Searching FRB with Jiamusi-66m Radio Telescope Speaker: Yezhao Yu Supervisor: Jinlin Han NAOC 2015.7.4, Mingantu

Outline Fast Radio Burst FRB Searching Conclusion Jiamusi-66m Radio Telescope FPGA Based Digital Backend Pulsar Observation with JMS-66m Detectability and Test Conclusion

Farst Radio Burst 10 FRBs discovered (9 by Parkes) Peak flux density: ~0.3 to 30 Jy @1.3GHz Width: <1.1 to 9.4 ms @1.3GHz DM: 375 to 1072 cm-3pc Possible Origin： Binary Neutron Star Mergers Binary White Dwarf Mergers Associate with GRB Axion Stars Young SNR pulsars Quark Nova （Thornton et al. science, 2013）

FRB Searching JMS-66m S-band Digital Backend Power Spectrum Single Pulse Searching (Personal Computer) Remove RFI De-dispersion Calculate S/N Ratio Data Analyse Draw the Result

JMS-66m Radio Telescope Jimusi, Heilongjiang Cassegrain system S band Center @ 2250MHz Bandwidth: ~130MHz Tsys: ~74K X band Center @ 8310MHz Bandwidth: ~180MHz Tsys: ~78K Picture from Internet Jiamusi-66m (JMS-66m for shart) is one of the antenna of Chinese Deep Space Network (CDSN), providing measuring and control supprot for Chang'e III and IV missions. (Ministry of Science and Technilogy)

FPGA Based Digital Backend Made by Southeast University, Nanjing Main observe modes: Bandwidth 150M, 256 channels, sampling time 0.2ms Bandwidth 150M, 128 channels, sampling time 0.1ms hardware software interface

Pulsar Observation with JMS-66m 2015.4.15 ~ 4.23 @S-band 35 nulling pulsars and 3 millisecond pulsars 28 nulling pulsars' observed time ≥ 3 hour 2015.6.13 ~ 6.25 @S-band 34 pulsars, include 6 millisecond pulsars Each pulsar's observed time ≥ 0.5 hour Cassiopeia A for more than 6 hour All data recorded using PSRFITS format.

PSRB0329+54 Observe Time：11 hours Results： Clear single pluses (256 channels, 0.2 ms mode) Observe Time：11 hours Results： Clear single pluses Scintillation Nulling (Result from Chen Wang) Phase vs. Frequency Phase vs. Time (5 hours) Time vs. Frequency（12s）

MSP J2145-0750 Observe Time：25 minutes Results： (128 channels, 0.1 ms mode) Observe Time：25 minutes Results： Integrated pulse profile (Result from Pengfei Wang) Phase vs. Frequency Phase vs. Time (25 min)

Detectablity and Test Sensitivity Single-pulse Detectablility Test with Pulsars Next Step

Sensitivity Here, k is the Boltzmann constant, Tsys is the system noise temperature, η is the antenna efficiency, np is the number of polarisations, Δt is the sampling and the Δf is the observe bandwidth. For our system, Tsys = 74K, η= 60%, np = 2, Δt = 0.2ms, Δf = 130MHz The sensitivity ΔS = 0.437 Jy

Single-pulse Detectability Using a signal-to-noise ratio threshold (S/N)=7, and with smearing the sampling time into 0.4, 0.8 ms, we can calculate the weekest dectectable pulse peak flux density Speak Δt (ms) 0.2 0.4 0.8 1.6 Speak (Jy) 3.059 2.163 1.530 1.082 If used (S/N)=5, than the Speak would be 2.185, 1.545, 1.093 Jy Note that this is the sensitivity for single pulse. For pulsar, it can be much more sensitive.

For us: Directly dected Detect after smearing DM (pc cm-3) observed width @~1.3GHz (ms) peak flux density (Jy) Fluence @~1.3GHz (Jy ms) Lorimer burst 375 5 30±10 J1852-08 745 7.3 0.41 FRB 11020 910 5.6±0.1 1.3 8.0 FRB 110627 677 <1.4 0.4 0.7 FRB 110703 1072 <4.3 0.5 1.8 FRB 120127 521 <1.1 0.6 FRB 121102 557.4±3 3.0±0.5 FRB 011025 790±3 9.4±0.2 0.3 <2.82 FRB 140514 562.7(6) FRB 131104 779±0.2 1.1±0.1 For us: Directly dected Detect after smearing The FRB event rate RFRB(F>3Jy ms) = ~1.0×104 sky-1day-1 . For our system (beam width 7 arcmin), we may need >4years waiting for an FRB.

Test 1: Single-pulse search result for pulsar B0355+54 Name: B0355+54 DM: 57.1420 cm-3pc P0: 0.1563824177774 s S1400: 23 mJy RFI removed Pulser width: ~17ms @1.4GHz The left: DM value vs. time for all pulses with S/N ratio greater than 4σ. Right top: DM value vs. Number of pulses with S/N ratio greater than 4σ. Right bottom: DM value vs. S/N ratio of pulses with S/N ratio greater than 4σ.

Test 2: Single-pulse search result for pulsar B0525+21 Name: B0525+21 DM: 50.937 cm-3pc P0: 3.74553925030 s S1400: 9 mJy RFI removed Pulser width: ~210ms @1.4GHz (has two subpulsers, each width is ~105ms) The left: DM value vs. time for all pulses with S/N ratio greater than 4σ. Right top: DM value vs. Number of pulses with S/N ratio greater than 4σ. Right bottom: DM value vs. S/N ratio of pulses with S/N ratio greater than 4σ.

Next Step The searching program now is run in CPU. In order to detect the FRB faster, a GPU based single-pulse searching program is under development. What have been done: a. GPU based de-dispersion (direct & tree) b. GPU based S/N ratio calculation What will be done: a. GPU based RFI removment b. More automation

Conclusion Although JMS-66m is an antenna of CDSN, not for radio astronomy, we confirmed that it is able to do radio observation at its S band. Both hardware and software is prepared for single-pulse searching. Such searching will begin soon. Then what we need to do is waiting for a strong enough FRB. Thank you