Publications (51)
European Pulsar Timing Array Limits on Continuous Gravitational Waves from Individual Supermassive Black Hole Binaries
Stanislav Babak, Antoine Petiteau, Alberto Sesana +33
We have searched for continuous gravitational wave (CGW) signals produced by individually resolvable, circular supermassive black hole binaries (SMBHBs) in the latest EPTA dataset,…
Discovery of PSR J1227-4853: A transition from a low-mass X-ray binary to a redback millisecond pulsar
Jayanta Roy, Paul S. Ray, Bhaswati Bhattacharyya +12
XSS J12270-4859 is an X-ray binary associated with the Fermi LAT gamma-ray source 1FGL J1227.9-4852. In 2012 December, this source underwent a transition where the X-ray and optica…
The European Pulsar Timing Array: current efforts and a LEAP toward the future
Robert D. Ferdman, Rutger van Haasteren, Cees G. Bassa +22
The European Pulsar Timing Array (EPTA) is a multi-institutional, multi-telescope collaboration, with the goal of using high-precision pulsar timing to directly detect gravitationa…
Finding pulsars with LOFAR
Joeri van Leeuwen, Ben Stappers
We investigate the number and type of pulsars that will be discovered with the low-frequency radio telescope LOFAR. We consider different search strategies for the Galaxy, for glob…
New results from LOFAR
Vladislav Kondratiev, Ben Stappers, the LOFAR Pulsar Working Group
The LOw Frequency Array, LOFAR, is a next generation radio telescope with its core in the Netherlands and elements distributed throughout Europe. It has exceptional collecting area…
Multi-wavelength Observations of the Radio Magnetar PSR J1622-4950 and Discovery of its Possibly Associated Supernova Remnant
Gemma E. Anderson, B. M. Gaensler, Patrick O. Slane +29
We present multi-wavelength observations of the radio magnetar PSR J1622-4950 and its environment. Observations of PSR J1622-4950 with Chandra (in 2007 and 2009) and XMM (in 2011)…
An optical bow shock around the nearby millisecond pulsar J2124-3358
Bryan Gaensler, Heath Jones, Ben Stappers
We report the discovery of an H-alpha-emitting bow-shock nebula powered by the nearby millisecond pulsar J2124-3358. The bow shock is very broad, and is highly asymmetric about the…
Probing the neutron star interior and the Equation of State of cold dense matter with the SKA
Anna Watts, Renxin Xu, Cristobal Espinoza +15
With an average density higher than the nuclear density, neutron stars (NS) provide a unique test-ground for nuclear physics, quantum chromodynamics (QCD), and nuclear superfluidit…
Multiwavelength observations of a new black-widow millisecond pulsar PSR J1544-2555
Sergio Belmonte Diaz, Tinn Thongmeearkom, Adipol Phosrisom +20
We report the discovery of a new black-widow millisecond pulsar, PSR J1544-2555, associated with the Fermi-LAT source 4FGL J1544.2-2554. Optical, radio, and gamma-ray observations…
Study of eclipses for Redback pulsar J12274853
Sanjay Kudale, Jayanta Roy, Bhaswati Bhattacharyya +2
We present a multi-frequency study of eclipse properties of a transitional redback millisecond pulsar J12274853 discovered in 2014 with the GMRT. Emission from this pulsar is ec…
Evolution of the Magnetic Field Structure of the Crab Pulsar
Andrew Lyne, Francis Graham-Smith, Patrick Weltevrede +4
Pulsars are highly-magnetised rotating neutron stars and are well-known for the stability of their signature pulse shapes, allowing high-precision studies of their rotation. Howeve…
The LOFAR Transients Key Project
Rob Fender, Robert Braun, Ben Stappers +18
LOFAR, the Low Frequency Array, is a new radio telescope under construction in the Netherlands, designed to operate between 30 and 240 MHz. The Transients Key Project is one of the…
Finding pulsars with LOFAR
