Evidence for unusual dynamical effects in the halo of NGC 5128 (Centaurus A)

Abstract

view Abstract Citations (44) References (23) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Evidence for Unusual Dynamical Effects in the Halo of NGC 5128 (Centaurus A) Hesser, J. E. ; Harris, H. C. ; Harris, G. L. H. Abstract New observations bring to 35 the number of spectroscopically confirmed globular clusters in NGC 5128. At radii less than about 11 arcmin the ensemble-average cluster velocity appears to exceed by about 4 simga the systemic velocity of the galaxy, while at larger radii the two values agree. Several sources of possible systematic error are eliminated by the new data, suggesting that this peculiar result is not likely to have arisen from a statistical fluctuation. These inner clusters lie beyond the obvious bulge light but within the faintest outer isophotes, and generally have redder colors than more distant ones. It is suggested that whatever phenomenon produced the warped dust lane and/or the faint optical 'shells' around NGC 5128 may also be related to the unexpected cluster velocities. If the phenomenon involved a merger, the cluster velocity observations would appear to suggest that the last merger occurred more recently than a dynamical crossing time. Publication: The Astrophysical Journal Pub Date: April 1986 DOI: 10.1086/184651 Bibcode: 1986ApJ...303L..51H Keywords: Elliptical Galaxies; Globular Clusters; Stellar Motions; Astronomical Spectroscopy; Radial Velocity; Velocity Distribution; Astrophysics; CLUSTERS: GLOBULAR; GALAXIES: INDIVIDUAL NGC NUMBER: NGC 5128; GALAXIES: INDIVIDUAL NAME: CENTAURUS A; GALAXIES: INTERNAL MOTIONS full text sources ADS | data products SIMBAD (35) NED (14)