The Microchannel X-ray Telescope on Board the SVOM Satellite

TL;DR

The paper introduces the MXT, a compact X-ray telescope for the SVOM mission, capable of precise localization and detection of gamma-ray burst afterglows, demonstrating the viability of small, lightweight X-ray telescopes for space science.

Contribution

It presents the design, specifications, and expected performance of the MXT, a novel micro-channel optics-based X-ray telescope for the SVOM satellite.

Findings

Expected localization accuracy better than 1 arc min

Effective area of about 45 cm² at 1 keV

Suitable for detecting most SVOM GRB afterglows

Abstract

We present the Micro-channel X-ray Telescope (MXT), a new narrow-field (about 1{\deg}) telescope that will be flying on the Sino-French SVOM mission dedicated to Gamma-Ray Burst science, scheduled for launch in 2021. MXT is based on square micro pore optics (MPOs), coupled with a low noise CCD. The optics are based on a "Lobster Eye" design, while the CCD is a focal plane detector similar to the type developed for the seven eROSITA telescopes. MXT is a compact and light (<35 kg) telescope with a 1 m focal length, and it will provide an effective area of about 45 cmsq on axis at 1 keV. The MXT PSF is expected to be better than 4.2 arc min (FWHM) ensuring a localization accuracy of the afterglows of the SVOM GRBs to better than 1 arc min (90\% c.l. with no systematics) provided MXT data are collected within 5 minutes after the trigger. The MXT sensitivity will be adequate to detect the afterglows for almost all the SVOM GRBs as well as to perform observations of non-GRB astrophysical objects. These performances are fully adapted to the SVOM science goals, and prove that small and light telescopes can be used for future small X-ray missions.