IRCS

Introduction

The Infrared Camera and Spectrograph (IRCS) is installed at the Infrared Nasmyth focus of Subaru Telescope and incorporates two 1024² ALADDIN III arrays which are sensitive from 0.9−5.6 μm. IRCS is designed to deliver diffraction limited images from 2 μm and up, 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 Adaptive Optics (AO188) attached regarldess of using adaptive optics, and relies on AO188 for guiding without a separate autoguider.

• Basic instrument parameters
• Current status of the instrument

Imaging

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 camera is equipped with a range of broad and narrow-band filters in its three filter wheels.

• Available filters and sensitivities
• Guide for exposure time estimation
• ETC (Exposure Time Calculator) for imaging 
• OTC (Overhead and Total observing time Calculator) for imaging
  
• Other information
Optical layout, Coronagraph mask, distortion, bad pixels, and image anomalies

Grism spectroscopy

The camera section of IRCS provides a number of grisms which provide a low resolution (R = 100-2000) spectroscopic capability. Slit widths of 0.1-0.9'' are available.

• Grism settings, sensitivities and exposure time
• System efficiency
• Reflective slits
• ETC (Exposure Time Calculator) for grism spectroscopy
• OTC (Overhead and Total observing time Calculator) for grism spectroscopy
• Other information
Comparison lines and OH lines

Echelle spectroscopy

IRCS has a cross-dispersed echelle spectrograph, providing spectral resolution up to 20 000. The IRCS echelle provides a pixel scale of 55 mas along the slit and slit widths of 0.14'', 0.27'' (providing half the spectral resolution), or 0.54'' (providing one-quarter the spectral resolution). The camera-side detector is used as a slit viewer.

• Configurations and sensitivities
• Wavelength coverage of echelle orders
Response functions and Echelle Simulator
• Guide for exposure time estimation
• ETC (Exposure Time Calculator) for echelle spectroscopy
• OTC (Overhead and Total observing time Calculator) for echelle spectroscopy
• Other information
Line lists, bad pixel, and one-order filters

Note: We 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. The NH₃ gas cell can be used in a part of K-band with IRCS + AO188 mode. Please contact to IRCS + AO188 support astronomer for further information. 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).

Polarimetry

IRCS provides several linear polarimetry modes in 0.95−4.80 μm as 'Shared-Risk' mode. Imaging polarimetry is available for Y-, J-, H-, K(K')-, L'-, and M'-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 must contact Dr. Tamura (motohide.tamura_at_nao.ac.jp) and the primary support astronomer if they are planning to submit any kind of proposal with polarimetry mode observation.

• Basic specification
• Exposure time guide line
  
• Polarization efficiency and instrumental polarization
• Imaging polarimetry
• Spectropolarimetry
• Observation procedures and strategy

Observation Preparation

• General informaion for proposal preparations
• IRCS User Manual prepared by K.Helminiak
• Preparation for OPE(Observation Procedure Execution) file
• IRCS Observation Log Sheets

Citations

When referring to IRCS in a paper, please use the following citation. The papers can be downloaded from links below.

• The Infrared Camera and Spectrograph for the Subaru Telescope by Tokunaga et al. (900kb PDF)
• IRCS: Infrared Camera and Spectrograph for the Subaru Telescope by Kobayashi et al. (2Mb gzipped postscript).

Further information

• L'-band background variation since 2004: [vs DATE] [vs Wavelength]
• Current Filters, Slits, Grisms/Prism, etc.
• FITS header information

Contacts

Questions regarding IRCS should be directed to the primary support astronomer (Yuhei Takagi, takagi__at__naoj.org).

Please note that all numbers on these pages are subject to change as the performance of IRCS is better determined.

Jul 28 2023