18 results
The Rapid ASKAP Continuum Survey IV: continuum imaging at 1367.5 MHz and the first data release of RACS-mid
- S. W. Duchesne, A. J. M. Thomson, J. Pritchard, E. Lenc, V. A. Moss, D. McConnell, M. H. Wieringa, M. T. Whiting, Z. Wang, Y. Wang, K. Rose, W. Raja, Tara Murphy, J. K. Leung, M. T. Huynh, A. W. Hotan, T. Hodgson, G. H. Heald
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- Journal:
- Publications of the Astronomical Society of Australia / Volume 40 / 2023
- Published online by Cambridge University Press:
- 02 August 2023, e034
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The Australian SKA Pathfinder (ASKAP) is being used to undertake a campaign to rapidly survey the sky in three frequency bands across its operational spectral range. The first pass of the Rapid ASKAP Continuum Survey (RACS) at 887.5 MHz in the low band has already been completed, with images, visibility datasets, and catalogues made available to the wider astronomical community through the CSIRO ASKAP Science Data Archive (CASDA). This work presents details of the second observing pass in the mid band at 1367.5 MHz, RACS-mid, and associated data release comprising images and visibility datasets covering the whole sky south of $\delta_{\text{J2000}}=+49^\circ$. This data release incorporates selective peeling to reduce artefacts around bright sources, as well as accurately modelled primary beam responses. The Stokes I images reach a median noise of 198 $\mu$Jy PSF$^{-1}$ with a declination-dependent angular resolution of 8.1–47.5 arcsec that fills a niche in the existing ecosystem of large-area astronomical surveys. We also supply Stokes V images after application of a widefield leakage correction, with a median noise of 165 $\mu$Jy PSF$^{-1}$. We find the residual leakage of Stokes I into V to be $\lesssim 0.9$–$2.4$% over the survey. This initial RACS-mid data release will be complemented by a future release comprising catalogues of the survey region. As with other RACS data releases, data products from this release will be made available through CASDA.
Effects of a 15h Journey Followed by Either 12h Starvation or Ad Libitum Hay on the Behaviour and Blood Chemistry of Sheep
- M S Cockram, J E Kent, N K Waran, I M McGilp, R E Jackson, J R Amory, E L Southall, T O'Riordan, T I McConnell, B S Wilkins
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- Animal Welfare / Volume 8 / Issue 2 / May 1999
- Published online by Cambridge University Press:
- 11 January 2023, pp. 135-148
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In a 2x2 factorial design, (n=6) sheep were either transported by road for 15h or kept in their home pens, and then either starved for 12h with access to water or offered hay ad libitum, with access to water. All groups were offered hay and water 12h after transport. Behavioural observations and measurements of dehydration and feed restriction were made before, during, and for 24h post-transport, to evaluate the implications of these procedures for the welfare of sheep.
After the journey, the immediate priority for the sheep was to eat. Consumption of hay increased water intake and reduced the time spent lying down. The plasma Cortisol concentration was greater in sheep which had been starved during the 12h post-transport period, than in those offered hay during this time; and the plasma free fatty acid concentration was greater in sheep which had been transported than in those which had not. Although transported sheep kept without hay during the first 12h post-transport drank more water than those which had not been transported, the mean time before they drank was greater than 7h. During the transport period, there was less lying behaviour in transported sheep than in non-transported sheep but transported sheep did not lie down more posttransport than non-transported ones. This work suggests that sheep should be offered both feed and water after a 15h journey. However, when feed was not available after a 15h journey, drinking and resting did not appear to be immediate priorities.
GASKAP-HI pilot survey science I: ASKAP zoom observations of Hi emission in the Small Magellanic Cloud
- N. M. Pingel, J. Dempsey, N. M. McClure-Griffiths, J. M. Dickey, K. E. Jameson, H. Arce, G. Anglada, J. Bland-Hawthorn, S. L. Breen, F. Buckland-Willis, S. E. Clark, J. R. Dawson, H. Dénes, E. M. Di Teodoro, B.-Q. For, Tyler J. Foster, J. F. Gómez, H. Imai, G. Joncas, C.-G. Kim, M.-Y. Lee, C. Lynn, D. Leahy, Y. K. Ma, A. Marchal, D. McConnell, M.-A. Miville-Deschènes, V. A. Moss, C. E. Murray, D. Nidever, J. Peek, S. Stanimirović, L. Staveley-Smith, T. Tepper-Garcia, C. D. Tremblay, L. Uscanga, J. Th. van Loon, E. Vázquez-Semadeni, J. R. Allison, C. S. Anderson, Lewis Ball, M. Bell, D. C.-J. Bock, J. Bunton, F. R. Cooray, T. Cornwell, B. S. Koribalski, N. Gupta, D. B. Hayman, L. Harvey-Smith, K. Lee-Waddell, A. Ng, C. J. Phillips, M. Voronkov, T. Westmeier, M. T. Whiting
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- Journal:
- Publications of the Astronomical Society of Australia / Volume 39 / 2022
- Published online by Cambridge University Press:
- 07 February 2022, e005
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We present the most sensitive and detailed view of the neutral hydrogen ( ${\rm H\small I}$ ) emission associated with the Small Magellanic Cloud (SMC), through the combination of data from the Australian Square Kilometre Array Pathfinder (ASKAP) and Parkes (Murriyang), as part of the Galactic Australian Square Kilometre Array Pathfinder (GASKAP) pilot survey. These GASKAP-HI pilot observations, for the first time, reveal ${\rm H\small I}$ in the SMC on similar physical scales as other important tracers of the interstellar medium, such as molecular gas and dust. The resultant image cube possesses an rms noise level of 1.1 K ( $1.6\,\mathrm{mJy\ beam}^{-1}$ ) $\mathrm{per}\ 0.98\,\mathrm{km\ s}^{-1}$ spectral channel with an angular resolution of $30^{\prime\prime}$ ( ${\sim}10\,\mathrm{pc}$ ). We discuss the calibration scheme and the custom imaging pipeline that utilises a joint deconvolution approach, efficiently distributed across a computing cluster, to accurately recover the emission extending across the entire ${\sim}25\,\mathrm{deg}^2$ field-of-view. We provide an overview of the data products and characterise several aspects including the noise properties as a function of angular resolution and the represented spatial scales by deriving the global transfer function over the full spectral range. A preliminary spatial power spectrum analysis on individual spectral channels reveals that the power law nature of the density distribution extends down to scales of 10 pc. We highlight the scientific potential of these data by comparing the properties of an outflowing high-velocity cloud with previous ASKAP+Parkes ${\rm H\small I}$ test observations.
