JEM–X: The X-ray monitor aboard INTEGRAL

TLDR

The JEM–X monitor delivers arcminute‑resolution X‑ray spectra and imaging in the 3–35 keV band, enabling precise identification of gamma‑ray sources and the interpretation of combined X‑ray and gamma‑ray observations. JEM–X is a coded‑aperture instrument comprising two identical, coaligned telescopes, each with a 500 cm² detector and an inverted coded mask that together provide 3′ angular resolution over a ~10° field of view.

Abstract

The JEM–X monitor provides X-ray spectra and imaging with arcminute angular resolution in the 3 to 35 keV band. The good angular resolution and the low energy response of JEM–X plays an important role in the identification of gamma ray sources and in the analysis and scientific interpretation of the combined X-ray and gamma ray data. JEM–X is a coded aperture instrument consisting of two identical, coaligned telescopes. Each of the detectors has a sensitive area of 500 cm2, and views the sky through its own coded aperture mask. The two coded masks are inverted with respect to each other and provides an angular resolution of 3' across an effective field of view of about 10° diameter.