What is Known About the Polarization of Starlight in the Southern Hole. (arXiv:2006.15201v1 [astro-ph.CO])

What is Known About the Polarization of Starlight in the Southern Hole. (arXiv:2006.15201v1 [astro-ph.CO])
<a href="http://arxiv.org/find/astro-ph/1/au:+Bhoj_P/0/1/0/all/0/1">Praneet Bhoj</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gerasimov_R/0/1/0/all/0/1">Roman Gerasimov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Keating_B/0/1/0/all/0/1">Brian Keating</a>

Among the greatest mysteries in cosmology are the flatness problem,
concerning the lack of curvature of the universe, and the homogeneity problem,
questioning why the universe is almost isotropic despite having regions that
are causally disconnected. These problems served as motivation for the theory
of inflation, which suggests a period of exponential expansion in the early
universe, and the inflationary origin of the universe can be traced by B-mode
polarization. In an effort to better understand the potential foreground
systematics, especially the levels of polarized dust emission, we queried the
Heiles catalog to produce a list of starlight polarization data in the
so-called “Southern Hole”, which is an approximately $20times20$ degree region
centered at RA: $00^h12^m00^s$ and DEC: $-59{deg}18’00”$ that is being
examined by multiple CMB polarization experiments. Because magnetic field tends
to dictate the orientation of dust grains, which in turn determines how
starlight is polarized, starlight polarization can be used to trace magnetic
fields. Therefore, to improve our understanding of the properties of this
region, we used this catalog, along with Gaia data as tracers of the
three-dimensional distribution of dust, as a potential indicator of magnetic
field orientation throughout the galaxy in the Southern Hole region. We then
analyzed these data with the hope that magnetic field data can be used to
create a template to aid in the subtracting contamination of CMB B-mode
searches by polarized dust emission. While the results of the analysis are
promising, we found that the currently available data are severely inadequate
for the purpose of creating a template, thus demonstrating the need for
improved and more uniform coverage of the Southern Hole when it comes to
polarization measurements.

Among the greatest mysteries in cosmology are the flatness problem,
concerning the lack of curvature of the universe, and the homogeneity problem,
questioning why the universe is almost isotropic despite having regions that
are causally disconnected. These problems served as motivation for the theory
of inflation, which suggests a period of exponential expansion in the early
universe, and the inflationary origin of the universe can be traced by B-mode
polarization. In an effort to better understand the potential foreground
systematics, especially the levels of polarized dust emission, we queried the
Heiles catalog to produce a list of starlight polarization data in the
so-called “Southern Hole”, which is an approximately $20times20$ degree region
centered at RA: $00^h12^m00^s$ and DEC: $-59{deg}18’00”$ that is being
examined by multiple CMB polarization experiments. Because magnetic field tends
to dictate the orientation of dust grains, which in turn determines how
starlight is polarized, starlight polarization can be used to trace magnetic
fields. Therefore, to improve our understanding of the properties of this
region, we used this catalog, along with Gaia data as tracers of the
three-dimensional distribution of dust, as a potential indicator of magnetic
field orientation throughout the galaxy in the Southern Hole region. We then
analyzed these data with the hope that magnetic field data can be used to
create a template to aid in the subtracting contamination of CMB B-mode
searches by polarized dust emission. While the results of the analysis are
promising, we found that the currently available data are severely inadequate
for the purpose of creating a template, thus demonstrating the need for
improved and more uniform coverage of the Southern Hole when it comes to
polarization measurements.

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