Pulsar Studies at Urumqi

1. Pulsar Studies at Urumqi Na Wang Urumqi Observatory, NAOC

2. History of Urumqi Observatory • Nov 1957: Founded, Urumqi Satellite Observation Station, Chinese Academy Of Sciences (CAS) • Oct 1987: Urumqi Observatory, CAS • Apr 2001: Urumqi Observatory, National Astronomical Observatories of CAS

3. The Nanshan Station of Urumqi Observatory • Built in 1993 as a VLBI station • 76 km to the south Urumqi • Altitude: 2080 m • On Tianshan Mountain, called Nanshan

4. Pulsars in brief • ~1750 known, Galaxy, period～1s • MSPs(~ 0.003 s): Binary, recycled, stable 0.001s 0.01s 0.1s 1s 10s NASA/GSFC; Walt Feimer/Allied Signal

6. Pulsar timing system at Urumqi Center Frequency:1540 MHz Total Bandwidth: 320 MHz Filterbank: 2x128x2.5 MHz PCI-DIO-32HS:Data card PCI-DIO-96:Control card GPIB: Start time

7. Work done at Urumqi • Glitch & Timing noise • Proper motion • Scintillation: DISS & RISS • Emission & single pulse • Transient source • Searching Future • New backend • 80m • Application: GW, navigation & time keeper

8. Glitch & Timing Noise Study

9. Unusual glitch behaviours of two young pulsars Urumqi: Detected a slow glitch in PSR B1822-09 (J1825-0935) • For the slow glitch, there was a continuous increase in frequency for about 300~d followed by a return to the initial state for the next 500~d. • Associated with the spin-up process is a decreasing slow-down rate (increasing ) which lasted 120~d with maximum • . The slow-down rate then decayed to approximately the pre-glitch level within 220~d. • The fractional changes in frequency and frequency derivative before and after the slow glitch are and • respectively. Similar glitches were also observed in PSR B1822-09 by Shabanova & Urama (2000)

10. Detected one glitch in PSR J1835-1106 • Significant cubic terms with opposite signal are present in the pre- and post-glitch data, suggesting a sign change in at the time of the glitch. • The jump in at MJD 52220 has the reversed sign of before and after the glitch. There was little or no change in at the time of the glitch. Zou,W.Z.; Wang,N.; Wang,H.X.; Manchester R. N. et al. 2004, MNRAS, 354, 811

11. Observations of Six Glitches in PSR B1737-30

12. Observations of Six Glitches in PSR B1737-30 Zou, W. Z.; Wang, N.; Manchester, R. N.; Urama, J. O.; Hobbs, G.; Liu, Z. Y.; Yuan, J. P.: MNRAS, accepted.

13. Observations of Six Glitches in PSR B1737-30 n= -3(1)

14. Pulsar timing at Urumqi Astronomical Observatory: observing system and results Residual: few hundred us Period accuracy: 0.1ns or better Updated rotational parameters Wang,N.; Manchester,R.N.; Zhang,J.; Wu,X.J. et al.: 2001, MNRAS, 328, 855

16. Glitch Model: Fractional decay Q = △νd/△νg Size △ν/ν=10-6 time constant τd=400 d

17. ◇ Amplitude in ΔP and agree with our observation ◇ In agreement with the Crab pulsar glitch: ◇ Correlation in sign

18. Timing measurements and proper motions of 74 pulsars using the Nanshan radio telescope Zou,W.Z.; Hobbs,G.; Wang,N. ; Manchester R. N. et al.: 2005, MNRAS, 362, 1189

19. Projected directions of the proper motions for the 74 pulsars in our sample relative to the Galactic Plane

20. Analyzed timing noise for 100 pulsars, to study the effect of timing noise to the accuracy of pulsar position measurement Red noise White noise

21. 拟投MNRAS • Long term monitoring of RRAT 1819－1458 • RRATs are discovered in 2006 • 11 known, 3pdot • Our observations started from 2007, 174pulses （a）宽爆信号 （b）窄爆信号 （c）双峰脉冲 （d）RRAT脉冲和地面干扰。

22. RRAT1819－1458: timing residual of the observed 174 pulses. Zhao, C. S.; Esamdin et al, 2009, MNRAS, in preparing

23. Long-term scintillation observations of five pulsars at 1540 MHz • Observe every 9 d, 2001 Jan – 2002 Jun • 2－6hr，2－4min sub-integration • Pulsars： PSR B0329+54 PSR B1823+26 PSR B1929+10 PSR B2020+28 PSR B2021+51 Wang,N.; Manchester,R.N.; Johnston,S.; Rickett,Bet al.: 2005, MNRAS, 358, 270

24. Dynamic spectra of PSR B0329+54 DM＝26.8 pc cm-3 Dist = 1.06 kpc 3 hr obs. Δtd～10-30 min Δνd ～5-15 MHz

25. Secondary Spectra, Two dimensional FFT of dynamic spectrum Observing the structure of central image !

26. Modulation indices Observed > prediction !!

27. Frequency dependence of DISS parameters a. Bhat, Rao & Gupta 1999 b. Gupta, Rickett & Lyne 1994 c. Stinebring, Fainon & Mckinnon 1996 d. Our results

28. Kolmogorov Spectrum β=3.67

29. Daily Observations of Interstellar Scintillation in PSR B0329+54 Obs: Mar 12—31, 2004

30. Daily Observations of Interstellar Scintillation in PSR B0329+54

31. Structure Function

32. Cross correlation Wang, N.; Yan, Z.; Manchester, R. N. et al.: 2008, MNRAS, 385, 1393

33. Other projects • Searching for Radio Pulsars in 3EG Sources at Urumqi Observatory Dong,J.; Wang,N.: 2006, ChJAS, 6b, 294 • Monitoring of Pulse Intensity and Mode Changing for PSR B0329+54 Liu,Z.Y.; Wang,N.; Urama,J.O. et al: 2006, ChJAS, 6b, 64

34. Timing Noise Yuan J. P. et al, 2009, MNRAS, in preparing

35. V1: Pulsar Timing Data Acquisition—PTDA，written in Visual C++, by N. Wang V2:Pulsar Observing —POP，Linux version, fits, written in C, by Z. Y. Liu Block Diagram for Online Program • Threads: • setting the digitizer parameters • data sampling • data unpacking & checking time synchronization, folding of channel data • de-dispersion, display • save data to disk • communicating with telescope computer Timing mode Single pulse mode Search mode

36. Future New back-end system • Digital filter-bank • Coherent de-disperse

37. A plan for 80m radio telescope • 80m • Freq：up to 22 GHz • digital filter-bank • Multi-beam Gravitation wave Pulsars as clock Deep space navigation Pulsar monitoring ABC Collaboration for Global Pulsar Monitoring (Australia，Britain，China)

39. 49°10′ 73°33′ 96°22′ 34°20′