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Galactic Recycling: The HI Ring Around NGC 1533

Emma Ryan-Weber·Rachel Webster·Kenji Bekki
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Abstract

We report the discovery of a new HI ring around the S0 galaxy NGC 1533. The ring orbits at a radius of 35 kpc, well outside the optical extent of the galaxy. We have conducted N-body/SPH numerical simulations to show this HI ring could be the merger remnant of a tidally destroyed galaxy. We find no optical component associated with the HI ring. However, observations hint at H-alpha emission associated with the SE part of the ring only. The H-alpha is in the form of a few very small isolated emission line regions. The large HI velocity dispersions (up to 30 km/s) and velocity gradients (up to 50 km/s/kpc) in this region indicate the H-alpha emission could be due to star formation triggered by clouds colliding within the ring.

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Emma Ryan-Weber, Rachel Webster, Kenji Bekki. 2002-09-17. Galactic Recycling: The HI Ring Around NGC 1533. https://doi.org/10.1007/978-94-010-0115-1_40

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