UCSB South Pole 1994 CMB anisotropy measurement constraints on open and flat-$\Lambda$ CDM cosmogonies

• Main Authors: Ganga, K, Ratra, B, Gundersen, J O, Sugiyama, N
• Language: English
• Published: 1996
• Subjects: Astrophysics and Astronomy; Lambda; South Pole; South pole
• Online Access: http://cds.cern.ch/record/297519

We analyze the 1994 UCSB South Pole CMB anisotropy data in the context of realistic open and flat-lambda CDM cosmogonies. Ignoring calibration and beamwidth uncertainties, we repeat the nominal beamwidth, flat bandpower, likelihood analyses of Gundersen (1995) for the SP94 combined Ka, Q, and (full) Ka + Q data subsets. Our results are consistent with those of G95 to within the expected numerical uncertainty. Accounting for calibration and beamwidth uncertainties, the Ka + Q data set is most consistent with the CMB anisotropy shape in \Omega_0 \sim 0.1-0.2 open models (amongst all the models we consider here), and is not as consistent with those in old (t_0 \gap 15 - 16 Gyr), high baryon density (\Omega_B \gap 0.0175h^{-2}), low density (\Omega_0 \sim 0.2 - 0.4), flat-\Lambda models. Conclusions regarding model compatibility drawn from the SP94 Ka and Q data subsets are consistent with these results. For the Ka, Q, and Ka + Q data subsets the CMB anisotropy shape in open CDM models with \Omega_0 = 0.1 -- 0.3 and 0.4 (with a larger h and lower \Omega_B), and in the flat bandpower model, ensures that these models are always within 1\sigma of the most likely low-density open model. Open models with \Omega_0 = 0.5 (with a smaller h and a larger \Omega_B), fiducial CDM, and all flat-\Lambda models we consider, are always more than 1\sigma away from the most likely low-density open model. For the Ka, Q, and Ka + Q data subsets analyzed at the nominal beamwidths, the least likely model CMB anisotropy shape is always within \sim 1.4 - 1.6\sigma of the most likely low-density open model, so the SP94 data do not rule out any of the models we consider here at the 2\sigma level.