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Submillimetre source counts: first results from SCUBA  [PDF]
Robert G. Mann,The UK Submillimetre Survey Consortium
Physics , 1999,
Abstract: The SCUBA submillimetre camera has opened up new possibilities for tracing the evolution of active star formation in dusty galaxies to high redshift, with profound implications for our understanding of the star formation history of the Universe and the contribution from galaxies to the anisotropy of the microwave sky. We review results from several submillimetre surveys started during SCUBA's first year of operation, and discuss their future development, together with other projects that will greatly improve our understanding of the extragalactic point source contribution to the submillimetre sky in the era of MAP and Planck.
A SCUBA-2 850 micron survey of protoplanetary discs in the sigma Orionis cluster  [PDF]
Jonathan P. Williams,Lucas A. Cieza,Sean M. Andrews,Iain M. Coulson,Amy J. Barger,Caitlin M. Casey,Chian-Chou Chen,Lennox L. Cowie,Michael Koss,Nicholas Lee,David B. Sanders
Physics , 2013, DOI: 10.1093/mnras/stt1407
Abstract: We present the results from a large 850 micron survey of the sigma Orionis cluster using the SCUBA-2 camera on the James Clerk Maxwell Telescope. The 0.5-degree diameter circular region we surveyed contains 297 young stellar objects with an age estimated at about 3Myr. We detect 9 of these objects, 8 of which have infrared excesses from an inner disc. We also serendipitously detect 3 non-stellar sources at > 5sigma that are likely background submillimetre galaxies. The 9 detected stars have inferred disc masses ranging from 5 to about 17MJup, assuming similar dust properties as Taurus discs and an ISM gas-to-dust ratio of 100. There is a net positive signal toward the positions of the individually undetected infrared excess sources indicating a mean disc mass of 0.5 MJup . Stacking the emission toward those stars without infrared excesses constrains their mean disc mass to less than 0.3MJup, or an equivalent Earth mass in dust. The submillimetre luminosity distribution is significantly different from that in the younger Taurus region, indicating disc mass evolution as star forming regions age and the infrared excess fraction decreases. Submillimeter Array observations reveal CO emission toward 4 sources demonstrating that some, but probably not much, molecular gas remains in these relatively evolved discs. These observations provide new constraints on the dust and gas mass of protoplanetary discs during the giant planet building phase and provide a reference level for future studies of disc evolution.
Quasars as probes of the submillimetre cosmos at z>5: I. Preliminary SCUBA photometry  [PDF]
Robert S. Priddey,Kate G. Isaak,Richard G. McMahon,E. I. Robson,C. P. Pearson
Physics , 2003, DOI: 10.1046/j.1365-8711.2003.07076.x
Abstract: We present submillimetre continuum observations of a sample of some of the highest redshift quasars currently known, made with the SCUBA bolometer array on the JCMT. The median redshift of the sample is 5.3. Two z>5 objects are strong (6 sigma) detections, with S(850um)>10mJy. A firm (5 sigma) detection is obtained for the z=5.7 quasar SDSS J1044-0125; and SDSS J1306+0356, at z=6.0, is detected with a signal-to-noise approx. 4. For the remainder of the sample we have obtained sensitive (sigma=1.5mJy) upper limits. Submm spectral indices measured for two of the sources are consistent with thermal reradiation from dust, rather than from synchrotron emission. Sensitive 450um upper limits imply that the dust is cool,suggesting large dust masses only 1Gyr after the Big Bang.
The SCUBA Local Universe Galaxy Survey I: First Measurements of the Submillimetre Luminosity and Dust Mass Functions  [PDF]
L. Dunne,S. A. Eales,M. G. Edmunds,R. J. Ivison,P. Alexander,D. L. Clements
Physics , 2000, DOI: 10.1046/j.1365-8711.2000.03386.x
Abstract: We have used SCUBA to observe a complete sample of 104 galaxies selected at 60 microns from the IRAS BGS and we present here the 850 micron measurements. Fitting the 60,100 and 850 micron fluxes with a single temperature dust model gives the sample mean temperature T=36 K and beta = 1.3. We do not rule out the possibility of dust which is colder than this, if a 20 K component was present then our dust masses would increase by factor 1.5-3. We present the first measurements of the luminosity and dust mass functions, which were well fitted by Schechter functions (unlike those 60 microns). We have correlated many global galaxy properties with the submillimetre and find that there is a tendancy for less optically luminous galaxies to contain warmer dust and have greater star formation efficiencies (cf. Young 1999). The average gas-to-dust ratio for the sample is 581 +/- 43 (using both atomic and molecular hydrogen), significantly higher than the Galactic value of 160. We believe this discrepancy is due to a cold dust component at T < 20 K. There is a suprisingly tight correlation between dust mass and the mass of molecular hydrogen as estimated from CO measurements, with an intrinsic scatter of ~50%.
