TMT Science and Instrument WS 2011
March 30, 2011, Victoria BC

MICHI:
Mid-Infrared Camera
High-disperser,& IFU spectrograph
M. Honda (Kanagawa U),
Y.K. Okamoto (Ibaraki U),
A. Tokunaga (UH), C. Packham (UF)MICHI team

TMT Science and Instrument WS 2011
March 30, 2011, Victoria BC

MICHI:
Mid-Infrared Camera
High-disperser,& IFU spectrograph
未知 (みち) = “Unknown Things”
Instrument for challenge to the unknowns

Outline A brief history and collaborators
 IFU Science cases of TMT/MICHI Required instrument parameters & uniqueness Overall current Instrument design & key tech.

A brief history and collaborators

MICHI has been studied by Japanese & US astronomers
since 2008

Instrument design team (13)
 M. Chun (UH), T. Fujiyoshi (Subaru), M. Honda (Kanagawa U),

H. Kataza(ISAS), Y. K. Okamoto (Ibaraki), T. Onaka (UT), C. Packham (UF),
M. Richter (UC Davis), I. Sakon (UT), C. M. Telesco (UF),A. Tokunaga (UH), C. Warner (UF), T. Yamashita (NAOJ)

Instrument science team (24) J. Carr (NRL), K. Enya, H. Fujiwara (ISAS), T. Fujiyoshi (Subaru), M.

Honda (Kanagawa U), T. Kotani (ISAS), J. Najita (NOAO), T. Matsuo(NAOJ), Y. K. Okamoto (Ibaraki), T. Ootsubo (Tohoku), M. Takami (ASIAA),
M. Richter(UC Davis), C. M. Telesco (UF), A. Tokunaga (UH), C. M. Wright(UNSW@ADFA), M. Chiba (Tohoku), M. Imanishi (NAOJ), N. Levenson(Gemini), T. Minezaki (UT), C. Packham (UF), Y. Ita (Tohoku), H. Izumiura(NAOJ), M. Matsuura (University College London), I. Sakon (UT)Industrical partners M. Rodgers, J. McGuire (ORA), Y. Ikeda (Photocoding), Sumitomo HeavyIndustry

MICHI presentations at SPIE @San Diego in June 2010
 Instrument reference document (0th version) submitted tothe J-TMT office of NAOJ in August 2010
Science Cases of MICHI MICHI covers wide areas of modern astronomy

 C. Packham’s talk High-dispersion spectroscopy  M. Richter’s talk
 Low-dispersion spectroscopy with IFU  this talk Imaging, spectroscopy Merits of MICHI IFU N-band low-R spec.
 High observing efficiency (no slit-loss, adjusting) Reveal 2D dust distribution efficiently like imaging!
 Rich dust features
 Amorphous silicate: ~9.8mm
 Crystalline olivine: 10.1, 10.5, 11.2mm
 Crystalline pyroxene : 9.3, 10.8, 11.7mm
 PAH:7.7, 8.6, 11.2, 12.7mm
 Full use of TMT’s high spatial resolution advantage

IFU N-band low-R spectroscopy ofplanet forming disksb Pic image(Telesco+2005)

Spatially resolved N-band spectraof b Pic debris disk (Okamoto+2004)
 Spatial difference of dust featureCentral condensation of crystalline
silicate grains
 Several local peaks of small
amorphous silicate
Spatially resolved spectra by Subaru (Okamoto+2004)

IFU N-band low-R spectroscopy ofArtist’s view of b Pic planetesimal disk planet forming disks
Spatially resolved N-band spectraof b Pic debris disk (Okamoto+2004)
 Spatial difference of dust featureCentral condensation of crystalline
silicate grains
 Several local peaks of small
amorphous silicate
 Multiple planetesimal belts
Planet imaged!
8-15AU
Lagrange et al, 2010

IFU N-band low-R spectroscopy ofplanet forming disksb Pic image (Telesco+2005)

