The Kinematics of the Outer Halo of M87
Radial velocities are presented for a new sample of globular clusters in the outer halo of M87 at a distance of 300''–540'' (24–43 kpc) from the center of this galaxy. These are used to augment our previously published data, and an analysis of the rotation and velocity dispersion of the M87 globular cluster system is carried out. The rotation is ~300 km s^(-1) at R = 32 kpc, at which point the velocity dispersion is also still quite high, ~450 km s^(-1). The high rotation is interesting. The outer halo of M87 is, as was found in our previous kinematic analysis, very massive.
Additional Information© 2000 The American Astronomical Society. Received 1999 August 16; accepted 1999 September 28. Based in large part on observations obtained at the W. M. Keck Observatory, which is operated jointly by the California Institute of Technology and the University of California. The entire Keck/LRIS user community owes a huge debt to J. Nelson, G. Smith, B. Oke, and many other people who have worked to make the Keck Telescope and LRIS a reality. We are grateful to the W. M. Keck Foundation, and particularly its late president, Howard Keck, for the vision to fund the construction of the W. M. Keck Observatory. We thank J. Blakeslee and P. Côté for helpful discussions.
Published - Cohen_2000_AJ_119_162.pdf
Accepted Version - 9909471.pdf