Joeri van Leeuwen, Ben Stappers
We investigate the number and type of pulsars that will be discovered with the low-frequency radio telescope LOFAR. We consider different search strategies for the Galaxy, for glob…
Long-Period Transients as a new frontier in time-domain astronomy
Manisha Caleb, Dougal Dobie, Natasha Hurley-Walker +8
Long-period radio transients (LPTs) are relatively new astrophysical objects occupying the observational gap between canonical pulsars and slowly varying radio variables. They emit…
European Pulsar Timing Array Limits On An Isotropic Stochastic Gravitational-Wave Background
Lindley Lentati, Stephen R. Taylor, Chiara M. F. Mingarelli +33
We present new limits on an isotropic stochastic gravitational-wave background (GWB) using a six pulsar dataset spanning 18 yr of observations from the 2015 European Pulsar Timing…
Very Long Baseline Interferometry Measured Proper Motion and Parallax of the -ray Millisecond Pulsar PSR J0218+4232
Yuanjie Du, Jun Yang, Robert M. Campbell +3
PSR J02184232 is a millisecond pulsar (MSP) with a flux density 0.9 mJy at 1.4 GHz. It is very bright in the high-energy X-ray and -ray domains. We conducted an astro…
A Massive-born Neutron Star with a Massive White Dwarf Companion
Ismael Cognard, Paulo C. C. Freire, Lucas Guillemot +10
We report on the results of a 4-year timing campaign of PSR~J2222, a 2.44-day binary pulsar with a massive white dwarf (WD) companion, with the Nançay, Effelsberg and Lovel…
LOFAR, LEAP and beyond: Using next generation telescopes for pulsar astrophysics
Michael Kramer, Ben Stappers
Radio astronomy has benefited greatly from advances in technology and will continue to do so in the future. In fact, we are experiencing a revolution in the way radio astronomy is…
Early Pulsar Observations with LOFAR
Jason Hessels, Ben Stappers, Anastasia Alexov +10
This contribution to the proceedings of "A New Golden Age for Radio Astronomy" is simply intended to give some of the highlights from pulsar observations with LOFAR at the time of…
Switched magnetospheric regulation of pulsar spin-down
Andrew Lyne, George Hobbs, Michael Kramer +2
Pulsars are famed for their rotational clock-like stability and their highly-repeatable pulse shapes. However, it has long been known that there are unexplained deviations (often t…
The Third Fermi Large Area Telescope Catalog of Gamma-ray Pulsars
David A. Smith, Philippe Bruel, Colin J. Clark +156
We present 294 pulsars found in GeV data from the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope. Another 33 millisecond pulsars (MSPs) discovered in deep radio…
The Subpulse Modulation Properties of Pulsars and its Frequency Dependence
Patrick Weltevrede, Ben Stappers, R. T. Edwards
A large sample of about two hundred pulsars have been observed to study their subpulse modulation at an observing wavelength of (when achievable) both 21 and 92 cm using the Wester…
Pulsar bow shocks as probes of warm neutral gas
Bryan Gaensler, Ben Stappers, Shami Chatterjee +3
Pulsars have mean space velocities >~500 km/s. The consequent ram pressure results in tight confinement of the star's energetic wind, driving a bow shock into the surrounding mediu…
Radio Pulse Profile Evolution of Magnetar Swift J1818.0-1607
Rebecca Fisher, Elliot Butterworth, Kaustubh Rajwade +9
The shape and polarisation properties of the radio pulse profiles of radio-loud magnetars provide a unique opportunity to investigate their magnetospheric properties. Gaussian Proc…
Wide-band timing of GMRT discovered millisecond pulsars
Shyam S. Sharma, Jayanta Roy, Bhaswati Bhattacharyya +6
Modeling of frequency-dependent effects, contributed by the turbulence in the free electron density of interstellar plasma, is required to enable the detection of the expected impr…