With the IFU, we can reveal 2D dust distribution at once !
• Vertical distribution of dust for edge-on disks• For face-on disks, 2D dust distribution is essential for
tracing planetesimal belts
 Slit-scan  time-consuming !
• MICHI/IFU provide spatially resolved spectra up to 22x
faster than slit scanning
Necessary for optimal use of precious observing time of TMTIFU N-band low-R spectroscopy ofplanet forming disks
Spatially resolved N-band spectraof b Pic debris disk (Okamoto+2004)
 Spatial difference of dust featureCentral condensation of crystalline
silicate grains
 Several local peaks of small
amorphous silicate Multiple planetesimal belts

With the IFU, we can reveal 2D dust distribution at once !
• Vertical distribution of dust for edge-on disks• For face-on disks, 2D dust distribution is essential for
tracing planetesimal belts
 Slit-scan  time-consuming !
• MICHI/IFU provide spatially resolved spectra up to 22x
faster than slit scanning
Necessary for optimal use of precious observing time of TMTIFU N-band low-R spectroscopy ofdust forming evolved starsHow grains are formed and supplied to the ISM ?
A part of FOV of MICHI’s IFU

Circumstellar envelopes(CSEs) of AGBs
 WRs/SNe/SNRs(SliceWidth)

Where and what grains
are there ?
 Detailed comparison
with dust/molecule
formation theory

Pixelsize

2.2mm images of IRC10216 atdifferent epochs (Osterbart+ 2000)

 Contribution to understanding mass-loss history/mechanism

 IFU is also useful for other objects
 AGNs, comets, etc…

Tempel 1 after
Deep Impact

Required instrument parameters
Imaging

Low-R spectroscopy w IFU

Long-slit mod-R
spectroscopy

High-R
spectroscopy

Wavelength coverage [mm]7.3-13.8
16.0-25.0

7-14

7.3-13.8,
16.0-25.0

7.3-13.8,
16.0-25.0

FOV

28.1x28.1”

5” x 2”

28.1” x (0.1-0.3)”

2” x (0.1-0.3)”

Spatial resolution

Diffraction limited value w/ MIRAO （0.08”@10mm, 0.16”@20mm ）Spectral resolution
R= l / Dl

R～10-100

OthersPolarimetry (for imaging and mod-R spectroscopy)
Option: High-contrast imaging & IFU spectroscopy such as
coronagraph/aperture-masking observations (under consideration)

R～250 (or500)

R～810 @ 10mm
R～1,100 @ 20mm

R～120,000 @ 10mm
R～60,000 @ 20mm

Improvements from MIRES following science requirements
 Addition of Low-dispersion spectroscopy with IFU
 Applicable to much broader area of important astronomical topics
 Internal cold chopper Enables low-dispersion spectroscopy and improved imaging performance Polarimetry
 High-contrast observing capability for exoplanets is under consideration, too.
 Improved throughput with reflective optics

Uniqueness of MICHI to space facilities

High-R spectroscopy & polarimetry are not available for space telescopes
Imaging, low-R spectroscopy w IFU with >4.5 times better spatial resolution
JWST has higher sensitivity but worse spatial resolution.
Ex.1) JWST/MIRI will not spatially resolve the disks and CSEs of AGBs
 Ex.2) MICHI covers exoplanets close to central stars which are not probed by JWST.
TMTJWSTSPICA

Telescope

30m

6.5m

3.2m

MIR Instrument

MICHI (with MIR AO)MIRIMIRACLE, MIRMES, MIRHES

Wavelength

N, Q

5-28mm

5-38mmSpatial resolution

0.08’’@N
0.16’’@Q

0.4’’@10mm,0.8’’@20mm

0.8’’@10mm
1.6’’@20mm

Spectral resolution
R(spectroscopy)~300-500@N (IFU)~900@N~1600@Q~105 @N,Q~100 @5-14mm~2100-3700 @5-29mm

