scholarly journals Diagnostics of timing noise in middle-aged pulsars

2019 ◽  
Vol 487 (4) ◽  
pp. 5854-5861 ◽  
Author(s):  
Nakornping Namkham ◽  
Phrudth Jaroenjittichai ◽  
Simon Johnston
Keyword(s):  
Gravitational Wave ◽  
Radio Telescope ◽  
Strong Correlation ◽  
Radio Pulsars ◽  
Middle Aged ◽  
Monthly Basis ◽  
Millisecond Pulsars ◽  
Pulsar Timing ◽  
Timing Noise

ABSTRACT Radio pulsars are often used as clocks in a wide variety of experiments. Imperfections in the clock, known as timing noise, have the potential to reduce the significance of, or even thwart e.g. the attempt to find a stochastic gravitational wave (GW) background. We measure the timing noise in a group of 129 mostly middle-aged pulsars (i.e. characteristic ages near 1 Myr) observed with the Parkes radio telescope on a monthly basis since 2014. We examine four different metrics for timing noise, but it remains unclear which, if any, provides the best determination. In spite of this, it is evident that these pulsars have significantly less timing noise than their younger counterparts, but significantly more than the (much older) millisecond pulsars (MSPs). As with previous authors, we find a strong correlation between timing noise and the pulsar spin-down rate, $\dot{\nu}$. However, for a given $\dot{\nu}$ there is a spread of about a factor of 30 in the strength of the timing noise likely indicating that nuclear conditions in the interior of the stars differ between objects. We briefly comment on the implications for GW detection through pulsar timing arrays as the level of timing noise in MSPs may be less than predicted.

scholarly journals Timing of young radio pulsars – II. Braking indices and their interpretation

2020 ◽  
Vol 494 (2) ◽  
pp. 2012-2026 ◽  
Author(s):  
A Parthasarathy ◽  
S Johnston ◽  
R M Shannon ◽  
L Lentati ◽  
M Bailes ◽  
...  
Keyword(s):  
Time Scales ◽  
Radio Telescope ◽  
Archival Data ◽  
Radio Pulsars ◽  
Pulsar Timing ◽  
Timing Noise

ABSTRACT In Paper I of this series, we detected a significant value of the braking index (n) for 19 young, high-$\dot{E}$ radio pulsars using ∼10 yr of timing observations from the 64-m Parkes radio telescope. Here, we investigate this result in more detail using a Bayesian pulsar timing framework to model timing noise and to perform selection to distinguish between models containing exponential glitch recovery and braking index signatures. We show that consistent values of n are maintained with the addition of substantial archival data, even in the presence of glitches. We provide strong arguments that our measurements are unlikely due to exponential recovery signals from unseen glitches even though glitches play a key role in the evolution of a pulsar’s spin frequency. We conclude that, at least over decadal time-scales, the value of n can be significantly larger than the canonical 3 and discuss the implications for the evolution of pulsars.

scholarly journals PULSAR TIMING ARRAYS

2013 ◽  
Vol 22 (01) ◽  
pp. 1341008 ◽  
Author(s):  
BHAL CHANDRA JOSHI
Keyword(s):  
Gravitational Wave ◽  
Gravitational Waves ◽  
Low Frequency ◽  
Radio Pulsars ◽  
Very Low Frequency ◽  
Pulsar Timing ◽  
Gravitational Wave Background ◽  
Pulsar Timing Array ◽  
Current Operating

In the last decade, the use of an ensemble of radio pulsars to constrain the characteristic strain caused by a stochastic gravitational wave background has advanced the cause of detection of very low frequency gravitational waves (GWs) significantly. This electromagnetic means of GW detection, called Pulsar Timing Array (PTA), is reviewed in this paper. The principle of operation of PTA, the current operating PTAs and their status are presented along with a discussion of the main challenges in the detection of GWs using PTA.

scholarly journals Gravitational wave research using pulsar timing arrays

2017 ◽  
Vol 4 (5) ◽  
pp. 707-717 ◽  
Author(s):  
George Hobbs ◽  
Shi Dai
Keyword(s):  
Gravitational Wave ◽  
High Precision ◽  
Low Frequency ◽  
Millisecond Pulsars ◽  
Pulsar Timing ◽  
Distributed Array ◽  
The Status ◽  
Wave Research ◽  
Near Future ◽  
Pulsar Timing Array

Abstract A pulsar timing array (PTA) refers to a program of regular, high-precision timing observations of a widely distributed array of millisecond pulsars. Here we review the status of the three primary PTA projects and the joint International Pulsar Timing Array project. We discuss current results related to ultra-low-frequency gravitational wave searches and highlight opportunities for the near future.