45 Years of Rotation of the Crab Pulsar
Andrew Lyne, Christine Jordan, Francis Graham-Smith +3
The 30-Hz rotation rate of the Crab pulsar has been monitored at Jodrell Bank Observatory since 1984 and by other observatories before then. Since 1968, the rotation rate has decre…
Search for gravitational wave signals from known pulsars in LIGO-Virgo O3 data using the 5n-vector ensemble method
Luca D'Onofrio, Rosario De Rosa, Cristiano Palomba +16
The 5n-vector ensemble method is a multiple test for the targeted search of continuous gravitational waves from an ensemble of known pulsars. This method can improve the detection…
A 34 Yr Timing Solution of the Redback Millisecond Pulsar Terzan 5A
Alexandra C. Rosenthal, Scott M. Ransom, Kyle A. Corcoran +12
We present a 34-year timing solution of the redback pulsar system Terzan 5A (Ter5A). Ter5A, also known as B174424A or J17482446A, has a 11.56 ms pulse period, a 0.1 sol…
Commensal image plane transient search methods with the SKAO
Alex Andersson, Dougal Dobbie, Natasha Hurley-Walker +7
This chapter outlines the key, state of the art, techniques required to conduct commensal image plane transient searches. Using significant experience and expertise from conducting…
Searching for the signatures of jet-ISM interactions in X-ray binaries
James Miller-Jones, Christian Kaiser, Tom Maccarone +8
Jets from X-ray binaries are continuously injecting matter and energy into the surrounding interstellar medium (ISM). However, there exist to date relatively few cases where jet-IS…
Measuring pulsar profile variations with 2-D Gaussian process regression
Michael J. Keith, Renée Spiewak, Andrew G. Lyne +3
Time-correlated variations in the pulse profiles of radio pulsars provide insights into changes in their magnetospheres. For a small number of pulsars (~20), these variations have…
The GMRT High-Resolution Southern Sky Survey for pulsars and transients -- VII: Timing of Spider MSP J1242-4712, A Bridge Between Redback and Black Widow Pulsars
Ankita Ghosh, Bhaswati Bhattacharyya, Andrew Lyne +7
We present the timing solution for the 5.31-ms spider millisecond pulsar (MSP) J1242-4712, discovered with the GMRT. PSR J1242-4712 orbits a companion of minimum mass 0.08 M$_{\odo…
LOFAR Transients and the Radio Sky Monitor
Rob Fender, Ralph Wijers, Ben Stappers +1
The study of transient and variable low-frequency radio sources is a key goal for LOFAR, with an extremely broad science case ranging from relativistic jets sources to pulsars, exo…
FRB 20210405I: a nearby Fast Radio Burst localised to sub-arcsecond precision with MeerKAT
Laura Nicole Driessen, Ewan Barr, David Buckley +19
We present the first sub-arcsecond localised Fast Radio Burst (FRB) detected using MeerKAT. FRB 20210405I was detected in the incoherent beam using the MeerTRAP pipeline on 2021 Ap…
Gravitational Wave Hotspots: Ranking Potential Locations of Single-Source Gravitational Wave Emission
Joseph Simon, Abigail Polin, Andrea Lommen +4
The steadily improving sensitivity of pulsar timing arrays (PTAs) suggests that gravitational waves (GWs) from supermassive black hole binary (SMBHB) systems in the nearby universe…
Investigation of a Machine learning methodology for the SKA pulsar search pipeline
Shashank Sanjay Bhat, Thiagaraj Prabu, Ben Stappers +4
The SKA pulsar search pipeline will be used for real time detection of pulsars. Modern radio telescopes such as SKA will be generating petabytes of data in their full scale of oper…
A Radio Flare in the Long-Lived Afterglow of the Distant Short GRB 210726A: Energy Injection or a Reverse Shock from Shell Collisions?
