In Orbit Performance of the MAXI/SSC onboard the ISS

TL;DR

This paper reports on the in-orbit performance of the MAXI/SSC X-ray CCD camera onboard the ISS, highlighting its operational status, observational capabilities, and initial results from sky surveys since 2009.

Contribution

It presents the first all-sky survey using X-ray CCDs from space, detailing the instrument's design, operation, and initial performance metrics.

Findings

CCD functions properly in orbit

Detected multiple point and extended X-ray sources

Observation efficiency reduced to about 30% due to edge glow

Abstract

We report here the in orbit performance of the CCD camera (MAXI/SSC) onboard the International Space Station (ISS). It was commissioned in August, 2009. This is the first all-sky survey mission employing X-ray CCDs. It consists of 32 CCDs each of which is 1 inch square. It is a slit camera with a field of view of 1deg.5x 90deg and scans the sky as the rotation of the ISS. The CCD on the SSC is cooled down to the working temperature around -60degC by the combination of the peltier cooler, a loop heat pipe and a radiator. The standard observation mode of the CCD is in a parallel sum mode (64-binning). The CCD functions properly although it suffers an edge glow when the Sun is near the field of view (FOV) which reduces the observation efficiency of the SSC down to about 30%. The performance of the CCD is continuously monitored both by the Mn-K X-rays and by the Cu-K X-rays. There are many sources detected, not only point sources but extended sources. Due to the lack of the effective observation time, we need more observation time to obtain an extended emission analysis extraction process.