What are we made of? Most of the atoms and elements we know of are formed within stars, either during their life (winds) or during powerful end-of-life phenomena called supernovae. In fact, different mechanisms of metal creation exist in the Universe and elements were not formed evenly during its history. To investigate this chemical enrichment, one must look in the X-rays at the hot gas within clusters of galaxies – the intra cluster medium (ICM) – which is continuously enriched through time by the billions of stars contained in its galaxies. However, to perform meaningful studies of the enrichment through cosmic time, a combination of a high-resolution spatially-resolved spectroscopy and a large telescope collective area is required. For this reason, the Athena/X-IFU will be the breakthrough instrument to investigate metal formation and circulation in the Universe.

In this paper, we tested the power of the X-IFU to fulfill this specific science objective. Using a set of simulated clusters derived from hydrodynamical simulations, we performed synthetic observations of this sample of objects through time, up to a redshift z=2 (10.4 billion years ago) with a completely realistic set-up (including e.g., background, instrumental effects). We demonstrated that with routine 100 ks observations, the X-IFU will be able to study the enrichment with unprecedented accuracy out to the outskirts of the clusters and provide solid answers to the origin of their metal content.

This work is paramount in the Athena context, as it shows the power of the mission in answering some of the key astrophysical questions of our time. It also serves as a feasibility study of the X-IFU, consolidating the current design and the need for spatially-resolved high-resolution spectroscopy.

Cucchetti et al. – Athena X-IFU synthetic observations of galaxy clusters to probe the chemical enrichment of the Universe.

Date: 26/09/2018 Astronomy & Astrophyics

From November 2017, papers related to the X-IFU published in journals or conference proceedings are made available from this page. Click here to access the papers. Enjoy the reading !

If you are a member of the X-IFU consortium and you wish to upload a paper then click here.

You can also follow this ADS link to get the full list of ADS referenced X-IFU related papers.

Defocussing of the Athena optics is now a requirement and can be considered in evaluating the count rate performance of the X-IFU. Defocussing spreads the source counts over a large number of pixels (1000). Each pixel can sustain a count rate of the order of 40-50 cps. A Crab like source would produce about 90 000 cps over the full TES array. Therefore it is obvious that with defocussing, the X-IFU is capable of observing bright point sources.

Broad band (0.2-12 keV) high resolution and total throughputs

High throughput for mid and high resolution events (spectral resolution less than 10 eV) is certainly required around the Iron like between 5 and 8 keV. The use of Be filters would remove a large fraction of the soft photons and therefore reduce the overall count rate of point sources while preserving the interesting events above 5 keV. The X-IFU can achieve throughputs as high as 70% with maximum defocussing and the use of Be filter. The above number will reduce (by a few 10% at 1 Crab) if events affected by cross talk are removed.

The high+mid resolution event fraction in the 5-8 keV band.

The figures shown above are courtesy of Philippe Peille (December 2016), on behalf of the end-to-end simulator team.

Overview papers

• The Athena X-ray Integral Field Unit - D. Barret et al.
• X-IFU technical challenge - Th. Lam Trong

Instrument oriented papers

• The focal plane assembly for the Athena X-ray Integral Field Unit instrument - B. Jackson et al.
• Transition-edge sensor pixel parameter design of the microcalorimeter array for the x-ray integral field unit on Athena-r (B&W version available)- S. J. Smith et al.
• Preliminary thermal architecture of the X-IFU instrument dewar - I. Charles et al.
• Development of frequency domain multiplexing for the X-ray Integral Field unit (X-IFU) on the Athena - H. Akamatsu et al.
• Optimising the multiplex factor of the frequency domain multiplexed readout of the TES-based microcalorimeter imaging array for the X-IFU instrument on the Athena x-ray observatory - van der Kuur et al.
• Gain drift compensation with no-feedback-loop developed for the X-IFU:ATHENA readout chain - D. Prêle et al.
• Conceptual design of the X-IFU Instrument Control Unit on board the ESA Athena mission - L. Corcione et al.
• The filter wheel and filters development for the X-IFU instruments onboard Athena - E. Bozzo et al.
• Surface investigation and aluminum oxide estimation on test filters for the ATHENA X-IFU and WFI detectors - L. Sciortino et al.
• Temperature effects on the performances of the ATHENA X-IFU thermal filters - M. Barbera et al.

• Updates on the background estimates for the X-IFU instrument onboard of the ATHENA mission - S. Lotti et al.
• The Cryogenic Anti-Coincidence detector for ATHENA X-IFU pulse analysis of the AC-S7 single pixel prototype - M. D'Andrea et al.
• The Cryogenic AntiCoincidence detector for ATHENA X-IFU-a program overview - C. Macculi et al.
• The mechanical and EM simulations of the CryoAC for the ATHENA X-IFU - D. Corsini et al.
• The new cryogenic silicon monolithic micro-bridged Anticoincidence detector for the X-IFU of ATHENA - M. Biasotti et al.

End-to-end simulation oriented papers

• TESSIM a simulator for the Athena-X-IFU - J. Wilms et al.
• Performance assessment of different pulse reconstruction algorithms for the ATHENA X-ray Integral Field Unit - Ph. Peille et al.
• Microcalorimeter pulse analysis by means of principle component decomposition - C.P. de Vries et al.
• The impact of crosstalk in the X-IFU instrument on Athena science cases - R. den Hartog et al.
• Observing the WHIM with Athena - T. Brand et al.

- The Athena mission proposal

- The Hot and Energetic Universe White Paper

- The X-ray Integral Field Unit (X-IFU) - Preliminary description

- X-IFU master presentations in zipped keynote and zipped PDF

• The X-ray Integral Field Unit (X-IFU) for Athena - Ravera et al.
  and the accompanying talk can be downloaded here
• The DRE, the digital readout electronics for Athena X-IFU - Ravera et al.
• The Cryogenic AntiCoincidence detector for Athena: the progress towards the final pixel design - Macculi et al.
• Background simulations for the Athena X-IFU instrument: impact on the instrumental design - Lotti et al.
• Requirements for the detectors and read-out of Athena X-IFU - Den Hartog et al.
• Towards Mo/Au based TES detectors for Athena/X-IFU - Fabrega et al.
• Baseline design of the thermal blocking filters for the X-IFU detector on board ATHENA - Barbera et al.
• Athena end-to-end simulations - Wilms et al.