Ground-based CCD astrometry with wide-field imagers - II. A star catalog for m 67: WFI@2.2 m MPG/ESO astrometry, FLAMES @ VLT radial velocities

Context. The solar-age open cluster M 67 (C0847+120, NGC 2682) is a touchstone in studies of the old Galactic disk. Despite its outstanding role, the census of cluster membership for M 67 at fainter magnitudes and their properties are not well-established. Aims. Using proprietary and archival ESO data, we have obtained astrometric, photometric, and radial velocities of stars in a 34 x 33 arcmin(2) field centered on the old open cluster M 67. Methods. The two-epoch archival observations separated by 4 years and acquired with the Wide-Field Imager at the 2.2 m MPG/ESO telescope were reduced with our new astrometric techniques, as described in the first paper in this series. The same observations served to derive calibrated BVI photometry in M 67. Radial velocities were measured using the archival and new spectroscopic data obtained at the VLT. Results. We have determined relative proper motions and membership probabilities for similar to 2400 stars. The precision of proper motions for optimally exposed stars is 1.9 mas yr(-1), gradually degrading down to similar to 5 mas yr(-1) at V = 20. Our relatively precise proper motions at V > 16 were first obtained in this magnitude range for M 67. Radial velocities were measured for 211 stars in the same field. We also present a detailed comparison with recent theoretical isochrones from several independent groups. Conclusions. For the M 67 area, we provide positions, calibrated BVI photometry, relative proper motions, membership probabilities, and radial velocities. We demonstrate that ground-based CCD mosaic observations just a few years apart are producing proper motions, allowing reliable membership determination. We have produced a catalog that is electronically available to the astronomical community.