The Athena X-ray Integral Field Unit

Didier Barret (1) , Thien Lam Trong (2) , Jan-Willem den Herder , Luigi Piro , Massimo Cappi , Juhani Huovelin , Richard Kelley , J. Miguel Mas-Hesse , Kazuhisa Mitsuda , Stéphane Paltani , Gregor Rauw , Agata Rozanska , Joern Wilms , Simon Bandler , Marco Barbera , Xavier Barcons , Enrico Bozzo , Maria Teresa Ceballos , Ivan Charles (3) , Elisa Costantini , Anne Decourchelle (4) , Roland den Hartog , Lionel Duband (3) , Jean-Marc Duval (3) , Fabrizio Fiore , Flavio Gatti , Andrea Goldwurm (5) , Brian Jackson , Peter Jonker , Caroline Kilbourne , Claudio Macculi , Mariano Mendez , Silvano Molendi , Piotr Orleanski , François Pajot (1) , Etienne Pointecouteau (1) , Frederick Porter , Gabriel W. Pratt (4) , Damien Prêle (5) , Laurent Ravera (1) , Kosuke Sato , Joop Schaye , Keisuke Shinozaki , Tanguy Thibert , Luca Valenziano , Veronique Valette (2) , Jacco Vink , Natalie Webb (1) , Michael Wise , Noriko Yamasaki , Françoise Delcelier-Douchin (2) , Jean-Michel Mesnager (2) , Bernard Pontet (2) , Alice Pradines (2) , Graziella Branduardi-Raymont , Esra Bulbul , Mauro Dadina , Stefano Ettori , Alexis Finoguenov , Yasushi Fukazawa , Agnieszka Janiuk , Jelle Kaastra , Pasquale Mazzotta , Jon Miller , Giovanni Miniutti , Yaël Nazé , Fabrizio Nicastro , Salvatore Sciortino , Aurora Simionescu , Jose Miguel Torrejon , Benot Frezouls (2) , Hervé Geoffray (2) , Philippe Peille (2) , Corinne Aicardi (2) , Jérôme André (2) , Antoine Clénet (1) , Christophe Daniel (2) , Christophe Etcheverry (2) , Emilie Gloaguen (2) , Gilles Hervet (2) , Antoine Jolly (2) , Aurélien Ledot (2) , Irwin Maussang (2) , Alexis Paillet (2) , Roseline Schmisser (2) , Bruno Vella (2) , Jean-Charles Damery (2) , Kevin Boyce , Michael Dipirro , Simone Lotti , Denis Schwander (2) , Stephen Smith , Bert-Joost van Leeuwen , Henk van Weers , Nicolas Clerc (1) , Beatriz Cobo , Thomas Dauser , Jelle de Plaa , Christian Kirsch , Edoardo Cucchetti (1) , Megan Eckart , Philippe Ferrando (4) , Lorenzo Natalucci

1 IRAP - Institut de recherche en astrophysique et planétologie
2 CNES - Centre National d'Études Spatiales [Toulouse]
3 INAC - Institut Nanosciences et Cryogénie
4 AIM (UMR7158 / UMR_E_9005 / UM_112) - Astrophysique Interprétation Modélisation
5 APC (UMR_7164) - AstroParticule et Cosmologie

The X-ray Integral Field Unit (X-IFU) is the high resolution X-ray spectrometer of the ESA Athena X-ray observatory. Over a field of view of 5' equivalent diameter, it will deliver X-ray spectra from 0.2 to 12 keV with a spectral resolution of 2.5 eV up to 7 keV on ~5 arcsecond pixels. The X-IFU is based on a large format array of super-conducting molybdenum-gold Transition Edge Sensors cooled at about 90 mK, each coupled with an absorber made of gold and bismuth with a pitch of 249 microns. A cryogenic anti-coincidence detector located underneath the prime TES array enables the non X-ray background to be reduced. A bath temperature of about 50 mK is obtained by a series of mechanical coolers combining 15K Pulse Tubes, 4K and 2K Joule-Thomson coolers which pre-cool a sub Kelvin cooler made of a 3He sorption cooler coupled with an Adiabatic Demagnetization Refrigerator. Frequency domain multiplexing enables to read out 40 pixels in one single channel. A photon interacting with an absorber leads to a current pulse, amplified by the readout electronics and whose shape is reconstructed on board to recover its energy with high accuracy. The defocusing capability offered by the Athena movable mirror assembly enables the X-IFU to observe the brightest X-ray sources of the sky (up to Crab-like intensities) by spreading the telescope point spread function over hundreds of pixels. Thus the X-IFU delivers low pile-up, high throughput (>50%), and typically 10 eV spectral resolution at 1 Crab intensities, i.e. a factor of 10 or more better than Silicon based X-ray detectors. In this paper, the current X-IFU baseline is presented, together with an assessment of its anticipated performance in terms of spectral resolution, background, and count rate capability. The X-IFU baseline configuration will be subject to a preliminary requirement review that is scheduled at the end of 2018.

Domaines: Instrumentations et Détecteurs [physics.ins-det]; Astrophysique [astro-ph]

Didier Barret, Thien Lam Trong, Jan-Willem den Herder, Luigi Piro, Massimo Cappi, et al.. The Athena X-ray Integral Field Unit. SPIE Astronomical Telescopes + Instrumentation 2018, Jun 2018, Austin, United States. pp.106991G, ⟨10.1117/12.2312409⟩. ⟨hal-01876196⟩