THESEUS

THESEUS

Transient High-Energy Sky and Early Universe Surveyor

SHORT DESCRIPTION

THESEUS is a mission concept proposed in response to the European Space Agency (ESA) call for a future medium-class M7 mission within the Cosmic Vision long-term science mission program. The mission – already an M5 candidate and led by Italy – is one of the five selected candidates and has as its Principal Investigator Lorenzo Amati of the INAF-Bologna Astronomical Observatory.

THESEUS’ primary scientific objectives respond to the Cosmic Vision program theme: “How did the universe originate and what is it made of?”, also impacting the themes of “The Universe in Gravitational Waves” and “The Hot and Energetic Universe”. THESEUS will be a mission dedicated to the astronomy of transient phenomena up to high redshift and of the electromagnetic counterparts of gravitational waves.

The THESEUS space mission will study in particular long Gamma-Ray Bursts (GRBs) to answer key questions about the early Universe. Long GRBs, produced by the collapse of massive stars, are like lighthouses that illuminate the material surrounding them and separating us from them. They therefore allow us to probe the chemical composition of interstellar material and understand when and how quickly the Universe went from being opaque to the radiation produced by its constituents to transparent. Furthermore, the detection of these gamma-ray bursts up to very high redshifts will allow us to understand how primordial stars formed. At the same time, THESEUS will monitor the sky in search of short transients that, as we know from the 2017 discoveries, are produced by the merger of neutron stars in binary star systems. These sources, which produce gravitational waves detectable by ground-based interferometers such as LIGO and Virgo, represent the tools for multi-messenger astronomy, combining the information carried by light and the gravitational signal.

THESEUS on-board instrumentation includes:

• Soft X-ray Imager (SXI, 0.3 – 5 keV): a pair of lobster-eye X-ray telescopes;
• InfraRed Telescope (IRT, 0.7 – 1.8 μm): an infrared telescope;
• X-Gamma rays Imaging Spectrometer (XGIS, 2 keV – 20 MeV): a pair of coded mask units, using monolithic X-ray and gamma detectors, based on scintillator crystal rods coupled to silicon photodetectors.

The launch planned for 2037 makes possible synergy with other experiments, such as the Einstein Telescope and possibly Athena and Lisa, as well as the Cherenkov Telescope Array Observatory and the Square Kilometer Array, operating in the tera-electronvolt and radio bands respectively. 

ROLE OF THE OBSERVATORY

Italy, which leads the THESEUS Consortium, will have the following roles: PI of the XGIS instrument and responsible for the design, testing, simulation and calibration phase and responsible for the instrument operations center – PI of the Transient Warning System (TBU, Trigger Broadcasting Unit) – Head of the Project Office – Contribution to the Scientific Data Center (SDC). In addition, the Italian Space Agency (ASI) will provide, for the launch, the ground station of the Luigi Broglio Space Center in Malindi (as an in-kind contribution). INAF-Brera Astronomical Observatory is responsible for the design and construction of the IRT infrared telescope, which is a game-changer compared to past and future missions for the study of gamma-ray transients. In fact, IRT will be able to measure the redshift of the long GRBs detected by THESEUS in the early universe within a few hours of the event.

Two of our researchers have a key role in the mission. Giancarlo Ghirlanda is responsible for the working group that deals with the study of scientific performances and simulations for the detection of long GRBs in the early universe. Stefano Covino is responsible for the study and development of the IRT telescope with the GoLEM group of our Observatory.

OBSERVATORY STAFF INVOLVED

Giancarlo Ghirlanda – giancarlo.ghirlanda AT inaf.it
Stefano Covino – stefano.covino AT inaf.it
Om Sharan Salafia – om.salafia AT inaf.it
Lara Nava – ruolo – lara.nava AT inaf.it
Paolo D’Avanzo – paolo.davanzo AT inaf.it
Maria Grazia Bernardini – maria.bernardini AT inaf.it
Sergio Campana – sergio.campana AT inaf.it
Gianpiero Tagliaferri – gianpiero.tagliaferri AT inaf.it
Giovanni Pareschi – giovanni.pareschi AT inaf.it
Marco Riva – marco.riva AT inaf.it

TIMELINE

2018 – 2037

WEBSITE

THESEUS

CONTACT

CREDITS

Web page content: G. Ghirlanda e S. Covino.