Long-term monitoring of RRAT J1819-1458HU HuiDonghuhd@uao.ac.cnUrumqi Observatory, NAOCJuly 27, 2009Rotating Radio Transients Observation

Rotating Radio Transients (RRATs)11 discovered and published on Nature (M. A. McLaughlin et al. 2006)Characters of the 11 RRATsBursts duration between 2 and 30 msAverage time intervals between bursts range from 4 minutes to 3 hoursPeriodicities, 0.4-7sDetectible flux duration

http://www.as.wvu.edu/~pulsar/rratalog/

About RRAT J1819-1458Mclaughlin et al. 2006, Nature 439, 817Burst rate: 17 per hourBurst duration: 2 msPeak flux : ~3.6 Jy

Single pulses timingP: 4.26 sP-dot: 576 10-15 s/s DM: 196 (3) pc cm-3

Age: 117 KyrBsurf: 5 1013 GaussRadio observations X-ray observations The Chandra observation detected the X-ray counterpart (Reynolds et al. 2006).

XMMNewton, discovered the X-ray pulsations with the period predicted by the timing of radio bursts. Mclaughlin et al. (2007)So, what is it?

Observation system and de-dispersion method128 channels, with bandwidth 2.5M Hz2 polarizations,Center frequency is 1540M Hz

Observations of RRATsGiant pulses of some pulsarsSearch of extremely strong pulses from pulsars PSR B0656+14 Weltevrede et al. 2006 ApJ645 147Small-time-scale radio transients searchMonitoring of magnetars (AXP & SGRs)Based on the Filter-Bank de-dispersion system, We developed software to search rare and strong single pulses.Since March 2007:Identifying the signal

Long Term monitoring of RRAT J1819-1458-- Timing results from 162 burstsUpdated to Mar. 2008Esamdin et al. 2008MNRAS, 389, 1399DM=196.0(4)

Long Term monitoring of RRAT J1819-1458-- Timing results from 162 burstsSingle pulse timingUpdated to Mar. 2008Esamdin et al. 2008MNRAS, 389, 1399

Long Term monitoring of RRAT J1819-1458-- Timing results from 162 burstsTiming positionTiming residuals and pulse phasesBimodal distribution of pulse phase?In fact, there are even moreUpdated to Mar. 2008Esamdin et al. 2008MNRAS, 389, 1399

About 350 strong bursts detected updated to June 2009Long-Term monitoring of RRAT J1819-1458Timing irregularity: First glitch detected in RRAT Epoch around MJD 54580

Long-Term monitoring of RRAT J1819-1458Top left: Timing residuals with 1st glitch fitted.Bottom right: Timing residuals with both glitches fitted

Long Term monitoring of RRAT J1819-1458Glitch parameters got:Epoch of Glitch 1: MJD 54572: 1.989(8)10-09 Hz(dot):8.11(7)10-17 Hz s-1

Epoch of Glitch 2: MJD 54870: 1.02(1) 10-09 Hz(dot): 1.8(2) 10-17 Hz s-1The second glitch is too small?

Long Term monitoring of RRAT J1819-1458

Summary:In observation of hundreds of hours, we detected about 350 dispersed bursts of RRAT J18191458 with the signal-to-noise ratios (S/Ns) above 5 threshold. The S/N of the strongest burst is 13.3.The sources DM measured through our data is 196.0 0.4 pc cm3. Our timing position with 2 error is consistent with the position of its X-ray counterpart CXOU J181934.1145804. 2 glitches detected in observation during 800 days, with first one at MJD 54572, the other one at MJD 54870.The distribution of the timing residuals is bimodal before the first glitch, but has only one main component between the 2 glitches, and becomes bimodal again after the second glitch.Careful study of the radio bursts properties is necessary to get a more accurate parameter of the second glitch.Long Term monitoring of RRAT J1819-1458

Thanks!And, Thanks to YUAN J.P. ZHAO C.S. and A. Esamdin