English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

An application of an optimal statistic for characterizing relative orientations

MPS-Authors

Jow,  Dylan L.
Max Planck Institute for Astronomy, Max Planck Society and Cooperation Partners;

Hill,  Ryley
Max Planck Institute for Astronomy, Max Planck Society and Cooperation Partners;

Scott,  Douglas
Max Planck Institute for Astronomy, Max Planck Society and Cooperation Partners;

Soler,  J. D.
Max Planck Institute for Astronomy, Max Planck Society and Cooperation Partners;

Martin,  P. G.
Max Planck Institute for Astronomy, Max Planck Society and Cooperation Partners;

Devlin,  M. J.
Max Planck Institute for Astronomy, Max Planck Society and Cooperation Partners;

Fissel,  L. M.
Max Planck Institute for Astronomy, Max Planck Society and Cooperation Partners;

Poidevin,  F.
Max Planck Institute for Astronomy, Max Planck Society and Cooperation Partners;

Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Jow, D. L., Hill, R., Scott, D., Soler, J. D., Martin, P. G., Devlin, M. J., et al. (2018). An application of an optimal statistic for characterizing relative orientations. Monthly Notices of the Royal Astronomical Society, 474, 1018-1027.


Cite as: https://hdl.handle.net/21.11116/0000-0005-CCF8-E
Abstract
We present the projected Rayleigh statistic (PRS), a modification of the classic Rayleigh statistic, as a test for non-uniform relative orientation between two pseudo-vector fields. In the application here, this gives an effective way of investigating whether polarization pseudo-vectors (spin-2 quantities) are preferentially parallel or perpendicular to filaments in the interstellar medium. For example, there are other potential applications in astrophysics, e.g. when comparing small-scale orientations with larger scale shear patterns. We compare the efficiency of the PRS against histogram binning methods that have previously been used for characterizing the relative orientations of gas column density structures with the magnetic field projected on the plane of the sky. We examine data for the Vela C molecular cloud, where the column density is inferred from Herschel submillimetre observations, and the magnetic field from observations by the Balloon- borne Large-Aperture Submillimetre Telescope in the 250-, 350- and 500-μm wavelength bands. We find that the PRS has greater statistical power than approaches that bin the relative orientation angles, as it makes more efficient use of the information contained in the data. In particular, the use of the PRS to test for preferential alignment results in a higher statistical significance, in each of the four Vela C regions, with the greatest increase being by a factor 1.3 in the South- Nest region in the 250 - μ m band.