CIAO
Kyoto3DII

COMICS

Important notice (2011/08/15)

Because of the telescope cooling system incident, the Cassegrain Auto Guider (AG) system is unavailable for the remainder of this semester (S11B, 2011/08-2012/01), and this may still be the case in the first half of next semester (S12A, 2012/02-07).

Consequently, observations that rely heavily on the availability of AG system could be somewhat compromised; however, please note that since longest integration achievable with COMICS is quite short (about a few minutes - this is because the number of short exposures that can be saved at a time is finite), COMICS observations should not be affected too severely by the unavailability of AG system.

Nonetheless, if you have any concerns or questions, please contact Support Scientist.

COMICS gallery

Introduction

The Cooled Mid-Infrared Camera and Spectrometer (COMICS) can be installed at the Cassegrain focus of Subaru Telescope and provides both imaging and spectroscopic capabilities from 7.5-25 um. It has been optimized for use in the N-band (7.5-13.5 um). Six 320 x 240 Si:As BIB detectors are used: five for the spectrometer and one for imaging/slit viewing.

Please also visit the COMICS web page at JAXA (Japan Aerospace Exploration Agency), provided by the instrument group. [External link]

Listed below are some numbers to illustrate what can be expected from one hour of actual observing time (elapsed time) using COMICS.

N-band imaging using the N11.7-filter (bandwidth = 1.0um) yields a sensitivity of 0.76 mJy (1-sigma), for a point source which can be chopped and nodded on-chip to maximise the observing efficiency. For an extended source which must be chopped and nodded off-chip, the time spent on-source is halved and the sensitivity is worsened by a factor of sqrt(2) to 1.1 mJy.
Q-band imaging using the Q18.8-filter (bandwidth = 0.9um) yields a 1-sigma sensitivity of 11 mJy (again, for a point-source chopped/nodded on-chip). Also, in the Q-band, the detector must be read out partially to maximise the efficiency. An extended object which requires the full array will increase the readout time and require nodding off-chip. For the Q18.8-filter, these factors worsen the sensitivity to about 24 mJy.
N-band medium-resolution (R ~ 2,500) spectroscopy, covers the entire N-band in two grating positions and provides a 1-sigma sensitivity of 63 mJy for a point-source that can be chopped along the slit. For an extended source, it is 89 mJy.
Q-band medium-resolution (R ~ 2,500) spectroscopy will reach a 1-sigma sensitivity of 510 mJy (point source) and 720 mJy (extended source).

You can download a copy of SPIE2000 paper COMICS: The Cooled Mid-Infrared Camera and Spectrometer for the Subaru Telescope by Kataza et al. (560kb gzipped postscript). Note that some of the filters differ in specification from the design values listed in this paper.

You can also download a copy of SPIE2002 paper Improved performances and capabilities of the cooled mid-infrared camera and spectrometer (COMICS) for the Subaru telescope by Okamoto et al. (350kb pdf file).

Imaging

The camera/slit viewer uses a plate scale of 0.13'' to provide a field of view of 42'' x 32''.

Spectroscopy

The spectrometer has a plate scale of 0.165''/pixel, producing a 40'' slit. Slit widths of 2, 3, 4, and 6 pixels are available. The entire N-band can be covered at a resolution of R ~ 2500 in two settings, and a low-resolution mode (R~ 250) and a high-resolution mode (R ~ 8500) around 12.8 um are also available.

Further information

Questions regarding COMICS should be directed to Takuya Fujiyoshi.