fast low frequency pulsar survey
DESCRIPTION
FAST Low Frequency Pulsar Survey. Youling Yue ( 岳友岭 ) FAST Project, NAOC PKU Astrophysics Colloquium 2012. outline. Current FAST receivers Receiver for early pulsar survey: Low frequency (~400MHz) 7-beam receiver Pulsar survey simulation using PSRPOP Gravitational wave detection limits - PowerPoint PPT PresentationTRANSCRIPT
FAST Low Frequency Pulsar Survey
Youling Yue (岳友岭 )FAST Project, NAOC
PKU Astrophysics Colloquium 2012
outline
• Current FAST receivers• Receiver for early pulsar survey:
Low frequency (~400MHz) 7-beam receiver• Pulsar survey simulation using PSRPOP• Gravitational wave detection limits• RFI• Single beam wideband receiver
No Band (GHz) Beams Pol. CryoTsys(K)
Science
1 0.07 – 0.14 1 RCP LCP
no1000
High-z HI(EoR),PSR, VLBI, Lines
2 0.14 – 0.28 1 RCP LCP
no400
High-z HI(EoR),PSR, VLBI, Lines
3 0.28 – 0.56 1 or multi RCP LCP
no150
High-z HI(EoR),PSR, VLBI, LinesSpace weather, Low frequency DSN
4 0.56 – 1.02 1 RCP LCP
yes60
High-z HI(EoR),PSR, VLBI, LinesExo-planet science
5 0.320 – 0.334 1 RCP LCP
no200
HI,PSR,VLBIEarly sciences
6 0.55 – 0.64 1 RCP LCP
yes60
HI,PSR,VLBIEarly Sciences
7 1.15 – 1.72 1 L wide RCP LCP
yes25
HI,PSR,VLBI,SETI,Lines
8 1.05 – 1.45 19 Lnarrow multibeam
RCP LCP
yes25
HI and PSR survey, Transients
9 2.00 – 3.00 1 RCP/LCP
yes25
PTA, DSN, VLBI, SETI
FAST receivers
From C. J. Jin
Need a receiver
• To work at low frequency (<1GHz) to meet early stage pointing accuracy
• To do a whole FAST sky pulsar survey (L-band 19-beam is not the best one)
7-beam receiver
• Propose to build a 7-beam receiver for early drift-scan pulsar survey, freq ~400-560MHz
• Similar design like current multibeam receivers, easy to build, ready in early 2016
Parkes Effelsberg Arecibo FAST
Pulsar science for 7-beam receiver
• Low frequency drift-scan pulsar survey– Detect ~2300 normal pulsar (~1700 new)– Detect ~300 MSP (~200 new), good for GW
detection • M31/M33 pulsar survey (tracking)• Radio transient survey– Use same data set (piggyback)– good option for a whole FAST sky (2.3π) survey
before PAF receiver is available
7-beam receiver details
• Optimized for pulsar (transients) survey at early science stage (Sept 2016 or earlier)
• Freq ~400MHz, BW ~150MHz (1/3 freq)• Cooled, Tsys without sky ~30K or less• Light weight• Horn, dipole, etc, not PAF• Inexpensive (maybe <1 Million USD)• Use 19-beam backends• data ~2.4PB (one whole FAST sky scan)
Drift survey simulation with PSRPOP
• FAST sky drift-scan survey for pulsar• Integration time ~40s at 400MHz• Two working case– Spherical surface, illuminated aperture Dill decrease as
frequency increase, Dill ~ 200m*(f/400MHz)^1/4 (very early stage)
– 300m diameter parabola• Two population– Normal pulsar– Millisecond pulsar
Drift survey simulation PSRPOP
PSRPOP website: http://psrpop.sourceforge.net/
Blue: ~100k pulsar generated Red: ~2300 detected by FAST
spherical surface
BW = 1/3 freqIntegration time ~60s *(400MHz/freq)Dill ~ 200m at 400MHz
Number of Normal pulsar detected
300m parabola
BW = 1/3 freqIntegration time ~40s *(400MHz/freq)
400MHz side is favored because of faster survey speed
Number of Normal pulsar detected
MSP survey simulation
• Normal pulsar and MSP are of different population: different spectral index, spatial distribution, etc
• Change spectral index and spectral index deviation so that the simulation meets both Parkes multibeam survey and 70cm survey
• Search through the parameter space to find the best point
Sample (~100k pulsar) generated by matching PMB results (L-band)Constrain spectral index and its deviation by matching 70cm survey Green region meets the observed ~20 MSPs from 70cm survey
17
GW detection limits adding new MSP from FAST drift scan survey36 from IPTA + 40 from FASTplot from K. J. Lee
Single beam wideband receiver for early pulsar timing
• Effelsberg, GBT, Parkes, Arecibo are developing or discussing wide band pulsar timing receivers ~500MHz-3GHz~700MHz-4GHz
• For FAST pulsar timing– 500MHz-3GHz
• For FAST early science ~270MHz-1450MHz– Low end limited by RFI– High end covers HI
Akgiray & Weinreb 2011