The Rapid ASKAP Continuum Survey Paper II: First Stokes I Source Catalogue Data Release
- Part of
- Catherine L. Hale, D. McConnell, A. J. M. Thomson, E. Lenc, G. H. Heald, A. W. Hotan, J. K. Leung, V. A. Moss, T. Murphy, J. Pritchard, E. M. Sadler, A. J. Stewart, M. T. Whiting
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- Publications of the Astronomical Society of Australia / Volume 38 / 2021
- Published online by Cambridge University Press:
- 14 December 2021, e058
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The Rapid ASKAP Continuum Survey (RACS) is the first large sky survey using the Australian Square Kilometre Array Pathfinder (ASKAP), covering the sky south of $+41^\circ$ declination. With ASKAP’s large, instantaneous field of view, ${\sim}31\,\mathrm{deg}^2$ , RACS observed the entire sky at a central frequency of 887.5 MHz using 903 individual pointings with 15 minute observations. This has resulted in the deepest radio survey of the full Southern sky to date at these frequencies. In this paper, we present the first Stokes I catalogue derived from the RACS survey. This catalogue was assembled from 799 tiles that could be convolved to a common resolution of $25^{\prime\prime}$ , covering a large contiguous region in the declination range $\delta=-80^{\circ}$ to $+30^\circ$ . The catalogue provides an important tool for both the preparation of future ASKAP surveys and for scientific research. It consists of $\sim$ 2.1 million sources and excludes the $|b|<5^{\circ}$ region around the Galactic plane. This provides a first extragalactic catalogue with ASKAP covering the majority of the sky ( $\delta<+30^{\circ}$ ). We describe the methods to obtain this catalogue from the initial RACS observations and discuss the verification of the data, to highlight its quality. Using simulations, we find this catalogue detects 95% of point sources at an integrated flux density of $\sim$ 5 mJy. Assuming a typical sky source distribution model, this suggests an overall 95% point source completeness at an integrated flux density $\sim$ 3 mJy. The catalogue will be available through the CSIRO ASKAP Science Data Archive (CASDA).
The ASKAP Variables and Slow Transients (VAST) Pilot Survey
- Part of
- Tara Murphy, David L. Kaplan, Adam J. Stewart, Andrew O’Brien, Emil Lenc, Sergio Pintaldi, Joshua Pritchard, Dougal Dobie, Archibald Fox, James K. Leung, Tao An, Martin E. Bell, Jess W. Broderick, Shami Chatterjee, Shi Dai, Daniele d’Antonio, Gerry Doyle, B. M. Gaensler, George Heald, Assaf Horesh, Megan L. Jones, David McConnell, Vanessa A. Moss, Wasim Raja, Gavin Ramsay, Stuart Ryder, Elaine M. Sadler, Gregory R. Sivakoff, Yuanming Wang, Ziteng Wang, Michael S. Wheatland, Matthew Whiting, James R. Allison, C. S. Anderson, Lewis Ball, K. Bannister, D. C.-J. Bock, R. Bolton, J. D. Bunton, R. Chekkala, A. P Chippendale, F. R. Cooray, N. Gupta, D. B. Hayman, K. Jeganathan, B. Koribalski, K. Lee-Waddell, Elizabeth K. Mahony, J. Marvil, N. M. McClure-Griffiths, P. Mirtschin, A. Ng, S. Pearce, C. Phillips, M. A. Voronkov
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- Publications of the Astronomical Society of Australia / Volume 38 / 2021
- Published online by Cambridge University Press:
- 12 October 2021, e054
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The Variables and Slow Transients Survey (VAST) on the Australian Square Kilometre Array Pathfinder (ASKAP) is designed to detect highly variable and transient radio sources on timescales from 5 s to $\sim\!5$ yr. In this paper, we present the survey description, observation strategy and initial results from the VAST Phase I Pilot Survey. This pilot survey consists of $\sim\!162$ h of observations conducted at a central frequency of 888 MHz between 2019 August and 2020 August, with a typical rms sensitivity of $0.24\ \mathrm{mJy\ beam}^{-1}$ and angular resolution of $12-20$ arcseconds. There are 113 fields, each of which was observed for 12 min integration time, with between 5 and 13 repeats, with cadences between 1 day and 8 months. The total area of the pilot survey footprint is 5 131 square degrees, covering six distinct regions of the sky. An initial search of two of these regions, totalling 1 646 square degrees, revealed 28 highly variable and/or transient sources. Seven of these are known pulsars, including the millisecond pulsar J2039–5617. Another seven are stars, four of which have no previously reported radio detection (SCR J0533–4257, LEHPM 2-783, UCAC3 89–412162 and 2MASS J22414436–6119311). Of the remaining 14 sources, two are active galactic nuclei, six are associated with galaxies and the other six have no multi-wavelength counterparts and are yet to be identified.
