Galactic Clouds Obscure View of Early Universe

Stargazers know all too well the challenges of observing the night sky on a cloudy evening. Fortunately, waiting a night or two can help to resolve the issue. But what happens if these clouds are light years away and lie seemingly dormant in the middle of one’s line of sight (LOS)?

Susan E. Clark, Member in the School of Natural Sciences, is co-author of a paper published today in Astronomy & Astrophysics which investigates the effects of LOS obstructions, specifically the distortions caused by interstellar dust situated between us and the microwave radiation left over from the Big Bang.

Our view of the polarized cosmic microwave background is obscured by polarized emission from magnetic dust clouds in our own Milky Way. This research uses new probes of the three-dimensional structure of galactic magnetic fields and interstellar dust to enhance our understanding of the complexity of this foreground dust emission.

The study was led by Vincent Pelgrims of the Institute of Astrophysics of the Foundation for Research and Technology – Hellas (IA-FORTH) and University of Crete in Greece. The team consisted of an international collaboration of scientists from the Institute for Advanced Study, Princeton University, and Caltech in the USΑ and the University of Oslo in Norway.

Clark is supported by the Friends of the Institute for Advanced Study Membership. In addition to her work polarized cosmic microwave background foregrounds, her research is focused on magnetohydrodynamic instabilities and the magnetic interstellar medium.

Clark's work in this area is further reflected in two recent papers that appeared in the Astrophysical Journal:

"Mapping the Magnetic Interstellar Medium in Three Dimensions over the Full Sky with Neutral Hydrogen" by S. E. Clark and Brandon S. Hensley (December 2019)

"Maps of the Number of H I Clouds along the Line of Sight at High Galactic Latitude" by G. V. Panopoulou and D. Lenz (October 2020)

Read more at Astronomy & Astrophysics and IA-FORTH.


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