ART-XC: Astronomical Roentgen Telescope – X-ray Concentrator

ART Logo


The Astronomical Roentgen Telescope – X-ray Concentrator (ART-XC) instrument on board the Spectrum-Roentgen-Gamma (SRG) mission was launched on July 13, 2019, and is on its way to a Sun-Earth L2 halo orbit. ART-XC is an X-ray grazing incidence mirror telescope array developed by the Russian Space Research Institute (IKI) and the All-Russian Scientific Research Institute for Experimental Physics (VNIIEF). NASA's Marshall Space Flight Center (MSFC) developed and fabricated the X-ray mirrors.

ART schematic

ART-XC is composed of seven mirror modules co-aligned with seven CdTe double-sided strip focal plane detectors. ART-XC will operate over the energy range of 4−30 keV, with an angular resolution of less than 1 arcminute on-axis, a field of view of ~0.3 square degree and an energy resolution of about 9% at 14 keV. The ART-XC primary mission will be to perform a four-year all-sky survey simultaneously with the other SRG instrument, eROSITA, followed by three years of pointed observations.

ART mirror module

The 2.7 m focal length ART-XC telescope consists of 7 mirror modules co-aligned to 7 CdTe double-sided strip detectors. Each ART mirror module has 28 nested Ni/Co mirror shells of length 580 mm and ranging in diameter from 49 mm to 145 mm. Each shell is coated with 10 nm Ir to improve high energy reflectivity.

ART detector

Each ART focal plane detector is built around a high quality ~30x30x1 mm CdTe crystal manufactured by Acrorad of Japan. The IKI-built electrode configuration is double-sided strips forming a Schottky barrier diode with anode (top) and cathode strip layers oriented perpendicular to each other providing 48x48 ‘pixels’ of 595 micron pitch (~45”). Two VA64TA1 ASICs, designed by Gamma Medica-Ideas of Norway, are used to read out the two sets of 48 channels. A 100 micron thick Be window protects each detector.

ART orbit

SRG launched from Baikonur, Kazakhstan, 13 July 2019 and is being delivered into a halo orbit at Sun-Earth L2. SRG will then execute a 4-year all-sky survey by orbiting approximately about the Sun-Earth axis with a 4-hr period. After this survey, SRG will spend 3 years on pointed observations of selected celestial objects including galaxy clusters, active galactic nuclei, and Galactic sources.

The ART-XC team at Marshall Space Flight Center is developing various tools to aid ART-XC enthusiasts in estimating ART-XC scientific performance. These include modules for, e.g., the sixte simulator and the PIMMS portable interactive multi-mission simulator tool and various CalDB files and documentation. These will be made available as they are developed.