41 citations · 150 across the 31 of their papers we have counts for
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Constraints on Supermassive Black Hole Binaries from the Lack of Resolvable Sources in the NANOGrav 15-yr Dataset
Emiko C. Gardiner, Kayhan Gültekin, Philippe Turgeon +116
Pulsar timing arrays (PTAs) have found evidence of a gravitational wave background (GWB) consistent with a population of supermassive black hole binaries (SMBHBs), but have not yet…
Mitigating the Timing Impact of Anomalous Pulse Profile Shape Variability in PSR J1713+0747 with Gaussian Component Modeling
Shania A. Nichols, Michael T. Lam, Gabriella Agazie +31
The North American Nanohertz Observatory for Gravitational Waves (NANOGrav) achieves sub-microsecond timing precision for several millisecond pulsars in its pulsar timing array (PT…
The NANOGrav 15 yr and 20 yr Datasets: Timing Events and Pulse Shape Changes
Ben Jacobson-Bell, James M. Cordes, Shami Chatterjee +61
The average pulse shape of a pulsar is typically stable over decadal timescales, enabling estimation of pulse times of arrival to better than a small fraction of the pulse width us…
Gravitational Wave Measurement of the - Intrinsic Scatter at High Redshift
Cayenne Matt, Kayhan Gültekin, Gabriella Agazie +109
The observed GWB spectrum is higher in amplitude than model predictions by a factor of 2-3. Using a semi-analytic model, we evaluate the effect of a high-scatter supermassive black…
The NANOGrav 15 yr Data Set: Piecewise Power-Law Reconstruction of the Gravitational-Wave Background
Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald +108
The NANOGrav 15-year (NG15) data set provides evidence for a gravitational-wave background (GWB) signal at nanohertz frequencies, which is expected to originate either from a cosmi…
Is there a retrograde accretion disk around 4U 162667? Tracking torque reversals with a state-space model
Joseph O'Leary, Andrew Melatos, Tom Kimpson +5
X-ray timing studies of the persistent, Galactic, accretion-powered pulsar 4U 162667 reveal torque reversals, during which the pulse frequency alternates between multiyea…
Measuring the crust-superfluid coupling time-scale for 105 UTMOST pulsars with a Kalman filter
Wenhao Dong, Andrew Melatos, Nicholas J. O'Neill +2
Crust-superfluid coupling plays an important role in neutron star rotation, particularly with respect to timing noise and glitches. Here, we present new timing-noise-based estimate…
Inferring Mbh-Mbulge Evolution from the Gravitational Wave Background
Cayenne Matt, Kayhan Gultekin, Luke Kelley +104
We test the impact of an evolving supermassive black hole (SMBH) mass scaling relation (Mbh-Mbulge) on the predictions for the gravitational wave background (GWB). The observed GWB…
The NANOGrav 15 yr Data Set: Targeted Searches for Supermassive Black Hole Binaries
Nikita Agarwal, Gabriella Agazie, Akash Anumarlapudi +116
We present the first targeted searches for continuous gravitational waves (CWs) from 114 active galactic nuclei (AGN) that may host supermassive black hole binaries, using the NANO…
Observing Rayleigh-Taylor stable and unstable accretion through a Kalman filter analysis of X-ray pulsars in the Small Magellanic Cloud
Joseph O'Leary, Andrew Melatos, Tom Kimpson +5
Global, three-dimensional, magnetohydrodynamic simulations of Rayleigh-Taylor instabilities at the disk-magnetosphere boundary of rotating, magnetized, compact stellar objects reve…
The NANOGrav 15 yr Data Set: Harmonic Analysis of the Pulsar Angular Correlations
Gabriella Agazie, Jeremy G. Baier, Paul T. Baker +86
Pulsar timing array observations have found evidence for an isotropic gravitational wave background with the Hellings-Downs angular correlations, expected from general relativity.…
The NANOGrav 15 Yr Data Set: Removing Pulsars One by One from the Pulsar Timing Array
Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald +102
Evidence has emerged for a stochastic signal correlated among 67 pulsars within the 15-year pulsar-timing data set compiled by the NANOGrav collaboration. Similar signals have been…
Inference on inner galaxy structure via gravitational waves from supermassive binaries
Yifan Chen, Matthias Daniel, Daniel J. D'Orazio +107
The detection of a stochastic gravitational wave background by pulsar-timing arrays indicates the presence of a population of supermassive black hole binaries. Although the observe…
The NANOGrav 15 yr Data Set: Running of the Spectral Index
Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald +102
The NANOGrav 15-year data provides compelling evidence for a stochastic gravitational-wave (GW) background at nanohertz frequencies. The simplest model-independent approach to char…
The NANOGrav 15 yr data set: Posterior predictive checks for gravitational-wave detection with pulsar timing arrays
Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald +99
Pulsar-timing-array experiments have reported evidence for a stochastic background of nanohertz gravitational waves consistent with the signal expected from a population of superma…
Measuring the magnetic dipole moment and magnetospheric fluctuations of accretion-powered pulsars in the Small Magellanic Cloud with an unscented Kalman filter
Joseph O'Leary, Andrew Melatos, Tom Kimpson +5
Many accretion-powered pulsars rotate in magnetocentrifugal disequilibrium, spinning up or down secularly over multi-year intervals. The magnetic dipole moment of such systems…
The NANOGrav 15 yr Data Set: Looking for Signs of Discreteness in the Gravitational-wave Background
Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald +97
The cosmic merger history of supermassive black hole binaries (SMBHBs) is expected to produce a low-frequency gravitational wave background (GWB). Here we investigate how signs of…
Analysing radio pulsar timing noise with a Kalman filter: a demonstration involving PSR J13596038
Nicholas J. O'Neill, Patrick M. Meyers, Andrew Melatos
In the standard two-component crust-superfluid model of a neutron star, timing noise can arise when the two components are perturbed by stochastic torques. Here it is demonstrated…
Measuring the magnetic dipole moment and magnetospheric fluctuations of SXP 18.3 with a Kalman filter
J. O'Leary, A. Melatos, N. J. O'Neill +4
The magnetic dipole moment of an accretion-powered pulsar in magnetocentrifugal equilibrium cannot be inferred uniquely from time-averaged pulse period and aperiodic X-ray flux…
The NANOGrav 12.5-year data set: A computationally efficient eccentric binary search pipeline and constraints on an eccentric supermassive binary candidate in 3C 66B
Gabriella Agazie, Zaven Arzoumanian, Paul T. Baker +85
The radio galaxy 3C 66B has been hypothesized to host a supermassive black hole binary (SMBHB) at its center based on electromagnetic observations. Its apparent 1.05-year period an…
The NANOGrav 15-year Gravitational-Wave Background Methods
Aaron D. Johnson, Patrick M. Meyers, Paul T. Baker +93
Pulsar timing arrays (PTAs) use an array of millisecond pulsars to search for gravitational waves in the nanohertz regime in pulse time of arrival data. This paper presents rigorou…