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Fabry-Perot Measurements of the Dynamics of Globular Cluster Cores: M15 (NGC~7078)

K. Gebhardt·C. Pryor·T. B. Williams·J. E. Hesser
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Abstract

We report the first use of the Rutgers Imaging Fabry-Perot Spectrophotometer to study the dynamics of the cores of globular clusters. We have obtained velocities for cluster stars by tuning the Fabry-Perot to take a series of narrow-band images at different wavelengths across one of the Na D (5890 AA) absorption lines. Measuring the flux in every frame yields a short portion of the spectrum for each star simultaneously. This proves to be a very efficient method for obtaining accurate stellar velocities; in crowded regions we are able to measure hundreds of velocities in 3-4 hours of observing time. We have measured velocities with uncertainties of less than 5 km/s for 216 stars within 1.5' of the center of the globular cluster M15 (NGC 7078). The paper is a uuencoded compressed postscript file.

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K. Gebhardt, C. Pryor, T. B. Williams, J. E. Hesser. 1994-02-24. Fabry-Perot Measurements of the Dynamics of Globular Cluster Cores: M15 (NGC~7078). https://doi.org/10.1086/117017

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