The Instrument of the Imaging X-ray Polarimetry Explorer
Creators: name: Soffitta, Paolo
name: Baldini, Luca
name: Bellazzini, Ronaldo
name: Costa, Enrico
name: Latronico, Luca
name: Muleri, Fabio
name: Del Monte, Ettore
name: Fabiani, Sergio
name: Minuti, Massimo
name: Pinchera, Michele
name: Sgrò, Carmelo
name: Spandre, Gloria
name: Trois, Alessio
name: Amici, Fabrizio
name: Andersson, Hans
name: Attinà, Primo
name: Bachetti, Matteo
name: Barbanera, Mattia
name: Borotto, Fabio
name: Brez, Alessandro
name: Brienza, Daniele
name: Caporale, Ciro
name: Cardelli, Claudia
name: Carpentiero, Rita
name: Castellano, Simone
name: Castronuovo, Marco
name: Cavalli, Luca
name: Cavazzuti, Elisabetta
name: Ceccanti, Marco
name: Centrone, Mauro
name: Ciprini, Stefano
name: Citraro, Saverio
name: Amico, Fabio D'
name: Alba, Elisa D'
name: Di Cosimo, Sergio
name: Di Lalla, Niccolò
name: Di Marco, Alessandro
name: Di Persio, Giuseppe
name: Donnarumma, Immacolata
name: Evangelista, Yuri
name: Ferrazzoli, Riccardo
name: Hayato, Asami
name: Kitaguchi, Takao
name: La Monaca, Fabio
name: Lefevre, Carlo
name: Loffredo, Pasqualino
name: Lorenzi, Paolo
name: Lucchesi, Leonardo
name: Magazzu, Carlo
name: Maldera, Simone
name: Manfreda, Alberto
name: Mangraviti, Elio
name: Marengo, Marco
name: Matt, Giorgio
name: Mereu, Paolo
name: Morbidini, Alfredo
name: Mosti, Federico
name: Nakano, Toshio
name: Nasimi, Hikmat
name: Negri, Barbara
name: Nenonen, Seppo
name: Nuti, Alessio
name: Orsini, Leonardo
name: Perri, Matteo
name: Rollins, Melissa Pesce
name: Piazzolla, Raffaele
name: Pilia, Maura
name: Profeti, Alessandro
name: Puccetti, Simonetta
name: Rankin, John
name: Ratheesh, Ajay
name: Rubini, Alda
name: Santoli, Francesco
name: Sarra, Paolo
name: Scalise, Emanuele
name: Sciortino, Andrea
name: Tamagawa, Toru
name: Tardiola, Marcello
name: Tobia, Antonino
name: Vimercati, Marco
name: Xie, Fei
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: While X-ray Spectroscopy, Timing and Imaging have improved verymuch since 1962, when the first astronomical non-solar source was discovered, especially with the launch of Newton/X-ray Multi-Mirror Mission, Rossi/X-ray Timing Explorer and Chandra/Advanced X-ray Astrophysics Facility, the progress of X-ray polarimetry has been meager. This is in part due to the lack of sensitive polarization detectors, in part due to the fate of approved missions and in part because the celestial X-ray sources appeared less polarized than expected. Only one positive measurement has been available until now. Indeed the eight Orbiting Solar Observatory measured the polarization of the Crab nebula in the 70s. The advent of techniques of microelectronics allowed for designing a detector based on the photoelectric effect in gas in an energy range where the optics are efficient in focusing X-rays. Herewe describe the Instrument, which is the major contribution of the Italian collaboration to the SmallExplorer mission called IXPE, the Imaging X-ray Polarimetry Explorer, which will be flown in late 2021. The instrument, is composed of three Detector Units, based on this technique, and a Detector Service Unit. Three Mirror Modules provided by Marshall Space Flight Center focus X-rays onto the detectors. In the following we will show the technological choices, their scientific motivation and the results from the calibration of the Instrument. IXPE will perform imaging, timing and energy resolved polarimetry in the 2-8 keV energy band opening this window of X-ray astronomy to tens of celestial sources of almost all classes.
description: 25 pages, 12 figures, 5 tables (accepted for publication in Astronomical Journal)