U.S.-Italy Cooperative Research: Low-Frequency Measurementsof the Cosmic Microwave Background Radiation

该奖项将支持由加州大学伯克利分校的George Smoot教授领导的一组研究人员与意大利米兰大学Degli Studi di Milano的Giorgio Sironi教授合作开展工作。研究人员计划从阿蒙森-斯科特南极站对宇宙微波背景辐射（CMBR）温度进行改进的测量。这个意大利小组将测量频率为。8和2.5 GHz，而美国团队将在1.5、3.8和7.5 GHz频率上进行测量。2.5 GHz和3.8 GHz辐射计的测量已经产生了重大的科学结果；有了升级的设备和更有利的南极地点，预计将获得更准确的结果，以补充、验证和扩展合作者以前的测量结果。此外，将使用现有仪器进行90GHz范围内的大气测量。结合目前的高频测量和来自宇宙背景探测器（CoBE）卫星的非常精确的高频数据，这些测量将更准确地确定CMBR频谱的形状，从而提供有关早期宇宙热历史的有用信息，这将显著影响星系形成和粒子物理理论。此外，大气测量可以提供用一套仪器在广泛的大气和气象条件下获得的宝贵数据，从而有助于测试现有的大气排放模型。

This award will support a group of investigators headed by Professor George Smoot of the University of California-Berkeley in collaborative work with Professor Giorgio Sironi of the Universita Degli Studi di Milano in Milan, Italy. The investigators plan to carry out improved measurements of the cosmic microwave background radiation (CMBR) temperature from the Amundsen-Scott South Pole Station. The Italian group will make measurements at frequencies of .8 and 2.5 GHz, while the U.S. team will make measurements at frequencies of 1.5, 3.8, and 7.5 GHz. Already, measurements taken by 2.5 and 3.8 GHz radiometers have yielded scientifically significant results; with upgraded equipment and the more advantageous South Pole site, it is expected that more accurate results will be obtained that will supplement, verify, and extend previous measurements by the collaborators. In addition, atmospheric measurements in the 90GHz range will be done, using existing instruments. In combination with current measurements at higher frequencies and with very accurate high frequency data from the Cosmic Background Explorer (CoBE) satellite, these measurements will more accurately determine the shape of the CMBR spectrum and thus provide useful information about the thermal history of the early universe, significantly affecting theories of galaxy formation and particle physics. In addition, the atmospheric measurement could help test existing models of atmospheric emission by providing valuable data taken with a single set of instruments over a wide range of atmospheric and meteorological conditions.