Gravitational wave detector OGRAN as multi-messenger project of RAS-MSU

TL;DR

The paper presents an upgraded gravitational wave detector OGRAN, designed for multi-messenger detection of collapsing stars in collaboration with the BUST neutrino telescope, with sensitivity estimates and joint data analysis methods.

Contribution

It introduces a modernized OGRAN detector integrated with BUST for multi-messenger astrophysics and discusses sensitivity improvements and data analysis algorithms.

Findings

OGRAN achieves a sensitivity of 10^{-20} in metric perturbations.

Joint detection probability formulas are developed for OGRAN and BUST.

Sensitivity can be improved with moderate cooling of the acoustical mode.

Abstract

Modernized version of the combined opto-acoustical gravitational wave detector OGRAN is presented. Located in the deep underground of the Baksan Neutrino Observatory this setup is aimed to work on the program of collapsing stars searching for in multi-channel manner with the neutrino telescope BUST. The both instruments have the sensitivity allowing a registration of collapses in our Galaxy as rare events with the estimated probability 0:03 year-1. The OGRAN narrow band sensitivity at the kilohertz frequency is limited by its acoustical mode thermal noise achieving 10^{-20} in term of metric perturbations. A possible algorithm of the joint data analysis for the both instruments is developed and resulting formulae of the right detection probability are given. A future increasing of the OGRAN sensitivity associated with the moderate cooling (nitrogen temperature) of the acoustical mode is also discussed.