J/MNRAS/497/3097ivo://CDS.VizieR/J/MNRAS/497/3097doi:10.26093/cds/vizier/bg-fh-30sCDSMa Y.K.Mao S.A.Ordog A.Brown J.C.2026-08-03T07:29:59Z2023-10-31T14:46:34ZCDS support team

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

cds-question@unistra.frradio-sourcespolarimetrymagnetic-fieldsastrometryThe Milky Way is one of the very few spiral galaxies known to host large-scale magnetic field reversals. The existence of the field reversal in the first Galactic quadrant near the Sagittarius spiral arm has been well established, yet poorly characterized due to the insufficient number of reliable Faraday depths (FDs) from extragalactic radio sources (EGSs) through this reversal region. We have therefore performed broad-band (1-2GHz) spectropolarimetric observations with the Karl G. Jansky Very Large Array (VLA) to determine the FD values of 194 EGSs in the Galactic longitude range of 20{deg}-52{deg} within +/-5{deg} from the Galactic mid-plane, covering the Sagittarius arm tangent. This factor of five increase in the EGS FD density has led to the discovery of a disparity in FD values across the Galactic mid-plane in the Galactic longitude range of 40{deg}-52{deg}. Combined with existing pulsar FD measurements, we suggest that the Sagittarius arm can host an odd-parity disc field. We further compared our newly derived EGS FDs with the predictions of three major Galactic magnetic field models, and concluded that none of them can adequately reproduce our observational results. This has led to our development of new, improved models of the Milky Way disc magnetic field that will serve as an important step towards major future improvements in Galactic magnetic field models.2020MNRAS.497.3097Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/497/3097CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)J/ApJ/702/1230 : Rotation measure image of the sky (Taylor+, 2009)J/ApJ/728/97 : VLA rotation measures in the Galactic plane (Van Eck+, 2011)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/497/3097https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/497/3097http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/497/3097https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/497/3097https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/497/3097http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/497/3097GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/497/3097/table1 (RM-Synthesis results for on-axis targets)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/497/3097/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/497/3097/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/497/3097/table1?GETtext/xml+votable180.050000true281.0628-13.21390.005555555555555556Cone search capability for table J/MNRAS/497/3097/table2 (RM-Synthesis results for off-axis targets)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/497/3097/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/497/3097/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/497/3097/table2?GETtext/xml+votable180.050000true279.4851-11.37310.005555555555555556Cone search capability for table J/MNRAS/497/3097/tableb1 (Total Intensities and Spectral Indices of On-axis Targets)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/497/3097/tableb1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/497/3097/tableb1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/497/3097/tableb1?GETtext/xml+votable180.050000true281.0628-13.21390.005555555555555556Cone search capability for table J/MNRAS/497/3097/tableb2 (Total Intensities and Spectral Indices of Off-axis Targets)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/497/3097/tableb2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/497/3097/tableb2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/497/3097/tableb2?GETtext/xml+votable180.050000true279.4851-11.37310.0055555555555555565/7591 6/29170 29174-29175 29179 29181-29183 29520 29522 29524 29527 29530 29535 29541-29543 29553 29556-29558 29561-29562 29564 29566-29567 29653 29864 29866-29867 30209-30210 30220 30227 30232 30237 30247 30252 30255-30256 30263-30264 30266-30267 30278 30285-30287 30298-30299 30305 30307-30310 30313-30315 30321-30323 30327 30330 30340 30353 30358-30360 30401 30403 30405 30407 30415 30417-30418 30425-30426 30428 30436 30449 30451-30452 30454 30463 