Information for S18A

IRCS provides several linear polarimetry modes in 0.95−4.16 μm as 'Shared-Risk' mode.
Users who want to propose polarimetry observation SHOULD contact to Dr. Tamura (; the PI of the waveplate unit). Please contact to Tae-Soo Pyo ( and Hiroshi Terada( for more detailed information and performance limitations in advance before the submission of their proposals.
Please see "Polarimetry" section for more detailed information about new polarimetry mode.
IRCS provides Grism and Echelle spectroscopy for open use service program. Please refer Call for Proposals for more information.



The Infrared Camera and Spectrograph (IRCS) can be installed at the  Infrared Nasmyth focus of Subaru Telescope and incorporates two 10242 ALADDIN III arrays which are sensitive from 0.9−5.6μm. IRCS has been designed to deliver diffraction limited images from 2−5μm, as well as providing spectroscopy with grisms and a cross-dispersed echelle. The camera can also be used as a slit viewer for the echelle spectroscopy. IRCS is always operated with AO188 attached regarldess of using adaptive optics, and relies on AO188 for guiding without a separate autoguider.   Two papers describing IRCS are available: When referring to IRCS in a paper, please use the following citation


The imaging mode of IRCS provides two plate scales, of 20 and 52 mas per pixel, producing fields of view of 21'' and 54'', respectively. The 20 mas scale is designed to be used with the Adaptive Optics system, while the 52 mas scale is suitable for general-purpose imaging. The camera is equipped with a range of broad and narrow-band filters in its three filter wheels. 

Grism spectroscopy 

The camera section of IRCS also has grisms (providing spectral resolutions R = 100-2000). 

Echelle spectroscopy 

IRCS also has a cross-dispersed echelle (providing spectral resolution up to 20 000). The highest spectral resolutions can only be obtained with very narrow (0.14'') slits, which are not recommended without Adaptive OpticsWe provide an NH3 gas absorption cell function for a high-precision radial velocity measurement at the 30 m s-1 level even with the spectral resolving power of IRCS (R = 20,000). The NH3 gas cell can be used in a part of K-band with IRCS + AO188 mode only. If you have any question, please contact to IRCS + AO188 support astronomer. The IR gas cell was provided by Andreas Seifahrt (University of Chicago) in collaboration with colleagues at the university of Goettingen (Germany) and Lund Observatory (Sweden).


IRCS provides several linear polarimetry modes in 0.95−4.16 μm as 'Shared-Risk' mode. Imaging polarimetry is available for Y-, J-, H-, K(K')-, and L'-bands. Spectropolarimetry is available with zJH-, HK-, K-, and L-grisms in 52 mas mode only. Please be advised that circular polarimetry is not available. Users should contact to Dr. Tamura ( , Tae-Soo Pyo (, and Hiroshi Terada ( for more detailed information if they have any plan of the polarimetry mode observation.

Further information

 Preparing Observation

Questions regarding IRCS should be directed to Ji Hoon Kim ( Please note that all numbers on these pages are subject to change as the performance of IRCS is better determined. 

7 August 2017 

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