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The High Time Resolution Universe Survey Backend

The High Time Resolution Universe Survey Backend. Bailes, van Straten, Jameson, McMahon, Werthimer, Keith. Motivation. Pulsars Surveys The multiBOB Processing Results MeerKAT. Crab pulsar. “Noisy”. Pulsars go this way. Pulsar recycling. “Smooth”. Magnetic Field - Period Diagram.

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The High Time Resolution Universe Survey Backend

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  1. The High Time Resolution Universe Survey Backend Bailes, van Straten, Jameson, McMahon, Werthimer, Keith.

  2. Motivation • Pulsars • Surveys • The multiBOB • Processing • Results • MeerKAT

  3. Crab pulsar “Noisy” Pulsars go this way Pulsar recycling “Smooth” Magnetic Field - Period Diagram “Noisy”

  4. Parkes Multibeam Surveys • Discovered 850+ pulsars • Double pulsar (0737) • NS+NS binaries (1756) • Magnetar-like pulsars • NS+WD pulsars (1141) • Superb timing pulsars (1909) • Had poor frequency resolution

  5. Galactic Distribution • Need to hit the plane

  6. DM contours & known MSPs Free Electron Density

  7. Pulse Dispersion

  8. Pulsar Dispersion Smearing DM=100, B=3 MHz, 1350 MHz, t=1.1ms

  9. 40 s wide!! PSR J1909-3744

  10. 30 Jy one-off 5ms burst DM = 375 Not seen again in 90 hours observing. What is it? Extreme RRAT? Supernova event? Coalesced NS-NS? Black hole evaporation? Cleverly dispersed RFI? Aliens? tdm f-2 tscat f-4 Single pulses: the past 2 years Lorimer et al. 2007

  11. iBOB Xeon Disk MultiBOB • 13 x • iBOB + 10 Gb ethernet + server + 1.5 TB disk • iBOBs integrate FFTs on each pol for 64 us • We select best 8 bits on each pol • Talk over 10 Gb 10Gb CPU cluster casper psrdada linux Swinproc/sigproc

  12. Introducing: BPSR • MultiBOB 13 beam spectrometer • 1024 channels, 64 us sampling, 3.3K each! • High Time Resolution Universe Survey • Request: • ~200 days of Parkes time over 4 years • Discover 100s more pulsars • Fastest pulsars • Gb link to Green Machine

  13. Procedure • Form average bandpasses from first 10s • 2-bit digitize thereafter • Write to file + sigproc (Lorimer) header

  14. PKS Multibeam Tsamp = 250 us ChBW = 3 MHz Nbit = 1 5 TB High Time Resolution Universe Tsamp = 64 us ChBW = 0.4 MHz Nbit = 2 ~1000 TB (150K in tapes) A tale of two surveys

  15. PKS Multibeam Tsamp = 250 us ChBW = 3 MHz Nbit = 1 5 TB High Time Resolution Universe Tsamp = 64 us ChBW = 0.4 MHz Nbit = 2 ~500 TB A tale of two surveys

  16. Supercomputing @ Swinburne The Green Machine • installed May/June 2007 • 185 Dell PowerEdge1950 nodes • 2 quad-core processors (Clovertown: Intel Xeon 64-bit 2.33 GHz) • 16GB RAM • 1TB disk -> 300 TB total • 1640 cores/14 Tflops • 20 Gb infiniband (Q1 2009) • 83 kW .vs. 130 kW cooling Machines: ~1.2M Fuel: ~100K/yr

  17. DM=297 P=2.149ms

  18. HITRUN processing • Requires 1040 Clovertown cores for real time • Debird(transpose): 3 mins + 10 mins • Dedisperse: 80 mins • FFT: 15 mins • Fold: 60 mins • Optimize: 5 mins • Total: ~3 hours/ 4cores

  19. Supercomputing 1 Teraflops for 1K 128 GB/s RAM BW 1M = 128 TB/s 1 Petaflop 300 kW!!! ?

  20. HITRUN processing • GPU processing • Debird (transpose): 3 mins + 10 mins, 1.5 sec + 17 sec (FFT) • Dedisp: 80 mins, 5 mins • FFT: 15 mins, 30 sec • Fold: 60 mins, ??? • Optimize: 5 mins, ??? • Total: ~3 hours/ 4cores, 10 min • 1 Tesla S1070 has 4xGPUs • Equivalent to 36 servers or 288 cores (10K) • Real time search with 4 S1070s? (40K) • Supermicro make a Nehalem + 2 x Tesla • 10 of these ~100K

  21. Storage vs Real time processing • 1,000,000,000 MB / (53 MB/s) = 220 days • 1,000,000,000 MB = 150K / copy • GPU farm ~ 100 K • Observers • 200K • Parkes Telescope • 2,000 K

  22. 1623-4949B • ~4 Second pulsar • DM ~1000 • 300 sigma! • B - 1014 G! • Profile changes • Timing noise

  23. 1623 humps

  24. 1623 position

  25. Operations • MultiBOB comms sensitive. • MultiBOBs hate LO changes. • No failures in ~year (x13). • Combination of software & hardware good • Didn’t know algorithm without trying • Wish-list • “Saturation”

  26. MeerKAT as a pulsar finder? • In total power • Like a 36 m dish • FoV like a 12 m ~ 30 x PKS • G sqrt(Bt) • PKS MB = 1 • MeerKAT = 0.5 • Ultra-compact coherent machine? • 8 x 8 2D (32x32) 2D FFTs (300m x 300m) • #Telescope beams? ~1024 beams • MeerKAT = 2.1 (gain/T) x 1.7(sqrt t) = ~3xPKS

  27. Data Rates? • 1024 channels • 2 bits • 1024 = 32 x 32 beams • 8 kHz sampling • 4 GB/s cf Raw rate of 81 x 1.2 GB/s/telescope • 300 MHz BW

  28. Real time GPU/CPU Petaflop processor • @8 kHz, 2x faster real time/beam • Next-gen GPU (2Tflops), 4x faster? • Need 256 GPUs • 128 Supermicros + 2xGPU • Only 1.3 M

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