We have reÐned the analysis of the data from the FIRAS (Far-InfraRed Absolute Spectrophotometer) on board the COBE (COsmic Background Explorer). The FIRAS measures the di †erence between the cosmic microwave background and a precise blackbody spectrum. We Ðnd new, tighter upper limits on general deviations from a blackbody spectrum. The rms deviations are less than 50 parts per million of the peak of the cosmic microwave background radiation. For the Comptonization and chemical potential, we Ðnd o y o \ 15 ] 10~6 and o k o \ 9 ] 10~5 (95% conÐdence level [CL]). There are also reÐne-ments in the absolute temperature, 2.728^0.004 K (95% CL), the dipole direction, (l, b) \ (264¡ .14 0.30, (95% CL), and the amplitude, 3.372^0.014 mK (95% CL). All of these results 48¡ .26^0.30) agree with our previous publications.
We present a determination of the cosmic microwave background dipole amplitude and direction from the COBE Di erential Microwave Radiometers (DMR) rst year of data. Data from the six DMR channels are consistent with a Dopplershifted Planck function of dipole amplitude T = 3:365 0:027 mK toward direction (l II ; b II ) = (264:4 0:3 ; 48:4 0:5 ). The implied velocity of the Local Group with respect to the CMB rest frame isṽ LG = 627 22 km s 1 toward (l II ; b II ) = (276 3 ; 30 3 ). DMR has also mapped the dipole anisotropy resulting from the Earth's orbital motion about the Solar system barycenter, yielding a measurement of the monopole CMB temperature T 0 at 31.5, 53, and 90 GHz, T 0 = 2:75 0:05 K. Subject headings: cosmic microwave background | cosmology: observations 2
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.