6 papers
Lucky Strikes: On the Origins of GW190814 Through Isolated Binary Evolution
Ignacio Magaña Hernandez, Katelyn Breivik
The asymmetric nature of GW190814, particularly its mass ratio (), has made its astrophysical origin elusive. We explore isolated binary evolution as a potential ex…
AT2025ulz and S250818k: Deep X-ray and radio limits on off-axis afterglow emission and prospects for future discovery
Brendan O'Connor, Roberto Ricci, Eleonora Troja +15
The first joint electromagentic (EM) and gravitational wave (GW) detection, known as GW170817, marked a critical juncture in our collective understanding of compact object mergers.…
AT2025ulz and S250818k: Investigating early time observations of a subsolar mass gravitational-wave binary neutron star merger candidate
Xander J. Hall, Malte Busmann, Hauke Koehn +32
Over the past LIGO--Virgo--KAGRA (LVK) observing runs, it has become increasingly clear that identifying the next electromagnetic counterparts to gravitational-wave (GW) neutron st…
AT2025ulz and S250818k: Leveraging DESI spectroscopy in the hunt for a kilonova associated with a sub-solar mass gravitational wave candidate
Xander J. Hall, Antonella Palmese, Brendan O'Connor +47
On August 18th, 2025, the LIGO--Virgo--KAGRA collaboration reported a sub-threshold gravitational wave candidate detection consistent with a sub-solar-mass neutron star merger, den…
Spectral siren cosmology from gravitational-wave observations in GWTC-4.0
Ignacio Magaña Hernandez, Antonella Palmese
Gravitational wave standard sirens offer a promising avenue for cosmological inference, particularly in measuring the expansion history of the universe. Traditionally, bright siren…
Astrophysics informed Gaussian processes for gravitational-wave populations: Evidence for the onset of the pair-instability supernova mass gap
Ignacio Magaña Hernandez, Antonella Palmese
We analyze binary black hole (BBH) mergers from the latest Gravitational Wave Transient Catalog (GWTC-3) using a flexible, non-parametric framework to infer the underlying black ho…