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The Latest on Beamformed Data and the Status of LOTAAS

transientskp
December 04, 2012

The Latest on Beamformed Data and the Status of LOTAAS

Jason Hessels

transientskp

December 04, 2012
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  1. Jason Hessels (ASTRON / UvA) The Latest on Beam-Formed Data

    & the Start of LOTAAS +LOFAR Pulsar Working Group TKP - Amsterdam - December 4th, 2012
  2. TKP - Amsterdam - December 4th, 2012 Coherent Stokes Incoherent

    Stokes Beam-Formed Observation I IQUV XXYY I Online coherent dedispersion (test only) 1, 16, 32, 64, 128, 256 channels per subband 5us - 10ms (or more) time res. 1-300 TABs 1-8 SAPs 1-8 SAPs (+) (+ imaging) LOFAR v1.0: Beam-Formed Modes All written to HDF5 with metadata
  3. TKP - Amsterdam - December 4th, 2012 LOFAR Tied-Array Beams

    with the Full Core Circa 2010 State-of-the-art State-of-the-art Circa 2011 State-of-the-art Circa 2012 Evolution of Beam-Formed modes
  4. TKP - Amsterdam - December 4th, 2012 #stations x 1.0

    #stations x 0.85 sqrt(#stations) Sensitivity Scaling of Core Tied-Array Beams Modestly Bright Pulsar
  5. TKP - Amsterdam - December 4th, 2012 Superterp Tied-Array Beam

    Mapping Shows that a “tune-up” is needed
  6. TKP - Amsterdam - December 4th, 2012 Sensitivity Scaling of

    Core Tied-Array Beams Very Bright Pulsar #stations x 1.0 sqrt(#stations) (#stations)^0.75
  7. TKP - Amsterdam - December 4th, 2012 Also using 8-bit

    mode to go from 15-95MHz LBA B0809+74
  8. TKP - Amsterdam - December 4th, 2012 Pilot LOFAR Pulsar

    Surveys • LPPS (incoherent survey): ~1/2 of North. Hem., 7 SAPs,1 hour pointings. • LOTAS (coherent survey): ~1000 sq deg., 19 TABs, 17- minute pointing. • Processing near completion, still lots of candidates to inspect. • So far 5 independent discoveries of very recent GBT discoveries at 350MHz.
  9. TKP - Amsterdam - December 4th, 2012 LOFAR Tied-Array All-Sky

    Survey (LOTAAS) • Use 8-bit mode • 3 SAPs of 36MHz each • 1hr per pointing (1.5hr all-sky by end... new param. space) • 0.49ms time resolution, 6kHz frequency channels • Find millisecond pulsars out to DM ~ 50 pc cm-3 • 111 tied-array beams, 3 incoherent beams • 12 sq deg. total per ptg. from tied-array beams • 60 sq deg. total per ptg. from incoherent beams • Sparse coverage of North. Hem. takes 333 pointings • Dense coverage of North. Hem. takes 1000 pointings First (test) survey observations tonight!!!
  10. TKP - Amsterdam - December 4th, 2012 LOFAR Tied-Array All-Sky

    Survey (LOTAAS) • ~2x more sensitive than LOTAS (coh. pilot survey) • ~2x more sensitive than LPPS (incoh. pilot survey)
  11. TKP - Amsterdam - December 4th, 2012 Papers • LOFAR

    pulsar reference - A&A published • Wideband simultaneous observations - A&A published • B0943+10 simultaneous XMM - Science in press • B0809+74 drifting - A&A submitted • Ionospheric RM calibration - A&A submitted • Ultra-low-frequency pulses - early draft • Profiles of 100 pulsars - early draft • B0823+26 switching on - early draft • Pilot pulsar surveys - early draft
  12. TKP - Amsterdam - December 4th, 2012 Papers • B0943+10

    radio properties • B0943+10 geometry • Deep search of M31 • Low-frequency pulsar spectra • Survey of pulsar RMs • LOTAAS description and first discoveries • MSP timing • Polarized profiles • Scattering properties • Crab giant pulses
  13. TKP - Amsterdam - December 4th, 2012 Wish list for

    Sinterklaas • Parallel observations • Online RFI excision • Real-time searches imbedded in the correlator