Australian square kilometre array pathfinder: I. system description
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- A. W. Hotan, J. D. Bunton, A. P. Chippendale, M. Whiting, J. Tuthill, V. A. Moss, D. McConnell, S. W. Amy, M. T. Huynh, J. R. Allison, C. S. Anderson, K. W. Bannister, E. Bastholm, R. Beresford, D. C.-J. Bock, R. Bolton, J. M. Chapman, K. Chow, J. D. Collier, F. R. Cooray, T. J. Cornwell, P. J. Diamond, P. G. Edwards, I. J. Feain, T. M. O. Franzen, D. George, N. Gupta, G. A. Hampson, L. Harvey-Smith, D. B. Hayman, I. Heywood, C. Jacka, C. A. Jackson, S. Jackson, K. Jeganathan, S. Johnston, M. Kesteven, D. Kleiner, B. S. Koribalski, K. Lee-Waddell, E. Lenc, E. S. Lensson, S. Mackay, E. K. Mahony, N. M. McClure-Griffiths, R. McConigley, P. Mirtschin, A. K. Ng, R. P. Norris, S. E. Pearce, C. Phillips, M. A. Pilawa, W. Raja, J. E. Reynolds, P. Roberts, D. N. Roxby, E. M. Sadler, M. Shields, A. E. T. Schinckel, P. Serra, R. D. Shaw, T. Sweetnam, E. R. Troup, A. Tzioumis, M. A. Voronkov, T. Westmeier
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- Publications of the Astronomical Society of Australia / Volume 38 / 2021
- Published online by Cambridge University Press:
- 05 March 2021, e009
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In this paper, we describe the system design and capabilities of the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope at the conclusion of its construction project and commencement of science operations. ASKAP is one of the first radio telescopes to deploy phased array feed (PAF) technology on a large scale, giving it an instantaneous field of view that covers $31\,\textrm{deg}^{2}$ at $800\,\textrm{MHz}$. As a two-dimensional array of 36$\times$12 m antennas, with baselines ranging from 22 m to 6 km, ASKAP also has excellent snapshot imaging capability and 10 arcsec resolution. This, combined with 288 MHz of instantaneous bandwidth and a unique third axis of rotation on each antenna, gives ASKAP the capability to create high dynamic range images of large sky areas very quickly. It is an excellent telescope for surveys between 700 and $1800\,\textrm{MHz}$ and is expected to facilitate great advances in our understanding of galaxy formation, cosmology, and radio transients while opening new parameter space for discovery of the unknown.
The Rapid ASKAP Continuum Survey I: Design and first results
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- D. McConnell, C. L. Hale, E. Lenc, J. K. Banfield, George Heald, A. W. Hotan, James K. Leung, Vanessa A. Moss, Tara Murphy, Andrew O’Brien, Joshua Pritchard, Wasim Raja, Elaine M. Sadler, Adam Stewart, Alec J. M. Thomson, M. Whiting, James R. Allison, S. W. Amy, C. Anderson, Lewis Ball, Keith W. Bannister, Martin Bell, Douglas C.-J. Bock, Russ Bolton, J. D. Bunton, A. P. Chippendale, J. D. Collier, F. R. Cooray, T. J. Cornwell, P. J. Diamond, P. G. Edwards, N. Gupta, Douglas B. Hayman, Ian Heywood, C. A. Jackson, Bärbel S. Koribalski, Karen Lee-Waddell, N. M. McClure-Griffiths, Alan Ng, Ray P. Norris, Chris Phillips, John E. Reynolds, Daniel N. Roxby, Antony E. T. Schinckel, Matt Shields, Chenoa Tremblay, A. Tzioumis, M. A. Voronkov, Tobias Westmeier
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- Publications of the Astronomical Society of Australia / Volume 37 / 2020
- Published online by Cambridge University Press:
- 30 November 2020, e048
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The Rapid ASKAP Continuum Survey (RACS) is the first large-area survey to be conducted with the full 36-antenna Australian Square Kilometre Array Pathfinder (ASKAP) telescope. RACS will provide a shallow model of the ASKAP sky that will aid the calibration of future deep ASKAP surveys. RACS will cover the whole sky visible from the ASKAP site in Western Australia and will cover the full ASKAP band of 700–1800 MHz. The RACS images are generally deeper than the existing NRAO VLA Sky Survey and Sydney University Molonglo Sky Survey radio surveys and have better spatial resolution. All RACS survey products will be public, including radio images (with $\sim$ 15 arcsec resolution) and catalogues of about three million source components with spectral index and polarisation information. In this paper, we present a description of the RACS survey and the first data release of 903 images covering the sky south of declination $+41^\circ$ made over a 288-MHz band centred at 887.5 MHz.
ASKAP commissioning observations of the GAMA 23 field
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- Denis A. Leahy, A. M. Hopkins, R. P. Norris, J. Marvil, J. D. Collier, E. N. Taylor, J. R. Allison, C. Anderson, M. Bell, M. Bilicki, J. Bland-Hawthorn, S. Brough, M. J. I. Brown, S. Driver, G. Gurkan, L. Harvey-Smith, I. Heywood, B. W. Holwerda, J. Liske, A. R. Lopez-Sanchez, D. McConnell, A. Moffett, M. S. Owers, K. A. Pimbblet, W. Raja, N. Seymour, M. A. Voronkov, L. Wang
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- Publications of the Astronomical Society of Australia / Volume 36 / 2019
- Published online by Cambridge University Press:
- 19 July 2019, e024
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We have observed the G23 field of the Galaxy AndMass Assembly (GAMA) survey using the Australian Square Kilometre Array Pathfinder (ASKAP) in its commissioning phase to validate the performance of the telescope and to characterise the detected galaxy populations. This observation covers ~48 deg2 with synthesised beam of 32.7 arcsec by 17.8 arcsec at 936MHz, and ~39 deg2 with synthesised beam of 15.8 arcsec by 12.0 arcsec at 1320MHz. At both frequencies, the root-mean-square (r.m.s.) noise is ~0.1 mJy/beam. We combine these radio observations with the GAMA galaxy data, which includes spectroscopy of galaxies that are i-band selected with a magnitude limit of 19.2. Wide-field Infrared Survey Explorer (WISE) infrared (IR) photometry is used to determine which galaxies host an active galactic nucleus (AGN). In properties including source counts, mass distributions, and IR versus radio luminosity relation, the ASKAP-detected radio sources behave as expected. Radio galaxies have higher stellar mass and luminosity in IR, optical, and UV than other galaxies. We apply optical and IR AGN diagnostics and find that they disagree for ~30% of the galaxies in our sample. We suggest possible causes for the disagreement. Some cases can be explained by optical extinction of the AGN, but for more than half of the cases we do not find a clear explanation. Radio sources aremore likely (~6%) to have an AGN than radio quiet galaxies (~1%), but the majority of AGN are not detected in radio at this sensitivity.
