TopPage

Contents

Notes for S23B

Introduction

The Mid-Infrared Multi-field Imager for gaZing at the UnKnown Universe (MIMIZUKU) is the first-generation (mid-)infrared instrument on the TAO telescope that enables imaging and low-resolution spectroscopic observations in a wavelength range of 1-38 microns. The wide wavelength coverage is achieved by having three optical channels, NIR, MIR-S, and MIR-L, covering 1-5.3, 7-26, and 24-38 microns, respectively. MIMIZUKU has a unique opto-mechanical system called a "field stacker" that enables simultaneous observations of target and reference objects within a distance of less than 25 arcmin. This feature improves the accuracy and reliability of photometric and spectroscopic data. The overview of TAO/MIMIZUKU is also summarized in the fact sheet linked below.

Entrance window

For the entrance window of the MIMIZUKU optics, KBr window and diamond window are available. This semester, a diamond window is equipped. The diamond window has absorption bands in the L and M bands, and the sensitivity in these bands is not good.

NIR

The NIR channel has a HAWAII-1RG (HgCdTe 1k-format) array with a cut-off wavelength of 5.3 microns and covers 1-5.3 microns. The atmospheric transmittance and the wavelength coverage of each observing mode are shown below.

NIRmodesAll.jpgNIRmode27.jpg
Available modes and atmospheric transmittance smoothed with a Gaussian profile with an FWHM of 0.002 um-1.Atmospheric transmittance covered by the 2.7-um spectroscopy mode smoothed with a Gaussian profile with an FWHM of 0.00056 um-1.

Basic parameters

Wavelength Coverage1-5.3 microns
Detector1k-format HgCdTe array
(Teledyne HAWAII-1RG 5.3um-cutoff)
Pixel Scale0.069"/pix18 um/pix
Field of View1.2' x 1.2'w/o Field Stacker
36" x 1.2' x 2 fieldsw/ Field Stacker
Final F number8.76
Spatial Resolutionalmost seeing-limitedfor details, see here.
Imaging FiltersJ, H, Ks, L', and M'
SpectroscopyKL and LM bands with R~200
2.7-um band with R~660
Slit0.96" x 36"wider region (2.7" width) also available.

Imaging

Spectroscopy

MIR-S

The MIR-S channel has an Aquarius array (Si:As 1k-format) array and covers 7-26 microns. The atmospheric transmittance and the wavelength coverage of each observing mode are shown below.

MIRmodesN.jpgMIRmodesQ.jpg
N-band modes and atmospheric transmittance smoothed with a Gaussian profile with an FWHM of 0.0005 um-1.Same as the left figure but for the Q band.

Basic parameters

Wavelength Coverage7-26 microns
Detector1k-format Si:As IBC array
(Raytheon Aquarius)
Pixel Scale0.11"/pix30 um/pix
Field of View2.0' x 2.0'w/o Field Stacker
59" x 2.0' x 2 fieldsw/ Field Stacker
Final F number8.76
Spatial Resolutionalmost diffraction-limitedfor details, see here.
Imaging Filters7.7, 9.8, 11.5, 13.1,
16.7, 17.9, 20.9, and 24.5 um
SpectroscopyN band with R~170
Q band with R~110
Slit0.58" x 57" x 2 slits
1.1" x 57" x 2 slits

Imaging

Spectroscopy

MIR-L

The MIR-L channel has a 128px-format Si:Sb array and covers 24-38 microns.

MIRmodes30_NoSmooth.jpg
Modes in 30-um band and the atmospheric transmittance.

Basic parameters

Wavelength Coverage24-38 microns
Detector128-format Si:Sb BIB array
(DRS MF-128)
Pixel Scale0.24"/pix75 um/pix
Field of View31" x 31"w/o Field Stacker
15" x 31' x 2 fieldsw/ Field Stacker
Final F number10.5
Spatial Resolutionalmost diffraction-limitedfor details, see here.
Imaging Filters32 and 37 um
SpectroscopyN/A
SlitN/A

Imaging

Spectroscopy

Currently, not available.

Field Stacker

FS.jpg
Schematic view of the Field Stacker system placed on the MIMIZUKU chamber that houses the optics.

The Field Stacker (FS) is a special opto-mechanical system installed on MIMIZUKU. It has two movable pick-off mirrors and one combining mirror that introduce lights from two different sky fields to the optics. This mechanism allows us to observe two objects in the two sky fields simultaneously. If you observe your science target and a telluric standard simultaneously using FS, the accuracy and reliability of atmospheric correction might be improved by canceling out the temporal variation of the atmospheric absorption. This feature is expected to be useful to perform long-term monitoring observations, and actually, its usefulness was confirmed in the engineering observations performed at the Subaru telescope (c.f., Michifuji et al. 2020, Kamizuka et al. 2020). Usefulness at the TAO site will be examined in future. In observations, you can choose to use it or not.


Front page   New Page list Search Recent changes   Help   RSS of recent changes