Payload study activities on the International X-ray Observatory

Abstract

The International X-ray Observatory (IXO) is an L class mission candidate within the science programme Cosmic Vision 2015-2025 of the European Space Agency, with a planned launch by 2020. IXO is an international cooperative project, pursued by ESA, JAXA and NASA. By allowing astrophysical observations between 100 eV and 40 keV using a very large effective collecting area mirror and state-of-the art instruments, IXO would represent the new generation X-ray observatory, following the XMM-Newton, Astro-H and Chandra heritage. The IXO mission concept is based on a single aperture telescope with an external diameter of about 3.5 m and a focal length of 20 m. The focal plane consists of a fixed and a moveable instrument platform (FIP and MIP respectively). The model payload consists of a suite of five instruments which can each be located at the telescope's focus by the MIP, these are: 1. a wide field imager (WFI) based on a silicon DEPFET array; 2. a Hard-X-ray Imager (HXI), which will be integrated together with the WFI; 3. an X-ray microcalorimeter spectrometer (XMS); 4. an X-ray Polarimeter camera (X-POL) based on a gas cell with integrated anode array; 5. a High-Time Resolution Spectrometer (HTRS) based on a silicon drift detector array. In addition, the FIP will carry a grating spectrometer (XGS) mounted in a fixed position and which will allow simultaneous observations with the on-axis instrument. This paper provides a summary of the preliminary results achieved during the assessment activities presently ongoing at ESA. Whereas we will provide a brief overview on the overall spacecraft design, we will focus on the payload description, characteristics, the technology used and the accommodation on the instrument platform.