Genevieve Schroeder, Lauren Rhodes, Tanmoy Laskar +32
We present the discovery of the radio afterglow of the short -ray burst (GRB) 210726A, localized to a galaxy at a photometric redshift of . While radio observations…
Large magnetic field variations towards the Galactic Centre magnetar, PSR J1745-2900
Gregory Desvignes, Ralph Eatough, Ue-Li Pen +13
Polarised radio emission from PSR J1745-2900 has already been used to investigate the strength of the magnetic field in the Galactic Centre, close to Sagittarius A*. Here we report…
Long-Term Radio Timing Observations of the Transition Millisecond Pulsar PSR~J1023+0038
Anne M. Archibald, Victoria M. Kaspi, Jason W. T. Hessels +3
The radio millisecond pulsar PSR J1023+0038 exhibits complex timing and eclipse behavior. Here we analyze four years' worth of radio monitoring observations of this object. We obta…
A highly magnetized long-period radio transient exhibiting unusual emission features
Yunpeng Men, Sam McSweeney, Natasha Hurley-Walker +2
Long-period radio transients are a new class of astrophysical objects that exhibit periodic radio emission on timescales of tens of minutes. Their true nature remains unknown; poss…
Non-detection of a pulsar-powered nebula in Puppis A, and implications for the nature of the radio-quiet neutron star RX J0822-4300
Bryan Gaensler, Douglas Bock, Ben Stappers
We report on a deep radio search for a pulsar wind nebula associated with the radio-quiet neutron star RX J0822-4300 in the supernova remnant Puppis A. The well-determined properti…
UK Astronomy Science and Technology Roadmap: STFC Astronomy Advisory Panel Roadmap 2022
Stephen Serjeant, James Bolton, Poshak Gandhi +4
This document summarises the UK astronomy community's science and technology priorities for funding and investments in the coming decades, following a series of national community…
PuMaII: A wide band pulsar machine for the WSRT
Ramesh Karuppusamy, Ben Stappers, Willem van Straten
The Pulsar Machine II (PuMa II) is the new flexible pulsar processing backend system at the Westerbork Synthesis Radio Telescope (WSRT), specifically designed to take advantage of…
Pulsar Science with the SKA
Michael Kramer, Ben Stappers
The SKA will be transformational for many areas of science, but in particular for the study of neutron stars and their usage as tools for fundamental physics in the form of radio p…
FPGA-based Matched Filter Group Optimisation for SKA Pulsar Search Engine
Haomiao Wang, Ben Stappers, Prabu Thiagaraj +1
Pulsar search is one of the main tasks for the Square Kilometre Array (SKA), implemented in the central signal processor (CSP) sub-element. As most the characteristics of undiscove…
A Radio-loud Magnetar in X-ray Quiescence
Lina Levin, Matthew Bailes, Samuel Bates +12
As part of a survey for radio pulsars with the Parkes 64-m telescope we have discovered PSR J1622-4950, a pulsar with a 4.3-s rotation period. Follow-up observations show that the…
The Binary Nature of PSR J2032+4127
Andrew Lyne, Ben Stappers, Michael Keith +4
PSR J2032+4127 is a gamma-ray and radio-emitting pulsar which has been regarded as a young luminous isolated neutron star. However, its recent spin-down rate has extraordinarily in…
The Astrophysics of Fast Radio Bursts
Alice P. Curtin, Marcin GawroÅski, Jason Hessels +11
Fast radio bursts (FRBs) provide a glimpse of high-energy astrophysical phenomena in other galaxies. They point the way to extreme conditions that are currently undetectable by any…
A low frequency study of PSRs B1133+16, B1112+50, and B0031-07
Ramesh Karuppusamy, Ben Stappers, Maciej Serylak
The low frequency (110--180 MHz) capabilities of the Westerbork Synthesis Radio Telescope (WSRT) are used to characterise a large collection of single pulses from three low magneti…
Localisation and host galaxy identification of new Fast Radio Bursts with MeerKAT
Inés Pastor-Marazuela, Alexa C. Gordon, Ben Stappers +18
Accurately localising fast radio bursts (FRBs) is essential for understanding their birth environments and for their use as cosmological probes. Recent advances in radio interferom…
A highly polarised radio jet during the 1998 outburst of the black hole transient XTE J1748-288
Catherine Brocksopp, James Miller-Jones, Rob Fender +1
XTE J1748-288 is a black hole X-ray transient which went into outburst in 1998 June. The X-ray lightcurves showed canonical morphologies, with minor variations on the ``Fast Rise E…