Expected Gamma-Ray Burst Detection Rates and Redshift Distributions for the BlackCAT CubeSat Mission

TL;DR

The BlackCAT CubeSat mission is designed to detect and localize high-redshift gamma-ray bursts, with simulations predicting about 42 detections annually, including a significant fraction at redshift greater than 3.5, enabling valuable cosmological studies.

Contribution

This paper presents the first detailed sensitivity simulations for BlackCAT, estimating its detection rates, localization accuracy, and redshift distribution of gamma-ray bursts.

Findings

BlackCAT expected to detect 42 GRBs per year.

Approximately 7-10% of detections will be at z > 3.5.

Localization precision within 55 arcseconds.

Abstract

We report the results of an extensive set of simulations exploring the sensitivity of the BlackCAT CubeSat to long-duration gamma-ray bursts (GRBs). BlackCAT is a NASA APRA-funded CubeSat mission for the detection and real-time sub-arcminute localization of high-redshift ($z\gtrsim 3.5$) GRBs. Thanks to their luminous and long-lived afterglow emissions, GRBs are uniquely valuable probes of high-redshift star-forming galaxies and the intergalactic medium. In addition, each detected GRB with a known redshift serves to localize a region of high-redshift star formation in three dimensions, enabling deep follow-on searches for host galaxies and associated local and large-scale structures. We explore two distinct models for the GRB redshift distribution and luminosity function, both consistent with Swift observations. We find that, for either model, BlackCAT is expected to detect a mean of 42 bursts per year on-orbit, with 6.7% to 10% of these at $z>3.5$. BlackCAT bursts will be localized to $r_{90} \lesssim 55^{\prime\prime}$ precision and reported to the community within seconds. Due to the mission orbit and pointing scheme, bursts will be located in the night sky and well-placed for deep multiwavelength follow-up observations. BlackCAT is on schedule to achieve launch readiness in 2025.