J/MNRAS/514/3024ivo://CDS.VizieR/J/MNRAS/514/3024doi:10.26093/cds/vizier.75143024CDSLi P.-S.Lopez-Rodriguez E.Soam A.Klein R.I.2024-08-22T20:15:45Z2022-06-30T08:38:49ZCDS support team

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

cds-question@unistra.frmolecular-cloudspolarimetryWe present the stability analysis of two regions, OMC-3 and OMC-4, in the massive and long molecular cloud complex of Orion A. We obtained 214um HAWC+/SOFIA polarization data, and we make use of archival data for the column density and C^18^O (1-0) emission line. We find clear depolarization in both observed regions and that the polarization fraction is anti-correlated with the column density and the polarization-angle dispersion function. We find that the filamentary cloud and dense clumps in OMC-3 are magnetically supercritical and strongly subvirial. This region should be in the gravitational collapse phase and is consistent with many young stellar objects (YSOs) forming in the region. Our histogram of relative orientations (HROs) analysis shows that the magnetic field is dynamically sub-dominant in the dense gas structures of OMC-3. We present the first polarization map of OMC-4. We find that the observed region is generally magnetically subcritical except for an elongated dense core, which could be a result of projection effect of a filamentary structure aligned close to the line-of-sight. The relative large velocity dispersion and the unusual positive shape parameters at high column densities in the HROs analysis suggest that our viewing angle may be close to axes of filamentary substructures in OMC-4. The dominating strong magnetic field in OMC-4 is unfavorable for star formation and is consistent with much fewer YSOs than in OMC-3.2022MNRAS.514.3024Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/514/3024CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/514/3024https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/514/3024http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/514/3024https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/514/3024https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/514/3024http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/514/3024GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/514/3024/list (List of fits files)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/514/3024/list?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/514/3024/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/514/3024/list?GETtext/xml+votable180.050000true83.82616-5.018170.0055555555555555566/21438 22805https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/514/3024?format=asciidefaultJ/MNRAS/514/3024/listList of fits filesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintObs.dateObservation datestime.epoch;obsnullablesizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitschar