TES microcalorimeter development for future Italian X-ray astronomy missions

A program for developing TES Ir–Au microcalorimeters for contributions to the XEUS detector and for applications to future Italian X-ray astronomy missions is under course. In particular, we will briefly describe ESTREMO, currently one of the possible options in the future national plans. Its main scientific goals are the spectroscopic study of extreme astrophysical objects, characterized by very large energy release over short time scale, in particular gamma-ray bursts and transient compact objects, and the study of the early and close-by Universe by using gamma-ray bursts as cosmological beacons. Presently, the energy resolution of our Ir–Au detector has been improved to about 5 eV at 6 keV, with rise time of about 10 μs and fall time of few hundreds of microseconds. We are developing and studying the suitable absorbers for high count rate performances.