Mission

newASTROGAM is our proposal for Europe's next Gamma observatory within the ESA call for a Medium-sized and for a Fast mission opportunity 2025.
A mission overview is available on arxiv.

Timeline

May 21st, 2025: Step-1 proposal submission
October 7, 2025: Announcement of Step-1 proposal results
March 19, 2026: Step-2 proposal submission (upon invitation)
November 2026: Selection of missions for study
2041: Approximate launch

Mission overview (pdf)

MeV to GeV companion for multimessenger astronomy

newASTROGAM will close the MeV gap for multi-wavelength, multi-messenger coverage of the sky (with SKAO, JWST, E-ELT, Athena, CTAO, and GW detectors...), with special focus on transient phenomena. Its portfolio includes all-sky mapping of diffuse emission and monitoring of transient activities of thousands of sources such as pulsars, stellar and supermassive black holes, GRBs, magnetars, supernovae and kilonovae.

Design concept

Silicium Tracker - Double sided Si strip detectors (DSSDs) for excellent spectral resolution and fine 3D position resolution
3D-imaging Calorimeter - CsI(Tl) crystals readout by Si photo-detectors for efficient photon absorption
Anticoincidence detector to veto charged-particle induced background; plastic scintillators readout by SiPMs
X-ray coded mask for adding hard X-ray monitoring and imaging cababilty at 15-40 keV

Mission profile

Satellite platform: Thales Alenia Space Multi-Mission Platform product line
Launcher: Vega-C, separated mass: 1612 kg
Low-Earth equatorial orbit (inclination i < 5°, eccentricity e < 0.01, altitude 550 - 600 km) for optimal background environment
All-sky scanning mode maximises sky coverage over a day
nearly inertial pointing for ToO observations
In-orbit operation: 3 years (provisions for 5+ years)

Multi-purpose observatory

newASTROGAM will offer all relevant tools for Gamma-ray astronomy. Its technology is space-proven, ready & reliable.

imaging
polarimetry
line and continuum spectroscopy
fast timing and transient detection capabilities
at least an order of magnitude better sensitivity than any previous, current, or planned MeV mission

Measurement Principle

Interactions of photons with matter in the newASTROGAM energy range is dominated by Compton scattering from 100 keV up to about 15 MeV in silicon, and by electron-positron pair production in the field of a target nucleus at higher energies. newASTROGAM maximises its efficiency for imaging and spectroscopy of energetic Gamma rays by using both processes.

Power of polarization

newASTROGAM will have unprecedented polarimetric capabilities to study objects emitting jets (GRBs, blazars, X-ray binaries) or with strong B-field (pulsars, magnetars). It will observe Gammy-ray polarisation from cosmological sources (GRBs, blazars) in a yet unexplored energy rangeand help to answer fundamental questions of physics related to quantum gravity (vacuum birefringence) and axions.

Silicon Tracker

The Silicon Tracker is the heart of the newASTROGAM payload. Within the tracker, the cosmic Gamma-rays undergo a first Compton scattering or a pair conversion. It is based on the technology of double sided Si strip detectors to measure the energy and the 3D position of each interaction with an excellent energy and spatial resolution.

3D-imaging Calorimeter

The Calorimeter is designed to efficiently absorb the Compton scattered Gamma rays and electron-positron pairs. It is made of an array of small scintillation crystals read out by silicon drift photodetectors (in the baseline design) to achieve the required energy resolution (about 5% at 662 keV), outperforming previous instruments.

Anticoincidence (AC) System

An AC system vetoes the prompt-reaction background induced by solar or cosmic-ray particles (as opposed to the delayed background due to the satellite material activation); it is designed with plastic scintillator tiles covering the instrument to detect charged relativistic particles with an efficiency exceeding 99.99%.

Angular resolution

newASTROGAM will achieve a very good angular resolution both in the MeV and GeV domains, i.e. improving the angular resolution of the CGRO/COMPTEL telescope at 1 MeV by a factor of ∼ 3.5 and that of the Fermi/LAT instrument at 100 MeV by a factor of ∼ 2. The expected improvement compared to the planned COSI mission is by a factor of 1.7 at 511 keV.

Leap in Sensitivity

newASTROGRAM will improve the sensitivity in the medium-energy Gamma-ray domain (1–50 MeV) by more than an order of magnitude compared to previous missions. It will provide an important leap in continuum sensitivity over a wide energy band from about 200 keV to 50 MeV – and a gain in line sensitivity of at least an order of magnitude over SPI and between 2.4 and 106 over COSI.

Field of View

Simulations predict a field of view (FoV) of for example:

FoV at 150 keV: solid angle coverage Ω = 3.8 sr
FoV at 1 MeV: solid angle coverage Ω = 2.9 sr
FoV at 30 MeV: solid angle coverage Ω = 3.5 sr