Studying the internal kinematics of galaxies using the calcium infrared triplet

The Ca II IR triplet lines 8498, 8542, and 8662 Å are strong in a wide variety of stellar types, making this an ideal spectral region for studying the internal kinematics of neighboring galaxies. With the calcium triplet it is possible to measure systemic velocity, velocity dispersion, and line strength even in galaxies whose light is dominated by young stars, hot gas, or nonthermal emission. Results are given for some sample galaxies, including radial profiles of v, σ, and γ for M31, M32, and NGC 1068. Both M31 and M32 show a cusplike rise in velocity dispersion of 30% - 50% in the central few parsecs. These data suggest a rising M/L in each nucleus perhaps due to a black hole of order 106-7 solar masses.