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20092026
most citedThe NANOGrav 15-year Data Set: Evidence for a Gravitational-Wave Background

1.5k citations · 4k across the 39 of their papers we have counts for

collaborators

42 papers

astro-ph.CO2026

Realization Variance of Gravitational Wave Background Anisotropies from Shot Noise for Pulsar Timing Arrays

Meng-Xiang Lin, Adam Lidz, Chung-Pei Ma

Shot-noise anisotropies in the nHz gravitational wave background (GWB) are a promising target for pulsar timing arrays (PTAs). If the nHz GWB is sourced by merging supermassive bla…

astro-ph.IM2026

Pulsar Timing Array Sensitivity to Anisotropy: Empirical Sensitivity Curves, Scaling Relations, and the Multi-Resolution Pixel Basis

Taha T. Moursy, Nihan S. Pol, Gabriella Agazie +115

We quantify pulsar timing array (PTA) sensitivity to anisotropy in the gravitational wave background using the cross-correlation based Fisher information matrix in the pixel and sp…

astro-ph.CO2026

The NANOGrav 15 yr Data Set: Impacts of Customized Chromatic Noise Models on Gravitational Wave Analyses

Nikita Agarwal, Gabriella Agazie, Alessandra Amosso +120

We report updated nHz gravitational wave (GW) significance, characterization, and interpretations using the customized chromatic-noise models (CNMs) developed in Larsen, Baier et a…

astro-ph.GA2026

Prospects of resolving and localising individual supermassive black hole binaries with pulsar timing arrays: the host ranking challenge

Niccolò Veronesi, Maria Charisi, Polina Petrov +5

Pulsar Timing Arrays (PTAs) are soon expected to detect individually resolved supermassive black hole (SMBH) binaries, opening the possibility for multi-messenger discoveries. The…

astro-ph.HE2026

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…

astro-ph.CO2026

Analytical Estimates of Gravitational Wave Background Anisotropies from Shot Noise and Large-Scale Structure in Pulsar Timing Arrays

Meng-Xiang Lin, Adam Lidz, Chung-Pei Ma

An important next step for pulsar timing arrays (PTAs) is to measure anisotropies in the gravitational wave background (GWB) at nano-Hz frequencies. We calculate the expecte…

astro-ph.HE2026

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…

astro-ph.GA2025

Mapping the Stellar Kinematics in the Central 240 Parsecs of M87 with the James Webb Space Telescope

Refa M. Al-Amri, Jonelle L. Walsh, Emily R. Liepold +2

The supermassive black hole (SMBH) in the giant elliptical galaxy M87 is one of the most well-studied in the local universe, but the stellar- and gas-dynamical SMBH mass measuremen…

astro-ph.IM2025

Expectations for the first supermassive black-hole binary resolved by PTAs I: Model efficacy

Levi Schult, Polina Petrov, Stephen R. Taylor +4

One of the most promising targets for Pulsar Timing Arrays (PTAs) is identifying an individual supermassive black hole binary (SMBHB) out of the population of binaries theorized to…

astro-ph.IM2025★ 1 cited

Expectations for the first supermassive black-hole binary resolved by PTAs II: Milestones for binary characterization

Polina Petrov, Levi Schult, Stephen R. Taylor +4

Following the recent evidence for a gravitational wave (GW) background found by pulsar timing array (PTA) experiments, the next major science milestone is resolving individual supe…

astro-ph.HE2025★ 4 cited

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…

astro-ph.HE2025★ 11 cited

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…

astro-ph.GA2025

The MASSIVE Survey. XX. A Triaxial Stellar Dynamical Measurement of the Supermassive Black Hole Mass and Intrinsic Galaxy Shape of Giant Radio Galaxy NGC 315

Jacob Pilawa, Emily R. Liepold, Chung-Pei Ma +2

We present a new dynamical measurement of the supermassive black hole mass and intrinsic shape of the stellar halo of the massive radio galaxy NGC 315 as part of the MASSIVE survey…

gr-qc2025

The NANOGrav 15-year Data Set: Search for Gravitational Wave Memory

Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald +102

We present the results of a search for nonlinear gravitational wave memory in the NANOGrav 15-year data set. We find no significant evidence for memory signals in the dataset, with…

astro-ph.GA2025

A 22-Billion Solar Mass Black Hole in Holmberg 15A with Keck KCWI Spectroscopy and Triaxial Orbit Modeling

Emily R. Liepold, Chung-Pei Ma, Jonelle L. Walsh

Holmberg 15A (H15A), the brightest cluster galaxy of Abell 85, has an exceptionally low central surface brightness even among local massive elliptical galaxies with distinct stella…

astro-ph.HE2024

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.…

astro-ph.HE2024

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…

astro-ph.HE2024★ 4 cited

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…

astro-ph.HE2024

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…

astro-ph.GA2024

Big Galaxies and Big Black Holes: The Massive Ends of the Local Stellar and Black Hole Mass Functions and the Implications for Nanohertz Gravitational Waves

Emily R. Liepold, Chung-Pei Ma

We construct the galaxy stellar mass function (GSMF) by combining the GSMF at stellar masses from the census study of Leja et al. (2020) and…

astro-ph.HE2024★ 4 cited

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…

astro-ph.GA2024★ 19 cited

Identifying Host Galaxies of Supermassive Black Hole Binaries Found by PTAs

Polina Petrov, Stephen R. Taylor, Maria Charisi +1

Supermassive black hole binaries (SMBHBs) present us with exciting opportunities for multi-messenger science. These systems are thought to form naturally in galaxy mergers and ther…

astro-ph.HE2024★ 19 cited

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…

astro-ph.GA2024

TriOS Schwarzschild Orbit Modeling: Robustness of Parameter Inference for Masses and Shapes of Triaxial Galaxies with Supermassive Black Holes

Jacob Pilawa, Emily R. Liepold, Chung-Pei Ma

Evidence for the majority of the supermassive black holes in the local universe has been obtained dynamically from stellar motions with the Schwarzschild orbit superposition method…