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Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/94198
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- Spatially resolved spectroscopy of starburst and post-starburst galaxies in the rich z~0.55 cluster CL 0016+16
- Pracy, Michael B.; Couch, Warrick J.; Kuntschner, Harald
- We have used the Low Resolution Imaging Spectrograph on the W. M. Keck I telescope to obtain spatially resolved spectroscopy of a small sample of six ‘post-starburst’ and three ‘dusty-starburst’ galaxies in the rich cluster CL 0016+16 at z = 0.55. We use this to measure radial profiles of the Hδ and [OII]λ3727 lines which are diagnostic probes of the mechanisms that give rise to the abrupt changes in star formation rates in these galaxies. In the post-starburst sample we are unable to detect any radial gradients in the Hδ line equivalent width — although one galaxy exhibits a gradient from one side of the galaxy to the other. The absence of Hδ gradients in these galaxies is consistent with their production via interaction with the intra-cluster medium; however, our limited spatial sampling prevents us from drawing robust conclusions. All members of the sample have early-type morphologies, typical of post-starburst galaxies in general, but lack the high incidence of tidal tails and disturbances seen in local field samples. This argues against a merger origin and adds weight to a scenario where truncation by the intra-cluster medium is at work. The post-starburst spectral signature is consistent over the radial extent probed with no evidence of [OII]λ3727 emission and strong Hδ absorption at all radii, i.e. the post-starburst classification is not an aperture effect. In contrast the ‘dusty-starburst’ sample shows a tendency for a central concentration of [OII]λ3727 emission. This is most straightforwardly interpreted as the consequence of a central starburst. However, other possibilities exist such as a non-uniform dust distribution (which is expected in such galaxies) and/or a non-uniform starburst age distribution. The members of the sample exhibit late-type and irregular morphologies.
- Publication type
- Journal article
- Research centre
- Swinburne University of Technology. Faculty of Information and Communication Technologies. Centre for Astrophysics and Supercomputing
- Publications of the Astronomical Society of Australia, Vol. 27, no. 3 (2010), pp. 360-373
- Publication year
- CSIRO Publishing
- Publisher URL
- Copyright © Astronomical Society of Australia 2010. Accepted manuscript of the paper reproduced here in accordance with the copyright policy of the publisher.