SWIFT

SWIFT

Neil Gehrels Swift Observatory

BREVE DESCRIZIONE

Swift is a NASA medium explorer-class satellite built in collaboration with Italy and the United Kingdom. The name is not an acronym but refers to the English name for the swift, one of the birds with the most agile and fastest flight, and was chosen to recall the satellite’s rapid aiming, guaranteed by a gyroscopic system controlled by electric motors.

The satellite is dedicated to the study and interpretation of gamma-ray bursts (GRBs). Launched in 2004, Swift has been observing the high-energy universe for almost 20 years.

Swift has three instruments (BAT, UVOT, XRT). The Burst Alter Telescope (BAT) is a wide-field instrument that works in hard X-rays. BAT is responsible for detecting GRBs. Once a new GRB is discovered, Swift autonomously re-points the small-field instruments, the X-Ray Telescope (XRT) and the UtraViolet Optical Telescope (UVOT), in 60-120 seconds to observe the GRB in X-rays and optical-UV. Swift observes about 70-100 GRBs per year and, thanks to its unique fast re-pointing capability – to date, no satellite rotates, moves and re-points faster than Swift – it is able to observe the entire temporal evolution of GRBs, from the burst to their slow fading, weeks or months later.

The initial mission objectives for Swift were:

• determine the origin of GRBs;
• classify GRBs and search for new types;
• determine how the lightning shock wave evolves and interacts with the surrounding environment;
• using GRBs to study the early universe;
• to perform a sensitive census of the sky in the hard X-ray band.

All these scientific goals have been achieved and Swift still manages to reserve new surprises for us. Furthermore, thanks to the speed and flexibility of re-pointing, Swift has been and is used over the years to study all types of high-energy sources: from comets to stars, to compact galactic objects, to active galactic nuclei, to galaxies and galaxy clusters, often making new discoveries in every sector, and becoming a point of reference for time domain astronomy. Swift has also given a fundamental contribution to the study of the optical counterparts of gravitational wave events, having been the only satellite to have observed their ultraviolet emission. On April 3, 2024, the new observation run of the gravitational interferometers (the so-called O4b) began, to which Swift will give a unique contribution by searching in real time for the electromagnetic counterpart of gravitational events in X-rays and in the bluest band of the optical spectrum.

ROLE OF THE OBSERVATORY

L’INAF-Osservatorio Astronomico di Brera ha fornito l’ottica per il telescopio a raggi X (XRT) ed ha costruito un piccolo telescopio robotico ottico-infrarosso da terra (REM) dedicato al monitoraggio dell’emissione ottico-infrarossa dei GRB. Diversi ricercatori OAB sono membri attivi del gruppo Swift-Italia e partecipano alla gestione scientifica del satellite in qualità di Burst Advocate (BA) e XRT Burst Specialist (XBS), per le osservazioni rapide e di follow-up di GRB rivelati da Swift, 24 ore su 24 e 7 giorni su 7, perché i GRB sono imprevedibili. L’analisi e l’interpretazione di queste osservazioni, ovvero i dati provenienti dal satellite Swift accoppiati con osservazioni simultanee da telescopi terrestri, permette di studiare in dettaglio le proprietà dei GRB per comprenderne la natura. Come Swift, anche in OAB abbiamo allargato i nostri interessi scientifici studiando anche le sorgenti transienti del cielo in banda X.

INAF-Brera Astronomical Observatory provided the optics for the X-ray telescope (XRT) and built a small ground-based robotic optical-infrared telescope (REM) dedicated to monitoring the optical-infrared emission of GRBs. Several OAB researchers are active members of the Swift-Italia group and participate in the scientific management of the satellite as Burst Advocate (BA) and XRT Burst Specialist (XBS), for rapid and follow-up observations of GRBs detected by Swift, 24/7, because GRBs are unpredictable. The analysis and interpretation of these observations, i.e. data from the Swift satellite coupled with simultaneous observations from ground-based telescopes, allows us to study in detail the properties of GRBs to understand their nature. Like Swift, also in OAB we have broadened our scientific interests by also studying transient sources in the sky in the X-ray band.

OBSERVATORY STAFF INVOLVED

Sergio Campana – PI of the Italian group and XRT telescope calibration manager – sergio.campana AT inaf.it
Maria Grazia Bernardini – Scientist – maria.bernardini AT inaf.it
Stefano Covino – Scientist – stefano.covino AT inaf.it
Paolo D’Avanzo – Scientist – paolo.davanzo AT inaf.it
Chiara Salvaggio – Scientist – chiara.salvaggio AT inaf.it
Tullia Sbarrato – Scientist – tullia.sbarrato AT inaf.it
Gianpiero Tagliaferri – Scientist – gianpiero.tagliaferri AT inaf.it

TIMELINE

2004 –

WEBSITE

Swift – Italia

Swift – NASA

CONTACT

CREDITS

Web page content: S. Campana