J/ApJ/875/64ivo://CDS.VizieR/J/ApJ/875/64doi:10.26093/cds/vizier.18750064CDSEswaraiah C.Lai S.-P.Ma Y.Pandey A.K.Jose J.Chen Z.Samal M.R.,Wang J.-W.Sharma S.Ojha D.K.2020-12-07T11:52:09Z2020-10-09T08:10:50ZCDS support team

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

cds-question@unistra.frpolarimetryinfrared-photometryvisible-astronomybroad-band-photometryextinctionmolecular-cloudsWe present results based on the optical R-band observations of the polarization of 280 stars distributed toward the dark globule LDN1225. Parallaxes from Gaia data release 2 along with the polarization data of ~200 stars have been used to (a) constrain the distance of LDN 1225 as 830+/-83pc, (b) determine the contribution of interstellar polarization, and (c) characterize the dust properties and delineate the magnetic field (B-field) morphology of LDN 1225. We find that B-fields are more organized and exhibit a small dispersion of 12{deg}. Using the ^12^CO molecular line data from the Purple Mountain Observatory, along with the column density and dispersion in B-fields, we estimate the B-field strength to be ~56+/-10{mu}G, the ratio of magnetic to turbulent pressure to be ~3+/-2, and the ratio of mass to magnetic flux (in units of the critical value) to be <1. These results indicate the dominant role of B-fields in comparison to turbulence and gravity in rendering the cloud support. B-fields are aligned parallel to the low-density parts (traced by a ^12^CO map) of the cloud; in contrast, they are neither parallel nor perpendicular to the high-density core structures (traced by ^13^CO and C^18^O maps). LDN1225 hosts two 70{mu}m sources, which seem to be low-mass Class 0 sources. The ratio of total to selective extinction derived using optical and near-infrared photometric data is found to be anomalous (RV=3.4), suggesting the growth of dust grains in LDN 1225. The polarization efficiency of dust grains follows a power law with an index of -0.7, implying that optical polarimetry traces B-fields in the outer parts of the cloud.2019ApJ...875...64Ehttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/875/64CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/183 : UBVRI Photometric Standards (Landolt 1992)II/226 : Stellar polarization catalogs agglomeration (Heiles, 2000)I/345 : Gaia DR2 (Gaia Collaboration, 2018)VI/128 : Log of CGPS exposures (Taylor+, 2003-)VII/7 : Lynds' Catalogue of Dark Nebulae (LDN) (Lynds 1962)VII/191 : Catalogue of Southern Dark Clouds (Hartley+ 1986)VIII/39 : Composite CO Survey of the Milky Way (Dame+ 1987)VII/244 : Atlas and Catalog of Dark Clouds (Dobashi+, 2005)J/ApJS/110/21 : Molecular clouds in Cepheus and Cassiopeia (Yonekura+ 1997)J/A+A/383/631 : Catalogue of dust clouds in the Galaxy (Dutra+, 2002)J/ApJS/144/47 : Outer galaxy molecular cloud catalog (Brunt+, 2003)J/MNRAS/369/1822 : Distances to nine dark globules (Maheswar+, 2006)J/ApJ/716/893 : Polarisation at 850mu{m} in OMC-2 & OMC-3 (Poidevin+, 2010)J/ApJ/741/21 : Polarization of stars in Taurus (Chapman+, 2011)J/ApJ/751/138 : VRIJHK photometry of IRAS 09149-4743 region (Santos+, 2012)J/A+A/556/A65 : LDN 1570 BV(RI)c polarisation & photom. (Eswaraiah+, 2013)J/ApJ/764/172 : UBVRI photometry of stars toward NGC 1931 (Pandey+, 2013)J/other/NewA/19.1 : Ages and masses of NGC1893 PMS stars (Pandey+, 2013)J/A+A/569/L1 : Polarization hole in a starless core (Alves+, 2014)J/ApJ/793/126 : L204 - Cloud 3 polarimetry and photometry (Cashman+, 2014)J/A+A/567/A109 : Carina nebula optically identified YSOs (Kumar+, 2014)J/ApJ/807/5 : R-band polarimetry