Physical properties of the WAIS Divide ice core
- Joan J. Fitzpatrick, Donald E. Voigt, John M. Fegyveresi, Nathan T. Stevens, Matthew K. Spencer, Jihong Cole-Dai, Richard B. Alley, Gabriella E. Jardine, Eric D. Cravens, Lawrence A. Wilen, T.J. Fudge, Joseph R. Mcconnell
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- Journal of Glaciology / Volume 60 / Issue 224 / 2014
- Published online by Cambridge University Press:
- 10 July 2017, pp. 1181-1198
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The WAIS (West Antarctic Ice Sheet) Divide deep ice core was recently completed to a total depth of 3405 m, ending 50 m above the bed. Investigation of the visual stratigraphy and grain characteristics indicates that the ice column at the drilling location is undisturbed by any large-scale overturning or discontinuity. The climate record developed from this core is therefore likely to be continuous and robust. Measured grain-growth rates, recrystallization characteristics, and grain-size response at climate transitions fit within current understanding. Significant impurity control on grain size is indicated from correlation analysis between impurity loading and grain size. Bubble-number densities and bubble sizes and shapes are presented through the full extent of the bubbly ice. Where bubble elongation is observed, the direction of elongation is preferentially parallel to the trace of the basal (0001) plane. Preferred crystallographic orientation of grains is present in the shallowest samples measured, and increases with depth, progressing to a vertical-girdle pattern that tightens to a vertical single-maximum fabric. This single-maximum fabric switches into multiple maxima as the grain size increases rapidly in the deepest, warmest ice. A strong dependence of the fabric on the impurity-mediated grain size is apparent in the deepest samples.
Simulated Trading for Maryland's Nitrogen Loadings in the Chesapeake Bay
- James C. Hanson, K. E. McConnell
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- Agricultural and Resource Economics Review / Volume 37 / Issue 2 / October 2008
- Published online by Cambridge University Press:
- 15 September 2016, pp. 211-226
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We investigate nutrient trading for point and non-point sources for the Bay Restoration Fund in Maryland. We demonstrate how to use the proceeds from the tax revenue to mimic a market by trading high-cost upgrades of sewage treatment plants for low-cost winter cover crops. Under an optimistic assumption about costs for non-point sources and naïve assumptions about the lag from planting cover crops to changes in nitrogen load, we calculate that 100 percent of abatement could be achieved at 56 percent of total costs, while in a pessimistic scenario, 100 percent of abatement could be could be achieved at 83 percent of total costs.
The Australian Square Kilometre Array Pathfinder: Performance of the Boolardy Engineering Test Array
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- D. McConnell, J. R. Allison, K. Bannister, M. E. Bell, H. E. Bignall, A. P. Chippendale, P. G. Edwards, L. Harvey-Smith, S. Hegarty, I. Heywood, A. W. Hotan, B. T. Indermuehle, E. Lenc, J. Marvil, A. Popping, W. Raja, J. E. Reynolds, R. J. Sault, P. Serra, M. A. Voronkov, M. Whiting, S. W. Amy, P. Axtens, L. Ball, T. J. Bateman, D. C.-J. Bock, R. Bolton, D. Brodrick, M. Brothers, A. J. Brown, J. D. Bunton, W. Cheng, T. Cornwell, D. DeBoer, I. Feain, R. Gough, N. Gupta, J. C. Guzman, G. A. Hampson, S. Hay, D. B. Hayman, S. Hoyle, B. Humphreys, C. Jacka, C. A. Jackson, S. Jackson, K. Jeganathan, J. Joseph, B. S. Koribalski, M. Leach, E. S. Lensson, A. MacLeod, S. Mackay, M. Marquarding, N. M. McClure-Griffiths, P. Mirtschin, D. Mitchell, S. Neuhold, A. Ng, R. Norris, S. Pearce, R. Y. Qiao, A. E. T. Schinckel, M. Shields, T. W. Shimwell, M. Storey, E. Troup, B. Turner, J. Tuthill, A. Tzioumis, R. M. Wark, T. Westmeier, C. Wilson, T. Wilson
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- Publications of the Astronomical Society of Australia / Volume 33 / 2016
- Published online by Cambridge University Press:
- 09 September 2016, e042
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We describe the performance of the Boolardy Engineering Test Array, the prototype for the Australian Square Kilometre Array Pathfinder telescope. Boolardy Engineering Test Array is the first aperture synthesis radio telescope to use phased array feed technology, giving it the ability to electronically form up to nine dual-polarisation beams. We report the methods developed for forming and measuring the beams, and the adaptations that have been made to the traditional calibration and imaging procedures in order to allow BETA to function as a multi-beam aperture synthesis telescope. We describe the commissioning of the instrument and present details of Boolardy Engineering Test Array’s performance: sensitivity, beam characteristics, polarimetric properties, and image quality. We summarise the astronomical science that it has produced and draw lessons from operating Boolardy Engineering Test Array that will be relevant to the commissioning and operation of the final Australian Square Kilometre Array Path telescope.
The Parkes-MIT-NRAO Southern Sky Survey at 4850 MHz
- M. Griffith, A. E. Wright, A. J. Hunt, E. Troup, R. D. Ekers, P. Buckett, D. J. Cooke, G. Freeman, J. Glowacki, D. Jennings, U. Knop, B. Lam, I. McGovern, D. McConnell, R. P. Norris, R. Otrupcek, R. Twardy, T. Williams, G. Behrens, C. Chestnut, B. F. Burke, A. Fletcher, K. S. Russell, A. Savage, J. Lim, A. E. Vaughan, S. Côté, M. Anderson, A. Hons, G. L. White, S. Amy, A. Burgess, S. Chan, L. Cram, A. Gray, W. Walsh, D. Campbell-Wilson, V. McIntyre, P. Randall, M. Suters, W. J. Zealey
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- Publications of the Astronomical Society of Australia / Volume 9 / Issue 2 / 1991
- Published online by Cambridge University Press:
- 25 April 2016, pp. 243-245
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During 1990 we surveyed the southern sky using a multi-beam receiver at frequencies of 4850 and 843 MHz. The half-power beamwidths were 4 and 25 arcmin respectively. The finished surveys cover the declination range between +10 and −90 degrees declination, essentially complete in right ascension, an area of 7.30 steradians. Preliminary analysis of the 4850 MHz data indicates that we will achieve a five sigma flux density limit of about 30 mJy. We estimate that we will find between 80 000 and 90 000 new sources above this limit. This is a revised version of the paper presented at the Regional Meeting by the first four authors; the surveys now have been completed.
