Localization Of WMAP Non-Gaussian Regions And Correlations With Foreground Galaxies | Posted on:2011-05-28 | Degree:Master | Type:Thesis | Country:China | Candidate:B Fan | Full Text:PDF | GTID:2120330338990468 | Subject:Astrophysics | Abstract/Summary: | PDF Full Text Request | TheCosmicMicrowaveBackground(CMB)hasbroughtwithusalargeamountofknowledge of the early universe, however, its power is not limited to the early universeresearch, many other cosmic effects will affect the CMB photons which are travellingon their journey, leaving imprints on the CMB signals we received. In this work, welocalize non-Gaussian areas on WMAP with two distinct methods: the wavelet methodand the auto-correlation approach. Both methods point to similar non-Gaussian areaswith analogous features. We analyze these areas with the help of data from the SDSSand the NVSS with cavities found at high significant. Further statistical tests show theprobability that those large and obvious cavity arises from fluctuation is less than 2%.We show that out results favors the the ISW effect explanation of the underlying origin.If confirmed, we have localized two visual sources of the ISW effect and provide a dataset for the further analysis.
| Keywords/Search Tags: | Cosmology, WMAP, non-Gaussian, wavelet, auto-correlation, Dark energy, ISW | PDF Full Text Request | Related items |
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