J/ApJ/720/1045ivo://CDS.VizieR/J/ApJ/720/1045doi:10.26093/cds/vizier.17201045CDSAndersson B.-G.Potter S.B.2017-06-22T14:28:33Z2012-07-13T07:47:22ZCDS support team

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

cds-question@unistra.frpolarimetryvisible-astronomybroad-band-photometrymolecular-cloudsextinctioninterstellar-mediumWe have obtained optical multi-band polarimetry toward sightlines through the Chamaeleon I cloud, particularly in the vicinity of the young B9/A0 star HD 97300. We show, in agreement with earlier studies, that the radiation field impinging on the cloud in the projected vicinity of the star is dominated by the flux from the star, as evidenced by a local enhancement in the grain heating. By comparing the differential grain heating with the differential change in the location of the peak of the polarization curve, we show that the grain alignment is enhanced by the increase in the radiation field. We also find a weak, but measurable, variation in the grain alignment with the relative angle between the radiation field anisotropy and the magnetic field direction. Such an anisotropy in the grain alignment is consistent with a unique prediction of modern radiative alignment torque theory and provides direct support for radiatively driven grain alignment.2010ApJ...720.1045Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/720/1045CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/259 : The Tycho-2 Catalogue (Hog+ 2000)I/297 : NOMAD Catalog (Zacharias+ 2005)J/MNRAS/267/755 : Polarimetry in the Chamaeleon I Dark Cloud (McGregor+, 1994)J/AJ/121/974 : JHK photometry in Cha I (Gomez+, 2001)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/720/1045https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/720/1045http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/720/1045https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/720/1045https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/720/1045http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/720/1045GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/720/1045/polarim (SAAO observations and polarimetry results)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/720/1045/polarim?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/720/1045/polarim?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/720/1045/polarim?GETtext/xml+votable180.050000true164.7790417-77.02786110.0055555555555555566/36951 36956 36957 36959 37122 37123 37128 37129 371303.322582951404819e-19 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/720/1045?format=asciiOpticaldefaultJ/ApJ/720/1045/polarimSAAO observations and polarimetry resultsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar namemeta.id;meta.maincharRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainVmagJohnson V magnitudemagphot.mag;em.opt.Vfloate_VmagMean error on Vmagmagstat.error;phot.mag;em.opt.VfloatB-VJohnson B-V color indexmagphot.color;em.opt.B;em.opt.Vfloate_B-VMean error on B-Vmagstat.error;phot.color;em.opt.BfloatNotesAdditional notesmeta.noteCatCross-match with NOMAD and Tycho catalogs within 2"meta.ref.urlintnullablePU? Polarisation in U band%phys.polarization;em.opt.Ufloatnullablee_PU? Uncertainty on PU%stat.errorfloatnullablepaU? Position angle of PU (East of North)degpos.posAngintnullablee_paU? Uncertainty on paUdegstat.errorintnullablePB? Polarisation in B band%phys.polarization;em.opt.Bfloatnullablee_PB? Uncertainty on PB%stat.errorfloatnullablepaB? Position angle of PB (East of North)degpos.posAngintnullablee_paB? Uncertainty on paBdegstat.errorintnullablePV? Polarisation in V band%phys.polarization;em.opt.Vfloatnullablee_PV? Uncertainty on PV%stat.errorfloatnullablepaV? Position angle of PV (East of North)degpos.posAngintnullablee_paV? Uncertainty on paVdegstat.errorintnullablePR? Polarisation in R band%phys.polarization;em.opt.Rfloatnullablee_PR? Uncertainty on PR%stat.errorfloatnullablepaR? Position angle of PR (East of North)degpos.posAngintnullablee_paR? Uncertainty on paRdegstat.errorintnullablePI? Polarisation in I band%phys.polarization;em.opt.Ifloatnullablee_PI? Uncertainty on PI%stat.errorfloatnullablepaI? Position angle of PI (East of North)degpos.posAngintnullablee_paI? Uncertainty on paIdegstat.errorintnullableSpTMK spectral typesrc.spTypecharf_SpT[ab] Flag on SpT (2)meta.codechar(B-V)0Johnson B-V color index; correctedmagphot.color;em.opt.B;em.opt.VfloatE_(B-V)0? Positive error on (B-V)0magstat.error;stat.maxfloatnullablee_(B-V)0? Negative error on (B-V)0magstat.errorfloatnullableAV? Visual extinctionmagphys.absorption;em.opt.VfloatnullableE_AV? Positive error on AVmagstat.error;stat.maxfloatnullablee_AV? Negative error on AVmagstat.errorfloatnullablePmax? Maximum polarization%phys.polarization;stat.maxfloatnullablee_Pmax? Pmax uncertainty%stat.errorfloatnullableLmax? Wavelength of maximum polarization ({lambda}_max_)umphys.polarization;stat.maxfloatnullablee_Lmax? Lmax uncertaintyumstat.errorfloatnullablePA? Average position angle for the observed filters (East of North)degpos.posAng;stat.meanfloatnullablee_PA? PA uncertaintydegstat.errorfloatnullable