data in Lupus I region (Franco+, 2015)J/A+A/588/A104 : Molecular clouds and star formation (Gong+, 2016)J/ApJ/828/59 : Molecular clouds in the Milky Way with CO obs. (Su+, 2016)J/ApJ/850/195 : RCW 57A NIR polarimetry and photometry (Eswaraiah+, 2017)J/MNRAS/467/2943 : NGC 7538 region YSOs (Sharma+, 2017)J/ApJ/849/157 : Polarimetry obs. toward IC5146 bckg stars (Wang+, 2017)J/A+A/618/A163 : Stokes param. of Bok globules bckg stars (Jorquera+, 2018)http://www.radioast.nsdc.cn/mwisp.php : Milky Ways Imaging Scroll Paintinghttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/875/64https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/875/64http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/875/64https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/875/64https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/875/64http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/875/64GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/875/64/table2 (Rc band polarization data)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/875/64/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/875/64/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/875/64/table2?GETtext/xml+votable180.050000true347.65867561.511168890.005555555555555556Cone search capability for table J/ApJ/875/64/table3 (Photometric data of 689 stars with their photometric uncertainties less than 0.1mag)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/875/64/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/875/64/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/875/64/table3?GETtext/xml+votable180.050000true347.6721666761.655360830.005555555555555556Cone search capability for table J/ApJ/875/64/table7 (Total extinction Av values of 57 stars derived using NIR extinction method)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/875/64/table7?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/875/64/table7?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/875/64/table7?GETtext/xml+votable180.050000true347.6812583361.531180830.005555555555555556Cone search capability for table J/ApJ/875/64/table4 (Weighted mean polarization measurements)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/875/64/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/875/64/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/875/64/table4?GETtext/xml+votable180.050000true344.2222166762.166270.0055555555555555565/3920 6/14307 14308 14311 14313 14315 14316 14317 14318 15685 15686 15687 156928.650015785639275e-20 1.7003137259100215e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/875/64?format=asciiOpticalInfrareddefaultJ/ApJ/875/64/table2Rc band polarization dataIR[X ] Stars with NIR excessmeta.codecharMmStellar Class (1)meta.code.membercharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPhotDisplay the photometric measurements for this star (link to Table 3)meta.ref.urlintnullablePSeq[1/280] Identifier, sequential running numbermeta.id;meta.mainintprimaryAvDisplay the extinction measurements for this star (link to Table 7)meta.ref.urlcharRAJ2000[23] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[61] Degree of Declination (J2000)pos.eq.dec;meta.mainPol-Rc[0.3/8.2] Rc-band polarization%phys.polarizationfloate_Pol-Rc[0.1/1.1] Uncertainty in Pol-Rc%stat.errorfloatPA-Rc[6/132] Position angle of Rc polarizationdegpos.posAng;phys.polarizationinte_PA-Rc[1/14] Uncertainty in PA-Rcdegstat.errorintJmag[7.72/14.79] 2MASS J band magnitudemagphot.mag;em.IR.Jfloate_Jmag[0.02/0.06]? Uncertainty in Jmagmagstat.error;phot.magfloatnullableHmag[6.57/14.35] 