The Advanced Telescope for High ENergy Astrophysics (ATHENA) is an X-ray observatory planned for launch in 2034 aboard an Ariane 6 expendable launch vehicle. The mission was selected and now under development by the European Space Agency (ESA) as part of their Cosmic Vision program to address the Hot and Energetic Universe science theme. The mission is an ESA led project with contributions from institutes in Europe, United States, and Japan.
ATHENA has a 12 m focal length X-ray telescope with a large effective area. X-rays are collected by two focal plane instruments: the Wide Field Imager (WFI) and X-ray Integral Field Unit (X-IFU). The observatory will be placed in a halo orbit around the Earth-Sun L2 Lagrange point with a nominal mission lifetime of 5 years with possible extension of a further 5 years. The L1 orbit is being evaluated as back-up option.
ATHENA is a down-sized version of the abandoned NASA/JAXA/ESA International X-ray Observatory (IXO), which itself was a merger of the ESA XEUS and NASA Constellation-X mission proposals.
Mission Characteristics
Lifetime
2034 launch with 5 year nominal mission; additional 5 year extended mission option
Special Features
Two detectors sharing a single telescope, with large area high spatial resolution capabilties
Lifetime
2034 launch with 5 year nominal mission; additional 5 year extended mission option
Special Features
Two detectors sharing a single telescope, with large area high spatial resolution capabilties
Payload
Instrument
Characteristic
Details
Telescope
Effective Area
≥ 1.4 m2 at 1 keV ≤ 0.25 m2 at 6 keV
Focal Length
12 m
Angular Resolution
5″ (HEW)
The telescope uses grazing incidence silicone pore optics with an instrument switching mechanism, based on a set of hexapods, allows each of the two detectors to be located at the mirror focus at any given time. The same mechanism allows to defocus the mirror Point Spread Function (PSF), permitting the X-IFU to observe bright X-ray sources.
Wide Field Imager (WFI)
Energy Range
0.2–15 keV
Field of View
40′ × 40′
Angular Resolution
5″
Energy Resolution
≤170 eV at 7 keV
Time Resolution
5 ms (LDA) 80 µs (FD)
The WFI detector comprises a Large Detector Array (LDA) and a Fast Detector (FD) both using depleted p-channel field-effect transistors (DEPFET). The LDA is an array of 2×2 detectors, each with 512×512 pixels. The FD is optimized for bright point sources with an array of 64×64 pixels.
X-ray Integral Field Unit (X-IFU)
Energy Range
0.2–12 keV
Effective Area
∼5800 cm 2 at 1 keV ∼880 cm2 at 7 keV
Field of View
5′
Angular Resolution
∼5″
Energy Resolution
4 eV (design goal 3 eV) at 7 keV
Time Resolution
10 µs
X-ray calorimeter with an array of cryogenically cooled transition edge detectors. Current design anticipates ∼1500 pixels (versus 36 pixels in the current XRISM Resolve calorimeter).
Telescope
Effective Area
≥ 1.4 m2 at 1 keV ≤ 0.25 m2 at 6 keV
Focal Length
12 m
Angular Resolution
5″ (HEW)
The telescope uses grazing incidence silicone pore optics with an instrument switching mechanism, based on a set of hexapods, allows each of the two detectors to be located at the mirror focus at any given time. The same mechanism allows to defocus the mirror Point Spread Function (PSF), permitting the X-IFU to observe bright X-ray sources.
Wide Field Imager (WFI)
Energy Range
0.2–15 keV
Field of View
40′ × 40′
Angular Resolution
5″
Energy Resolution
≤170 eV at 7 keV
Time Resolution
5 ms (LDA) 80 µs (FD)
The WFI detector comprises a Large Detector Array (LDA) and a Fast Detector (FD) both using depleted p-channel field-effect transistors (DEPFET). The LDA is an array of 2×2 detectors, each with 512×512 pixels. The FD is optimized for bright point sources with an array of 64×64 pixels.
X-ray Integral Field Unit (X-IFU)
Energy Range
0.2–12 keV
Effective Area
∼5800 cm 2 at 1 keV ∼880 cm2 at 7 keV
Field of View
5′
Angular Resolution
∼5″
Energy Resolution
4 eV (design goal 3 eV) at 7 keV
Time Resolution
10 µs
X-ray calorimeter with an array of cryogenically cooled transition edge detectors. Current design anticipates ∼1500 pixels (versus 36 pixels in the current XRISM Resolve calorimeter).
Science Goals
Study how matter assembles within galaxies and galaxy clusters
Measure the history of the chemical composition of the Universe through time
Study acceretion processing in compact objects
Find the earliest super-massive black holes and tracing their growth despite the obscuration of heavy dust and gas
Study transient phenomena such as gamma-ray burst sources with a fast target of opportunity system
