The Large Area Detector of LOFT: the Large Observatory for X-ray Timing

TL;DR

LOFT's Large Area Detector was designed for fast X-ray timing near black holes and neutron stars, offering unprecedented variability studies, but was not selected for launch despite a robust design.

Contribution

The paper presents the detailed design and capabilities of the LAD instrument, highlighting its potential for revolutionizing X-ray variability studies.

Findings

LAD has a 10 m² effective area operating in 2-30 keV range.

The instrument can perform millisecond X-ray timing.

The design is robust and ready for future ESA proposals.

Abstract

LOFT (Large Observatory for X-ray Timing) is one of the five candidates that were considered by ESA as an M3 mission (with launch in 2022-2024) and has been studied during an extensive assessment phase. It is specifically designed to perform fast X-ray timing and probe the status of the matter near black holes and neutron stars. Its pointed instrument is the Large Area Detector (LAD), a 10 m 2 -class instrument operating in the 2-30keV range, which holds the capability to revolutionise studies of variability from X-ray sources on the millisecond time scales. The LAD instrument has now completed the assessment phase but was not down-selected for launch. However, during the assessment, most of the trade-offs have been closed leading to a robust and well documented design that will be re- proposed in future ESA calls. In this talk, we will summarize the characteristics of the LAD design and give an overview of the expectations for the instrument capabilities.