The Australian Square Kilometre Array Pathfinder: System Architecture and Specifications of the Boolardy Engineering Test Array
- A. W. Hotan, J. D. Bunton, L. Harvey-Smith, B. Humphreys, B. D. Jeffs, T. Shimwell, J. Tuthill, M. Voronkov, G. Allen, S. Amy, K. Ardern, P. Axtens, L. Ball, K. Bannister, S. Barker, T. Bateman, R. Beresford, D. Bock, R. Bolton, M. Bowen, B. Boyle, R. Braun, S. Broadhurst, D. Brodrick, K. Brooks, M. Brothers, A. Brown, C. Cantrall, G. Carrad, J. Chapman, W. Cheng, A. Chippendale, Y. Chung, F. Cooray, T. Cornwell, E. Davis, L. de Souza, D. DeBoer, P. Diamond, P. Edwards, R. Ekers, I. Feain, D. Ferris, R. Forsyth, R. Gough, A. Grancea, N. Gupta, J. C. Guzman, G. Hampson, C. Haskins, S. Hay, D. Hayman, S. Hoyle, C. Jacka, C. Jackson, S. Jackson, K. Jeganathan, S. Johnston, J. Joseph, R. Kendall, M. Kesteven, D. Kiraly, B. Koribalski, M. Leach, E. Lenc, E. Lensson, L. Li, S. Mackay, A. Macleod, T. Maher, M. Marquarding, N. McClure-Griffiths, D. McConnell, S. Mickle, P. Mirtschin, R. Norris, S. Neuhold, A. Ng, J. O’Sullivan, J. Pathikulangara, S. Pearce, C. Phillips, R. Y. Qiao, J. E. Reynolds, A. Rispler, P. Roberts, D. Roxby, A. Schinckel, R. Shaw, M. Shields, M. Storey, T. Sweetnam, E. Troup, B. Turner, A. Tzioumis, T. Westmeier, M. Whiting, C. Wilson, T. Wilson, K. Wormnes, X. Wu
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- Publications of the Astronomical Society of Australia / Volume 31 / 2014
- Published online by Cambridge University Press:
- 13 November 2014, e041
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This paper describes the system architecture of a newly constructed radio telescope – the Boolardy engineering test array, which is a prototype of the Australian square kilometre array pathfinder telescope. Phased array feed technology is used to form multiple simultaneous beams per antenna, providing astronomers with unprecedented survey speed. The test array described here is a six-antenna interferometer, fitted with prototype signal processing hardware capable of forming at least nine dual-polarisation beams simultaneously, allowing several square degrees to be imaged in a single pointed observation. The main purpose of the test array is to develop beamforming and wide-field calibration methods for use with the full telescope, but it will also be capable of limited early science demonstrations.
GASKAP—The Galactic ASKAP Survey
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- John M. Dickey, Naomi McClure-Griffiths, Steven J. Gibson, José F. Gómez, Hiroshi Imai, Paul Jones, Snežana Stanimirović, Jacco Th. Van Loon, Andrew Walsh, A. Alberdi, G. Anglada, L. Uscanga, H. Arce, M. Bailey, A. Begum, B. Wakker, N. Ben Bekhti, P. Kalberla, B. Winkel, K. Bekki, B.-Q. For, L. Staveley-Smith, T. Westmeier, M. Burton, M. Cunningham, J. Dawson, S. Ellingsen, P. Diamond, J. A. Green, A. S. Hill, B. Koribalski, D. McConnell, J. Rathborne, M. Voronkov, K. A. Douglas, J. English, H. Alyson Ford, F. J. Lockman, T. Foster, Y. Gomez, A. Green, J. Bland-Hawthorn, S. Gulyaev, M. Hoare, G. Joncas, J.-H. Kang, C. R. Kerton, B.-C. Koo, D. Leahy, N. Lo, V. Migenes, J. Nakashima, Y. Zhang, D. Nidever, J. E. G. Peek, D. Tafoya, W. Tian, D. Wu
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- Publications of the Astronomical Society of Australia / Volume 30 / 2013
- Published online by Cambridge University Press:
- 24 January 2013, e003
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A survey of the Milky Way disk and the Magellanic System at the wavelengths of the 21-cm atomic hydrogen (H i) line and three 18-cm lines of the OH molecule will be carried out with the Australian Square Kilometre Array Pathfinder telescope. The survey will study the distribution of H i emission and absorption with unprecedented angular and velocity resolution, as well as molecular line thermal emission, absorption, and maser lines. The area to be covered includes the Galactic plane (|b| < 10°) at all declinations south of δ = +40°, spanning longitudes 167° through 360°to 79° at b = 0°, plus the entire area of the Magellanic Stream and Clouds, a total of 13 020 deg2. The brightness temperature sensitivity will be very good, typically σT≃ 1 K at resolution 30 arcsec and 1 km s−1. The survey has a wide spectrum of scientific goals, from studies of galaxy evolution to star formation, with particular contributions to understanding stellar wind kinematics, the thermal phases of the interstellar medium, the interaction between gas in the disk and halo, and the dynamical and thermal states of gas at various positions along the Magellanic Stream.
