List of publications related to the X-IFU

You will find here X-IFU related publications.

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

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.

Ratios yields

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

arXiv:1809.08903 [astro-ph.CO]

List of X-IFU related papers

Improving the X-IFU count rate capability through defocussing

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

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.

SPIE 2016 papers (related to the X-IFU)