Aperture synthesis maps of CO emission from M51

Seven-arcsec-resolution maps of CO emission from the central 2 arcmin of M51 have been made with the Owens Valley millimeter-wave interferometer. Relative warm gas from giant molecular clouds is seen to be largely confined to arms coincident with the dust lanes, forming coherent structure on the scale about 3 kpc. There is a minimum of CO emission within 400 pc of the center. Integrated CO intensity maps are presented. Noncircular motion of the CO gas is evident from the velocity field.