GFT (Ground Follow-up Telescope)

The robotic Ground Follow-up Telescopes (GFT) play a crucial role in observing and studying Gamma-Ray Bursts (GRBs).

When an alert is received from the VHF network, these telescopes promptly (within 1 min following the onboard ECLAIRs trigger) repoint towards the GRB position to start observing and search for a GRB optical/near-infrared counterpart. These follow-up telescopes measure GRB positions with accuracies typically around 1 arcsecond and provide a flux sampling over time of the GRB afterglow emission in several bands (from optical to near infrared). They also measure crude estimates of the GRB redshift (i.e. its distance from Earth).

All the GFT results are then sent to the French Science Center (FSC) that will dispatch the alert messages to larger facilities like the NTT and the VLT in optical or ALMA in radio.

Site de SanPedro Martir

Left – View of the San Pedro Martir site in Mexico where the French GFT will be installed. Right – Image showing what the French GFT will look like.

In addition to the science payload in space, SVOM will include two follow-up telescopes composed of a primary mirror of at least 1 meter in diameter : one located at San Pedro Martir in Mexico under French responsability and another one at the Xinglong Observatory under Chinese responsability.


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Auteur : CEA - LAM & Olivier Godet