Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.atnf.csiro.au/lists/vlbiobs/att-0933/ASKAP_VLBI_Expression_of_Interest.pdf Дата изменения: Fri Jun 21 04:31:00 2013 Дата индексирования: Fri Feb 28 15:22:26 2014 Кодировка:

ASKAP Expression of Interest (EoI) 1) T itle

Version 1.0

18/11/2008

Title, investigators and their affiliations and brief abstract

The high resolution component of ASKAP: meeting the long baseline specifications for the SKA Investigators and their affiliations Prof. Steven Tingay Dr. Chris Phillips Prof. Sergei Gulyaev Mr. Tim Natusch Mr. Adam Deller Prof. Ray Norris Dr. Enno Middelberg Mr. Emil Lenc Prof. John Dickey Dr. Cormac Reynolds Dr. Hayley Bignall Dr. Richard Dodson Dr. Maria Rioja Mr. Aquib Moin Dr. Tasso Tzioumis Dr. Simon Ellingsen Dr. Roopesh Ojha Dr. Walter Brisken Brief abstract The combination of ASKAP, the existing Australian Long Baseline Array (LBA), new radio telescope facilities currently being built in New Zealand, innovative distributed software correlation facilities and high speed (10 Gbps) data transport networks allow a high resolution capability for ASKAP that is unmatched in terms of SKA demonstrators/pathfinders around the world. This high resolution component of ASKAP will be used to demonstrate scientific observations relevant to the SKA science case using long baselines that exceed the SKA specification (5500 km WA to NZ > 3000 km SKA specification) and use real-time data transport and processing techniques based on eVLBI. This ASKAP EoI complements and supports other ASKAP EoIs such as the long duration transient EoI of Chaterjee et al., the radio continuum survey EoI of Norris et al. and the OH maser EoI of xxxxxx et al. The high resolution component of ASKAP will use 1500 hours of observing time over a period of 5 years to investigate: · · Pulsars: proper motions, parallaxes, scintillation; Active Galactic Nuclei; ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( Curtin University of Technology) ATNF) Auckland University of Technology) Auckland University of Technology) NRAO) ATNF) Astronomisches Institut der UniversitДt Bochum) ATNF) University of Tasmania) Curtin University of Technology) Curtin University of Technology) University of Western Australia) University of Western Australia) Curtin University of Technology) ATNF) University of Tasmania) US Naval Observatory) NRAO)


· · · · · 2)

Compact extragalactic radio sources in wide-field continuum surveys; Gamma-ray burst afterglows; X-ray binary systems in our galaxy; OH masers; Cluster-cluster calibration techniques; Expected science outcomes

Pulsars: proper motions, parallaxes, scintillation (Deller) Active Galactic Nuclei (Ojha) Compact extragalactic radio sources in wide-field continuum surveys (Middelberg/Tingay/Lenc) Gamma-ray burst afterglows (Moin) X-ray binary systems in our galaxy (Tingay/Moin) OH masers (Ellingsen) Cluster-cluster calibration techniques (Rioja) Much material already in Johnston et al (2008, Experimental Astronomy, in press) and Johnston et al. (2007, PASA, 24, 174). 3) Technical details

Technical details of the functional requirements exist in internal ATNF ASKAP documents that have been generated by Phillips, Tzioumis and Tingay over the last 12 months. Can reproduce here. Also figures and information in Johnston et al. (2007, PASA, 24, 174). * Observing time and possible piggyback/commensal surveys 1500 hrs over a 5 year period is ~12 days per year or approximately 3 ­ 4 days per current VLBI session (use of ASKAP for approximately half of all VLBI sessions) * Angular, spectral and time resolution Angular resolution of ~ 5 mas (1.4 GHz). Spectral and time resolution flexible and dependant on project. * Instantaneous and total required bandwidth 300 MHz dual polarisation * Observing frequency 1.4 and 1.6 GHz centre frequencies.


* Survey speed & point source and/or brightness sensitivity Survey speed not applicable. Point source sensitivity ~20 uJy/beam * Dynamic range (spectral or continuum) Continuum dynamic range 200:1 * Required data products Baseband data recorded to VLBI data acquisition unit and baseband data transmitted via network to distributed software correlator. * Required polarisation products & polarisation purity RCP/LCP, 10% leakage * Sky coverage

* Survey strategy * Any other relevant details for technical assessment (e.g. tied array beams, VLBI capability). Tied array beams. How many? Sub-arraying capability. VLBI data recording and transmission capability. 4) Concept design & commissioning contribution

Design of portable data acquisition unit (Italian DAS/Mark5 recorder + disks in half sie 19" rack) Funds to help build a portable data acquisition unit ($50k) and provide disks Data correlation services Data processing and verification services as part of commissioning Postdoctoral support to do the science and senior supervisory overview of the individual projects.