Contributors
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- By Rose Teteki Abbey, K. C. Abraham, David Tuesday Adamo, LeRoy H. Aden, Efrain Agosto, Victor Aguilan, Gillian T. W. Ahlgren, Charanjit Kaur AjitSingh, Dorothy B E A Akoto, Giuseppe Alberigo, Daniel E. Albrecht, Ruth Albrecht, Daniel O. Aleshire, Urs Altermatt, Anand Amaladass, Michael Amaladoss, James N. Amanze, Lesley G. Anderson, Thomas C. Anderson, Victor Anderson, Hope S. Antone, María Pilar Aquino, Paula Arai, Victorio Araya Guillén, S. Wesley Ariarajah, Ellen T. Armour, Brett Gregory Armstrong, Atsuhiro Asano, Naim Stifan Ateek, Mahmoud Ayoub, John Alembillah Azumah, Mercedes L. García Bachmann, Irena Backus, J. Wayne Baker, Mieke Bal, Lewis V. Baldwin, William Barbieri, António Barbosa da Silva, David Basinger, Bolaji Olukemi Bateye, Oswald Bayer, Daniel H. Bays, Rosalie Beck, Nancy Elizabeth Bedford, Guy-Thomas Bedouelle, Chorbishop Seely Beggiani, Wolfgang Behringer, Christopher M. Bellitto, Byard Bennett, Harold V. Bennett, Teresa Berger, Miguel A. Bernad, Henley Bernard, Alan E. Bernstein, Jon L. Berquist, Johannes Beutler, Ana María Bidegain, Matthew P. Binkewicz, Jennifer Bird, Joseph Blenkinsopp, Dmytro Bondarenko, Paulo Bonfatti, Riet en Pim Bons-Storm, Jessica A. Boon, Marcus J. Borg, Mark Bosco, Peter C. Bouteneff, François Bovon, William D. Bowman, Paul S. Boyer, David Brakke, Richard E. Brantley, Marcus Braybrooke, Ian Breward, Ênio José da Costa Brito, Jewel Spears Brooker, Johannes Brosseder, Nicholas Canfield Read Brown, Robert F. Brown, Pamela K. Brubaker, Walter Brueggemann, Bishop Colin O. Buchanan, Stanley M. Burgess, Amy Nelson Burnett, J. Patout Burns, David B. Burrell, David Buttrick, James P. Byrd, Lavinia Byrne, Gerado Caetano, Marcos Caldas, Alkiviadis Calivas, William J. Callahan, Salvatore Calomino, Euan K. Cameron, William S. Campbell, Marcelo Ayres Camurça, Daniel F. Caner, Paul E. Capetz, Carlos F. Cardoza-Orlandi, Patrick W. Carey, Barbara Carvill, Hal Cauthron, Subhadra Mitra Channa, Mark D. Chapman, James H. Charlesworth, Kenneth R. Chase, Chen Zemin, Luciano Chianeque, Philip Chia Phin Yin, Francisca H. Chimhanda, Daniel Chiquete, John T. Chirban, Soobin Choi, Robert Choquette, Mita Choudhury, Gerald Christianson, John Chryssavgis, Sejong Chun, Esther Chung-Kim, Charles M. A. Clark, Elizabeth A. Clark, Sathianathan Clarke, Fred Cloud, John B. Cobb, W. Owen Cole, John A Coleman, John J. Collins, Sylvia Collins-Mayo, Paul K. Conkin, Beth A. Conklin, Sean Connolly, Demetrios J. Constantelos, Michael A. Conway, Paula M. Cooey, Austin Cooper, Michael L. Cooper-White, Pamela Cooper-White, L. William Countryman, Sérgio Coutinho, Pamela Couture, Shannon Craigo-Snell, James L. Crenshaw, David Crowner, Humberto Horacio Cucchetti, Lawrence S. Cunningham, Elizabeth Mason Currier, Emmanuel Cutrone, Mary L. Daniel, David D. Daniels, Robert Darden, Rolf Darge, Isaiah Dau, Jeffry C. Davis, Jane Dawson, Valentin Dedji, John W. de Gruchy, Paul DeHart, Wendy J. Deichmann Edwards, Miguel A. De La Torre, George E. Demacopoulos, Thomas de Mayo, Leah DeVun, Beatriz de Vasconcellos Dias, Dennis C. Dickerson, John M. Dillon, Luis Miguel Donatello, Igor Dorfmann-Lazarev, Susanna Drake, Jonathan A. Draper, N. Dreher Martin, Otto Dreydoppel, Angelyn Dries, A. J. Droge, Francis X. D'Sa, Marilyn Dunn, Nicole Wilkinson Duran, Rifaat Ebied, Mark J. Edwards, William H. Edwards, Leonard H. Ehrlich, Nancy L. Eiesland, Martin Elbel, J. Harold Ellens, Stephen Ellingson, Marvin M. Ellison, Robert Ellsberg, Jean Bethke Elshtain, Eldon Jay Epp, Peter C. Erb, Tassilo Erhardt, Maria Erling, Noel Leo Erskine, Gillian R. Evans, Virginia Fabella, Michael A. Fahey, Edward Farley, Margaret A. Farley, Wendy Farley, Robert Fastiggi, Seena Fazel, Duncan S. Ferguson, Helwar Figueroa, Paul Corby Finney, Kyriaki Karidoyanes FitzGerald, Thomas E. FitzGerald, John R. Fitzmier, Marie Therese Flanagan, Sabina Flanagan, Claude Flipo, Ronald B. Flowers, Carole Fontaine, David Ford, Mary Ford, Stephanie A. Ford, Jim Forest, William Franke, Robert M. Franklin, Ruth Franzén, Edward H. Friedman, Samuel Frouisou, Lorelei F. Fuchs, Jojo M. Fung, Inger Furseth, Richard R. Gaillardetz, Brandon Gallaher, China Galland, Mark Galli, Ismael García, Tharscisse Gatwa, Jean-Marie Gaudeul, Luis María Gavilanes del Castillo, Pavel L. Gavrilyuk, Volney P. Gay, Metropolitan Athanasios Geevargis, Kondothra M. George, Mary Gerhart, Simon Gikandi, Maurice Gilbert, Michael J. Gillgannon, Verónica Giménez Beliveau, Terryl Givens, Beth Glazier-McDonald, Philip Gleason, Menghun Goh, Brian Golding, Bishop Hilario M. Gomez, Michelle A. Gonzalez, Donald K. Gorrell, Roy Gottfried, Tamara Grdzelidze, Joel B. Green, Niels Henrik Gregersen, Cristina Grenholm, Herbert Griffiths, Eric W. Gritsch, Erich S. Gruen, Christoffer H. Grundmann, Paul H. Gundani, Jon P. Gunnemann, Petre Guran, Vidar L. Haanes, Jeremiah M. Hackett, Getatchew