TANSPEC: TIFR-ARIES Near-infrared Spectrometer

Abstract

We present the design and performance of the TANSPEC, a medium-resolution 0.55–2.5 μm 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 narrowband filters, spectroscopy with short slits of 20″ length and different widths (from 0.″5 to 4.″0) in cross-dispersed mode at a resolving power R of ∼2750, and spectroscopy with long slits of 60″ length and different widths (from 0.″5 to 4.″0) in prism mode at a resolving power R of ∼100–350. TANSPEC’s imager mode provides a field of view of 60″ × 60″ with a plate scale of 0.″245 pixel−1 on the 3.6 m DOT. The TANSPEC was successfully commissioned during 2019 April–May, and the subsequent characterization and astronomical observations are presented here. The TANSPEC was made available to the worldwide astronomical community for science observations from 2020 October.

Post-outburst Evolution of Bona Fide FU Ori-type V2493 Cygnus: A Spectro-photometric Monitoring

“…We have spectroscopically monitored V2493 Cyg in the NIR wavelengths starting from 2014 March 07 until 2020 November 11 using the TIRSPEC mounted on 2 m HCT and TIFR-ARIES Near Infrared Spectrograph (TANSPEC; Ojha et al 2018;Sharma et al 2022) mounted on 3.6 m Devasthal Optical Telescope (DOT). TIRSPEC provides a wavelength coverage from 1 to 2.5 μm at a spectral resolution of ∼1200.…”

Optical Telescopes at Devasthal Observatory, Nainital

“…The UPSO-TIFR collaboration, initiated about 3 decades ago, has continued to progress in the area of back-end instrumentation, particularly for near-infrared (NIR) observations with the 3.6-m DOT. The TIRCAM2 (TIFR NIR Imaging Camera-II) is permanently mounted on a side port while TANSPEC (TIFR-ARIES NIR Spectrometer) can be mounted on the axial port of the 3.6-m DOT (Sharma et al 2022a;Ojha et al 2018). For observations in the optical band, both 4K x 4K CCD IMAGER and ARIES-Devasthal Faint Object Spectrograph and Camera (ADFOSC) developed and built by ARIES, are mounted on the axial port of the 3.6-m DOT (Omar et al 2019a;Dimple et al 2023).…”