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Session 49 - Elliptical Galaxies & Bulges.
Display session, Thursday, January 08
Several HST programs are planned in the near future to analyze the stellar dynamics in the nuclei of nearby bright galaxies using the long-slit spectroscopic mode of STIS. The main goal is to test possible relationships between supermassive black holes (dynamical evidence for which has been found in \approx 15 galaxies) and the galaxies which host them. One such program is our STIS GTO program designed to investigate interesting central structure and dynamics in early-type galaxies identified through previous HST observations using WFPC and FOS. The SB0 galaxy NGC 1023 (at a distance of 10 Mpc) is one of the target galaxies.
Since HST can provide useful S/N only in the central 0\farcs5, it is crucial to complement stellar-dynamical observations from HST with ground-based observations of a given galaxy. Such data provide for the removal of the bulge rotation from the nuclear profile, and establish the dynamical mass to light ratio on a global scale. Both of these are needed in order to interpret accurately the conditions in the nuclear region as revealed by HST.
Here we present our measurements of the stellar dynamics in NGC 1023 using ground-based long-slit spectroscopy obtained with the MDM 2.4 m and KPNO 4 m telescopes, covering the Mg b and calcium triplet absorption lines, respectively. We measure the stellar dynamics from these data using the Fourier Correlation Quotient method.
If the planned HST/STIS observations of NGC 1023 are received in time, we plan to present these data also.
Program listing for Thursday