Next Section: Introduction

NGC 7421: Surfing the Intracluster Medium?

Stuart D. Ryder
School of Physics, University of New South Wales,
Sydney 2052, Australia.
sdr@newt.phys.unsw.edu.au

G. Purcell, D. Davis, and V. Andersen
Department of Physics & Astronomy, University of Alabama,
Box 870324, Tuscaloosa AL 35487-0324, U.S.A.
purcell, davis, andersen@crux.astr.ua.edu

Abstract:

NGC 7421 is a barred spiral displaced from the centre of its optical envelope, with a ``bow-shock''-like western boundary, both suggestive of interaction with an intracluster medium. We have used 5 configurations of the ATCA to map the distribution and kinematics of HI in NGC 7421, and find supportive evidence for this scenario in the form of an HI ``wake''. When compared with ROSAT PSPC observations of the diffuse hot gas in the surrounding group of galaxies, these new ATCA results will allow us to place new constraints on the density and dynamics of the intracluster medium.

Keywords: galaxies: individual (NGC 7421) -- galaxies: kinematics and dynamics -- galaxies: intergalactic medium -- radio lines: galaxies

© Copyright Astronomical Society of Australia 1997