H-ATLAS/GAMA and HeViCS – dusty early-type galaxies in different environments

Agius, N.K. and di Serego Alighieri, S. and Viaene, S. and Baes, M. and Sansom, A.E. and Bourne, N. and Bland-Hawthorn, J. and Brough, S. and Davis, T.A. and De Looze, I. and Driver, S.P. and Dunne, L. and Dye, S. and Eales, S.A. and Hughes, T.M. and Ivison, R.J. and Kelvin, L.S. and Maddox, S. and Mahajan, S. and Pappalardo, C. and Robotham, A.S.G. and Rowlands, K. and Temi, P. and Valiante, E. (2015) H-ATLAS/GAMA and HeViCS – dusty early-type galaxies in different environments. Monthly Notices of the Royal Astronomical Society, 451 (4). pp. 3815-3835. ISSN 1365-2966

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Abstract

The Herschel Space Observatory has had a tremendous impact on the study of extragalactic dust. Specifically, early-type galaxies (ETG) have been the focus of several studies. In this paper, we combine results from two Herschel studies – a Virgo cluster study Herschel Virgo Cluster Survey (HeViCS) and a broader, low-redshift Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS)/Galaxy and Mass Assembly (GAMA) study – and contrast the dust and associated properties for similar mass galaxies. This comparison is motivated by differences in results exhibited between multiple Herschel studies of ETG. A comparison between consistent modified blackbody derived dust mass is carried out, revealing strong differences between the two samples in both dust mass and dust-to-stellar mass ratio. In particular, the HeViCS sample lacks massive ETG with as high a specific dust content as found in H-ATLAS. This is most likely connected with the difference in environment for the two samples. We calculate nearest neighbour environment densities in a consistent way, showing that H-ATLAS ETG occupy sparser regions of the local Universe, whereas HeViCS ETG occupy dense regions. This is also true for ETG that are not Herschel-detected but are in the Virgo and GAMA parent samples. Spectral energy distributions are fit to the panchromatic data. From these, we find that in H-ATLAS the specific star formation rate anticorrelates with stellar mass and reaches values as high as in our Galaxy. On the other hand HeViCS ETG appear to have little star formation. Based on the trends found here, H-ATLAS ETG are thought to have more extended star formation histories and a younger stellar population than HeViCS ETG.

Item Type: Article
Additional Information: This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Keywords: methods: statistical, galaxies: elliptical and lenticular, cD, galaxies: evolution, submillimetre: galaxies
Schools/Departments: University of Nottingham, UK > Faculty of Science > School of Physics and Astronomy
Identification Number: 10.1093/mnras/stv1191
Depositing User: Eprints, Support
Date Deposited: 27 Apr 2017 09:58
Last Modified: 13 Oct 2017 00:55
URI: http://eprints.nottingham.ac.uk/id/eprint/42355

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