Haile, Douglas John Hall, Nicholas Hammond, Daphne Hampson, Jehu J. Hanciles, Barry Hankins, Jennifer Haraguchi, Stanley S. Harakas, Anthony John Harding, Conrad L. Harkins, J. William Harmless, Marjory Harper, Amir Harrak, Joel F. Harrington, Mark W. Harris, Susan Ashbrook Harvey, Van A. Harvey, R. Chris Hassel, Jione Havea, Daniel Hawk, Diana L. Hayes, Leslie Hayes, Priscilla Hayner, S. Mark Heim, Simo Heininen, Richard P. Heitzenrater, Eila Helander, David Hempton, Scott H. Hendrix, Jan-Olav Henriksen, Gina Hens-Piazza, Carter Heyward, Nicholas J. Higham, David Hilliard, Norman A. Hjelm, Peter C. Hodgson, Arthur Holder, M. Jan Holton, Dwight N. Hopkins, Ronnie Po-chia Hsia, Po-Ho Huang, James Hudnut-Beumler, Jennifer S. Hughes, Leonard M. Hummel, Mary E. Hunt, Laennec Hurbon, Mark Hutchinson, Susan E. Hylen, Mary Beth Ingham, H. Larry Ingle, Dale T. Irvin, Jon Isaak, Paul John Isaak, Ada María Isasi-Díaz, Hans Raun Iversen, Margaret C. Jacob, Arthur James, Maria Jansdotter-Samuelsson, David Jasper, Werner G. Jeanrond, Renée Jeffery, David Lyle Jeffrey, Theodore W. Jennings, David H. Jensen, Robin Margaret Jensen, David Jobling, Dale A. Johnson, Elizabeth A. Johnson, Maxwell E. Johnson, Sarah Johnson, Mark D. Johnston, F. Stanley Jones, James William Jones, John R. Jones, Alissa Jones Nelson, Inge Jonsson, Jan Joosten, Elizabeth Judd, Mulambya Peggy Kabonde, Robert Kaggwa, Sylvester Kahakwa, Isaac Kalimi, Ogbu U. Kalu, Eunice Kamaara, Wayne C. Kannaday, Musimbi Kanyoro, Veli-Matti Kärkkäinen, Frank Kaufmann, Léon Nguapitshi Kayongo, Richard Kearney, Alice A. Keefe, Ralph Keen, Catherine Keller, Anthony J. Kelly, Karen Kennelly, Kathi Lynn Kern, Fergus Kerr, Edward Kessler, George Kilcourse, Heup Young Kim, Kim Sung-Hae, Kim Yong-Bock, Kim Yung Suk, Richard King, Thomas M. King, Robert M. Kingdon, Ross Kinsler, Hans G. Kippenberg, Cheryl A. Kirk-Duggan, Clifton Kirkpatrick, Leonid Kishkovsky, Nadieszda Kizenko, Jeffrey Klaiber, Hans-Josef Klauck, Sidney Knight, Samuel Kobia, Robert Kolb, Karla Ann Koll, Heikki Kotila, Donald Kraybill, Philip D. W. Krey, Yves Krumenacker, Jeffrey Kah-Jin Kuan, Simanga R. Kumalo, Peter Kuzmic, Simon Shui-Man Kwan, Kwok Pui-lan, André LaCocque, Stephen E. Lahey, John Tsz Pang Lai, Emiel Lamberts, Armando Lampe, Craig Lampe, Beverly J. Lanzetta, Eve LaPlante, Lizette Larson-Miller, Ariel Bybee Laughton, Leonard Lawlor, Bentley Layton, Robin A. Leaver, Karen Lebacqz, Archie Chi Chung Lee, Marilyn J. Legge, Hervé LeGrand, D. L. LeMahieu, Raymond Lemieux, Bill J. Leonard, Ellen M. Leonard, Outi Leppä, Jean Lesaulnier, Nantawan Boonprasat Lewis, Henrietta Leyser, Alexei Lidov, Bernard Lightman, Paul Chang-Ha Lim, Carter Lindberg, Mark R. Lindsay, James R. Linville, James C. Livingston, Ann Loades, David Loades, Jean-Claude Loba-Mkole, Lo Lung Kwong, Wati Longchar, Eleazar López, David W. Lotz, Andrew Louth, Robin W. Lovin, William Luis, Frank D. Macchia, Diarmaid N. J. MacCulloch, Kirk R. MacGregor, Marjory A. MacLean, Donald MacLeod, Tomas S. Maddela, Inge Mager, Laurenti Magesa, David G. Maillu, Fortunato Mallimaci, Philip Mamalakis, Kä Mana, Ukachukwu Chris Manus, Herbert Robinson Marbury, Reuel Norman Marigza, Jacqueline Mariña, Antti Marjanen, Luiz C. L. Marques, Madipoane Masenya (ngwan'a Mphahlele), Caleb J. D. Maskell, Steve Mason, Thomas Massaro, Fernando Matamoros Ponce, András Máté-Tóth, Odair Pedroso Mateus, Dinis Matsolo, Fumitaka Matsuoka, John D'Arcy May, Yelena Mazour-Matusevich, Theodore Mbazumutima, John S. McClure, Christian McConnell, Lee Martin McDonald, Gary B. McGee, Thomas McGowan, Alister E. McGrath, Richard J. McGregor, John A. McGuckin, Maud Burnett McInerney, Elsie Anne McKee, Mary B. McKinley, James F. McMillan, Ernan McMullin, Kathleen E. McVey, M. Douglas Meeks, Monica Jyotsna Melanchthon, Ilie Melniciuc-Puica, Everett Mendoza, Raymond A. Mentzer, William W. Menzies, Ina Merdjanova, Franziska Metzger, Constant J. Mews, Marvin Meyer, Carol Meyers, Vasile Mihoc, Gunner Bjerg Mikkelsen, Maria Inêz de Castro Millen, Clyde Lee Miller, Bonnie J. Miller-McLemore, Alexander Mirkovic, Paul Misner, Nozomu Miyahira, R. W. L. Moberly, Gerald Moede, Aloo Osotsi Mojola, Sunanda Mongia, Rebeca Montemayor, James Moore, Roger E. Moore, Craig E. Morrison O.Carm, Jeffry H. Morrison, Keith Morrison, Wilson J. Moses, Tefetso Henry Mothibe, Mokgethi Motlhabi, Fulata Moyo, Henry Mugabe, Jesse Ndwiga Kanyua Mugambi, Peggy Mulambya-Kabonde, Robert Bruce Mullin, Pamela Mullins Reaves, Saskia Murk Jansen, Heleen L. Murre-Van den Berg, Augustine Musopole, Isaac M. T. Mwase, Philomena Mwaura, Cecilia Nahnfeldt, Anne Nasimiyu Wasike, Carmiña Navia Velasco, Thulani Ndlazi, Alexander Negrov, James B. Nelson, David G. Newcombe, Carol Newsom, Helen J. 