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The Good, the Bad and the Ugly: identifying FRATs triggers with TBB data

transientskp
January 09, 2014

The Good, the Bad and the Ugly: identifying FRATs triggers with TBB data

J. Emilio Enriquez

transientskp

January 09, 2014
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  1. Identifying ‘real’ FRATs J. Emilio Enriquez R. Heino Falcke, Sander

    ter Veen, Anya Bilous, Arthur Corstanje, Jörg Rachen, Pim Schellart LOFAR TKP Meeting 2014-01-09 1
  2. FRATs : Fast Radio Transients ž  Millisecond radio pulses — 

    ◦  —  —  —  —  —  —  2014-01-09 2
  3. FRATs : Fast Radio Transients ž  Millisecond radio pulses possibly

    originating from: —  Lorimer Bursts (FRBs) ◦  one time extragalactic burst —  Pulsars and RRATS —  Flaring stars —  Lightning from Saturn —  Jupiter aurora radio emission —  Exoplanets? —  ETI ?? 2014-01-09 3
  4. FRATs : Fast Radio Transients Detection and Verification ž  Detection

    —  Past and present: ◦  FRATs Trigger Code (Sander’s Talk) by parallel observations during LOTAAS (Cycle 0 & 1) and MSSS (tests before Cycle 0) so far. ◦  During Cycle 1 we are expanding to other regular observations (beamform and imaging). —  Future?: ◦  LOFAR related : ARTEMIS, AARTFAAC ◦  Multiwavelength: SWIFT/BAT, Fermi, … 2014-01-09 4
  5. FRATs : Fast Radio Transients Detection and Verification ž  Verification:

    Transient Buffer Boards (TBBs) —  Parallel System in LOFAR —  Ring buffer of raw data from each antenna —  Look back in time (5sec) —  Offline processing 2014-01-09 6
  6. FRATs : Fast Radio Transients FRATs TBB Goals ž  Pulse

    characterization of bright millisecond pulses —  High SNR by coherent addition of antennas/ stations. ž  Accurate position —  Multi-station Imaging 2014-01-09 7
  7. Pipelines ž  First stage pipeline: —  False positive detection — 

    Human learning ž  Second stage pipeline: —  TAB —  Imaging => Localization LOFAR locus013 NIJMEGEN Coma Cluster 2014-01-09 8
  8. Dispersion Measure (DM) ž  Dispersive nature of interstellar plasma: radio

    wave interaction with free electrons makes for slower group velocities for lower frequencies. ž  Time delay is calculated by: ž  DM Total column density of free electrons, or a distance estimate with ne models of the ISM. 2014-01-09 11
  9. The Good FRATS ž  Easy to identify —  Pulsars — 

    Jupiter bursts —  Solar flares —  … 2014-01-09 17
  10. The Bad FRATS ž  Cannot be identified as astrophysical source

    since no data —  Out of time range —  Bad Antennas 2014-01-09 25
  11. The Ugly FRATS ž  Hard to identify —  Bad antennas

    —  Side lobes ž  But with use of TBB data we can prettify the ugly FRATS. 2014-01-09 38
  12. Conclusion ž  With the use of TBBs to identify false

    positives. —  We can verify good FRATS candidates —  We can quickly identify bad candidates —  We can flag misbehaving antennas ž  We can also: —  We can localize triggers with better angular precision than the incoherent beam. —  Can study the pulses with higher SNR than the incoherent stokes since can add raw data coherently. —  Determine if the FRBs are astrophysical. 2014-01-09 39