Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.567163
Title: Limitations and advances in the field of far-infrared/submillimetre extragalactic astronomy or the trouble with terrahertz
Author: Raymond, Gwenifer
Awarding Body: Cardiff University
Current Institution: Cardiff University
Date of Award: 2011
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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
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.567163  DOI: Not available
Keywords: QB Astronomy
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