Shape asymmetry : a morphological indicator for automatic detection of galaxies in the post-coalescence merger stages

Show full item record



Permalink

http://hdl.handle.net/10138/190714

Citation

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: University of Helsinki, 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
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
Rights:


Files in this item

Total number of downloads: Loading...

Files Size Format View
stv2878.pdf 5.445Mb PDF View/Open

This item appears in the following Collection(s)

Show full item record