Instrumental and scientific simulations of the LOFT Wide Field Monitor

TL;DR

This paper discusses the simulations used to optimize the design and characterize the response of the LOFT Wide Field Monitor, an instrument aimed at monitoring X-ray sky variability and transient events.

Contribution

It presents detailed instrumental simulations for the LOFT WFM to enhance its design and response understanding for X-ray astrophysics observations.

Findings

Optimized WFM design based on simulation results

Characterized instrument response to isolated and crowded X-ray sources

Improved localization accuracy for transient events

Abstract

The Large Observatory for X-ray Timing (LOFT) is one of the five candidates that were considered by ESA as an M3 mission (with launch in 2022-2024). It is specifically designed to exploit the diagnostics of very rapid X-ray flux and spectral variability that directly probe the motion of matter down to distances very close to black holes and neutron stars, as well as the physical state of ultradense matter. The LOFT scientific payload is composed of the Large Area Detector (LAD), devoted to spectral-timing observation, and the Wide Field Monitor (WFM), whose primary goal it is to monitor the X-ray sky for transient events that need to be followed up with the LAD, and to measure the long-term variability of galactic X-ray sources and localize gamma-ray bursts. Here we describe the simulations carried out to optimize the WFM design and to characterize the instrument response to both isolated sources and crowded fields in the proximity of the galactic bulge.