1500@10-20mm
700@19-36mm
200@5-38mm
30000@4-8 &12-18mm

Sensitivity (5s1hr)

0.1mJy (N imaging)

0.4mJy (10mm imaging)

1mJy (10mm imaging)otherspolarimetry

FoV

27.5’’x27.5’’ (Imager)27.5” (R~900-1600)
2” (R~105)~2x5” (IFU)

74”x113” (Imager)
5.5” (R~100)~3x4 to ~7x8’’ (IFU)

5’x5’ (Imager)12”x(6or12)” (R~700-1500)~6” (R~30000 spec.)

Spectroscopic Sensitivity

Order of magnitude more sensitive than 8m-classeven at much higher spectral resolution

Point source sensitivity 10s in 1 hour elapsed timeSensitivity comparison is difficult especially in mid-IR

Observing/conditions assumptions can be widely different between groups
Spectral resolutions differ by >2 orders of magnitude
e.g. SPICA: R~0.2K & 30K, JWST: R~2-4K, MICHI: R~120K
Estimated from publications (simple scaling) or on-line calculators

Instrument design:
overall block diagram of optics

Detailed designs are in Tokunaga et al. 2010 & poster

Instrument design:
overall block diagram of optics
Imager & mid-dispersion
spectrographFore optics

high-dispersion
spectrographlow-dispersion
spectrographwith IFU

Modular design tomake alignment easierFore-optics
2nd pupil:
Chopper mirror

Insertable mirror to divert
light to the IFU

Fore optics

Coronagraph masks(for focal plane)
1st Cold pupil:
Filter wheel,HWP, Wollaston prism,
coronagraph masks

Slit wheel:
Reflective mirror  imagerReflective slit  mid-R spectrometerTransmissive slit  high-disperser

Imager & mid-dispersion spectrometer
1k x 1k Si:As array

Grism for mid-R spectrometer
Lens for pupil imaging(open for normal imaging)High-dispersionspectrographCan be used as slit viewer

Echelle grating•based on the experience ofTEXES and EXES
•Common for N,Q-bands•150mm x 674mm size

Cross-dispersion grating

2k x 2k Si:As array

Low-dispersion spectrograph with IFU
Image slicer type IFU

22slices for 2” x 5” FOV Set by scientific requirement
 important observing target size
are typically 1 to a few arcsec.
 Based on experiences of theprototype (MIRSIS) development at
Ibaraki Univ. in Japan.

IFU replayoptics

IFU unit

IFU (slicer &spectrometer)
2k x 2k Si:As array

array

spectrometer

Low-dispersion spectrograph with IFUMIRSIS optical bench @ lab

Image slicer type IFU

22slices for 2” x 5” FOV Set by scientific requirement
 important observing target size
are typically 1 to a few arcsec.
 Based on experiences of the
prototype (MIRSIS) development at
Ibaraki Univ. in Japan.

IFU replayoptics

IFU unit

IFU (slicer &spectrometer)
2k x 2k Si:As arrayarrayspectrometer

Key technologies of MICHIMICHI


IFU (image slicer system)







Possibly similar to Herschell chopper is applicable.
R&D activity for a voice coil system is planned for suitable system.

Large format detector array.
Prototype development is done in Japan.
Basic key technologies to make slicer optics is already established.
Now R&D activity for improved technologies for a large format IFU is inprogress.

Internal cold chopper.
Based on well developed techniques, in principle.
Owing to the revised design, large refractive material is now not required.

1k x 1k Si:As array exist; have to make 2k x 2k mosaic, but low technical risk(already planned by Raytheon).
Currently available “off the shelf”, but single source supplier…

High-contrast system such as coronagraphs/aperture-masks

R&D activity is in progress for SPICA.
Possible simple methods for the MICHI are already established.

 No high risk items. MICHI is already feasible

Design ComplianceDesign Compliance

MICHI is already feasible

Thank you for your listening !