2MASS H band magnitudemagphot.mag;em.IR.Hfloate_Hmag[0.02/0.06]? Uncertainty in Hmagmagstat.error;phot.magfloatnullableKsmag[5.85/14.28] 2MASS Ks band magnitudemagphot.mag;em.IR.Kfloate_Ksmag[0.02/0.1]? Uncertainty in Ksmagmagstat.error;phot.magfloatnullableDist[168/10070]? Gaia DR2 Distancepcpos.distance;pos.heliocentricintnullablee_Dist[1/5778]? Uncertainty in Distpcstat.errorintnullableD8[X ] Stars in 8' diameter circle in Figure 1(a) containing the star-forming region NGC 7538meta.codechar2MDisplay the 2MASS data (Cutri+ 2003, II/246) within 0.5"meta.ref.urlcharJ/ApJ/875/64/table3Photometric data of 689 stars with their photometric uncertainties less than 0.1magrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/689] Sequential running identifiermeta.id;meta.mainintPSeq[5/228]? Table 2 polarization data identifiermeta.id.crossintnullableRAJ2000[23] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[61] Degree of Declination (J2000)pos.eq.dec;meta.mainVmag[11.27/19.82] HCT/HFOSC V band magnitudemagphot.mag;em.opt.Vfloate_Vmag[0/0.041] Uncertainty in Vmagmagstat.error;phot.magfloatB-V[0.49/3.67] B-V color indexmagphot.color;em.opt.B;em.opt.Vfloate_B-V[0/0.1] Uncertainty in B-Vmagstat.error;phot.color;em.opt.BfloatV-R[-0.9/2.5]? V-R color indexmagphot.color;em.opt.V;em.opt.Rfloatnullablee_V-R[0.001/0.04]? Uncertainty in V-Rmagstat.error;phot.color;em.opt.VfloatnullableV-I[0.69/4.9] V-I color indexmagphot.color;em.opt.V;em.opt.Ifloate_V-I[0.001/0.1] Uncertainty in V-Imagstat.error;phot.color;em.opt.VfloatJmag[9.55/15.86] 2MASS J band magnitudemagphot.mag;em.IR.Jfloate_Jmag[0.02/0.09] Uncertainty in Jmagmagstat.error;phot.magfloatHmag[8.04/15.23] 2MASS H band magnitudemagphot.mag;em.IR.Hfloate_Hmag[0.03/0.1] Uncertainty in Hmagmagstat.error;phot.magfloatKsmag[7.47/14.85] 2MASS Ks band magnitudemagphot.mag;em.IR.Kfloate_Ksmag[0.02/0.1] Uncertainty in Ksmagmagstat.error;phot.magfloat2MDisplay the 2MASS data (Cutri+ 2003, II/246) within 0.5"meta.ref.urlcharJ/ApJ/875/64/table7Total extinction Av values of 57 stars derived using NIR extinction methodrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPSeq[5/228] Identifier, sequential running number, as in Table 2meta.id;meta.mainintRAJ2000[23] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[61] Degree of Declination (J2000)pos.eq.dec;meta.mainJ-H[0.19/0.57] NIR J-H colormagphot.color;em.IR.J;em.IR.Hfloate_J-H[0.03/0.06] Uncertainty in J-Hmagstat.error;phot.color;em.IR.JfloatH-Ks[0.06/0.22] NIR J-Ks colormagphot.color;em.IR.H;em.IR.Kfloate_H-Ks[0.04/0.08] Uncertainty in H-Ksmagstat.error;phot.color;em.IR.HfloatPol-Rc[0.8/4.7] Rc band polarization, percent (%)%phys.polarizationfloate_Pol-Rc[0.2/0.9] Uncertainty in Pol-Rc%stat.errorfloatAv[0.2/3.3] Total extinction in V-bandmagphys.absorptionfloate_Av[0.4/0.9] Uncertainty in Avmagstat.errorfloatJ/ApJ/875/64/table4Weighted mean polarization measurementsSetField Subset (1)meta.codecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFieldField Nameobs.fieldcharRAJ2000[22/23] Hour of Right Ascension (J2000) (2)pos.eq.ra;meta.mainDEJ2000[59/64] Degree of Declination (J2000) (2)pos.eq.dec;meta.mainPol[0.1/5.4]? Weighted mean polarization in percent%phys.polarizationfloatnullablee_Pol[0.02/0.5]? Uncertainty in Pol%stat.errorfloatnullablePA[27/163]? Weighted mean polarization position angledegpos.posAng;phys.polarizationintnullablee_PA[0/34]? Uncertainty in PAdegstat.errorintnullableFiltPassband filter (R, V or r')meta.notecharNs[0/12] Number of Starsmeta.numberintRefSource (3)meta.bibchar