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The Dynamics of the M87 Globular Cluster System

Cohen, Judith G. and Ryzhov, Anton (1997) The Dynamics of the M87 Globular Cluster System. Astrophysical Journal, 486 (1). pp. 230-241. ISSN 0004-637X. doi:10.1086/304518.

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We present the results from a study of the dynamics of the system of globular clusters around M87. After eliminating foreground galactic stars and background galaxies, we end up with a sample of 205 bona fide M87 globular clusters for which we have radial velocities determined from multislit spectra taken with the Low Resolution Imaging Spectrograph on the Keck Telescope. We find that the mean radial velocity of the M87 globular clusters agrees well with that of M87 itself and that the velocity histogram is well represented by a Gaussian distribution. We find evidence for rotation in the globular cluster system. We find that the observed velocity dispersion of the M87 globular cluster system increases with radius from 270 km s^(-1) at r = 9 kpc to ≈ 400 km s^(-1) at r = 40 kpc. The inferred mass-to-light ratio in solar units increases from 5 at r = 9 kpc to ≈ 30 at r = 40 kpc with M(r) ~ r^(1.7). The long-slit optical spectroscopy near the center of M87 and the recent analysis of the ROSAT X-ray data are in good agreement with this analysis near the nucleus and in the outer parts of M87, respectively.

Item Type:Article
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URLURL TypeDescription Paper
Cohen, Judith G.0000-0002-8039-4673
Additional Information:© 1997. The American Astronomical Society. Received 1997 January 24; accepted 1997 April 3. The entire Keck/LRIS user community owes a huge debt to Jerry Nelson, Gerry Smith, Bev 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 the referee, Tad Pryor, for his constructive suggestions that improved the analysis presented here. Publication charges were paid by NSF grant AST-9616729.
Funding AgencyGrant Number
W. M. Keck FoundationUNSPECIFIED
Subject Keywords:galaxies: halos; galaxies: individual (M87) ; galaxies: kinematics and dynamics; galaxies: star clusters
Issue or Number:1
Record Number:CaltechAUTHORS:20190529-103832596
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Official Citation:Judith G. Cohen and Anton Ryzhov 1997 ApJ 486 230
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:95860
Deposited By: George Porter
Deposited On:29 May 2019 21:23
Last Modified:16 Nov 2021 17:16

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