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Dust Polarization From Starlight Data (2001)

Abstract
We present a statistical analysis of the interstellar medium (ISM) polarization from the largest compilation available of starlight data, which comprises ~ 5500 stars. The measured correlation between the mean polarization degree and extinction indicates that ISM dust grains are not fully aligned with the uniform component of the large-scale Galactic magnetic field. Moreover, we estimate the ratio of the uniform to the random plane-of-the-sky components of the magnetic field to be B_u/B_r = 0.8. From the analysis of starlight polarization degree and position angle we find that the magnetic field broadly follows Galactic structures on large-scales. On the other hand, the angular power spectrum C_l of the polarization degree for Galactic plane data is found to be consistent with a power-law, C_l ~ l^{-1.5} (where l = 180 deg/\theta is the multipole order), for angular scales \theta > 10 arcmin. We argue that this data set can be used to estimate diffuse polarized emission at microwave frequencies.. Comment: 7 pages, 7 figures. To appear in proc. of the AIP conf. ``Astrophysical Polarized Backgrounds'', eds. S. Cecchini, S. Cortiglioni, R. Sault and C. Sbarra

Publication details
Download http://arxiv.org/abs/astro-ph/0111253
Repository arXiv (United States)
Keywords Astrophysics
Type text