A deep submillimetre survey of the Galactic Centre  [PDF]
D. Pierce-Price,J. S. Richer,J. S. Greaves,W. S. Holland,T. Jenness,A. N. Lasenby,G. J. White,H. E. Matthews,D. Ward-Thompson,W. R. F. Dent,R. Zylka,P. Mezger,T. Hasegawa,T. Oka,A. Omont,G. Gilmore
Physics , 2000, DOI: 10.1086/317884
Abstract: We present first results from a submillimetre continuum survey of the Galactic Centre `Central Molecular Zone' (CMZ), made with SCUBA on the James Clerk Maxwell Telescope. SCUBA's scan-map mode has allowed us to make extremely wide-field maps of thermal dust emission with unprecedented speed and sensitivity. We also discuss some issues related to the elimination of artefacts in scan-map data. Our simultaneous 850/450 micron maps have a total size of approximately 2.8 x 0.5 degrees (400 x 75 pc) elongated along the galactic plane. They cover the Sgr A region-including Sgr A*, the circumnuclear disc, and the +20 km/s and +50 km/s clouds; the area around the Pistol; Sgr B2-the brightest feature on the map; and at their Galactic Western and Eastern edges the Sgr C and Sgr D regions. There are many striking features such as filaments and shell-like structures, as well as point sources such as Sgr A* itself. The total mass in the Central Molecular Zone is greater than that revealed in previous optically-thin molecular line maps by a factor of ~3, and new details are revealed on scales down to 0.33 pc across this 400 pc wide region.
SCUBA - A submillimetre camera operating on the James Clerk Maxwell Telescope  [PDF]
Wayne S. Holland,Colin R. Cunningham,Walter K. Gear,Tim Jenness,Ken Laidlaw,John F. Lightfoot,E. I. Robson
Physics , 1998, DOI: 10.1117/12.317366
Abstract: The Submillimetre Common-User Bolometer Array (SCUBA) is one of a new generation of cameras designed to operate in the submillimetre waveband. The instrument has a wide wavelength range covering all the atmospheric transmission windows between 300 and 2000 microns. In the heart of the instrument are two arrays of bolometers optimised for the short (350/450 microns) and long (750/850 microns) wavelength ends of the submillimetre spectrum. The two arrays can be used simultaneously, giving a unique dual-wavelength capability, and have a 2.3 arc-minute field of view on the sky. Background-limited performance is achieved by cooling the arrays to below 100 mK. SCUBA has now been in active service for over a year, and has already made substantial breakthroughs in many areas of astronomy. In this paper we present an overview of the performance of SCUBA during the commissioning phase on the James Clerk Maxwell Telescope (JCMT).
SCUBA-2: on-sky calibration using submillimetre standard sources  [PDF]
Jessica T. Dempsey,Per Friberg,Tim Jenness,Remo P. J. Tilanus,Holly S. Thomas,Wayne S. Holland,Dan Bintley,David S. Berry,Edward L. Chapin,Antonio Chrysostomou,Gary R. Davis,Andrew G. Gibb,Harriet Parsons,E. Ian Robson
Physics , 2013, DOI: 10.1093/mnras/stt090
Abstract: SCUBA-2 is a 10000-bolometer submillimetre camera on the James Clerk Maxwell Telescope (JCMT). The instrument commissioning was completed in September 2011, and full science operations began in October 2011. To harness the full potential of this powerful new astronomical tool, the instrument calibration must be accurate and well understood. To this end, the algorithms for calculating the line-of-sight opacity have been improved, and the derived atmospheric extinction relationships at both wavebands of the SCUBA-2 instrument are presented. The results from over 500 primary and secondary calibrator observations have allowed accurate determination of the flux conversion factors (FCF) for the 850 and 450 micron arrays. Descriptions of the instrument beam-shape and photometry methods are presented. The calibration factors are well determined, with relative calibration accuracy better than 5 per cent at 850 microns and 10 per cent at 450 microns, reflecting the success of the derived opacity relations as well as the stability of the performance of the instrument over several months. The sample-size of the calibration observations and accurate FCFs have allowed the determination of the 850 and 450 micron fluxes of several well-known submillimetre sources, and these results are compared with previous measurements from SCUBA.
