Galaxy And Mass Assembly (GAMA): galaxy close pairs, mergers and the future fate of stellar mass

Robotham, A. S. G., Driver, S. P., Davies, L. J. M., Hopkins, A. M., Baldry, I. K., Agius, N. K., Bauer, A. E., Bland-Hawthorn, J., Brough, S., Brown, M. J. I., Cluver, M., De Propris, R., Drinkwater, M. J., Holwerda, B. W., Kelvin, L. S., Lara-Lopez, M. A., Liske, J., Lopez-Sanchez, A. R., Loveday, J., Mahajan, S., McNaught-Roberts, T., Moffett, A., Norberg, P., Obreschkow, D., Owers, M. S., Penny, S. J., Pimbblet, K., Prescott, M., Taylor, E. N., van Kampen, E. and Wilkins, S. M. (2014) Galaxy And Mass Assembly (GAMA): galaxy close pairs, mergers and the future fate of stellar mass. Monthly Notices of the Royal Astronomical Society, 444 4: 3986-4008. doi:10.1093/mnras/stu1604

Author Robotham, A. S. G.
Driver, S. P.
Davies, L. J. M.
Hopkins, A. M.
Baldry, I. K.
Agius, N. K.
Bauer, A. E.
Bland-Hawthorn, J.
Brough, S.
Brown, M. J. I.
Cluver, M.
De Propris, R.
Drinkwater, M. J.
Holwerda, B. W.
Kelvin, L. S.
Lara-Lopez, M. A.
Liske, J.
Lopez-Sanchez, A. R.
Loveday, J.
Mahajan, S.
McNaught-Roberts, T.
Moffett, A.
Norberg, P.
Obreschkow, D.
Owers, M. S.
Penny, S. J.
Pimbblet, K.
Prescott, M.
Taylor, E. N.
van Kampen, E.
Wilkins, S. M.
Title Galaxy And Mass Assembly (GAMA): galaxy close pairs, mergers and the future fate of stellar mass
Journal name Monthly Notices of the Royal Astronomical Society   Check publisher's open access policy
ISSN 0035-8711
Publication date 2014-11
Year available 2014
Sub-type Article (original research)
DOI 10.1093/mnras/stu1604
Open Access Status DOI
Volume 444
Issue 4
Start page 3986
End page 4008
Total pages 23
Place of publication Oxford, United Kingdom
Publisher Oxford University Press
Collection year 2015
Language eng
Formatted abstract
We use a highly complete subset of the Galaxy And Mass Assembly II (GAMA-II) redshift sample to fully describe the stellar mass dependence of close pairs and mergers between 108 and 1012 M⊙. Using the analytic form of this fit we investigate the total stellar mass accreting on to more massive galaxies across all mass ratios. Depending on how conservatively we select our robust merging systems, the fraction of mass merging on to more massive companions is 2.0–5.6 per cent. Using the GAMA-II data we see no significant evidence for a change in the close pair fraction between redshift z = 0.05 and 0.2. However, we find a systematically higher fraction of galaxies in similar mass close pairs compared to published results over a similar redshift baseline. Using a compendium of data and the function γM = A(1 + z)m to predict the major close pair fraction, we find fitting parameters of A = 0.021 ± 0.001 and m = 1.53 ± 0.08, which represents a higher low-redshift normalization and shallower power-law slope than recent literature values. We find that the relative importance of in situ star formation versus galaxy merging is inversely correlated, with star formation dominating the addition of stellar material below M and merger accretion events dominating beyond M. We find mergers have a measurable impact on the whole extent of the galaxy stellar mass function (GSMF), manifest as a deepening of the ‘dip’ in the GSMF over the next ∼Gyr and an increase in M by as much as 0.01–0.05 dex.
Keyword Galaxies evolution
Galaxies fundamental parameters
Galaxies interactions
Galaxies kinematics and dynamics
Galaxies luminosity function mass function
Ggalaxies stellar content
Digital Sky Survey
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Mathematics and Physics
Official 2015 Collection
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Citation counts: TR Web of Science Citation Count  Cited 18 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 19 times in Scopus Article | Citations
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