7 papers
No Evidence for Superradiant Axions in LIGO-Virgo-KAGRA GWTC-5 Binary Black Hole Spins
Orion Ning, Benjamin R. Safdi, Catherine Welch
The quantum chromodynamics (QCD) axion and axion-like particles may form bound clouds around spinning black holes (BHs) when their Compton wavelength is comparable to the BH gravit…
Crowdsourcing Gravitational Waves from Superradiant Axions
Sebastian A. R. Ellis, Orion Ning, Nicholas L. Rodd +1
Black hole superradiance is a powerful probe of ultralight axions. If nature contains a boson with a mass of order eV, will lead to…
Blazar Constraints on Axions through New Spectral Modulation Searches in 1ES 1959+650 & B2 1811+31
Andrea Giovanni De Marchi, Orion Ning, Tianzhuo Xiao
Blazars are unique astrophysical environments whose high-energy -ray spectra are susceptible to modulations in the presence of ultralight axions. We search for these modulation…
Cosmological Neutron Stars Produce Diffuse Axion X-Ray Signatures
Orion Ning, Kailash Raman, Benjamin R. Safdi
Axion-like particles can be abundantly produced through scattering processes in the cores of neutron stars (NSs). If they are ultralight ( eV), then they can…
Axion lines from nuclear de-excitations in galactic stellar populations
Orion Ning, Anupam Ray, Benjamin R. Safdi
We show that mono-energetic axions are produced in abundance through nuclear de-excitations in nearby galaxies such as M87, which is the central galaxy of the Virgo cluster, and th…
Probing the Axion-Electron Coupling with NuSTAR Observations of Galaxies
Orion Ning, Benjamin R. Safdi
We search for the existence of ultralight axions coupling to electrons and photons using data from the NuSTAR telescope directed toward the galaxies M82, M87, and M31. We focus on…