Degree-scale anisotropy in the cosmic microwave background: SP94 results

J. O. Gundersen, M. Lim, J. Staren, C. A. Wuensche, N. Figueiredo, T. C. Gaier, T. Koch, P. R. Meinhold, M. D. Seiffert, G. Cook, A. Segale, P. M. Lubin

Research output: Contribution to journalArticlepeer-review

83 Scopus citations


We present results from two observations of the cosmic microwave background (CMB) performed from the South Pole during the 1993-1994 austral summer. Each observation employed a 3° peak-to-peak sinusoidal, single-difference chop and consisted of a 20° × 1° strip on the sky. The first observation used a receiver which operates in three channels between 38 and 45 GHz (Q-band) with a FWHM beam which varies from 1° to 1°.15. The second observation overlapped the first observation and used a receiver which operates in four channels between 26 and 36 GHz (Ka-band) with a FWHM beam which varies from 1°.5 to 1?7. Significant correlated structure is observed in all channels for each observation. The spectrum of the structure is consistent with a CMB spectrum and is formally inconsistent with diffuse synchrotron and free-free emission at the 5 σ level. The amplitude of the structure is inconsistent with 20 K interstellar dust; however, the data do not discriminate against flat or inverted spectrum point sources. The root mean square amplitude (±1 σ) of the combined (Ka + Q) data is ΔTrms = 41.2+ 15.5-6.7 μK for an average window function which has a peak value of 0.97 at ℓ = 68 and drops to e-0.5 of the peak value at ℓ = 36 and ℓ = 106. A band power estimate of the CMB power spectrum, C, gives 〈Cℓ(ℓ + 1)/(2π)〉B = 1.77+1.58-0.54 × 10-10.

Original languageEnglish (US)
Pages (from-to)L57-L60
JournalAstrophysical Journal
Issue number2 PART 2
StatePublished - Apr 20 1995
Externally publishedYes


  • Cosmic microwave background
  • Cosmology: observations

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Degree-scale anisotropy in the cosmic microwave background: SP94 results'. Together they form a unique fingerprint.

Cite this