Measurements of Anisotropy in the Cosmic Microwave Background Radiation at Degree Angular Scales near the Stars Sigma Herculis and IOTA Draconis
Abstract
We present results from two four-frequency observations centered near the stars Sigma Herculis and Iota Draconis during the fourth flight of the Millimeter-wave Anisotropy eXperiment (MAX). The observations were made of 6 deg x 0.6 deg strips of the sky with a 1.4 deg peak to peak sinusoidal chop in all bands. The full width at half maximum (FWHM) beam sizes were calculated 0.55 deg +/- 0.05 deg at 3.5/cm and a 0.75 deg +/- 0.05 deg at 6, 9, and 14/cm. Significant correlated structures were observed at 3.5, 6, and 9/cm. The spectra of these signals are inconsistent with thermal emission from known interstellar dust populations. The extrapolated amplitudes of synchrotron and free-free emission are too small to account for the amplitude of the observed structures. If the observed structures are attributed to cosmic microwave background (CMB) anisotropy with a Gaussian autocorrelation function and a coherence angle of 25 min, then the most probable values at Delta T/TCMB = 3.1 +1.7-1.3x 10-5 for the Sigma Herculis scan, and Delta T/TCMB = 3.3+1.1-1.1 x 10-5 for the Iota Draconis scan (95% confidence upper, lower limits).
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1994
- DOI:
- 10.1086/187547
- Bibcode:
- 1994ApJ...433L..57C
- Keywords:
-
- Anisotropy;
- Background Radiation;
- Big Bang Cosmology;
- Radio Astronomy;
- Relic Radiation;
- Centimeter Waves;
- Cosmic Dust;
- Decimeter Waves;
- Radio Spectra;
- Superhigh Frequencies;
- Ultrahigh Frequencies;
- Astronomy;
- COSMOLOGY: COSMIC MICROWAVE BACKGROUND;
- COSMOLOGY: OBSERVATIONS