Pulsar Studies at Urumqi Na Wang Urumqi Observatory, NAOC

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

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

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

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

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

Glitch & Timing Noise Study

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. Urumqi: Detected a slow glitch in PSR B (J ) Similar glitches were also observed in PSR B by Shabanova & Urama (2000) Unusual glitch behaviours of two young pulsars

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 has the reversed sign of before and after the glitch. There was little or no change in at the time of the glitch. Detected one glitch in PSR J Zou, W. Z.; Wang, N.; Wang, H. X.; Manchester R. N. et al. 2004, MNRAS, 354, 811

Observations of Six Glitches in PSR B

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

n= -3(1) Observations of Six Glitches in PSR B

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

Glitch Model: Fractional decay Q = △ ν d / △ ν g Size △ ν/ν=10 -6 time constant τ d =400 d

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

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

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

20/25 Analyzed timing noise for 100 pulsars, to study the effect of timing noise to the accuracy of pulsar position measurement White noise Red noise

拟投 MNRAS Long term monitoring of RRAT 1819 － 1458 RRATs are discovered in 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。

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

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 B PSR B PSR B PSR B PSR B Wang, N.; Manchester, R. N.; Johnston, S.; Rickett, Bet al.: 2005, MNRAS, 358, 270

Dynamic spectra of PSR B DM ＝ 26.8 pc cm -3 Dist = 1.06 kpc 3 hr obs. Δt d ～ min Δν d ～ 5-15 MHz

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

Modulation indices Observed > prediction !!

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

Kolmogorov Spectrum β=3.67

Daily Observations of Interstellar Scintillation in PSR B Obs: Mar 12—31, 2004

Daily Observations of Interstellar Scintillation in PSR B

Structure Function

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

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 B Liu, Z. Y.; Wang, N.; Urama, J. O. et al: 2006, ChJAS, 6b, 64

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

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 Block Diagram for Online Program 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 Timing mode Single pulse mode Search mode

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

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

49°10′ 34°20′ 73°33′ 96°22′