scholarly journals Rotation Measure variations for millisecond pulsars

2012 ◽  
Vol 8 (S291) ◽  
pp. 568-570
Author(s):  
Wenming Yan ◽  
R. N. Manchester ◽  
Na Wang
Keyword(s):  
Radio Telescope ◽  
Position Angle ◽  
Polarization Mode ◽  
Millisecond Pulsars ◽  
Pulsar Timing ◽  
Rotation Measure ◽  
The Mean ◽  
Pulsar Timing Array

AbstractAs part of the Parkes Pulsar Timing Array (PPTA) project, frequent observations of 20 millisecond pulsars are made using the Parkes 64-m radio telescope. Variations in the mean position angle of the 20 millisecond pulsars can be studied by the PPTA data being recorded in full-polarization mode. We briefly discuss these results.

scholarly journals Tracking dispersion measure variations of timing array pulsars with the GMRT

2012 ◽  
Vol 8 (S291) ◽  
pp. 432-434 ◽  
Author(s):  
Ujjwal Kumar ◽  
Yashwant Gupta ◽  
Willem van Straten ◽  
Stefan Osłowski ◽  
Jayanta Roy ◽  
...  
Keyword(s):  
Solar Wind ◽  
Solar Corona ◽  
Radio Telescope ◽  
Line Of Sight ◽  
Dispersion Measure ◽  
Millisecond Pulsars ◽  
Preliminary Comparison ◽  
Pulsar Timing ◽  
Single Epoch ◽  
Pulsar Timing Array

AbstractWe present the results from nearly three years of monitoring of the variations in dispersion measure (DM) along the line-of-sight to 11 millisecond pulsars using the Giant Metrewave Radio Telescope (GMRT). These results demonstrate accuracies of single epoch DM estimates of the order of 5 × 10−4 cm−3 pc. A preliminary comparison with the Parkes Pulsar Timing Array (PPTA) data shows that the measured DM fluctuations are comparable. We show effects of DM variations due to the solar wind and solar corona and compare with the existing models.

scholarly journals Timing of young radio pulsars – I. Timing noise, periodic modulation, and proper motion

2019 ◽  
Vol 489 (3) ◽  
pp. 3810-3826 ◽  
Author(s):  
A Parthasarathy ◽  
R M Shannon ◽  
S Johnston ◽  
L Lentati ◽  
M Bailes ◽  
...  
Keyword(s):  
Bayesian Inference ◽  
Plasma Physics ◽  
Proper Motion ◽  
Noise Amplitude ◽  
Periodic Modulation ◽  
Proper Motions ◽  
Radio Pulsars ◽  
Arrival Times ◽  
Pulsar Timing ◽  
Timing Noise

ABSTRACT The smooth spin-down of young pulsars is perturbed by two non-deterministic phenomenon, glitches, and timing noise. Although the timing noise provides insights into nuclear and plasma physics at extreme densities, it acts as a barrier to high-precision pulsar timing experiments. An improved methodology based on the Bayesian inference is developed to simultaneously model the stochastic and deterministic parameters for a sample of 85 high-$\dot{E}$ radio pulsars observed for ∼10 yr with the 64-m Parkes radio telescope. Timing noise is known to be a red process and we develop a parametrization based on the red-noise amplitude (Ared) and spectral index (β). We measure the median Ared to be $-10.4^{+1.8}_{-1.7}$ yr3/2 and β to be $-5.2^{+3.0}_{-3.8}$ and show that the strength of timing noise scales proportionally to $\nu ^{1}|\dot{\nu }|^{-0.6\pm 0.1}$, where ν is the spin frequency of the pulsar and $\dot{\nu }$ is its spin-down rate. Finally, we measure significant braking indices for 19 pulsars and proper motions for 2 pulsars, and discuss the presence of periodic modulation in the arrival times of 5 pulsars.

scholarly journals Pulsar timing at Kalyazin (Russia)

2000 ◽  
Vol 177 ◽  
pp. 57-60
Author(s):  
O.V. Doroshenko ◽  
Yu.P. Ilyasov ◽  
V.V. Oreshko
Keyword(s):  
General Relativity ◽  
Local Time ◽  
Radio Telescope ◽  
Orthogonal Polarization ◽  
Hydrogen Maser ◽  
Radio Pulsars ◽  
Time Service ◽  
Binary Pulsars ◽  
Front End ◽  
Pulsar Timing

