Polarized Snaps

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Science  08 Sep 2006:
Vol. 313, Issue 5792, pp. 1364
DOI: 10.1126/science.313.5792.1364c

Buried in the patterns of the cosmic microwave background radiation that bathes the sky are clues to the structure of the universe. Ripples in temperature have been mapped in fine detail for several years, but further insight requires the mapping of polarized signatures that place extra constraints on early-universe physics. One pioneering experiment that has measured temperature anisotropies is BOOMERanG—Balloon Observations Of Millimetric Extragalactic Radiation and Geophysics—a balloon-borne array of bolometer detectors floated from Antarctica. In a 200-hour flight in January 2003, BOOMERanG succeeded in mapping detailed structures in polarized light at 145 GHz over a few percent of the full sky. In a series of papers, MacTavish et al., Montroy et al., Jones et al., and Piacentini et al. report the latest power spectra determinations of temperature, polarization, and temperature polarization cross-correlations. These results are consistent with recent measurements on degree scales by the Wilkinson Microwave Anisotropy Probe (WMAP) satellite but also extend to much higher resolution and offer finer sampling than has been achieved to date by other low-frequency experiments. The BOOMERanG data are consistent with the consensus cosmological model, a universe dominated by dark energy and cold dark matter. Some models of early structure formation are ruled out, notably defects, and adiabatic seed fluctuations are favored. — JB

Astrophys. J. 647, 799; 813; 823; 833 (2006).

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