Mechanical design of the pick-up arm prototype for TIFR-ARIES multi-object optical to near infrared spectrometer (TA-MOONS)

TIFR and ARIES are jointly developing a Multi-Object Optical to Near Infrared Spectrometer for conducting world’s largest spectroscopic survey of Young Stellar Objects (YSO’s) at Visible and Near Infrared (NIR) wavelength bands simultaneously. This will be installed at the 3.6-meter Devasthal Optical Telescope (DOT), at Nainital. The targeted resolution is R~2700. The capability of this instrument is to observe 8-sources simultaneously within the sky field of view (FoV) of 12 arc-min diameter; currently, no other instruments in the world have this capability. This design, what we call deployable slit concept, uses a mirror based pick-up arm system to feed the light from sources at the focal plane to the spectrometer. The 8-arms located around the focal plane brings the light from 8-sources within sky FoV of 12 arcmin diameter to form a compact staggered 1-dimensional slit that forms input to the two arm standard spectrometers. In this manuscript, we present our mechanical design of the prototype of a pickup arm.