David G Bonfield

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We present a technique to identify optical counterparts of 250-μm-selected sources from the Herschel–ATLAS survey. Of the 6621 250 μm > 32-mJy sources in our science demonstration Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.
Fibre Multi-Object Spectrograph (FMOS) is the first near-infrared instrument with a wide field of view capable of acquiring spectra simultaneously from up to 400 objects. It has been developed as a common-use instrument for the F/2 prime-focus of the Subaru Telescope. The field coverage of 30 diameter is achieved using a new 3-element corrector optimized in(More)
We present a comparison between Gaussian processes (GPs) and artificial neural networks (ANNs) as methods for determining photometric redshifts for galaxies, given training set data. In particular, we compare their degradation in performance as the training set size is degraded in ways which might be caused by the observational limitations of spectroscopy.(More)
FMOS: the Fiber Multiple-Object Spectrograph is the next common-use instrument of the Subaru Telescope, having a capability of 400 targets multiplicity in the near-infrared 0.9−1.8µm wavelength range with a field coverage of 30 diameter. FMOS consists of three units: 1) the prime focus unit including the corrector lenses, the Echidna fiber positioner, and(More)
The UK FMOS spectrograph forms part of Subaru's FMOS multi-object infrared spectroscopy facility. The spectrograph was shipped to Hilo in component form in August of 2007. We describe the integration sequence for the spectrograph, the results of cooldown tests using a new chiller unit fitted to the spectrograph at the telescope, and alignment tests of the(More)
Using mid-infrared and radio selection criteria, we pre-select a sample of candidate high-redshift type-2 quasars in the Subaru XMM-Newton Deep Field (SXDF). To filter out starburst contaminants, we use a bayesian method to fit the spectral energy distributions (SEDs) between 24-µm and B-band, obtain photometric redshifts, and identify the best candidates(More)
We measure star-formation rates (SFRs) and specific SFRs (SSFRs) of K s-selected galaxies from the VIDEO survey by stacking 1.4-GHz Very Large Array data. We split the sample, which spans 0 < z < 3 and stellar masses 10 8.0 < M * /M < 10 11.5 , into elliptical, irregular or starburst galaxies based on their spectral-energy distributions. We find that SSFR(More)
We present new results on the cosmic star formation history in the SXDS-UDS field out to z = 1.6. We compile narrow-band data from the Subaru Telescope and the Visible and In-frared Survey Telescope for Astronomy (VISTA) in conjunction with broad-band data from the SXDS and UDS, to make a selection of 5725 emission-line galaxies in 12 redshift slices,(More)
In this paper we investigate the performance of the likelihood ratio method as a tool for identifying optical and infrared counterparts to proposed radio continuum surveys with SKA precursor and pathfinder telescopes. We present a comparison of the in-frared counterparts identified by the likelihood ratio in the VISTA Deep Extragalactic Observations (VIDEO)(More)