The Update for S15B Applicants


MOIRCS Closure

    Due to the MOIRCS Upgrade Project (replacing detectors to H2RG as well as the detector control system), MOIRCS will be unavailable from 8 May 2015 untill early S15B. Currently we are targeting the on-sky test date to late July. The official re-open date is tentatively set to Oct 1st. Howver, we may start operation earlier than this.

    All observations after the upgrade will be executed under shared-risk policy. For the observing time estimate, please use the current performance (except for the case that new high observing effeciency is critical).

R1300 Grism Issue

    As has been annouced before, the overall performance of the R1300 grism is found to be poor for scientific observation. See the website for more detail. We do not recommend to use R1300 grism.

For MOS Applicants

    When you apply to the MOS observation, you must explicitly specify the required number of MOS masks (both for the Full and the Minimum Number of Nights) in the Sect 11 of the application form. And also, please justify why you need the requested number in the technical detail part in Sect 14. The number of MOS mask will be fixed once it is assigned by TAC's critical reviewing. The request for any backup mask is basically not permitted, unless there are any special reasons.

    Please note that the maximum number of MOS mask available for one contiguous observing period is 15.


We will have two instrument closure periods for "nuMOIRCS" Project during 2015-2016.

The detectors are to be changed to Hawaii2-RG. All electronics related to the detector readout will also be replaced (to SIDECAR ASIC + SAM System). The benefit is the significant reduction of the readout noise as well as the overhead for detector readout. Current plan is to execute the engineering work around May to July 2015. Some nights in August 2015 will then be used for the evaluation of the new system. Thus MOIRCS will be unavailable during next May to early S15B.

We are also planning to introduce the IFU spectroscopy function to MOIRCS, as well as the upgrade of the current MOS system and the control computers. The date of the downtime is still TBD, though it might happen in late 2015 to early 2016. We will update the schedule soon via this website.


MOIRCS (Multi-Object InfraRed Camera and Spectrograph) provides wide-field imaging and long-slit / multi-object (MOS) spectroscopic capabilities in the 0.9 ~ 2.5 µm spectral range under the natural seeing condition. The 4'×7' field of view is covered by two Hawaii-2 2048×2048 arrays with the spatial resolution of 0.117 arcsec/pixel.

For the imaging mode, the standard MKO YJHKs filters as well as some narrow-band filters are available. See the Imaging Mode Page for more details.

The MOS performance of MOIRCS spectroscopy mode is the most notable feature of the instrument. Using the cooled aluminium slit masks, MOIRCS can acquire about 40 object spectra simultaneously across 0.9~2.5 micron wavelength range. Currently low-resolution (R~500), medium-resolution (R~1300), and high-resolution (R~3000) modes are available. See the Spectroscopy Page for more details. All MOS observers/applicants should carefully read the MOS observation pages.

Instrument and Detector

Imaging mode

Spectroscopy mode

Instrument Citation

Please cite the following papers when you refer MOIRCS in your publication.
"Multi-Object Infrared Camera and Spectrograph (MOIRCS) for the Subaru Telescope I. Imaging"
Suzuki, R. et al. Publications of the Astronomical Society of Japan, 2008, Vol.60, No.6, pp.1347--1362.
"MOIRCS: Multi-Object Infrared Camera and Spectrograph for SUBARU"
Ichikawa, T. et al. 2006, in Proc. of SPIE, Vol. 6269, 38

Note that any data on the pages are subject to change.

Dr. Ichi Tanaka (MOIRCS Support Astronomer: email )

Updated 2015-02-04

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