TANSPEC: TIFR-ARIES Near Infrared Spectrometer

TL;DR

TANSPEC is a versatile near-infrared spectrometer and imager for the 3.6-m Devasthal Optical Telescope, offering multiple modes of operation and providing valuable data for astronomical research since 2020.

Contribution

This paper introduces the design, performance, and operational modes of TANSPEC, a new cryogenic near-infrared instrument for the 3.6-m DOT, expanding observational capabilities.

Findings

Successfully commissioned in 2019

Provides multiple observational modes with high resolution

Available for global astronomical community since 2020

Abstract

We present the design and performance of the TANSPEC, a medium-resolution $0.55-2.5~\mu$m cryogenic spectrometer and imager, now in operation at the 3.6-m Devasthal Optical Telescope (DOT), Nainital, India. The TANSPEC provides three modes of operation which include, photometry with broad- and narrow-band filters, spectroscopy with short slits of 20$^{\prime \prime}$ length and different widths (from 0.5$^{\prime \prime}$ to 4.0$^{\prime \prime}$) in cross-dispersed mode at a resolving power R of $\sim$2750, and spectroscopy with long slits of 60$^{\prime \prime}$ length and different widths (from 0.5$^{\prime \prime}$ to 4.0$^{\prime \prime}$) in prism mode at a resolving power R of $\sim$100-350. TANSPEC's imager mode provides a field of view of 60$^{\prime \prime} \times 60^{\prime \prime}$ with a plate scale of 0.245$^{\prime \prime}$/pixel on the 3.6-m DOT. The TANSPEC was successfully commissioned during April-May 2019 and the subsequent characterization and astronomical observations are presented here. The TANSPEC has been made available to the worldwide astronomical community for science observations from October 2020.