Polarization & photom. of stars toward LDN1225 Virtual Observatory Resource

Authors
  1. Eswaraiah C.
  2. Lai S.-P.
  3. Ma Y.
  4. Pandey A.K.
  5. Jose J.
  6. Chen Z.
  7. Samal M.R.,Wang J.-W.
  8. Sharma S.
  9. Ojha D.K.
  10. Published by
    CDS
Abstract

We 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.

Keywords
  1. Polarimetry
  2. Infrared photometry
  3. Optical astronomy
  4. Wide-band photometry
  5. Extinction
  6. Molecular clouds
Bibliographic source Bibcode
2019ApJ...875...64E
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IVOA Identifier IVOID
ivo://CDS.VizieR/J/ApJ/875/64
Document Object Identifer DOI
doi:10.26093/cds/vizier.18750064

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History

2020-10-09T08:10:50Z
Resource record created
2020-10-09T08:10:50Z
Created
2020-12-07T11:52:09Z
Updated

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