A Mapping Survey of the <sup>13</sup> CO and <sup>12</sup> CO Emission in Galaxies
A Mapping Survey of the <sup>13</sup> CO and <sup>12</sup> CO Emission in Galaxies
We present spectra of the extended 12CO and 13CO J=1-0 emission along the major axes of 17 nearby galaxies. Spatial variations in the ratio of CO and 13CO integrated intensities, R, are found in nearly every galaxy observed. There is an overall variation in R of 20-40% from the inner …