Latest news

11-02-2021 - Happy Women in Science Day!

Today, as every year on 11 February, we celebrate the International Day of Women and Girls in Science.

This year, we have asked scientists and engineers of the X-IFU Consortium to prepare short texts about their careers, work, and passions, as well as their advice for girls wanting to follow their path. They will be published on the X-IFU’s social media channels (Twitter and Facebook) from 11 to 19 February.

With the publication of these accounts, we strive to show the vital role played by the women of the X-IFU Consortium and the diversity of their experiences.


Some context

This day was established by the United Nations General Assembly to recognise the critical role women and girls play in science and technology.

It is an important occasion to be reminded that, as written on the United Nations website:

“According to UNESCO data (2014 - 2016), only around 30 per cent of all female students select STEM-related fields in higher education.”

For more information about this day:


26-01-2021 - The X-IFU Gazette #17 has been released!

Happy New Year 2021!

We hope that you have all enjoyed some well-deserved holidays and came back motivated for the beginning of this new year.

Back in November, we held the 12th X-IFU Consortium Meeting online and asked all participants to fill in a post-meeting survey. Thank you to all those who shared their feedback. The key results are presented in the first article.

The end of the year was also busy with the SPIE Digital Forum 2020. In the following article, you will find information about our members’ contributions.

Then, Joern Wilms, X-IFU Science Co-Investigator, gives us an introduction about the ‘missing baryons problem’ and the warm-hot intergalactic medium (WHIM). He also explains X-IFU’s role in better understanding the WHIM’s structure and properties.

We are lucky to welcome a second participant in our series “Meet the People of X-IFU”. Caroline Kilbourne from NASA’s Goddard tells us about her work and shares her enthusiasm about micro-calorimeters.

To conclude this first newsletter of the year, you will get a sneak peek at the new X-IFU website, before its launch in a few months. We hope you like it.

Happy Reading!


Click to read the X-IFU Newsletter #17


18-12-2020 - Happy New Year 2021


Another year is getting to an end, and 2020 will be remembered as the year of a pandemic, which affected our lives in many different ways. Despite the burden this situation has created, the development of X-IFU has moved forward, with several key decisions taken to secure its development path. A few days ago, we celebrated two years since the formal endorsement of the X-IFU Consortium by ESA. On this occasion, we published an article summarising the major highlights of the past two years, thus including a retrospective of 2020. We invite you to read it here.

2021 will be another important year for X-IFU, with industry providing its first feedback on the cryostat design, and with the X-IFU system requirement review expected later in the year, in preparation for the Athena adoption still planned for mid-2022. Hopefully, our members will be able to meet and discuss all these advancements during a face-to-face Consortium meeting in 2021.

Many of us feel the need for a well-deserved break. So let us, on behalf of the X-IFU Consortium, wish you happy holidays and a happy New Year!


Didier Barret & Vincent Albouys
X-IFU Principal Investigator & Project Manager


11-12-2020 - Two years ago: The X-IFU Consortium was endorsed by ESA

On the 11th of December 2018, exactly two years ago today, I received a letter from the ESA Director of Science, Günther Hasinger, stating:

“I have the pleasure to inform you that the Athena Instrument Consortia Consolidation process, started in July 2018, has been successfully completed. Based on the document provided by you on behalf of your proto-Consortium, the X-IFU instrument consortium for the Athena mission is endorsed by ESA in the structure and with the composition described in the provided documentation”.

Announcing the news to the Consortium, I wrote:

“This is a remarkable achievement, which demonstrates that ESA has gained confidence that we, as an international consortium, can deliver the great instrument that is X-IFU. This wouldn’t have been possible without your unfailing support from day one. So, let me thank you deeply for contributing to this success. This milestone behind us, let us now focus all our efforts on the upcoming Preliminary Requirement Review”.

And indeed, the next big thing to come was the Instrument Preliminary Requirement Review (IPRR). It was a rather intensive effort from the whole team. It started in January and on the 4th of November 2019, a board meeting held at ESTEC declared the X-IFU IPRR successful, with actions identified to pave the way to the Athena Mission Formulation Review (MFR) and beyond. A few days later, the MFR was also declared successful allowing Athena to move to its definition phase.

2020 will be remembered as the year of the pandemic, but for X-IFU, it was also the year in which two major programmatic and technical changes were implemented to put the instrument development on a safer path. The first one consisted in transferring the X-IFU cryostat and the cooling chain to the industry. It will now be provided under ESA responsibility by the industrial Prime which will build the Science Instrument Module of Athena. At the moment the Science Instrument Module and the X-IFU cryostat and cooling chain are studied by two Primes in competition (Airbus Defence and Space and Thalès Alénia Space).

