Galaxy And Mass Assembly (GAMA) : the bright void galaxy population in the optical and mid-IR.

Authors

S. J. Penny, University of Portsmouth
M. J. I. Brown, Monash University
K. A. Pimbblet, University of Hull
M. E. Cluver, The University of Western Cape
D. J. Croton, Swinburne University of Technology
M. S. Owers, Macquarie University
R. Lange, University of Western Australia
M. Alpaslan, NASA Ames Research Center
I. K. Baldry, Liverpool John Moores University
J. Bland-Hawthorn, University of Sydney
S. Brough, Australian Astronomical Observatory
S. P. Driver, University of Western Australia
Benne W. Holwerda, University of Louisville
A. M. Hopkins, Australian Astronomical Observatory
T. H. Jarrett, University of Cape Town
D. Heath Jones, Macquarie University
L. S. Kelvin, Universitat Innsbruck
M. A. Lara-Lopez, Universidad Nacional Autonoma de Mexico
J. Liske, Universität Hamburg
Angel R. Lopez-Sanchez, Australian Astronomical Observatory
J. Loveday, University of Sussex
M. Meyer, University of Western Australia
P. Norberg, Durham University
A. S. G. Robotham, University of Western Australia
M. Rodrigues, University Paris Diderot

Document Type

Article

Publication Date

11-2015

Department

Physics and Astronomy

Abstract

We examine the properties of galaxies in the Galaxies and Mass Assembly (GAMA) survey located in voids with radii >10 h−1 Mpc. Utilizing the GAMA equatorial survey, 592 void galaxies are identified out to z ≈ 0.1 brighter than Mr = −18.4, our magnitude completeness limit. Using the WHα versus [N ii]/Hα (WHAN) line strength diagnostic diagram, we classify their spectra as star forming, AGN, or dominated by old stellar populations. For objects more massive than 5 × 109 M⊙, we identify a sample of 26 void galaxies with old stellar populations classed as passive and retired galaxies in the WHAN diagnostic diagram, else they lack any emission lines in their spectra. When matched to Wide-field Infrared Survey Explorer mid-IR photometry, these passive and retired galaxies exhibit a range of mid-IR colour, with a number of void galaxies exhibiting [4.6] − [12] colours inconsistent with completely quenched stellar populations, with a similar spread in colour seen for a randomly drawn non-void comparison sample. We hypothesize that a number of these galaxies host obscured star formation, else they are star forming outside of their central regions targeted for single-fibre spectroscopy. When matched to a randomly drawn sample of non-void galaxies, the void and non-void galaxies exhibit similar properties in terms of optical and mid-IR colour, morphology, and star formation activity, suggesting comparable mass assembly and quenching histories. A trend in mid-IR [4.6] − [12] colour is seen, such that both void and non-void galaxies with quenched/passive colours <1.5 typically have masses higher than 1010 M⊙, where internally driven processes play an increasingly important role in galaxy evolution.

Comments

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society Copyright: 2015. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

https://doi.org/10.1093/mnras/stv1926

Original Publication Information

Penny, S. J., et al. "Galaxy And Mass Assembly (GAMA): The Bright Void Galaxy Population in the Optical and Mid-IR." 2015. Monthly Notices of the Royal Astronomical Society 453(4): 3519-3539.

ThinkIR Citation

Penny, S. J.; Brown, M. J. I.; Pimbblet, K. A.; Cluver, M. E.; Croton, D. J.; Owers, M. S.; Lange, R.; Alpaslan, M.; Baldry, I. K.; Bland-Hawthorn, J.; Brough, S.; Driver, S. P.; Holwerda, Benne W.; Hopkins, A. M.; Jarrett, T. H.; Jones, D. Heath; Kelvin, L. S.; Lara-Lopez, M. A.; Liske, J.; Lopez-Sanchez, Angel R.; Loveday, J.; Meyer, M.; Norberg, P.; Robotham, A. S. G.; and Rodrigues, M., "Galaxy And Mass Assembly (GAMA) : the bright void galaxy population in the optical and mid-IR." (2015). Faculty Scholarship. 187.
https://ir.library.louisville.edu/faculty/187

DOI

10.1093/mnras/stv1926