Science-advisor
REGISTER info/FAQ
Login
username
password
     
forgot password?
register here
 
Research articles
  search articles
  reviews guidelines
  reviews
  articles index
My Pages
my alerts
  my messages
  my reviews
  my favorites
 
 
Stat
Members: 3643
Articles: 2'487'895
Articles rated: 2609

28 March 2024
 
  » arxiv » astro-ph/9504072

 Article overview


Hot and Cold Spots in the First plus Second Year COBE/DMR Maps
Laura Cayon & George Smoot ;
Date 20 Apr 1995
Journal Astrophys.J. 452 (1995) 487
Subject astro-ph
AffiliationLawrence Berkeley Laboratory Center for Particle Astrophysics
AbstractDensity perturbations at the decoupling epoch produce angular fluctuations in the temperature of the Cosmic Microwave Background (CMB) radiation that may appear as hot and cold spots. Observational data of the CMB includes instrumental noise in addition to the cosmological signal. One would like to determine which of the observed spots are produced by the noise and which correspond to signal. In this work we first present a statistical analysis of the first plus second year COBE/DMR map at 53 GHz that reveals the presence of cosmological signal in the data. The analysis is based on Harrison-Zeldovich Monte Carlo realizations and utilizes a generalized $chi^2$ statistic. The method is applied to the number of spots and the fraction of the total area that appear above/below a certain value of the dispersion of the noise, including and excluding the quadrupole, giving $Q_{rms-PS}=15^{+3}_{-6}$, $18^{+5}_{-7} mu K$ and $Q_{rms-PS}=18^{+3}_{-4}$, $21pm6 mu K$, at the $95\%$ confidence level, respectively. The data taken by the COBE/DMR experiment during the first two years at three different frequencies (31, 53 and 90 GHz) are used to determine which of the spots observed at 53 GHz appear simultaneously in the other two channels. The significance of those spots is determined by comparison of their area and signal-to-noise with noise Monte Carlo simulations. We point out two cold spots and one hot spot at positions $(l,b)approx (-99^{circ},57^{circ}),(-21^{circ},-45^{circ}), (-81^{circ},-33^{circ})$ respectively, at the $95 \%$ confidence level.
Source arXiv, astro-ph/9504072
Services Forum | Review | PDF | Favorites   
 
Visitor rating: did you like this article? no 1   2   3   4   5   yes

No review found.
 Did you like this article?

This article or document is ...
important:
of broad interest:
readable:
new:
correct:
Global appreciation:

  Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.

browser claudebot






ScienXe.org
» my Online CV
» Free


News, job offers and information for researchers and scientists:
home  |  contact  |  terms of use  |  sitemap
Copyright © 2005-2024 - Scimetrica