The second change implemented early 2020 was the switch of the X-IFU detection readout scheme to Time Domain Multiplexing. The risk of not meeting the spectral resolution and field of view requirements and the risk induced by the system complexity was considered higher for Frequency Domain Multiplexing, our previous baseline, than it was for Time Domain Multiplexing readout.

As we speak, these two changes are being implemented with the objective of being able to support the upcoming reviews. The Intermediate Review is planned for April 2021 and the X-IFU System Requirement Review foreseen for September/October 2021, pending on the Primes ability to advance sufficiently on the cryostat design.

A new consortium organisation is now in place in support of these activities. It is under the leadership of Vincent Albouys, the CNES project manager appointed in March 2019 to succeed to Thien Lam Trong who had conducted X-IFU through a successful IPRR. The organisation is based on joint CNES and Consortium working groups, as well as regular reporting through various project level meetings.

The pandemic has changed our approach to virtual meetings with well identified pros and cons. While many of us feel the need for physical meetings, this will have a clear positive impact on reducing the travel footprint of X-IFU; an initiative launched before the pandemic that has received broad support within the Consortium. This is yet another achievement that we should also be collectively proud of.

To conclude, two years after the endorsement of the X-IFU Consortium by ESA, with a successful IPRR, changes in both the cryostat procurement scheme and in the detection readout scheme, as well as progresses made in many corners of the project, everything indicates that we have the capabilities and the right organisation to achieve the challenge of building the X-IFU for Athena, giving back to ESA the trust they placed in us.


Didier Barret
X-IFU Principal Investigator


10-12-2020 - SPIE Digital Forum 2020

The international society for optics and photonics (SPIE) is organising its annual Astronomical telescopes and instrumentation Symposium. This year, the event is held as a digital forum from 14 to 18 December, 2020. With the exception of some live plenaries, most sessions will be available on demand for registered participants.

X-IFU Consortium members are participating in this event with presentations and posters showing the latest developments of the instrument. You can find them in the section “Space telescopes and instrumentation 2020: Ultraviolet to Gamma Ray (Conference 11444)”.

We are listing below all X-IFU-related contributions to the SPIE 2020.

Presentations at SPIE

Session 7: Athena I

  • The X-ray Integral Field Unit instrument: Design and performances (SPIE Paper 11444-27) – Didier Barret, IRAP

Session 8: Athena II

  • The X-IFU focal plane assembly development model integration and first test results (SPIE Paper 11444-28) – Henk van Weers, SRON
  • Frequency domain multiplexing technology of transition-edge sensors for x-ray astronomy (SPIE Paper 11444-30) – Hiroki Akamatsu, SRON
  • Main sensor array detection chain sub-system for the X-IFU instrument (SPIE Paper 11444-29) - Hervé Geoffray, CNES


Posters at SPIE

Session P4: Posters – Athena

Session P17: Posters – Detectors


This article will be updated with the links to the published papers.

06-11-2020 - A virtual X-IFU Consortium Meeting #12

The 12th X-IFU Consortium Meeting (CM12) took place this week, from 2nd to 6th of November, 2020. Due to the current pandemic, this meeting was held, once again, virtually.

It was a very well attended meeting. For this second edition in a virtual setting, a total of 215 members registered and over 150 simultaneous participants gathered during the first session.

The schedule followed a usual mix of presentations from different members of the Consortium, a representative of the Wide Field Imager Consortium, as well as from the Athena team at ESA. In their talks, all speakers showed the unique and impressive skills of the team, the progresses made, and the many challenges ahead.

Vincent Albouys, X-IFU Project Manager said:

“The instrument design has made many progresses during the last months. We have a permanent objective of simplifying the instrument while keeping performances unchanged”.

In addition, participants welcomed a special guest speaker, Dr Céline Guivarch, a senior researcher at CIRED. She was invited as part of our on-going efforts to raise awareness about the environmental challenges the world is facing. Her highly inspiring talk focused on Climate change and inequality, and she also shared some useful suggestions for actions.

Lastly, to encourage interactivity, a Slack workspace was introduced for this CM which helped continue some of the discussions outside of the sessions. Virtual settings continually motivate us to test new ways of collaborating.

Thank you very much to all the participants, speakers, and chairs of this CM12.


Pictures of the participants

The X-IFU team would never miss an opportunity to take its group picture

20-10-2020 - The X-IFU Gazette #16 has been released!

This 16th issue opens with a short presentation of the next X-IFU Consortium meeting #12. We hope all consortium members are registered by now as we are looking forward to seeing you online.

The third X-IFU Working Group focusing on the TES - Detection Chain is introduced by Frank Brachet and Brian Jackson. If you missed the introduction for the other two Working Groups, you can check our previous newsletter.

