En réponse à la Roadmap community consultation d'Astronet
(https://www.astronet-eu.org/forums/roadmap-community-consultation), le CS du PNHE a envoyé une lettre au Board d'Astronet pour exprimer son mécontent vis à vis de la faible présence des thématiques et projets relevant des hautes énergies.
Voici la lettre:


To the Astronet Board,

We are writing this letter reacting to the Astronet call for comments, feedback or questions from the community to help finalising the reports of the Astronet working panels for the Astronet Science Vision and Infrastructure Roadmap for European Astronomy 2020-2030.

The French community of researchers in high-energy astrophysics would like to express its disappointment for the way high-energy astrophysics is considered in these documents.

In the last decades, high-energy astrophysics has proved to be a fundamental piece for our comprehension of the Universe. Indeed, it represents a major window of opportunity to study accretion, ejection, particle acceleration at all scales, as well as the physics of compact objects and dense matter. It also can be used to put indirect constraints on dark matter and study intergalactic fields. High energies play a major role also in multimessenger astrophysics. Indeed high-energy observations are a key to probe the origin of cosmic rays, and high-energy phenomena were found to be associated with gravitational waves or neutrino detections, impacting our knowledge on topics as diverse as the production of heavy elements in the Universe.

The high-energy community of theorists and observers keeps growing. There are many forthcoming facilities focused on high- and very high-energies, with substantial investments from the agencies of European countries. ATHENA and CTA are certainly the best examples, but many others can be found in the current and future high-energy projects where European researchers are deeply involved. Some space-based examples are XMM-Newton, INTEGRAL, Fermi, SVOM, as well as future projects such as the THESEUS satellites, and/or missions to observe the Universe in the MeV range, strongly supported by the community. Also, deep synergies have and are being built with diverse projects observing at other frequencies / messengers (current and future GW and neutrino detectors, ESO facilities, SKA and SKA precursors,...). Indeed we are now in an era where astrophysics can and must be approached by a multi-wavelength and multimessenger point of view.

High energies are explicitly mentioned in the Astronet project statement “The spectral studies range from radio-astronomy to gamma-rays and particles”, and high energies together with astroparticles formed one of the building blocks of previous Astronet Science vision and Roadmap documents, with dedicated panels. Surprisingly, the relevance of high-energy astrophysics contribution is absent or barely mentioned in the current reports. To provide a bare quantitative example, despite the involvement and investment of European researchers and funding agencies, CTA is mentioned twice and ATHENA three times in all documents, way less than facilities operating at other wavelengths, such as ELT, ALMA or SKA.

We think that this is due to two factors :

- the lack of (or very poor) representation of researchers working in the high energy and very high energy domains in the Astronet panels;

- the way the documents are structured. The approach based on the formation and evolution of Universe/Galaxies/Stars/planets is limited : it emphasizes the description of processes at specific scales,morethanthedescriptionandcomprehensionoftheastrophysicalphenomena. High-energy astrophysics strongly contributes to this last point, linking all the topics stated above, and is clearly penalized by the current approach.

We have been encouraging researchers in the field to be proactive, and send their comments via the Astronet platform on how to improve the reports. However, due to the current document structure, we warn that this is a difficult exercise.

We welcome your decision to interact with the community before finalizing these reports, and we hope that this letter will be considered in the steps to make the Astronet roadmap really representative of the European astrophysical community.

Best regards,
The Scientific Council of the Programme National Hautes Energies of CNRS/INSU

Susanna Vergani (director), Régis Terrier (President of the Scientific Council) And the members of the Scientific Council