SCUBA: A common-user submillimetre camera operating on the James Clerk Maxwell Telescope  [PDF]
Wayne S. Holland,E. I. Robson,Walter K. Gear,Colin R. Cunningham,John F. Lightfoot,Tim Jenness,Rob J. Ivison,Jason A. Stevens,Peter A. R. Ade,M. J. Griffin,William D. Duncan,J. A. Murphy,David A. Naylor
Physics , 1998, DOI: 10.1046/j.1365-8711.1999.02111.x
Abstract: SCUBA, the Submillimetre Common-User Bolometer Array, built by the Royal Observatory Edinburgh for the James Clerk Maxwell Telescope, is the most versatile and powerful of a new generation of submillimetre cameras. It combines a sensitive dual-waveband imaging array with a three-band photometer, and is sky-background limited by the emission from the Mauna Kea atmosphere at all observing wavelengths from 350 microns to 2 mm. The increased sensitivity and array size mean that SCUBA maps close to 10,000 times faster than its single-pixel predecessor (UKT14). SCUBA is a facility instrument, open to the world community of users, and is provided with a high level of user support. We give an overview of the instrument, describe the observing modes and user interface, performance figures on the telescope, and present a sample of the exciting new results that have revolutionised submillimetre astronomy.
The SCUBA Bright Quasar Survey II: unveiling the quasar epoch at submillimetre wavelengths  [PDF]
Robert S. Priddey,Kate G. Isaak,Richard G. McMahon,Alain Omont
Physics , 2002, DOI: 10.1046/j.1365-8711.2003.06279.x
Abstract: We present results of the first systematic search for submillimetre continuum emission from z=2, radio-quiet, optically-luminous quasars, using the SCUBA/JCMT. We have observed a homogeneous sample of 57 quasars in the redshift range 1.54) redshift. The target sensitivity of the survey (3sigma=10mJy at 850um) was chosen to enable efficient identification of bright submm sources, suitable for detailed follow-up. 9 targets are detected, with fluxes in the range 7-17mJy. Although there is a suggestion of variation of submm detectability between z=2 and z=4, this is consistent with the K-correction of a characteristic far-infrared spectrum. Additionally, the weighted mean fluxes of non-detections at z=2 and z>4 are comparable.
Observational limits to source confusion in the millimetre/submillimetre waveband  [PDF]
A W Blain,R J Ivison,Ian Smail
Physics , 1997, DOI: 10.1046/j.1365-8711.1998.01605.x
Abstract: The first observations to detect a population of distant galaxies directly in the submillimetre waveband have recently been made using the new Submillimetre Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope (JCMT). The results indicate that a large number of distant galaxies are radiating strongly in this waveband. Here we discuss their significance for source confusion in future millimetre/submillimetre-wave observations of both distant galaxies and cosmic microwave background radiation (CMBR) anisotropies. Earlier estimates of such confusion involved significant extrapolation of the results of observations of galaxies at small redshifts; our new estimates do not, as they are derived from direct observations of distant galaxies in the submillimetre waveband. The results have important consequences for the design and operation of existing and proposed millimetre/submillimetre-wave telescopes: the Planck Surveyor mission will be confusion-limited at frequencies greater than 350 GHz, even in the absence of galactic dust emission; 1-sigma confusion noise of 0.44 mJy/beam is expected for the JCMT/SCUBA at a wavelength of 850 microns; and the sub-arcsecond resolution of large millimetre/submillimetre-wave interferometer arrays will be required in order to execute very deep galaxy surveys. For the latest information see astro-ph/9806063.
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