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Limitations and advances in the field of far-infrared/submillimetre extragalactic astronomy or the trouble with terrahertz

Raymond, Gwenifer 2011. Limitations and advances in the field of far-infrared/submillimetre extragalactic astronomy or the trouble with terrahertz. PhD Thesis, Cardiff University.
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Abstract

I present new optical and infrared photometry for a statistically complete sample of seven sources selected at 1.1 mm. Comparing their photometric redshifts with redshifts from previous 850 μm selected surveys indicates that 1.1 mm selected surveys may be better at finding high redshift sources. I also perform a banded Ve/Va analysis on the sample, and find no evidence for a redshift cutoff in the space density of sources. However, the sample size is very small. I perform the same analysis on a statistically complete sample of 38 galaxies selected at 850 μm. I find a evidence for a drop off in space density of sources beyond between z∼1-2 as well as for the existence of two differently evolving sub-populations separated in luminosity. I present a sample of SPIRE sources, selected at 250 μm, with a set of previously collected ancillary photometry and either spectroscopic or photometric redshifts. I find that only ∼1/4 of the sources at redshifts z∼1 show evidence of undergoing a major merger. I find evidence to support a downsizing model of galaxy evolution, where the most massive galaxies form first. I find some correlation with star formation rate and the gas mass of a galaxy, therefore the drop in cosmic star formation rate since z = 1 may be caused by a coinciding drop in the average gas mass of galaxies over this era. Finally, I discuss the possibility of using imaging spectrometers to break through the confusion limit. Taking the SAFARI instrument as a test case I find that I can uniquely identify galaxies by their redshift, determined via an automated method. I find that this method works for galaxies with fluxes as much as ten times below the traditional continuum confusion limit. I also find that I can uniquely identify spectrally confused sources

Item Type: Thesis (PhD)
Status: Unpublished
Schools: Physics and Astronomy
Subjects: Q Science > QB Astronomy
Uncontrolled Keywords: Galaxy; Extragalactic; Evolution; Infrared; Submillimetre
Funders: STFC
Date of First Compliant Deposit: 30 March 2016
Last Modified: 19 Mar 2016 22:24
URI: http://orca-mwe.cf.ac.uk/id/eprint/15154

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