VizieR/J/ApJ/887/L7doi:10.26093/cds/vizier.18879007CDSShanahan R.Lemmer S.J.Stil J.M.Beuther H.Wang Y.Soler J.,Anderson L.D.Bigiel F.Glover S.C.O.Goldsmith P.Klessen R.S.,McClure-Griffiths N.M.Reissl S.Rugel M.Smith R.J.2021-07-05T13:10:52Z2021-06-24T15:25:16ZCDS support team

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

cds-question@unistra.frradio-sourcesmagnetic-fieldspolarimetryh-ii-regionsWe present first results for Faraday rotation of compact polarized sources (1-2GHz continuum) in The HI/OH/Recombination line (THOR) survey of the inner Galaxy. In the Galactic longitude range 39{deg}<l<52{deg}, we find rotation measures (RMs) in the range -310rad/m^2^<=RM<=+4219rad/m^2^, with the highest values concentrated within a degree of l=48{deg} at the Sagittarius arm tangent. Most of the high RMs arise in diffuse plasma, along lines of sight that do not intersect HII regions. For l>49{deg}, RM drops off rapidly, while at l<47{deg}, the mean RM is higher with a larger standard deviation than at l>49{deg}. We attribute the RM structure to the compressed diffuse warm ionized medium in the spiral arm, upstream of the major star formation regions. The Sagittarius arm acts as a significant Faraday screen inside the Galaxy. This has implications for models of the Galactic magnetic field and the expected amount of Faraday rotation of fast radio bursts from their host galaxies. We emphasize the importance of sensitivity to high Faraday depth in future polarization surveys.2019ApJ...887L...7Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/887/L7CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/psr : ATNF Pulsar Catalogue (Manchester+, 2005)VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)J/A+AS/83/539 : 21cm radio continuum survey. I. (Reich+ 1990)J/ApJS/145/213 : Rotation measures of compact sources in CGPS (Brown+, 2003)J/ApJ/663/258 : RMs of extragalactic sources in SGPS (Brown+, 2007)J/ApJ/702/1230 : Rotation measure image of the sky (Taylor+, 2009)J/ApJ/719/1104 : Massive star forming complexes in GLIMPSE (Rahman+, 2010)J/ApJ/720/1055 : VBLA observations of W51 Main/South (Sato+, 2010)J/ApJS/194/32 : HII Region Discovery Survey (HRDS). II. (Anderson+, 2011)J/ApJ/728/97 : VLA rotation measures in the Galactic plane (Van Eck+, 2011)J/ApJS/212/1 : The WISE catalog of Galactic HII regions (Anderson+, 2014)J/A+A/588/A97 : Continuum sources from the THOR survey (Bihr+, 2016)J/MNRAS/469/4034 : Broadband polarisation of radio AGN (O'Sullivan+, 2017)J/ApJS/234/11 : Pulsar rotation measures (Han+, 2018)J/A+A/619/A124 : THOR survey in northern Galactic plane (Wang+, 2018)J/ApJS/240/14 : SIGGMA: inner galaxy data release (Liu+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/887/L7https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/887/L7http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/887/L7https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/887/L7https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/887/L7http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/887/L7GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/887/L7/table1 (Rotation measure detections)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/887/L7/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/887/L7/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/887/L7/table1?GETtext/xml+votable180.050000true285.543625.44960.0055555555555555565/7651 7654 7672 7673 6/30423 30429 30592 30594 30595 30598 30600 30601 30603 30622 30623 30640 30641 30645 30647 30666 30697 30700 30701 30703 30706 30707 30712 30713 30714https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/887/L7?format=asciiRadiodefaultJ/ApJ/887/L7/table1Rotation measure detectionsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[BJB2016]Name from Wang+ (2018, J/A+A/619/A124)meta.id;meta.maincharS[9.2/1021.6]? Flux density from Wang+ (2018, J/A+A/619/A124) (1)mJyphot.flux.density;em.radio.750-1500MHzfloatnullablealpha[-1.41/0.35]? Spectral index from Wang+ (2018, J/A+A/619/A124) (1)spect.indexfloatnullablefP[0.94/20.33] Fractional polarization%phys.polarizationfloatRM[-310/4219] Rotation Measurerad.m**-2phys.polarization.rotMeasureinte_RM[1/95] Error in Rotation measurerad.m**-2stat.errorintHII1Nearest HII region by relative distance (2)meta.id.assocchard1[0.6/2601.1] Angular distance for HII1arcminpos.angDistancefloatd1rel[0.3/8.4] Distance divided by HII1 region radiuspos.distancefloatHII2Nearest HII region by angular distance (3)meta.id.assocchard2[0.6/43.3] Angular distance for HII2arcminpos.angDistancefloatd2rel[0.3/59.6] Distance divided by HII2 region radiuspos.distancefloatGLON[39/52.3] Galactic Longitudedegpos.galactic.lonGLAT[-1.12/1.24] Galactic Latitudedegpos.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