The origins of post-starburst galaxies at z <0.05
Permalink
Citation
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. |
| Other contributor: |
University of Helsinki, Department of Physics
University of Helsinki, 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 |
| Rights: |
Files in this item
Total number of downloads: Loading...
| Files | Size | Format | View |
|---|---|---|---|
| sty589.pdf | 5.005Mb |
View/ |
This item appears in the following Collection(s)
-
Articles from TUHAT CRIS [40275]
Related items
Showing items related by title, author, creator and subject.
-
(2016)We use the low-redshift Zurich Environmental Study (ZENS) catalog to study the dependence of the quenched satellite fraction at 10(10.0) M-circle dot -> 10(11.5) M-circle dot, and of the morphological mix of these quenched satellites, on three different environmental parameters: group halo mass, halo-centric distance, and large-scale structure (LSS) overdensity. Within the two mass bins into which we divide our galaxy sample, the fraction of quenched satellites is more or less independent of halo mass and the surrounding. LSS overdensity, but it increases toward the centers of the halos, as found in previous studies. The morphological mix of these quenched satellites is, however, constant with radial position in the halo, indicating that the well-known morphology-density relation results from the increasing fraction of quenched galaxies toward the centers of halos. If the radial variation in the quenched fraction reflects the action of two quenching processes, one related to mass and the other to environment, then the constancy with radius of the morphological outcome suggests that both have the same effect on the morphologies of the galaxies. Alternatively, mass and environment quenching may be two reflections of a single physical mechanism. The quenched satellites have larger bulge-to-total ratios (B/T) and smaller half-light radii than the star-forming satellites. The bulges in quenched satellites have very similar luminosities and surface brightness profiles, and any mass growth of the bulges associated with quenching cannot greatly change these quantities. The differences in the light-defined B/T and in the galaxy half-light radii are mostly due to differences in the disks, which have lower luminosities in the quenched galaxies. The difference in galaxy half-light radii between quenched and star-forming satellites is however larger than can be explained by uniformly fading the disks following quenching, and the quenched disks have smaller scale lengths than in star-forming satellites. This can be explained either by a differential fading of the disks with galaxy radius or the disks being generally smaller in the past, both of which would be expected in an inside-out disk growth scenario. The overall conclusion is that, at least at low redshifts, the structure of massive quenched satellites at these masses is produced by processes that operate before the quenching takes place. A comparison of our results with semianalytic models argues for a reduction in the efficiency of group halos in quenching their disk satellites and for mechanisms to increase the B/T of low-mass quenched satellites.
-
(2021)We use photometric redshifts and statistical background subtraction to measure stellar mass functions in galaxy group-mass (4.5-8 x 10(13) M-circle dot) haloes at 1 < z < 1.5. Groups are selected from COSMOS and SXDF, based on X-ray imaging and sparse spectroscopy. Stellar mass (M-stell(ar)) functions are computed for quiescent and star-forming galaxies separately, based on their rest-frame UVJ colours. From these we compute the quiescent fraction and quiescent fraction excess (QFE) relative to the field as a function of M-stel(lar). QFE increases with M-st(ellar), similar to more massive clusters at 1 < z < 1.5. This contrasts with the apparent separability of M-stellar, and environmental factors on galaxy quiescent fractions at z similar to 0. We then compare our results with higher mass clusters at 1 < z < 1.5 and lower redshifts. We find a strong QFE dependence on halo mass at fixed M-ste(ll)ar; well fit by a logarithmic slope of d(QFE)/dlog (M-halo) similar to 0.24 +/- 0.04 for all M-stellar and redshift bins. This dependence is in remarkably good qualitative agreement with the hydrodynamic simulation BAHAMAS, but contradicts the observed dependence of QFE on M-stellar. We interpret the results using two toy models: one where a time delay until rapid (instantaneous) quenching begins upon accretion to the main progenitor ( 'no pre-processing') and one where it starts upon first becoming a satellite ('pre-processing'). Delay times appear to be halo mass-dependent, with a significantly stronger dependence required without pre-processing. We conclude that our results support models in which environmental quenching begins in low-mass ( 1.
-
(2018)We present a 3 degrees x 3 degrees, 105-pointing, high-resolution neutral hydrogen (H I) mosaic of the M81 galaxy triplet, (including the main galaxies M81, M82, and NGC 3077, as well as dwarf galaxy NGC 2976) obtained with the Very Large Array C and D arrays. This H I synthesis mosaic uniformly covers the entire area and velocity range of the triplet. The observations have a resolution of similar to 20 '' or similar to 420 pc. The data reveal many small-scale anomalous velocity features highlighting the complexity of the interacting M81 triplet. We compare our data with Green Bank Telescope observations of the same area. This comparison provides evidence for the presence of a substantial reservoir of low-column density gas in the northern part of the triplet, probably associated with M82. Such a reservoir is not found in the southern part. We report a number of newly discovered kpc-sized low-mass H I clouds with H I masses of a few times 10(6) M-circle dot. A detailed analysis of their velocity widths show that their dynamical masses are much larger than their baryonic masses, which could indicate the presence of dark matter if the clouds are rotationally supported. However, due to their spatial and kinematical association with H I tidal features, it is more likely that the velocity widths indicate tidal effects or streaming motions. We do not find any clouds that are not associated with tidal features down to an H I mass limit of a few times 10(4) M-circle dot. We compare the H I column densities with resolved stellar density maps and find a star formation threshold around 3-6 x 10(20) cm(-2). We investigate the widths of the H I velocity profiles in the triplet and find that extreme velocity dispersions can be explained by a superposition of multiple components along the line of sight near M81 as well as winds or outflows around M82. The velocity dispersions found are high enough that these processes could explain the linewidths of damped-Ly alpha absorbers observed at high redshift.