David H. Hughes

The balloon-borne large-aperture submillimeter telescope forpolarimetry: BLAST-Pol

The Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLAST-Pol) is a suborbital mapping experiment designed to study the role played by magnetic fields in the star formation process. BLAST-Pol is the reconstructed BLAST telescope, with the addition of linear polarization capability. Using a 1.8m Cassegrain telescope, BLAST-Pol images the sky onto a focal plane that consists of 280 bolometric detectors in three arrays, observing simultaneously at 250, 350, and 500μm. The diffraction-limited optical system provides a resolution of 30at 250μm. The polarimeter consists of photolithographic polarizing grids mounted in front of each bolometer/ detector array. A rotating 4K achromatic half-wave plate provides additional polarization modulation. With its unprecedented mapping speed and resolution, BLAST-Pol will produce three-color polarization maps for a large number of molecular clouds. The instrument provides a much needed bridge in spatial coverage between larger-scale, coarse resolution surveys and narrow field of view, and high resolution observations of substructure within molecular cloud cores. The first science flight will be from McMurdo Station, Antarctica in December 2010.

A Bayesian Photometric Redshift Technique for Mm-Selected Galaxies

We present a Bayesian technique, which uses a luminosity function prior, to calculate photometric redshifts for optically-obscured starburst galaxies. An example is compared with previous Monte Carlo simulations.

Balloon-borne and ground-based sub-millimetre cosmological surveys: Breaking the “redshift deadlock”

In recent years sensitive submillimetre (sub-mm) and millimetre (mm) wavelength surveys have provided the opportunity to study star-formation in the high-z Universe. Identifying the formation epoch of clusters, massive galaxies and the first generations of stars, and understanding their subsequent evolution is now a realistic possibility. In this paper we describe how the combination of ambitious balloon-borne (BLAST) and ground-based sub-mm (or mm) surveys can provide the essential redshift information, with sufficient precision, to break the current deadlock that is preventing an accurate description of the star formation history of the sub-mm starburst galaxy population.

The Large Millimeter telescope Alfonso Serrano: scientific operation of the LMT 50-m, first results and next steps (Conference Presentation)

The Large Millimeter Telescope (LMT) Alfonso Serrano is a bi-national (Mexico and USA) telescope facility operated by the Instituto Nacional de Astrofisica, Optica y Electronica (INAOE) and the University of Massachusetts. The LMT is designed as a 50-m diameter single-dish millimeter-wavelength telescope that is optimized to conduct scientific observations at frequencies between ~70 and 350 GHz. The LMT is constructed on the summit of Sierra Negra at an altitude of 4600m in the Mexican state of Puebla. The site offers excellent mm-wavelength atmospheric transparency all-year round, and the opportunity to conduct submillimeter wavelength observations during the winter months. Following first-light observations in mid-2011, the LMT began regular scientific operations in 2014 with a shared-risk Early Science observing program using the inner 32-m diameter of the primary reflector with an active surface control system. The LMT has already performed successful VLBI observations at 3mm with the High Sensitivity Array and also at 1.3mm as part of the Event Horizon Telescope. Since early 2018 the LMT has begun full scientific operations as a 50-m diameter telescope, making the LMT 50-m the world´s largest single-dish telescope operating at 1.1mm. I will describe the current status of the telescope project, including the early scientific results from the LMT 50-m, as well the instrumentation development program, the plan to improve the overall performance of the telescope, and the on-going transition towards the formation of the LMT Observatory to support the scientific community in their use of the LMT to study the formation and evolution of structure at all cosmic epochs.

The local FIR Galaxy Colour-Luminosity distribution: A reference for BLAST, and Herschel/SPIRE sub-mm surveys

We measure the local galaxy far-infrared (FIR) 60-to-100 um colour-luminosity distribution using an all-sky IRAS survey. This distribution is an important reference for the next generation of FIR--submillimetre surveys that have and will conduct deep extra-galactic surveys at 250--500 um. With the peak in dust-obscured star-forming activity leading to present-day giant ellipticals now believed to occur in sub-mm galaxies near z~2.5, these new FIR--submillimetre surveys will directly sample the SEDs of these distant objects at rest-frame FIR wavelengths similar to those at which local galaxies were observed by IRAS. We have taken care to correct for temperature bias and evolution effects in our IRAS 60 um-selected sample. We verify that our colour-luminosity distribution is consistent with measurements of the local FIR luminosity function, before applying it to the higher-redshift Universe. We compare our colour-luminosity correlation with recent dust-temperature measurements of sub-mm galaxies and find evidence for pure luminosity evolution of the form (1+z)^3. This distribution will be useful for the development of evolutionary models for BLAST and SPIRE surveys as it provides a statistical distribution of rest-frame dust temperatures for galaxies as a function of luminosity.