30496 30499 30502 30504-30505 30511 30521-30523 30527 30594-30596 30600 30606-30607 30609 30611 30615 30623 30635-30636 30639 30646 30648 30654 30656-30657 30662 30667 30669 30672 30675 30682-30683 30692-30693 30698 30700 30702-30703 30705-30706 30712 32017 32023 32064 32066 32068 32070 320739.276497240453405e-25 9.276497240453405e-25https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/497/3097?format=asciiRadiodefaultJ/MNRAS/497/3097/table1RM-Synthesis results for on-axis targetsSimbadSimbad column added by the CDSmeta.ref.urlchar_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.raindexed_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.decindexedf_Name[*+ ] Flag on Name (1)meta.codecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource NVSS name (JHHMMSS-DDMMSS)meta.id;meta.maincharGLONGalactic longitudedegpos.galactic.lonGLATGalactic latitudedegpos.galactic.latFDnew? Faraday depth from this workrad.m**-2phys.polarization.rotMeasurefloatnullablee_FDnew? Error on FDnewrad.m**-2stat.errorfloatnullableFDVE11? Faraday depth from Van Eck et al. (2011ApJ...728...97V, Cat. J/ApJ/728/97)rad.m**-2phys.polarization.rotMeasureintnullablee_FDVE11? Error on FDVE11rad.m**-2stat.errorintnullableFDTSS09? Faraday depth from Taylor et al. (2009ApJ...702.1230T, Cat. J/ApJ/702/1230)rad.m**-2phys.polarization.rotMeasurefloatnullablee_FDTSS09? Error on TSS09rad.m**-2stat.errorfloatnullablepnewPolarization fraction from this work%phys.polarizationfloate_pnew? Error on pnew%stat.errorfloatnullablef_pnew[*] Flag on pnew (2)meta.codecharpTSS09? Polarization fraction from Taylor et al. (2009ApJ...702.1230T, Cat. J/ApJ/702/1230)%phys.polarizationfloatnullablee_pTSS09? Error on pTSS09%stat.errorfloatnullablepNVSS? Polarization fraction from Condon et al. (1998AJ....115.1693C, Cat. VIII/65)%phys.polarizationfloatnullablee_pNVSS? Error on pNVSS%stat.errorfloatnullableJ/MNRAS/497/3097/table2RM-Synthesis results for off-axis targets_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.raindexed_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.decindexedSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource NVSS name (JHHMMSS-DDMMSS)meta.id;meta.maincharf_Name[*] Flag on Name (1)meta.codecharGLONGalactic longitudedegpos.galactic.lonGLATGalactic latitudedegpos.galactic.latFDnew? Faraday depth from this workrad.m**-2phys.polarization.rotMeasurefloatnullablee_FDnew? Error on FDnewrad.m**-2stat.errorfloatnullablepnewPolarization fraction from this work%phys.polarizationfloate_pnew? Error on pnew%stat.errorfloatnullablef_pnew[*] Flag on pnew (2)meta.codecharpNVSS? Polarization fraction from Condon et al. (1998AJ....115.1693C, Cat. VIII/65)%phys.polarizationfloatnullablee_pNVSS? Error on pNVSS%stat.errorfloatnullableJ/MNRAS/497/3097/tableb1Total Intensities and Spectral Indices of On-axis Targetse_SNVSSError on SNVSSmJystat.errorfloat_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.raindexed_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.decindexedNameSource NVSS name (JHHMMSS-DDMMSS)meta.id;meta.maincharf_Name[*] Flag on Name (1)meta.codecharGLONGalactic longitudedegpos.galactic.lonGLATGalactic latitudedegpos.galactic.latalphaSpectral indexspect.indexfloate_alphaError on alphastat.error;pos.eq.rafloatS1.4Flux density at 1.4GHz from our observationsmJyphot.flux.density;em.radio.750-1500MHzfloate_S1.4Error on S1.4mJystat.errorfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSNVSSFlux density at 1.4GHz from NVSS (Condon et al. 1998AJ....115.1693C, Cat. VIII/65)mJyphot.flux.density;em.radio.750-1500MHzfloatJ/MNRAS/497/3097/tableb2Total Intensities and Spectral Indices of Off-axis Targets_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.raindexed_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.decindexedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource NVSS name (JHHMMSS-DDMMSS)meta.id;meta.maincharGLONGalactic longitudedegpos.galactic.lonGLATGalactic latitudedegpos.galactic.latalphaSpectral indexspect.indexfloate_alphaError on alphastat.error;pos.eq.rafloatS1.4Flux density at 1.4GHz from our observationsmJyphot.flux.density;em.radio.750-1500MHzfloate_S1.4Error on S1.4mJystat.errorfloatSNVSSFlux density at 1.4GHz from NVSS (Condon et al. 1998AJ....115.1693C, Cat. VIII/65)mJyphot.flux.density;em.radio.750-1500MHzfloate_SNVSSError on SNVSSmJystat.errorfloat