PDA

View Full Version : radiative alignment of dust grains for polarized emission



trinitree88
2012-Aug-23, 02:04 PM
One of the enduring mysteries driving astrophysicists/ astronomers/cosmologists to distraction...is the persistent 7 sigma Axis of Evil alignment of the asymmetry in the CMB with the solar system. Here's a paper that shows that the most likely cause of dust grains alignment is radiative transfer, and that the warmer, or nearer a star, the better the alignment. Since the sun sits fairly central in the Local Bubble, which is believed to have as it's origin, a series of type 2 supernovae over the last few million years from OB wanderers from the Centaurus-Sco Association. The dust could align from the recently posited Hall effect in extended clouds. With Antoniseb's recent paper on determining the orientation of stars spins by the tilt of the spectral lines....a check to see if most members in the Local Bubble are pretty much aligned,, would suggest that the encircling Bubble Wall might be the source of the Axis of Evil by adding a polarized grey body background.(an R Cor Bor type star going "supe" would have carbon nanotubes (blackest black). Subtracting that out might return the CMB to isotropic. Interesting project? pete

SEE:http://arxiv.org/abs/1208.4393

SEE:http://www.wired.com/wiredscience/2009/03/ultrablack/


SEE:http://www.cita.utoronto.ca/TALKS/Land-Nov23.pdf


SEE:https://www.cfa.harvard.edu/~adeolive/foreground.html

SEE:http://arxiv.org/abs/1208.2810

Jerry
2012-Aug-29, 04:53 AM
Majory heartburn with the premise.

Not the premise that polarized dust grain radiation transfer would screw up the CMB; but the premise that one could assume such polarization is predominate only in one celestial plane. While it is true the spectral distribution could weed out aligned grains; there is no reason to limit the space where polarized grains reside: If such a phenomenon exists, I don't think you can confidently weed out the foreground from the background...{thinking out loud} .Or perhaps you can, if at the same resolution, the PLANCK MWB tracks major features of the background in a way that is completely consistent with WMAP results. Is there any evidence of shift in the velocity or feature location in the Planck results relative to WMAP? When is that data due to be published - Feb 2014?