A5045268996- Pulsars and Gravitational Waves Research
- Radio Astronomy Observations and Technology
- Geophysics and Gravity Measurements
- Astrophysics and Cosmic Phenomena
- GNSS positioning and interference
- Astrophysical Phenomena and Observations
- Computational Physics and Python Applications
- Cosmology and Gravitation Theories
- Gamma-ray bursts and supernovae
- Mechanics and Biomechanics Studies
- Particle physics theoretical and experimental studies
- Advanced Frequency and Time Standards
Netherlands Institute for Radio Astronomy
2024-2025
University of Manchester
2019-2023
University of Cambridge
2019
University College London
2017
Abstract We describe system verification tests and early science results from the pulsar processor (PTUSE) developed for newly commissioned 64-dish SARAO MeerKAT radio telescope in South Africa. is a high-gain ( ${\sim}2.8\,\mbox{K Jy}^{-1}$ ) low-system temperature ${\sim}18\,\mbox{K at }20\,\mbox{cm}$ array that currently operates 580–1 670 MHz can produce tied-array beams suitable observations. This paper presents MeerTime Large Survey Project commissioning with PTUSE. Highlights include...
We present the largest single survey to date of average profiles radio pulsars, observed and processed using same telescope data reduction software. Specifically, we measurements for 1170 by Thousand Pulsar Array (TPA) programme at 64-dish SARAO MeerKAT telescope, in a frequency band from 856 1712 MHz. provide rotation measures (RM), dispersion measures, flux densities polarization properties. The catalogue includes 254 new RMs that substantially increase total number known pulsar RMs. Our...
ABSTRACT We report on the subpulse modulation properties of 1198 pulsars using Thousand-Pulsar-Array programme MeerKAT. About 35 per cent analysed exhibit drifting subpulses that are more pronounced towards death line, consistent with previous studies. estimate this common phenomenon is detectable in 60 overall pulsar population if high-quality data were available for all. This large study reveals evolution across unprecedented detail. In particular, we find period P3 follows a V-shaped...
We report here on initial results from the Thousand Pulsar Array (TPA) programme, part of Large Survey Project "MeerTime" MeerKAT telescope. The interferometer is used in tied-array mode band 856 to 1712~MHz, and wide coupled with large collecting area low receiver temperature make it an excellent telescope for study radio pulsars. TPA a 5 year project which aims observe (a) more than 1000 pulsars obtain high-fidelity pulse profiles, (b) some 500 these over multiple epochs, (c) long...
Abstract We present pulse width measurements for a sample of radio pulsars observed with the MeerKAT telescope as part Thousand-Pulsar-Array (TPA) programme in MeerTime project. For centre frequency 1284 MHz, we obtain 762 W10 across total bandwidth 775 where is at 10 per cent level peak. also measure about 400 values each four or eight sub-bands. Assuming, function rotation period P, this relationship can be described power law index μ = −0.29 ± 0.03. However, using orthogonal distance...
Abstract Motivated by the recent discoveries that six Ultraluminous X-ray Sources (ULXs) are powered highly super-Eddington pulsars, we searched for additional pulsating ULX (PULX) candidates identifying sources exhibit long-term flux variability of at least an order magnitude (a common feature seen in 6 known PULXs, which may potentially be related to transitions propeller regime). Expanding on previous studies, used available fluxes from XMM-Newton, Swift and Chandra, along with carefully...
ABSTRACT We present the detection of 107 pulsars with interstellar scintillation arcs at 856–1712 MHz, observed MeerKAT Thousand Pulsar Array Programme. Scintillation appear to be ubiquitous in clean, high S/N observations, their mainly limited by short observing durations and coarse frequency channel resolution. This led survey sensitive nearby, lightly scattered effective velocity – from a large proper motion, screen nearby pulsar, or near Earth. measure arc curvatures all our sources,...
Abstract We present a comprehensive analysis of the complex subpulse modulation patterns in PSR J1514−4834 (B1510−48) using L-band data from Thousand-Pulsar-Array (TPA) programme, complemented with further MeerKAT UHF-band data. demonstrate that periodic drifting subpulses and rapid amplitude period about 2 pulse periods coexist. It is established these two emission interfere form beat system, giving rise to multiple spectral features. develop new methodology which confirms expected...
ABSTRACT A number of pulsars are known to have profile evolution on time-scales months, often correlated with spin-down rate changes. Here, we present the first result from 3 yr monitoring observations MeerKAT as part Thousand Pulsar Array programme. This programme obtains high-fidelity pulse profiles for ∼ 500 pulsars, which enabled detection subtle changes in seven sources not previously exhibit long-term evolution. 2D Gaussian convolution is used highlight emission variability both phase...
We report on the discovery of a new, transient ultraluminous X-ray source (ULX) in galaxy NGC 7090. This new ULX, which we refer to as 7090 ULX3, was discovered via monitoring with $Swift$ during 2019-20, and date has exhibited peak luminosity $L_{\rm{X}} \sim 6 \times 10^{39}$ erg s$^{-1}$. Archival searches show that, prior its recent transition into ULX regime, ULX3 appeared exhibit fairly stable 10^{38}$ Such strong long-timescale variability may be reminiscent small population known...
ABSTRACT The Thousand-Pulsar-Array (TPA) programme currently monitors about 500 pulsars with the sensitive MeerKAT radio telescope by using subarrays to observe multiple sources simultaneously. Here we define adopted observing strategy, which guarantees that each target is observed long enough obtain a high-fidelity pulse profile, thereby reaching sufficient precision of simple shape parameter. This estimated from contribution system noise telescope, and pulse-to-pulse variability pulsar,...
We present a campaign designed to train the GRANDMA network and its infrastructure follow up on transient alerts detect their early afterglows. In preparation for O4 II campaign, we focused GRB as they are expected be an electromagnetic counterpart of gravitational-wave events. Our goal was improve our response start prompt observations soon possible better prepare fourth observational run LIGO-Virgo-Kagra (which started at end May 2023), future missions such SM. To receive, manage send out...
A number of pulsars are known to have profile evolution on timescales months, often correlated with spin-down rate changes. Here, we present the first result from 3 years monitoring observations MeerKAT as part Thousand Pulsar Array programme. This programme obtains high-fidelity pulse profiles for $\sim$ 500 pulsars, which enabled detection subtle changes in seven sources not previously exhibit long-term evolution. 2D Gaussian convolution is used highlight emission variability both phase...
We have used sensitive LOw Frequency ARray (LOFAR) observations of PSR B0809+74 at 15--62 MHz to study the anomalously intensive pulses, first reported by Ulyanov et al. (2006) 18--30MHz. Similarly al., we found that spectra strong pulses consist distinct bright patches. Moreover, these spectral patches were spotted drift upwards in frequency over course several pulse sequences. established this is not pulsar-intrinsic, but caused broadband ~20 second-long enhancements recorded signal, which...