323.06 Cosmic Microwave Background Small-Scale Structure: II. Model of the Foreground Emission<br /> (Gerrit L. Verschuur)

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Jan 6th at 3:10 PM until 3:20 PM




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Author(s): Gerrit L. Verschuur1, Joan T. Schmelz1

Institution(s): 1. Arecibo Observatory

We have investigated the possibility that a population of galactic electrons may contribute to the small-scale structure in the cosmic microwave background (CMB) found by WMAP and PLANCK. Model calculations of free-free emission from these electrons which include beam dilution produce a nearly flat spectrum. Data at nine frequencies from 22 to 100 GHz were fit with the model, which resulted in excellent values of reduced chi squared. The model involves three unknowns: electron excitation temperature, angular extent of the sources of emission, and emission measure. The resulting temperatures agree with the observed temperatures of related HI features. The derived angular extent of the continuum sources corresponds well with the observed angular extent of HI filamentary structures in the areas under consideration. The derived emission measures can be used to determine the fractional ionization along the path lengths through the emitting volumes of space. Understanding the role that free-free emission plays in the small-scale features observed by PLANCK and WMAP should allow us to create better masks of the galactic foreground. Pursuing such discoveries may yet transform our understanding of the origins of the universe.