PDA

View Full Version : Review of CMB Radiation



GOURDHEAD
2005-Jan-30, 08:01 PM
Here (http://www.theglobeandmail.com/servlet/ArticleNews/TPStory/LAC/20050129/BANG29/TPScience/) is some breaking (or braking) news on the CMBR. Here (http://archive.ncsa.uiuc.edu/Cyberia/Cosmos/SeedsStructure.html) is a discussion of why "inflation" was epicycled in to account for the difference in observed lumpyness from that expected from the smoothness predicted from the isotropy of the CMBR. Comments anyone.

antoniseb
2005-Jan-30, 08:31 PM
Thanks GOURDHEAD,

This is not exactly a new story to UT members, but it is interesting to see the story in the popular press. I noticed that the story did not provide any numbers correlating the intensity of the observations that may or may not be corrupted by the local solar system. I imagine tha this may be part of why the WMAP team is being slow with the second year data [which doesn't endear them to me]

The party line of course is what Charles Bennet said: "the newly discovered CMB correlations are most likely the product of chance." Buried in this statement is the fact that the WMAP team has acknowledged to the media that there IS something unexpected there. At the same time, while it may slightly alter some of the conclusions drawn at the release of the WMAP first year data, it will NOT substantially change the opinion that the universe is expanding, or that it started expanding about 13.7 billion years ago.

buzzlightbeer
2005-Aug-16, 04:07 PM
i also sent an email to the map dudes a while back and got a reply recently. ill post it here an an FYI for y'all.

To: WMAP dudes
From: Buzz
Topic: WMAP 2 Data

I was wondering why WMAP2 data is not available. Any news on what is happening with it? Is it publicly available for analysis? If not, now, will it be in the future? If so, when? etc :)))
Thank you!
Buzz.

Dear Buzz:

We have committed ourselves to releasing the next round of data by sometime this fall, but we have not set a firm date yet. We plan to include full-sky polarization maps with the next release and we have been working very hard to characterize the noise properties of the polarization data. Unfortunately, this job has turned out to be much more complex than we had hoped. Alas it is necessary because the polarization signal-to-noise ratio is so much lower than it is with the temperature signal. We hope you find the results to be worth the wait!

Sincerely,
Gary Hinshaw
for the WMAP science team

Zahl
2005-Aug-16, 08:01 PM
Very interesting! If they have had so much trouble with the noise, it could mean that the large angular scale polarization signal (a low-l bump due to reionization) is much weaker that expected, affecting the reionization history and first light scenarios of the universe.

cran
2005-Aug-17, 08:11 AM
:huh: err... I knew that! :unsure:

>psst&#33;< what did Zahl just say? :blink: