scholarly journals Evidence for profile changes in PSR J1713+0747 using the uGMRT

2021 ◽  
Vol 507 (1) ◽  
pp. L57-L61
Author(s):  
Jaikhomba Singha ◽  
Mayuresh P Surnis ◽  
Bhal Chandra Joshi ◽  
Pratik Tarafdar ◽  
Prerna Rana ◽  
...  
Keyword(s):  
Time Scale ◽  
Free Parameter ◽  
Shape Change ◽  
Timing Analysis ◽  
Chromatic Index ◽  
Pulsar Timing ◽  
Before And After ◽  
Profile Changes ◽  
Pulsar Timing Array ◽  
Profile Change

ABSTRACT PSR J1713+0747 is one of the most precisely timed pulsars in the international pulsar timing array experiment. This pulsar showed an abrupt profile shape change between 2021 April 16, (MJD 59320) and 2021 April 17 (MJD 59321). In this paper, we report the results from multi-frequency observations of this pulsar carried out with the upgraded Giant Metrewave Radio Telescope (uGMRT) before and after the event. We demonstrate the profile change seen in Band 5 (1260 MHz–1460 MHz) and Band 3 (300 MHz–500 MHz). The timing analysis of this pulsar shows a disturbance accompanying this profile change followed by a recovery with a time-scale of ∼159 days. Our data suggest that a model with chromatic index as a free parameter is preferred over models with combinations of achromaticity with DM bump or scattering bump. We determine the frequency dependence to be ∼ν+1.34.

scholarly journals A pulsar-based time-scale from the International Pulsar Timing Array

2019 ◽  
Vol 491 (4) ◽  
pp. 5951-5965 ◽  
Author(s):  
G Hobbs ◽  
L Guo ◽  
R N Caballero ◽  
W Coles ◽  
K J Lee ◽  
...  
Keyword(s):  
Time Scales ◽  
Time Scale ◽  
Limiting Factor ◽  
Radio Pulsars ◽  
Pulsar Timing ◽  
The Us ◽  
The Stability ◽  
Solar System Dynamics ◽  
Noise Models ◽  
Pulsar Timing Array

ABSTRACT We have constructed a new time-scale, TT(IPTA16), based on observations of radio pulsars presented in the first data release from the International Pulsar Timing Array (IPTA). We used two analysis techniques with independent estimates of the noise models for the pulsar observations and different algorithms for obtaining the pulsar time-scale. The two analyses agree within the estimated uncertainties and both agree with TT(BIPM17), a post-corrected time-scale produced by the Bureau International des Poids et Mesures (BIPM). We show that both methods could detect significant errors in TT(BIPM17) if they were present. We estimate the stability of the atomic clocks from which TT(BIPM17) is derived using observations of four rubidium fountain clocks at the US Naval Observatory. Comparing the power spectrum of TT(IPTA16) with that of these fountain clocks suggests that pulsar-based time-scales are unlikely to contribute to the stability of the best time-scales over the next decade, but they will remain a valuable independent check on atomic time-scales. We also find that the stability of the pulsar-based time-scale is likely to be limited by our knowledge of solar-system dynamics, and that errors in TT(BIPM17) will not be a limiting factor for the primary goal of the IPTA, which is to search for the signatures of nano-Hertz gravitational waves.

scholarly journals Pulsar timing array

2009 ◽  
Vol 5 (H15) ◽  
pp. 229-230
Author(s):  
Alexander E. Rodin
Keyword(s):  
Gravitational Waves ◽  
Time Scale ◽  
Reference Frames ◽  
Pulsar Time ◽  
Pulsar Timing ◽  
Pulsar Timing Array

AbstractSimultaneous timing of several pulsars distributed over the sky, so called Pulsar Timing Array (PTA), is used for a variety of metrological and astronomical applications. Three examples of PTA application are presented: link between celestial reference frames, ensemble pulsar time scale and detection of gravitational waves.

scholarly journals Timing analysis for 20 millisecond pulsars in the Parkes Pulsar Timing Array

2015 ◽  
Vol 455 (2) ◽  
pp. 1751-1769 ◽  
Author(s):  
D. J. Reardon ◽  
G. Hobbs ◽  
W. Coles ◽  
Y. Levin ◽  
M. J. Keith ◽  
...  
Keyword(s):  
Timing Analysis ◽  
Millisecond Pulsars ◽  
Pulsar Timing ◽  
Pulsar Timing Array

scholarly journals Pulsar time scale and its future application

2012 ◽  
Vol 8 (S291) ◽  
pp. 365-365
Author(s):  
Ding Chen ◽  
George Hobbs ◽  
William Coles ◽  
Richard Manchester
Keyword(s):  
Time Scale ◽  
Future Application ◽  
Pulsar Time ◽  
Pulsar Timing ◽  
Pulsar Timing Array

AbstractAn Ensemble Pulsar Time Scale (EPT) is derived based on the Pulsar Timing Array. It is interesting to compare the EPT with the TT terrestrial time scale, and get many new realization on the pulsar time scale and the algorithm. Some future interesting applications of the EPT are described and discussed.

scholarly journals The Parkes Pulsar Timing Array Project

2013 ◽  
Vol 30 ◽  
Author(s):  
R. N. Manchester ◽  
G. Hobbs ◽  
M. Bailes ◽  
W. A. Coles ◽  
W. van Straten ◽  
...  
Keyword(s):  
Timing Analysis ◽  
Time Derivative ◽  
Pulse Frequency ◽  
Data Set ◽  
Pulsar Timing ◽  
Timing Data ◽  
Timing Noise ◽  
Celestial Sphere ◽  
First Time ◽  
Pulsar Timing Array

AbstractA ‘pulsar timing array’ (PTA), in which observations of a large sample of pulsars spread across the celestial sphere are combined, allows investigation of ‘global’ phenomena such as a background of gravitational waves or instabilities in atomic timescales that produce correlated timing residuals in the pulsars of the array. The Parkes Pulsar Timing Array (PPTA) is an implementation of the PTA concept based on observations with the Parkes 64-m radio telescope. A sample of 20 ms pulsars is being observed at three radio-frequency bands, 50 cm (~700 MHz), 20 cm (~1400 MHz), and 10 cm (~3100 MHz), with observations at intervals of two to three weeks. Regular observations commenced in early 2005. This paper describes the systems used for the PPTA observations and data processing, including calibration and timing analysis. The strategy behind the choice of pulsars, observing parameters, and analysis methods is discussed. Results are presented for PPTA data in the three bands taken between 2005 March and 2011 March. For 10 of the 20 pulsars, rms timing residuals are less than 1 μs for the best band after fitting for pulse frequency and its first time derivative. Significant ‘red’ timing noise is detected in about half of the sample. We discuss the implications of these results on future projects including the International Pulsar Timing Array and a PTA based on the Square Kilometre Array. We also present an ‘extended PPTA’ data set that combines PPTA data with earlier Parkes timing data for these pulsars.

scholarly journals The Parkes Pulsar Timing Array Project

2009 ◽  
Vol 5 (H15) ◽  
pp. 233-233
Author(s):  
R. N. Manchester
Keyword(s):  
Solar System ◽  
Gravitational Waves ◽  
Time Scale ◽  
Millisecond Pulsars ◽  
Pulsar Timing ◽  
Pulsar Timing Array

AbstractThe Parkes Pulsar Timing Array project is timing 20 millisecond pulsars with the aims of detecting gravitational waves, establishing a time scale based on pulsar periods and improving solar-system ephemerides.

scholarly journals Mode changing in J1909−3744: the most precisely timed pulsar

2021 ◽  
Author(s):  
M T Miles ◽  
R M Shannon ◽  
M Bailes ◽  
D J Reardon ◽  
S Buchner ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Timing Analysis ◽  
Pulse Mode ◽  
Millisecond Pulsar ◽  
Pulsar Timing ◽  
The Individual ◽  
The Impact ◽  
Gravitational Wave Background ◽  
Green Bank Telescope ◽  
Pulsar Timing Array

Abstract We present baseband radio observations of the millisecond pulsar J1909−3744, the most precisely timed pulsar, using the MeerKAT telescope as part of the MeerTime pulsar timing array campaign. During a particularly bright scintillation event the pulsar showed strong evidence of pulse mode changing, among the first millisecond pulsars and the shortest duty cycle millisecond pulsar to do so. Two modes appear to be present, with the weak (lower signal-to-noise ratio) mode arriving 9.26 ±3.94 μs earlier than the strong counterpart. Further, we present a new value of the jitter noise for this pulsar of 8.20 ± 0.14 ns in one hour, finding it to be consistent with previous measurements taken with the MeerKAT (9 ± 3 ns) and Parkes (8.6 ± 0.8 ns) telescopes, but inconsistent with the previously most precise measurement taken with the Green Bank telescope (14 ± 0.5 ns). Timing analysis on the individual modes is carried out for this pulsar, and we find an approximate $10\%$ improvement in the timing precision is achievable through timing the strong mode only as opposed to the full sample of pulses. By forming a model of the average pulse from templates of the two modes, we time them simultaneously and demonstrate that this timing improvement can also be achieved in regular timing observations. We discuss the impact an improvement of this degree on this pulsar would have on searches for the stochastic gravitational wave background, as well as the impact of a similar improvement on all MeerTime PTA pulsars.

scholarly journals Searching for gravitational-wave bursts from cosmic string cusps with the Parkes Pulsar Timing Array

2020 ◽  
Vol 501 (1) ◽  
pp. 701-712
Author(s):  
N Yonemaru ◽  
S Kuroyanagi ◽  
G Hobbs ◽  
K Takahashi ◽  
X-J Zhu ◽  
...  
Keyword(s):  
False Alarm ◽  
Gravitational Wave ◽  
Cosmic String ◽  
Cosmic Strings ◽  
False Alarm Probability ◽  
String Tension ◽  
Detection Algorithm ◽  
Pulsar Timing ◽  
Upper Limits ◽  
Pulsar Timing Array

ABSTRACT Cosmic strings are potential gravitational-wave (GW) sources that can be probed by pulsar timing arrays (PTAs). In this work we develop a detection algorithm for a GW burst from a cusp on a cosmic string, and apply it to Parkes PTA data. We find four events with a false alarm probability less than 1 per cent. However further investigation shows that all of these are likely to be spurious. As there are no convincing detections we place upper limits on the GW amplitude for different event durations. From these bounds we place limits on the cosmic string tension of Gμ ∼ 10−5, and highlight that this bound is independent from those obtained using other techniques. We discuss the physical implications of our results and the prospect of probing cosmic strings in the era of Square Kilometre Array.

scholarly journals Ensemble Pulsar Time Study by Pulsar Timing Observations

2004 ◽  
Vol 218 ◽  
pp. 439-440
Author(s):  
Tinggao Yang ◽  
Guangren Ni
Keyword(s):  
Time Scale ◽  
Wavelet Decomposition ◽  
Time Study ◽  
Millisecond Pulsar ◽  
Millisecond Pulsars ◽  
Pulsar Time ◽  
Pulsar Timing ◽  
Timing Data ◽  
Gravitational Wave Background

Long term timing of multiple millisecond pulsars can contribute to the study of an ensemble pulsar time scale PTens. A wavelet decomposition algorithm (WDA) was applied to define a PTens using the available millisecond pulsar timing datA. The PTens obtained from WDA is more stable than those resulting from other algorithms. The Chinese 50 m radio telescope is specially designed for PTens study and detection of gravitational wave background via millisecond pulsars timing observations. A scheme for multiple millisecond pulsar timing and ensemble pulsar time study is discussed in some detail.

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