SPECTROSCOPY OF GLOBULAR-CLUSTERS IN NGC-4472

Citation
Rm. Sharples et al., SPECTROSCOPY OF GLOBULAR-CLUSTERS IN NGC-4472, The Astronomical journal, 115(6), 1998, pp. 2337-2344
Citations number
27
Categorie Soggetti
Astronomy & Astrophysics
Journal title
ISSN journal
00046256
Volume
115
Issue
6
Year of publication
1998
Pages
2337 - 2344
Database
ISI
SICI code
0004-6256(1998)115:6<2337:SOGIN>2.0.ZU;2-J
Abstract
Optical multislit spectra have been obtained for 47 globular clusters surrounding the brightest Virgo elliptical galaxy, NGC 4472 (M49). Inc luding data from the literature, we analyze velocities for a total sam ple of 57 clusters and present the first tentative evidence for kinema tic differences between the red and blue cluster populations that make up the bimodal color distribution of this galaxy. The redder clusters are more centrally concentrated and have a velocity dispersion of 240 km s(-1), compared with 320 km s(-1) for the blue dusters. The origin of this difference appears to be a larger component of systematic rot ation in the blue cluster system. The larger rotation in the more exte nded blue cluster system is indicative of efficient angular momentum t ransport, as provided by galaxy mergers. Masses estimated from the glo bular cluster velocities are consistent with the mass distribution est imated from X-ray data and indicate that the M/L-B rises to 50 (M/L)(. ) at 2.5R(e).