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Phan, Isabel Apawo Phiri, William S. F. Pickering, Derrick G. Pitard, William Elvis Plata, Zlatko Plese, John Plummer, James Newton Poling, Ronald Popivchak, Andrew Porter, Ute Possekel, James M. Powell, Enos Das Pradhan, Devadasan Premnath, Jaime Adrían Prieto Valladares, Anne Primavesi, Randall Prior, María Alicia Puente Lutteroth, Eduardo Guzmão Quadros, Albert Rabil, Laurent William Ramambason, Apolonio M. Ranche, Vololona Randriamanantena Andriamitandrina, Lawrence R. Rast, Paul L. Redditt, Adele Reinhartz, Rolf Rendtorff, Pål Repstad, James N. Rhodes, John K. Riches, Joerg Rieger, Sharon H. Ringe, Sandra Rios, Tyler Roberts, David M. Robinson, James M. Robinson, Joanne Maguire Robinson, Richard A. H. Robinson, Roy R. Robson, Jack B. Rogers, Maria Roginska, Sidney Rooy, Rev. Garnett Roper, Maria José Fontelas Rosado-Nunes, Andrew C. Ross, Stefan Rossbach, François Rossier, John D. Roth, John K. Roth, Phillip Rothwell, Richard E. 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Yee, Viktor Yelensky, Yeo Khiok-Khng, Gustav K. K. Yeung, Angela Yiu, Amos Yong, Yong Ting Jin, You Bin, Youhanna Nessim Youssef, Eliana Yunes, Robert Michael Zaller, Valarie H. Ziegler, Barbara Brown Zikmund, Joyce Ann Zimmerman, Aurora Zlotnik, Zhuo Xinping
- Edited by Daniel Patte, Vanderbilt University, Tennessee
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- The Cambridge Dictionary of Christianity
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- 05 August 2012
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- 20 September 2010, pp xi-xliv
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The Optimal Quantity of Land in Agriculture
- K. E. McConnell
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- Journal:
- Northeastern Journal of Agricultural and Resource Economics / Volume 18 / Issue 2 / October 1989
- Published online by Cambridge University Press:
- 10 May 2017, pp. 63-72
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- October 1989
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In 1952, when T. W. Schultz declared that land had lost its place as a unique factor of production, he was certainly right about U.S. agriculture. For the almost four decades since Schultz's prophetic analysis, output of U.S. agriculture has increased steadily while the exploited land base has slightly decreased. Land has not proved a constraint to production. Many varieties of technical change have kept the marginal product of land from falling, despite its increasingly intensive use.
Degradation of TiSi2/n+-Polysilicon Interfaces Due to High Temperature Processing
- K. Shenai, P. A. Piacente, G. A. Smith, N. Lewis, M. D. Mcconnell, J. F. Norton, E. L. Hall, B. J. Baliga
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- MRS Online Proceedings Library Archive / Volume 106 / 1987
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- 22 February 2011, 149
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- 1987
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Analytical results obtained from detailed Secondary Ion Mass Spectrometry (SIMS), Rutherford Backscattering Spectrometry (RBS), Auger analysis, Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) of ∼ 2000Å TiSi2/n+ polysilicon interfaces are reported for thermally annealed silicide samples and silicide samples subjected to further high temperature processing. The LPCVD polysilicon was heavily POCI3 doped at 900°C and TiSi was formed by rf sputtering 1000Å Ti and forming the silicide using ?wo successive thermal anneals at 600°C and 800°C in forming gas resulting in a silicide sheet resistance R of 1.45 Ω/□. The high temperature process stability of the silicide – polysilicon interface was investigated by systematically stressing the polycide at process temperatures in the range of 700° C to 1100° C. The silicide was stable for temperatures up to 900° C; however, significant degradation in the silicide sheet resistance, phosphorus, silicon, and titanium redistribution, and agglomeration and film breakage of TiSi2 were observed at higher process temperatures.
Aggregation in Recreation Economics: Issues of Estimation and Benefit Measurement
- K. E. McConnell, N. E. Bockstael
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- Journal:
- Northeastern Journal of Agricultural and Resource Economics / Volume 13 / Issue 2 / October 1984
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- 10 May 2017, pp. 181-186
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- October 1984
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Problems of aggregation plague applications of microeconomics. The theory is derived from postulates of behavior of individuals, but we often have data only for groups of individuals. The economics of outdoor recreation is no exception. This paper addresses the aggregation issue for estimating the demand for outdoor recreation. What are the estimation and welfare implications of using individual vs. aggregated observations, if the latter is all we have?