REMIR: The REM infrared camera to follow up the early phases of GRBs afterglows

REMIR is a, near-infrared camera, covering the 0.95-2.3 mu m range with 5 filters (z,J,H,Ks and H-2), mounted at one of the Nasmyth foci of the REM (Rapid Eye Mount) telescope. REM is a fully robotic fast-slewing 60 cut telescope, primarily designed to follow-tip the early phases of the afterglow of GRBs detected by dedicated instruments onboard satellites (like SWIFT, a satellite entirely dedicated to GRBs science launched the 12 November 2004). Moreover REM hosts a slitless spectrograph covering the range 0.45-0.95 mu m; with 30 sample points and with the possibility to perform broad-band V,R,I photometry (ROSS, REM Optical Slitless Spectrograph). The main task of REMIR is to perforin realtime NIR observations of GRBs detected by gamma-ray monitors onboard satellites, looking for any possible infrared transient source. As soon as a transient source is detected in the IR images; larger telescopes are promptly alerted to perform early spectroscopy of the afterglow. All the above operations are performed in a fully automatic way and without any human supervision. We present the results of on-site tests that have been done to characterize the RE 4111 camera, and the performances of the dedicated reduction pipeline AQuA (Automatic Quick Analysis), suited for fast transients detection.