activity
20242026
collaborators

6 papers

astro-ph.HE2026

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

Heavy seeds and the first black holes: Insights from the BRAHMA simulations

Aklant K. Bhowmick, Laura Blecha, Paul Torrey +9

From the luminous quasars at to the recent AGNs revealed by JWST, observations of the earliest black hole (BH) populations can provide unique constraints o…

astro-ph.GA2025

Dynamics of low-mass black hole seeds in the BRAHMA simulations using subgrid-dynamical friction: Impact on merger-driven black hole growth in the high redshift Universe

Aklant K. Bhowmick, Laura Blecha, Luke Z. Kelley +7

We analyze the dynamics of low-mass black hole (BH) seeds in the high-redshift () Universe using a suite of and BRAHMA cosmol…

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.GA2024

Signatures of black hole seeding in the local Universe: Predictions from the BRAHMA cosmological simulations

Aklant K Bhowmick, Laura Blecha, Paul Torrey +8

The first "seeds" of supermassive black holes (BHs) continue to be an outstanding puzzle, and it is currently unclear whether the imprints of early seed formation survive today. He…

astro-ph.HE2024

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…