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Instruments

The 3.6m DOT provides three Cassegrain ports for mounting instruments, i.e. main axial-port, side-port1 and side-port2. For these ports of the telescope, a total of four instruments have been developed, tested and commissioned. The technical information, scientific capabilities and latest update on these instruments are given below.

IMAGER is an optical imaging instrument covering wavelengths ranging from 400 to 900nm. It employs a 4096 x 4096 CCD camera with a pixel scale of about 0.1 arcsec on the telescope and it covers a field of view of 6.5 x 6.5 arcmin. The available filters are Bessel U,B,V,R,I and SDSS u,g,r,i,z. Imaging observations show that the instrument has the capability to observe sources up to 24.0 mag, 25.2 mag and 24.6 mag with 10% photometric accuracy in B, g, r band respectively, with corresponding effective exposures of 1200s, 3600s, and 4320s. Stellar images with FWHM of 0.55 arcsec in R-band have been recorded in best conditions. It can only be mounted on the axial-port of the telescope.

LATEST UPDATE
  • New updates will be posted here.
 
DOCUMENTATION FOR USERS
 
RECENT PUBLICATIONS
  1. Gagarin-day GRB 200412B: observations with the 3.6m Devasthal Optical Telescope
    Amit Kumar, S. B. Pandey, Amar Aryan, Brijesh Kumar, Kuntal Misra, a larger GRB Collaboration ;
    2020, GCN, 27653, 1k
  2. VR CCD Photometry of Variable Stars in the Globular Cluster NGC 4147
    Sneh Lata, A. K. Pandey, J. C. Pandey, R. K. S. Yadav, Shashi B. Pandey, Aashish Gupta, Tarun Bangia, Hum Chand, Mukesh K. Jaiswar, Yogesh C. Joshi, Mohit Joshi, Brijesh Kumar, T. S. Kumar, Biman J. Medhi, Kuntal Misra, Nandish Nanjappa, Jaysreekar Pant, Purushottam, B. Krishna Reddy, Sanjeet Sahu, Saurabh Sharma, Wahab Uddin, Shobhit Yadav;
    2019, AJ, 158, 51
  3. A multiwavelength analysis of a collection of short-duration GRBs observed between 2012 and 2015
    S. B. Pandey, Y. Hu, A. J. Castro-Tirado, A. S. Pozanenko, R. Sánchez-Ramírez, J. Gorosabel, 5 S. Guziy, M. Jelinek, J. C. Tello, S. Jeong, S. R. Oates, B. -B. Zhang, E. D. Mazaeva, A. A. Volnova, P. Yu. Minaev, H. J. van Eerten, M. D. Caballero-García, D. Pérez-Ramírez, M. Bremer, J.-M. Winters, I. H. Park, A. Nicuesa Guelbenzu, S. Klose, A. Moskvitin, V. V. Sokolov, E. Sonbas, A. Ayala, J. Cepa, N. Butler, E. Troja, A. M. Chernenko, S. V. Molkov, A. E. Volvach, R. Ya. Inasaridze, Sh. A. Egamberdiyev, O. Burkhonov, I. V. Reva, K. A. Polyakov, A. A. Matkin, A. L. Ivanov, I. Molotov, T. Guver, A. M. Watson, A. Kutyrev, W. H. Lee, O. Fox, O. Littlejohns, A. Cucchiara, J. Gonzalez, M. G. Richer, C. G. Román-Zúñiga, N. R. Tanvir, J. S. Bloom, J. X. Prochaska, N. Gehrels, H. Moseley, J. A. de Diego, E. Ramírez-Ruiz, E. V. Klunko, Y. Fan, X. Zhao, J. Bai, Ch. Wang, Y. Xin, Ch. Cui, N. Tungalag, Z.-K. Peng, Amit Kumar, Rahul Gupta, Amar Aryan, Brajesh Kumar, L. N. Volvach, G. P. Lamb, A. F. Valeev;
    2019, MNRAS, 485, 5894

TIRCAM2 can provide near infrared imaging observations in the wavelength range from 1 to 3.7 microns. It employs an InSb array with a pixel scale of 0.17 arcsec and it covers a field of view of 86.5 arcsec x 86.5 arcsec. It has broad-band J, H, K and narrow-band BrG, K-cont, PAH and nbL filters. Deep imaging observations show that the instrument has the capability to observe sources upto 19.0 mag, 18.8 mag and 18.0 mag with 10% photometric accuracy in J, H and K band respectively, with corresponding effective exposures of 550s, 550s and 1000s. Stellar images with FWHM of 0.45 arcsec in K-band were recorded in best conditions. Another highlight of this camera is the observational capability for sources upto magnitudes of 9.2 in the narrow L-band (nbL; λcen∼ 3.59 microns). Sources with strong polycyclic aromatic hydrocarbon (PAH) emission at 3.3 microns can also be detected with TIRCAM2. It is permanently mounted on the side-port1 of the telescope.

LATEST UPDATE
  • 2020-11-04 : TIRCAM2 is unmounted from the telescope for ground testing.
  • 2020-10-24 : TIRCAM2 is not available for observations due to some technical issues.
 
