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Development and Commissioning of LOFAR for Astronomy (DCLA) Huub Röttgering Leiden Observatory. Early July 2008. 13. September 2008. 15. 25. March 2010. 21. 22. 17. International Station Rollout. Effelsberg. Potsdam. Tautenburg. 10.
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Development and Commissioning of LOFAR for Astronomy (DCLA) Huub RöttgeringLeiden Observatory
International Station Rollout Effelsberg Potsdam Tautenburg 10
NL lofar: 20-25 core Stations & 20-25 outer stations E-lofar: 20-30 European stations? p. 10
2010: All LOFAR stations fully operational
LOFAR opens up the last ‘unexplored’ part of the spectrum wavelength region • Very Low Frequencies: 10-240 MHz • Detection of extremely distant objects, new physics, serendipity • High angular resolution: <1’’ at 200 MHz • Morphologies, Identification of sources • Nano second time resolution • Cosmic rays • Enormous Field of View • Rare (transient) objects • Sensitive polarization measurements • Magnetic fields • Low-Frequency Radio Spectroscopy • Neutral gas in the early universe
ExcellentData Quality Cygnus A (courtesy N. Jackson, J. Conway) 14 HBA stations (10 split core + 4 remote)
Status March 2010 3C196 field: 20 stations, 120-180 MHz, dynamic range of 10,000 (!), 960 sources • Station beamforming • Correlation of ~ Tbyte of station beams • Removal Radio interference • Calibration • Removal ionospheric corruption • Deconvolution • Widefield imaging
Status March 2010 3C196 field: 20 stations, 120-180 MHz, dynamic range of 10,000 (!), 960 sources • Data stream and reduction pipeline: • Station beamforming • Correlation of ~ Tbyte/s datastream from station beams • Removal radio frequence interference • Calibration • Removal ionospheric corruption • Deconvolution • Wide-field imaging • All main elements in place, but need significant fine-tuning • Station beamforming • Correlation of ~ Tbyte of station beams • Removal Radio interference • Calibration • Removal ionospheric corruption • Deconvolution • Widefield imaging
NOVA and LOFAR • Key-programs: driven the design • Cosmic ray showers (Nijmegen) • The epoch of reionization (Groningen) • The bursting and transient Universe (Amsterdam) • Surveying the low frequency universe: formation of AGN and galaxies (Leiden) • Coordinated national program • ASTRON: the instrument and standard software • NOVA funded project ‘Development and Commissioning of LOFAR for Astronomy (DCLA)’ • Testing and commissioning • Specialized software pipelines • Organization • PM: Michael Wise • Regular meetings on many levels • Large international involvement
Ultra High energy cosmic rays • Where and how are they produced? What are they made off? • Detection of Geosynchrotron emission from cosmic ray showers • Team led by Falcke and Horandel (Nijmegen) • DCLA: Detection and characterization
CR detection works Text 5 ms all sky image with the LOFAR transient buffer boards
Epoch of reionisation • When and how did EOR occur? • Detection EOR signal • Team led by de Bruyn, Zaroubi, Koopmans, Brentjens • Software: • Calibration and removal foregrounds • End-to-end simulation • Implementation on Graphics Processor Units (GPU)
EoR Simulation and reduction pipeline in place. Blue: Measured signal Dashed: Instr. Noise Red: True EoR Signal White/Gray: Extracted signal plus rms error Ingredients: simulated signal, foregrounds, ionosphere, beam forming, signal extraction
Transients and pulsars • Catalogue and characterize all transient radio sources (Gamma-ray bursts, jets, exo-planets, pulsars) • Team led by Wijers, Fender and Stappers • DCLA: write an pipeline for transient detection and characterization
Surveying the low-frequency sky • Goals • Main: 100 z>6 radio galaxies, 100 radio clusters at z>0.6, 50 z>2 protoclusters • Galaxies, clusters, physics of AGN and starbursts, the Galaxy, lensing, large scale structure, • Team led by • Huub Rottgering, Peter Barthel, Philip Best, Marcus Brüggen, Gianfranco Brunetti, Krzysztof Chyzy, John Conway, Matt Jarvis, Matt Lehnert, George Miley, Raffaella Morganti, Ignas Snellen • DCLA: • Source finding, characterization and cataloguing • Ionospheric calibration
Ionospheric model fitting 74 MHz VLA data Source finding and characterization Old new