Angular Power Spectrum of the Cosmic Microwave Background Anisotropy seen by the COBE DMR
Abstract
The angular power spectrum estimator developed by Peebles and Hauser & Peebles has been modified and applied to the 4 yr maps produced by the COBE DMR. The power spectrum of the observed sky has been compared to the power spectra of a large number of simulated random skies produced with noise equal to the observed noise and primordial density fluctuation power spectra of power-law form, with P(k) ~ kn. The best-fitting value of the spectral index in the range of spatial scales corresponding to spherical harmonic indices 3 <= l <~ 30 is an apparent spectral index napp = 1.13^{+0.3}_{-0.4} which is consistent with the Harrison-Zeldovich primordial spectral index npri = 1. The best-fitting amplitude for napp = 1 is \l(Q2_{{rms}}\right^{0.5} = 18 mu K.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1996
- DOI:
- 10.1086/310073
- arXiv:
- arXiv:astro-ph/9601059
- Bibcode:
- 1996ApJ...464L..21W
- Keywords:
-
- COSMOLOGY: COSMIC MICROWAVE BACKGROUND;
- COSMOLOGY: OBSERVATIONS;
- Astrophysics
- E-Print:
- 17 pages including 3 PostScript figures. Submitted to The Astrophysical Journal (Letters)