The origins of post-starburst galaxies at z <0.05
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Pawlik , M M , Aldeen , L T , Wild , V , Mendez-Abreu , J , Lahen , N , Johansson , P H , Jimenez , N , Lucas , W , Zheng , Y , Walcher , C J & Rowlands , K 2018 , ' The origins of post-starburst galaxies at z <0.05 ' , Monthly Notices of the Royal Astronomical Society , vol. 477 , no. 2 , pp. 1695-1730 . https://doi.org/10.1093/mnras/sty589
| Title: | The origins of post-starburst galaxies at z <0.05 |
| Author: | Pawlik, M. M.; Aldeen, L. Taj; Wild, V.; Mendez-Abreu, J.; Lahen, N.; Johansson, P. H.; Jimenez, N.; Lucas, W.; Zheng, Y.; Walcher, C. J.; Rowlands, K. |
| Contributor organization: | Department of Physics |
| Date: | 2018-06 |
| Language: | eng |
| Number of pages: | 36 |
| Belongs to series: | Monthly Notices of the Royal Astronomical Society |
| ISSN: | 0035-8711 |
| DOI: | https://doi.org/10.1093/mnras/sty589 |
| URI: | http://hdl.handle.net/10138/236712 |
| Abstract: | Post-starburst galaxies can be identified via the presence of prominent Hydrogen Balmer absorption lines in their spectra. We present a comprehensive study of the origin of strong Balmer lines in a volume-limited sample of 189 galaxies with 0.01 <z <0.05, log(M-star/M-circle dot) > 9.5 and projected axial ratio b/a > 0.32. We explore their structural properties, environments, emission lines, and star formation histories, and compare them to control samples of star-forming and quiescent galaxies, and simulated galaxy mergers. Excluding contaminants, in which the strong Balmer lines are most likely caused by dust-star geometry, we find evidence for three different pathways through the post-starburst phase, with most events occurring in intermediate-density environments: (1) a significant disruptive event, such as a gas-rich major merger, causing a starburst and growth of a spheroidal component, followed by quenching of the star formation (70 per cent of post-starburst galaxies at 9.5 <log(M-star/M-circle dot) <10.5 and 60 per cent at log(M-star/M-circle dot) > 10.5); (2) at 9.5 <log(M-star/M-circle dot) <10.5, stochastic star formation in blue-sequence galaxies, causing a weak burst and subsequent return to the blue sequence (30 per cent); (3) at log(M-star/M-circle dot) > 10.5, cyclic evolution of quiescent galaxies which gradually move towards the high-mass end of the red sequence through weak starbursts, possibly as a result of a merger with a smaller gas-rich companion (40 per cent). Our analysis suggests that active galactic nuclei (AGNs) are 'on' for 50 per cent of the duration of the post-starburst phase, meaning that traditional samples of post-starburst galaxies with strict emission-line cuts will be at least 50 per cent incomplete due to the exclusion of narrow-line AGNs. |
| Subject: |
galaxies: evolution
galaxies: interactions galaxies: starburst galaxies: stellar content galaxies: structure DIGITAL SKY SURVEY ACTIVE GALACTIC NUCLEI STAR-FORMATION HISTORIES SMOOTHED PARTICLE HYDRODYNAMICS INTERMEDIATE-REDSHIFT CLUSTERS STELLAR POPULATION GRADIENTS BUTCHER-OEMLER CLUSTERS HUBBLE-SPACE-TELESCOPE DELTA-STRONG GALAXIES SIMILAR-TO 1 115 Astronomy, Space science |
| Peer reviewed: | Yes |
| Rights: | unspecified |
| Usage restriction: | openAccess |
| Self-archived version: | publishedVersion |
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