ATHENA, Advanced Telecope for High-ENergy Astrophysics
ATHENA is the L2 mission candidate for the program “Cosmic Vision” of ESA with a launch currently foreseen in 2028. ATHENA will be a powerful X-ray observatory designed to address the Cosmic Vision science theme “The Hot and Energetic Universe”, namely the following two key astrophysical questions:
- How does ordinary matter assemble into the large-scale structures we see today? and
- How do black holes grow and shape the Universe?
To address the first question, it will be necessary to map hot gas structures in the Universe – specifically the gas in clusters and groups of galaxies, and the intergalactic medium – determine their physical properties and track their evolution through cosmic time.
To answer the second question, super-massive black holes (SMBH) must be revealed, even in obscured environments, out into the early Universe, and both the inflows and outflows of matter and energy as the black holes grow must be understood.
ATHENA will also allow addressing an ample range of other important astrophysical investigations, connected to studies of X-ray emission of Solar System objects, of Massive and Late-type stars, of Star forming regions, of Supernovae remnants, of X-ray Binaries, of galaxies in the local system, etc. for which a substantial amount of the available observing time will be devoted.
To address all those science questions ATHENA will be built around a large (~1.5 sq.m.) innovative X-ray mirror that will feed, one at the time, two distinct focal plane instruments: the X-IFU (X-ray Integral Field Unit), a 5 x 5 sq. arcm. detector based on a matrix of TES bolometer, with a angular resolution of ~ 5″, energy resolution of 2.5 eV and a sophisticated active anti-coincidence system to drastically reduce the instrumental background, and the WFI (Wide Field Instrument), a 40 x40 sq. arcm. detector based on matrices of DEP-FET pixels (sensors), with angular resolution of ~2.2″ and energy resolution of ~ 100 eV. Both focal plane instruments will be sensitive in the 0.3-12 keV bandpass.
During 2015 the mission has entered the phase A study that has been concluded with the succefull Mission Formulation Review (MFR) on November 12 2019. This enabled the Athena project at ESA to enter in the Phase B (definition). This is a key milestone towards the formal adoption of Athena by the ESA SPC, still scheduled for the end of 2021. Currently the Athena launch date is foreseen at the end of 2030.
International and national Partners
ATHENA has been proposed by a large team of European scientists and is also supported by Japanese and US scientists. The ATHENA collaboration includes all the major research centres actively working in high-energy astrophysics in Europe, US and Japan: IRAP, INAF/(Bologna, Roma, Milano, Palermo), MPE, SRON, Dept. Physics and Astronomy/University of Leicester, Institut de Fisica de Cantabria (CSIC-UC), etc. ATHENA is an ESA-lead mission with junior collaborations from JAXA and NASA.
For both focal plane instruments two consortia have been constituted and approved by ESA (after the successul MFR) that will have the responsability of instrument construction and delivery to ESA. As usual the focal plane instruments will be funded by national space agencies. The X-IFU PI and Co-PI are D. Barret (IRAP, France). J-W. den Herder (SRON, The Netherland), and L. Piro (INAF, Italy). The major funding agencies are CNES, SRON and ASI, with contributions from (in alphabetic order) Belgium, Finland, Germany, Ireland, Japan, Poland, Spain, Switzerland, United States. The WFI PI is K. Nandra (MPE, Germany), the instrument is being developed by a consortium consisting of the MPE (Germany), a consortium of German universities (ECAP, IAAT), the company PNSensor GmbH, together with partners in the United Kingdom (Leicester), France (IRAP Toulouse) and Italy (INAF-Bo & UNIPA/INAF-OAPA), etc.
OAPA role and participants
Athena is the result of a series of efforts to propose a winning concept for a large X-ray mission to follow the NASA Chandra and the ESA XMM-Newton X-ray observatories. Since 2002 researchers of INAF/OAPA and, today, of the Department of Physics and Chemistry of the Università di Palermo (DIFC/UNIPA), associate to INAF/OAPA, have been jointly involved in a series of studies and proposals that have now resulted in the selected Athena mission. Several INAF/OAPA and DIFC/UNIPA researchers have signed the Athena proposal, are members of science WGs, have chaired and are chairing WGs, are members of the X-IFU and of WFI consortia. For the X-IFU the OAPA/DIFC team is responsible of the definition and procurement of the thermal filters that will be mounted on the aperture cylinder of the cryostat housing the focal plane assembly, and collaborates to the design of additional optical blocking filters, mounted on a filter wheel, required to enable the observations of optically bright and very bright sources For the WFI the OAPA-DIFC team is responsible of the definition and procurement of the large area filter. Leading persons are S. Sciortino (OAPA) and M. Barbera (DIFC), who are members of the X-IFU Italian team lead by L. Piro, other contributing people are C. Argiroffi, A. Collura, U. Lo Cicero, M. Miceli, S. Orlando, L. Sciortino. S. Sciortino is currently serving (second term ends 4/2020) also as a member of the X-IFU Science Team.