A new method for classifying galaxy SEDs from multiwavelength photometry

Wild, Vivienne and Almaini, Omar and Cirasuolo, Michele and Dunlop, Jim and McLure, Ross and Bowler, Rebecca and Ferreira, Joao and Bradshaw, Emma and Chuter, Robert and Hartley, Will (2014) A new method for classifying galaxy SEDs from multiwavelength photometry. Monthly Notices of the Royal Astronomical Society, 440 (2). pp. 1880-1898. ISSN 1365-2966

[img]
Preview
PDF - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (11MB) | Preview

Abstract

We present a new method to classify the broad-band optical–near-infrared spectral energy distributions (SEDs) of galaxies using three shape parameters (super-colours) based on a principal component analysis of model SEDs. As well as providing a compact representation of the wide variety of SED shapes, the method allows for easy visualization of information loss and biases caused by the incomplete sampling of the rest-frame SED as a function of redshift. We apply the method to galaxies in the United Kingdom Infrared Telescope Infrared Deep Sky Survey Ultra Deep Survey with 0.9 < z < 1.2, and confirm our classifications by stacking rest-frame optical spectra for a fraction of objects in each class. As well as cleanly separating a tight red sequence from star-forming galaxies, three unusual populations are identifiable by their unique colours: very dusty star-forming galaxies with high metallicity and old mean stellar age; post-starburst galaxies which have formed _10 per cent of their mass in a recent unsustained starburst event; and metal-poor quiescent dwarf galaxies.We find that quiescent galaxies account for 45 per cent of galaxies with logM∗/M_ > 11, declining steadily to 13 per cent at logM∗/M_ = 10. The properties and mass function of the poststarburst galaxies are consistent with a scenario in which gas-rich mergers contribute to the growth of the low- and intermediate-mass range of the red sequence.

Item Type: Article
Schools/Departments: University of Nottingham, UK > Faculty of Science > School of Physics and Astronomy
Identification Number: 10.1093/mnras/stu212
Depositing User: Eprints, Support
Date Deposited: 06 Oct 2017 13:48
Last Modified: 14 Oct 2017 08:23
URI: http://eprints.nottingham.ac.uk/id/eprint/47056

Actions (Archive Staff Only)

Edit View Edit View