Xin liu and shuang nan zhang 2005 apj in press v630 astro ph 0504589 tsinghua university
Download
1 / 13

Xin Liu and Shuang Nan Zhang 2005, ApJ, in press, v630 (astro-ph/0504589) Tsinghua University - PowerPoint PPT Presentation


  • 95 Views
  • Uploaded on
  • Presentation posted in: General

Non-Gaussianity Due to Possible Residual Foreground Signals in Wilkinson Microwave Anistropy Probe First-Year Data Using Spherical Wavelet Approaches. Xin Liu and Shuang Nan Zhang 2005, ApJ, in press, v630 (astro-ph/0504589) Tsinghua University. Outline. Introduction

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha

Download Presentation

Xin Liu and Shuang Nan Zhang 2005, ApJ, in press, v630 (astro-ph/0504589) Tsinghua University

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Xin liu and shuang nan zhang 2005 apj in press v630 astro ph 0504589 tsinghua university

Non-Gaussianity Due to Possible Residual Foreground Signals in Wilkinson Microwave Anistropy Probe First-Year Data Using Spherical Wavelet Approaches

Xin Liu and Shuang Nan Zhang

2005, ApJ, in press, v630

(astro-ph/0504589)

Tsinghua University


Outline
Outline in

  • Introduction

    2. Wavelets on the sphere

    3. Non-Gaussianity analysis

    4. Results

    5. Conclusions and discussions


1 introduction
1. Introduction in

  • The importance of the test of non-Gaussianity of CMB temperature anisotropies

  • Current status of the test

  • Causes of the CMB non-Gaussianity

  • Foreground removal and the foreground template

  • Spherical wavelet approaches


2 wavelets on the sphere
2. Wavelets on the sphere in

  • The general theory

    • Spherical wavelet: the spherical counterpart of the planar wavelet

  • Practical implementation

    • Yet Another Wavelet toolbox (http://www.fyma.ucl.ac.be/projects/yawtb)

  • Spherical wavelet basis

    • Spherical Mexican Hat Wavelet and Spherical Morlet Wavelet


3 non gaussianity analysis
3. Non-Gaussianity analysis in

  • Non-Gaussianity statistics

  • Monte Carlo simulations


4 results
4. Results in

  • Spherical wavelet coefficient statistics




Xin liu and shuang nan zhang 2005 apj in press v630 astro ph 0504589 tsinghua university

Fig. 10a in Bennett et al. 2003



5 conclusions and discussions
5. Conclusions and Discussions in

  • In the wavelet space, deviations from Gaussianity are found in skewness at scales from 11 to 14 degrees on the sky and in kurtosis on scales smaller than 11 degrees.

  • Several possible non-Gaussian spots are detected in the real space.

  • On the possible sources of the detected non-Gaussianity:

    • Systematic effects have been excluded;

    • Foreground templates adopted by the WMAP team also make no significant contribution;

    • The most likely source of the detected non-Gaussianity is the residual foreground signals in the map.

  • It is still premature to test more precisely on the non-Gaussianity of the intrinsic CMB fluctuations before we can identify the origin of these foreground signals, understand its nature, and finally remove them from the CMB maps completely.


Wmap and egret cross correlation in wavelet space a foreground residual detection
WMAP and EGRET cross-correlation in wavelet space: in a foreground residual detection


ad
  • Login