Neutral Hydrogen in the Polar Ring Galaxy UGC 9796

Type Journal Article
Names A. L. Cox, L. S. Sparke, G. van Moorsel
Publication The Astronomical Journal
Volume 131
Issue 2
Pages 828-836
Date February 1, 2006
Library Catalog NASA ADS
Abstract We have used the Very Large Array to observe the polar ring galaxy UGC 9796 (II Zw 73; PRC A-06) in the 21 cm line of neutral hydrogen. All the neutral gas in this galaxy is associated with the polar ring. Our observations show that ~=5×109 Msolar of H I rotates in a plane projected about 25° from perpendicular to the equatorial plane of the early-type host galaxy, consistent with earlier observations in the Hα line. The outermost gas appears to bend away from the minor axis of the host system, in the same sense as the stellar ring. UGC 9796 is in a very gas-rich environment: our 21 cm images show five gas-rich companion galaxies in the same field within 100 km s-1, with a total of ~=2×1010 Msolar between them. However, we see no H I streamers connecting the systems or any other evidence for an ongoing interaction between UGC 9796 and its companions.
Tags GALAXIES: STRUCTURE, Radio Lines: Galaxies, galaxies: individual (UGC 9796), galaxies: kinematics and dynamics
UW-Madison Astronomy Home