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Dust Polarization From Starlight Data

Pablo Fosalba·Alex Lazarian·Simon Prunet·Jan A. Tauber
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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/θis the multipole order), for angular scales θ> 10 arcmin. We argue that this data set can be used to estimate diffuse polarized emission at microwave frequencies.

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Pablo Fosalba, Alex Lazarian, Simon Prunet, Jan A. Tauber. 2001-11-13. Dust Polarization From Starlight Data. https://doi.org/10.1063/1.1471821

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