We, then, have several contributions related to different parts of the instrument. Alice Pradines gives us an update about the cryostat handover to the industry and the processes in place to carry it through. Henk van Weers presents the mechanical vibration tests that the Focal Plane Assembly Development Model is undergoing. Ivan Charles explains how a cryostat will host and test the 2 K core demonstrator model.

Lastly, you will discover a new feature in the X-IFU newsletter: an interview with a Consortium member. Maite Ceballos from IFCA and Project Manager of the Event processor algorithm is the first one to play the game.

Happy reading!


Click to read the X-IFU Newsletter #16


10-09-2020 - Astronomers take actions to raise awareness on climate change

The Nature Astronomy journal has published, this Thursday, 10th of September, a series of articles written by astronomers about the link between astronomical research and the climate crisis.

This issue¹ highlights the need for urgent actions from all parts of society, including astronomers who, according to the articles, have a higher impact than the average citizen. Our environmental impact has been a major concern for the X-IFU Consortium over the past year (see our article on World Environment Day).

X-IFU’s Principal Investigator, Didier Barret, is co-author of an article focusing on the carbon footprint of large astronomy meetings. This topic is at the core of our commitments as we have decided in 2019 to reduce the number of physical meetings for X-IFU related activities. A move that was sped up due to the current pandemic.

The Nature Astronomy article compares two annual meetings of the European Astronomical Society, one held in Lyon in 2019 and the other held virtually in 2020. The participants’ travel footprint to join the meeting was estimated thanks to Didier Barret’s online travel footprint calculator². For the 2020 virtual edition, the authors evaluated the electrical consumption of both the organisers and the participants.

The results are self-evident:

  • 1,855t CO2-eq in 2019 (for 1,240 attendees in Lyon)
  • 588kg CO2-eq in 2020 (for 1,777 virtual participants)

The writers also offer some thoughts and insights regarding the organisation of future large meetings while continuing to reduce astronomers’ carbon footprint. This paper clearly shows that it is important for astronomers to take actions and we will continue our efforts in the right direction with the X-IFU Consortium.

Other articles from this issue focus on several typical activities of astronomers that result in greenhouse gas emissions, as well as on the impact of the climate crisis on astronomical research.

All articles are available at:


¹ Nature Astronomy, Volume 4, Issue 9

² Barret, 2020, Experimental Astronomy, Volume 49, Issue 3, p.183-216



21-07-2020 - Two postdoc positions to join the X-IFU team

Athena is the second large mission of the Cosmic Vision science program of the European Space Agency. Dedicated to the study of the Hot and Energetic Universe, Athena will carry a large aperture X-ray telescope, and two complementary focal plane instruments: the Wide Field Imager (WFI) and the X-ray Integral Field Unit (X-IFU). The X-IFU is a revolutionary instrument providing spatially resolved high resolution X-ray spectroscopy, with 2.5 eV spectral resolution over a field of view of 5 arcminute equivalent diameter. The X-IFU will be developed by an international Consortium, involving Europe, the United States and Japan. The X-IFU Principal Investigator is Didier Barret (IRAP, Toulouse, France). The French Space Agency (CNES) is the technical authority responsible for the overall development of the X-IFU.

The two positions are opened to candidates of any nationality holding a PhD. The applicants should have expertise in X-ray astronomy. They will be hosted at IRAP, and will work closely with members of the CNES project team, also located in Toulouse.



  • Application deadline: Thursday, September 17, 2020
  • Selection deadline: Friday, October 30, 2020
  • Starting date: At the latest Friday, January 1, 2021


More information about the positions and application procedure can be found at:


For any questions, please contact us at xifu [at]



20-07-2020 - The X-IFU Gazette #15 has been released!

This 15th issue brings you the latest X-IFU information right before the summer break!

We will start with an update on the cryostat handover to industry. Our Principal Investigator, Didier Barret, will give you some details about the various exchanges with the Primes considered for this new ESA-funded contract.

This will be followed by short introductions of two of the newly set-up X-IFU Working Groups (WG) written by their respective co-leads: Roland den Hartog and Philippe Peille for the Performance WG; Jean-Michel Mesnager and Jan-Willem den Herder for the System – Interface WG.

Then, you will get to discover the new X-IFU images that are available for download.

Lastly, Jiří Svoboda, as the Czech representative in the X-IFU Consortium Board, will present an overview of his country’s contribution to the instrument, the Remote Terminal Unit, and the work of the two institutes carrying it out. You will also get a glimpse of his own activities in his biography article.

We wish you all to stay safe and enjoy your summer.

Happy reading!