The HI-rich elliptical galaxy NGC 5266:
an old merger remnant?

R. Morganti
ATNF, CSIRO, PO Box 76, Epping, NSW2121, Australia
IRA, CNR, via Gobetti 101, 40129 Bologna, Italy
rmorgant@atnf.csiro.au
E.M. Sadler
School of Physics, University of Sydney, NSW2006, Australia
T.A. Oosterloo
ATNF, CSIRO, PO Box 76, Epping, NSW2121, Australia
A. Pizzella
F. Bertola
Dipartimento di Astronomia, Vicolo dell'Osservatorio 5, 35122 Padova, Italy

Abstract:

We present HI images for the dust-lane elliptical galaxy NGC5266. This galaxy contains more than M of HI and our data show that the neutral hydrogen extends to 8arcmin each side of the nucleus, or 8 times the optical half-light radius . Surprisingly, the outer HI gas extends almost orthogonal to the optical dust lane. The overall HI kinematics can be successfully modeled by assuming that the gas lies in two orthogonal planes -- in the plane of the dust lane in the central parts and perpendicular to this in the outer regions. The large amount of neutral gas observed and the HI morphology, suggest that this object may have formed from the merger of two gas rich spiral galaxies. If so, it probably represents a relatively old merger remnant since most of the HI\ appears settled. The mass-to-light ratio has also been derived with evidence for a dark matter halo around this galaxy.

© Copyright Astronomical Society of Australia 1997