AbstractRegular timing observations of millisecond and binary pulsars are made with the 64-m radio telescope at Kalyazin (Russia). Filterbank 160-channel receiver is used for observations at 0.6 GHz in two circular orthogonal polarization. Precise local time service (based upon a rubidium standards and hydrogen maser) is used for measurements of Times-of-Arrival (TOA) from radio pulsars. A local time scale is compared by GPS and TV-systems with the basic AT-scales (UTC(USNO) and UTC(SU)) within an accuracy about 50nsper day. Recently the second 1.4 GHz receiver (250 kHz × 64 channels) was constructed and installed at Kalyazin radio telescope. There is a possibility to combine a part of the 1.4 GHz back-end with the 2.2 GHz front-end to produce timing observations at three frequencies simultaneously. We present a results of precise timing observations conducted by the Kalyazin pulsar system. Most of data were obtained at 0.6 GHz in 1997–1999. The data will be used for valuable applications in fundamental metrology, interstellar medium, general relativity and pulsar physics itself.

scholarly journals Pulsar science at the Sardinia Radio Telescope

2017 ◽  
Vol 13 (S337) ◽  
pp. 392-393
Author(s):  
D. Perrodin ◽  
M. Burgay ◽  
A. Corongiu ◽  
M. Pilia ◽  
A. Possenti ◽  
...  
Keyword(s):  
Gravitational Wave ◽  
Radio Telescope ◽  
Galactic Center ◽  
Active Surface ◽  
Radio Bursts ◽  
Extraterrestrial Intelligence ◽  
Wave Detection ◽  
Pulsar Timing ◽  
Wide Range ◽  
Pulsar Timing Array

AbstractThe Sardinia Radio Telescope (SRT) is a modern, fully-steerable 64-m dish located in San Basilio, Sardinia (Italy). It is characterized by an active surface that allows it to cover a wide range of radio frequencies (300 MHz to 100 GHz). During SRT’s commissioning phase, we installed the hardware and software needed for pulsar observations. Since then, SRT has taken part in Large European Array for Pulsars and European Pulsar Timing Array observations for the purpose of gravitational wave detection. We have installed a new S-band receiver that will allow us to search for pulsars in the Galactic Center. We also plan to combine our efforts to search for Extraterrestrial Intelligence (SETI) with the search for pulsars and Fast Radio Bursts.

scholarly journals Commensal discovery of four fast radio bursts during Parkes Pulsar Timing Array observations

2019 ◽  
Vol 488 (1) ◽  
pp. 868-875 ◽  
Author(s):  
S Osłowski ◽  
R M Shannon ◽  
V Ravi ◽  
J F Kaczmarek ◽  
S Zhang ◽  
...  
Keyword(s):  
Radio Telescope ◽  
Spectral Properties ◽  
Signal To Noise Ratio ◽  
Radio Bursts ◽  
Signal To Noise ◽  
Fundamental Physics ◽  
Millisecond Pulsars ◽  
Pulsar Timing ◽  
Physics Experiments ◽  
Pulsar Timing Array

ABSTRACT The Parkes Pulsar Timing Array (PPTA) project monitors two dozen millisecond pulsars (MSPs) in order to undertake a variety of fundamental physics experiments using the Parkes 64-m radio telescope. Since 2017 June, we have been undertaking commensal searches for fast radio bursts (FRBs) during the MSP observations. Here, we report the discovery of four FRBs (171209, 180309, 180311, and 180714). The detected events include an FRB with the highest signal-to-noise ratio ever detected at the Parkes Observatory, which exhibits unusual spectral properties. All four FRBs are highly polarized. We discuss the future of commensal searches for FRBs at Parkes.

scholarly journals Pulsars and Gravitational Wave Detection

2005 ◽  
Vol 22 (3) ◽  
pp. 179-183 ◽  
Author(s):  
George Hobbs
Keyword(s):  
Gravitational Wave ◽  
Gravitational Waves ◽  
Radio Telescope ◽  
Gravitational Wave Detector ◽  
Gravitational Wave Detection ◽  
Wave Detection ◽  
Wave Detector ◽  
Stochastic Background ◽  
Pulsar Timing ◽  
Pulsar Timing Array

AbstractThe number of known millisecond pulsars has dramatically increased in the last few years. Regular observations of these pulsars may allow gravitational waves with frequencies ∼10−9 Hz to be detected. A ‘pulsar timing array’ is therefore complimentary to other searches for gravitational waves using ground-based or space-based interferometers that are sensitive to much higher frequencies. In this review we describe (1) the basic methods for using an array of pulsars as a gravitational wave detector, (2) the sources of the potentially detectable waves, (3) current limits on individual sources and a stochastic background, and (4) the new project recently started using the Parkes radio telescope.

Sign in / Sign up

Export Citation Format

Share Document