Volume 590, June 2016
|Number of page(s)||16|
|Published online||28 April 2016|
Galaxy And Mass Assembly (GAMA): Improved emission lines measurements in four representative samples at 0.07 <z < 0.3
GEPI, Observatoire de Paris, CNRS, University Paris Diderot,
5 place Jules Janssen,
2 Australian Astronomical Observatory, PO Box 915, North Ryde, NSW 1670, Australia
3 ICRAR,The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
4 Sydney Institute for Astronomy, School of Physics A28, University of Sydney, NSW 2006, Australia
5 University of the Western Cape, Robert Sobukwe Road, Bellville, Cape Town 7535, South Africa
6 Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, A.P. 70-264, 04510 Mexico, D.F., Mexico
7 Department of Physics and Astronomy, Macquarie University, NSW 2109, Australia
8 Department of Physics and Mathematics, University of Hull, Cottingham Road, Kingston-upon-Hull, HU6 7RX, UK
9 School of Physics, Monash University, Clayton, VIC 3800, Australia
10 School of Physics, the University of Melbourne, VIC 3010, Australia
11 Astrophysics Research Institute, Liverpool John Moores University, IC2, Liverpool Science Park, 146 Brownlow Hill, Liverpool, L3 5RF, UK
12 Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
Received: 25 November 2015
Accepted: 14 March 2016
This paper presents a new catalog of emission lines based on the GAMA II data for galaxies between 0.07 <z< 0.34. The catalog includes four subsamples containing 3000 galaxies drawn from the GAMA II survey and spanning four redshift windows. The four samples are representative of intermediate-mass galaxies down to log M∗> 9.4 at z ~ 0.1 and log M∗> 10.6 at z ~ 0.30. We have developed a dedicated code called MARVIN that automates the main steps of the data analysis, but imposes visual individual quality control of each measurement. We use this catalog to investigate how the sample selection influences the shape of the stellar mass – metallicity relation. We find that commonly used selection criteria on line detections and by AGN rejection could affect the shape and dispersion of the high-mass end of the M − Z relation. For log M∗> 10.6, common selection criteria reject about 65% of the emission-line galaxies. We also find that the relation does not evolve significantly from z = 0.07 to z = 0.34 in the range of stellar mass for which the samples are representative (log M∗> 10.6). For lower stellar masses (log M∗< 10.2) we are able to show that the observed 0.15 dex metallicity decrease in the same redshift range is a consequence of a color bias arising from selecting targets in the r-band. We highlight that this color selection bias affects all samples selected in r-band (e.g., GAMA and SDSS), even those drawn from volume-limited samples. Previously reported evolution of the M − Z relation at various redshifts may need to be revised to evaluate the effect of this selection bias.
Key words: galaxies: evolution / galaxies: ISM / galaxies: high-redshift
© ESO, 2016
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.