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An HI Study of the NGC 6744 System

Stuart D. Ryder 1 - Wilfred Walsh 2 - David Malin 3

1 Joint Astronomy Centre, 660 N. A'Ohoku Place, Hilo, HI 96720, U.S.A.
sryder@jach.hawaii.edu

2 Radioastronomisches Institut der Universität Bonn, Auf dem Hügel 71, Bonn D-53121, Germany.
wwalsh@astro.uni-bonn.de

3 Anglo-Australian Observatory, P.O. Box 296, Epping, NSW 1710, Australia.
dfm@aaoepp.aao.gov.au

Abstract:

We present the preliminary results of our 5-configuration, 20-pointing mosaic with the Australia Telescope Compact Array of the neutral hydrogen in the nearby spiral galaxy NGC 6744. The bulk of the HI resides in a ``ring'' underlying the outer optical disk, with 2 HI spiral arms extending further out to almost 1.5 optical radii. The velocity field is fairly regular, apart from evidence for streaming motions along the HI arms, and the influence of the companion IB(s)m galaxy NGC 6744A. We associate a cloud of HI at a heliocentric velocity of 846 km ${\rm s}^{-1}$ with another companion object, ESO 104-g44. Our attempts to construct a mass model for NGC 6744 suffer from poor resolution in the inner disk, and the uncertainty in the total HI flux of NGC 6744. We anticipate that HIPASS observations will be crucial in resolving the latter issue.

Keywords: galaxies: individual (NGC 6744) -- galaxies: interactions -- galaxies: kinematics and dynamics -- galaxies: spiral





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Next: Introduction

Amelia Ortiz-Gil
1999-02-16
ASKAP
Public