Shape asymmetry : a morphological indicator for automatic detection of galaxies in the post-coalescence merger stages
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Pawlik , M M , Wild , V , Walcher , C J , Johansson , P H , Villforth , C , Rowlands , K , Mendez-Abreu , J & Hewlett , T 2016 , ' Shape asymmetry : a morphological indicator for automatic detection of galaxies in the post-coalescence merger stages ' , Monthly Notices of the Royal Astronomical Society , vol. 456 , no. 3 , pp. 3032-3052 . https://doi.org/10.1093/mnras/stv2878
| Title: | Shape asymmetry : a morphological indicator for automatic detection of galaxies in the post-coalescence merger stages |
| Author: | Pawlik, M. M.; Wild, V.; Walcher, C. J.; Johansson, P. H.; Villforth, C.; Rowlands, K.; Mendez-Abreu, J.; Hewlett, T. |
| Contributor organization: | Department of Physics |
| Date: | 2016-03-01 |
| Language: | eng |
| Number of pages: | 21 |
| Belongs to series: | Monthly Notices of the Royal Astronomical Society |
| ISSN: | 0035-8711 |
| DOI: | https://doi.org/10.1093/mnras/stv2878 |
| URI: | http://hdl.handle.net/10138/190714 |
| Abstract: | We present a new morphological indicator designed for automated recognition of galaxies with faint asymmetric tidal features suggestive of an ongoing or past merger. We use the new indicator, together with pre-existing diagnostics of galaxy structure to study the role of galaxy mergers in inducing (post-) starburst spectral signatures in local galaxies, and investigate whether (post-) starburst galaxies play a role in the build-up of the 'red sequence'. Our morphological and structural analysis of an evolutionary sample of 335 (post-) starburst galaxies in the Sloan Digital Sky Survey DR7 with starburst ages 0 <t(SB) <0.6 Gyr, shows that 45 per cent of galaxies with young starbursts (t(SB) <0.1 Gyr) show signatures of an ongoing or past merger. This fraction declines with starburst age, and we find a good agreement between automated and visual classifications. The majority of the oldest (post-) starburst galaxies in our sample (t(SB) similar to 0.6 Gyr) have structural properties characteristic of early-type discs and are not as highly concentrated as the fully quenched galaxies commonly found on the 'red sequence' in the present day Universe. This suggests that, if (post-) starburst galaxies are a transition phase between active star-formation and quiescence, they do not attain the structure of presently quenched galaxies within the first 0.6 Gyr after the starburst. |
| Subject: |
galaxies: evolution
galaxies: interactions galaxies: starburst galaxies: structure DIGITAL-SKY-SURVEY SIMILAR-TO 1 SUPERMASSIVE BLACK-HOLES TRIGGERED STAR-FORMATION GAS-RICH MERGERS STARBURST GALAXIES RED-SEQUENCE E+A-GALAXIES FORMATION HISTORIES MERGING GALAXIES 115 Astronomy, Space science |
| Peer reviewed: | Yes |
| Rights: | unspecified |
| Usage restriction: | openAccess |
| Self-archived version: | publishedVersion |
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