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

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

3. Farst Radio Burst 10 FRBs discovered (9 by Parkes)
Peak flux density: ~0.3 to 30
Width: <1.1 to 9.4
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）

4. 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

5. JMS-66m Radio Telescope Jimusi, Heilongjiang Cassegrain system S band
2250MHz
Bandwidth: ~130MHz
Tsys: ~74K
X band
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)

6. 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

7. Pulsar Observation with JMS-66m~
35 nulling pulsars and 3 millisecond pulsars
28 nulling pulsars' observed time ≥ 3 hour ~
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.

8. 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）

9. 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)

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

11. 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 = Jy

12. 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, Jy
Note that this is the sensitivity for single pulse. For pulsar, it can be much more sensitive.

13. For us: Directly dected Detect after smearing
DM (pc cm-3)
observed width
@~1.3GHz (ms)
peak flux density (Jy)
(Jy ms)
Lorimer burst
375 5
30±10 J
745
7.3
0.41
FRB 11020
910
5.6±0.1
1.3
8.0
FRB
677
<1.4
0.4
0.7
FRB
1072
<4.3
0.5
1.8
FRB
521
<1.1
0.6
FRB
557.4±3
3.0±0.5
FRB
790±3
9.4±0.2
0.3
<2.82
FRB
562.7(6)
FRB
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.

14. Test 1: Single-pulse search result for pulsar B0355+54
Name: B
DM: cm-3pc
P0: s
S1400: 23 mJy
RFI removed
Pulser width:
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.

15. Test 2: Single-pulse search result for pulsar B0525+21
Name: B
DM: cm-3pc
P0: s
S1400: 9 mJy
RFI removed
Pulser width: (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.

16. 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

17. 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