DOCUMENTATION FOR USERS
 
RECENT PUBLICATIONS
  1. The disintegrating old open cluster Czernik 3
    Saurabh Sharma, Arpan Ghosh, D. K. Ojha, R. Pandey, T Sinha, A. K. Pandey, S. K. Ghosh, N. Panwar, S. B. Pandey
    2020, MNRAS, 498, 2309
  2. Further milliarcsecond resolution results on cool giants and binary stars from lunar occultations at Devashtal
    A. Richichi, Saurabh Sharma, T. Sinha, R. Pandey, A. Ghosh, D.K. Ojha, A.K. Pandey, M.B. Naik
    2020, MNRAS, 498, 2263
  3. PAH and nbL Features Detection in Planetary Nebulae NGC 7027 and BD +303639 with TIRCAM2 Instrument on 3.6m DOT
    Rahul Kumar Anand, Shantanu Rastogi, Brijesh Kumar, Arpan Ghosh, Saurabh Sharma, D.K. Ojha, S.K. Ghosh
    2020, JApA (arXiv:2020.01411)
  4. Prospects for star formation studies with infrared instruments (TIRCAM2 and TANSPEC) on the 3.6-m Devasthal Optical Telescope
    Devendra Ojha; Swarna Kanti Ghosh; Saurabh Sharma; Anil Kumar Pandey, ; Tapas Baug; Joe Philip Ninan, ; Brijesh Kumar, Manoj Puravankara, Savio D'Costa; Milind Naik; Satheesha Poojari, ; Shailesh Bhagat, ; Rajesh Jadhav, ; Ganesh Meshram, ; Pradeep Sandimani, Sanjay Gharat; Chandrakant Bakalkar
    2018, BSRSL, 87, 58-87

ADFOSC is a low resolution slit-spectrograph and camera having sensitivity in the wavelength range 350 nm to 1050 nm. It uses a 4096 x 4096 deep-depletion fringe-suppressed E2V CCD camera with a pixel (px) scale of ~0.2 arcsec and it covers a field of view of 13.6 x 13.6 arcmin. The available filters are broad-band SDSS u,g,r,i,z and narrow-band (10.2 nm width) with central wavelengths at 491.6, 660.9, 674.3, and 683.3 nm. The spectral dispersions provided by different grisms are in the range of 0.1 to 0.7 nm/px and an 8’ long slit with different available widths (0.4” - 3.2”) can be used. Imaging observations show that the instrument has the capability to detect sources upto ~24.5 mag AB (i-band) with 10% photometric accuracy in r-band in effective exposure of ~2 hours in dark nights. Stellar images with FWHM of 0.9 arcsec in r-band were recorded in May 2020 in best sky conditions. Spectroscopic observations with the instrument show that a spectroscopic trace of g=19 mag source at 5-sigma level can be detected in 10 minutes of exposure at ~0.2 nm/px dispersion. Hg-Ar, Ne, and continuum lamps are available for spectral calibration. The CCD camera is in development mode and presently it shows some departures from linearity at low-light and bright-light conditions, which needs to be corrected using an IRAF script. It can only be mounted on the axial main-port of the telescope.

LATEST UPDATE
  • New updates will be posted here
 
DOCUMENTATION FOR USERS
 
RECENT PUBLICATIONS
  1. Optical detection of a GMRT-detected candidate high-redshift radio galaxy with 3.6-m Devasthal optical telescope
    Amitesh Omar, A. Saxena, K. Chand, et al. ; 2019, JApA, 40, 9; (arXiv : 1902.05856)

TANSPEC is a medium resolution spectrograph and camera having sensitivity in the wavelength range from 550 to 2540 nm. It employs a 1024 x 1024 H1RG array with a pixel scale of 0.25 arcsec and it covers a field of view of 1 arcmin x 1 arcmin. It offers broad-band photometry in r, i, Y, J, H, K and narrow-band H2 and BrG filters. Stellar images with FWHM of 0.5 arcsec in K-band were recorded in Feb 2020 in best conditions. The object of 18 mag in K has been imaged successfully detected in 1-min exposure. It is possible to detect sources at J, H, K of 19.5, 18.9, 18.4 mag respectively at 10 sigma level in 10 minutes exposure. R~23 mag source is detected in 1 hour exposure.
  For spectroscopy, it employs a 2048 x 2048 H2RG array and it can be used in cross-dispersed mode (R~2750) as well as in prism mode (R~100-350). The slits available in these modes have widths between 0.5 to 4.0 arcsec. It is possible to take R ~ 2750 (~100-350) spectra of J=14.3 (17.3) mag source in 1 hour at 100-sigma level for stellar sources with FWHM of 1 arcsec. TANSPEC can only be mounted on the axial-port of the telescope. Proposals should be considered for science verification in the early cycles, when the focus will be on stabilizing TANSPEC instrument.
  For high-resolution spectroscopic mode the proposers should add about 50% of the overhead (excluding lamp / standard stars). In the imaging mode the overhead is about 30% (for dithering, filter change, readout etc).

LATEST UPDATE
  • 2020-11-21 : For new plots on sensitivity and resolution from the latest data, click here.
  • 2020-11-18 : Grating wheel has developed some technical issue and hence any spectroscopic observations cannot be executed at the moment, though, the proposers may like to utilise the instrument in the imaging mode if that suits their science requirement. The technical issue is unlikely to be resolved in cycle 2020-DOT-C2.
 
DOCUMENTATION FOR USERS
 
RECENT PUBLICATIONS
  1. Prospects for star formation studies with infrared instruments (TIRCAM2 and TANSPEC) on the 3.6-m Devasthal Optical Telescope
    Devendra Ojha; Swarna Kanti Ghosh; Saurabh Sharma; Anil Kumar Pandey, ; Tapas Baug; Joe Philip Ninan, ; Brijesh Kumar, Manoj Puravankara, Savio D'Costa; Milind Naik; Satheesha Poojari, ; Shailesh Bhagat, ; Rajesh Jadhav, ; Ganesh Meshram, ; Pradeep Sandimani, Sanjay Gharat; Chandrakant Bakalkar
    2018, BSRSL, 87, 58-87