activity
20222026
most citedGetting More Out of Black Hole Superradiance: a Statistically Rigorous Approach to Ultralight Boson Constraints from Black Hole Spin Measurements

11 citations · 22 across the 10 of their papers we have counts for

collaborators
Showing astro-ph.HEShow all

8 papers · 1 filter

astro-ph.HE2026

Spin Demographics of Active Supermassive Black Holes: Updated Estimates from X-ray reflection and Future opportunities

Julia M. Sisk-Reynes, Christopher S. Reynolds, James H. Matthews +5

Understanding the growth of supermassive black holes (SMBHs) requires observational constraints on how their angular momentum (or spin) varies with mass, since the relative importa…

astro-ph.HE2025★ 1 cited

Evidence for Supermassive Black Hole Binaries

Martin G. H. Krause, Martin A. Bourne, Silke Britzen +10

We review the state of the evidence for the existence and observational appearance of supermassive black hole binaries. Such objects are expected from standard hierarchical galaxy…

astro-ph.HE2025★ 3 cited

The Advanced X-ray Imaging Satellite (AXIS) Community Science Book

Michael Koss, Nafisa Aftab, Steven W. Allen +395

The AXIS Community Science Book represents the collective effort of 592 scientists worldwide to define the transformative science enabled by the Advanced X-ray Imaging Satellite (A…

astro-ph.HE2025

Determining the spatial origin of X-ray and optical emission in the strongly lensed radio-quiet quasar GraL J065904.1+162909 to hundreds of parsecs

Julia Sisk-Reynes, Daniel Schwartz, Anna Barnacka +2

We perform milliarcsecond X-ray astrometry of the quadruply lensed radio-quiet quasar GraL J065904.1+162909 (J0659). This quasar is lensed into four images and was disc…

astro-ph.HE2023

Current and Future constraints on Very-Light Axion-Like Particles from X-ray observations of cluster-hosted Active Galaxies

Julia M. Sisk-Reynes, Christopher S. Reynolds, James H. Matthews

We discuss our recent constraints on the coupling of Very-Light Axion-Like Particles (of masses ) to electromagnetism from observations of the…

astro-ph.HE2022★ 7 cited

Physics Beyond the Standard Model with Future X-ray Observatories: Projected Constraints on Very-Light Axion-Like Particles with and

Júlia Sisk-Reynés, Christopher S. Reynolds, Michael L. Parker +2

Axion-Like Particles (ALPs) are well-motivated extensions of the Standard Model of Particle Physics and a generic prediction of some string theories. X-ray observations of bright A…