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The mid/far infrared hosts a wealth of spectral information that allows direct determination of the physical state of matter in a large variety of astronomical objects, unhindered by foreground obscuration. Accessing this domain is essential for astronomers to much better grasp the fundamental physical processes underlying the evolution of many types of celestial objects, ranging from protoplanetary systems in our own milky way to 10-12 billion year old galaxies at the high noon of galaxy formation in our universe. The joint ESA/JAXA SPICA mission will give such access for the astronomical community at large, by providing an observatory with unprecedented mid- to far-infrared imaging, polarimetric and spectroscopic capabilities.

Measurements in the infrared wavelength domain allow us to assess directly the physical state and energy balance of cool matter in space, thus enabling the detailed study of the various processes that govern the formation and early evolution of stars and planetary systems in the Milky Way and of galaxies over cosmic time. Previous infrared missions, from IRAS to Herschel, have revealed a great deal about the obscured Universe, but sensitivity has been limited because up to now it has not been possible to fly a telescope that is both large and cold. Such a facility is essential to address key astrophysical questions, especially concerning galaxy evolution and the development of planetary systems. SPICA is a mission concept aimed at taking the next step in mid- and far-infrared observational capability by combining a large and cold telescope with instruments employing state-of-the-art ultra-sensitive detectors. The mission concept foresees a 2.5-meter diameter telescope cooled to below 8 K. Rather than using liquid cryogen, a combination of passive cooling and mechanical coolers will be used to cool both the telescope and the instruments. With cooling not dependent on a limited cryogen supply, the mission lifetime can extend significantly beyond the required three years. The combination of low telescope background and instruments with state-of-the-art detectors means that SPICA can provide a huge advance on the capabilities of previous missions. The SPICA instrument complement offers spectral resolving power ranging from ~50 through 11000 in the 17-230 µm domain as well as ~28.000 spectroscopy between 12 and 18 µm. Additionally, SPICA will be capable of efficient 30-37 µm broad band mapping, and small field spectroscopic and polarimetric imaging in the 100-350 µm range. SPICA will enable far infrared spectroscopy with an unprecedented sensitivity of ~5x10-20 W/m2 (5σ/1hr) - at least two orders of magnitude improvement over what has been attained to date. With this exceptional leap in performance, new domains in infrared astronomy will become accessible, allowing us, for example, to unravel definitively galaxy evolution and metal production over cosmic time, to study dust formation and evolution from very early epochs onwards, and to trace the formation history of planetary systems.

Scalp hemodynamics contaminates the signals from functional near-infrared spectroscopy (fNIRS). Numerous methods have been proposed to reduce this contamination, but no golden standard has yet been established. Here we constructed a multi-layered solid phantom to experimentally validate such methods. This phantom comprises four layers corresponding to epidermides, dermis/skull (upper dynamic layer), cerebrospinal fluid and brain (lower dynamic layer) and the thicknesses of these layers were 0.3, 10, 1, and 50 mm, respectively. The epidermides and cerebrospinal fluid layers were made of polystyrene and an acrylic board, respectively. Both of these dynamic layers were made of epoxy resin. An infrared dye and titanium dioxide were mixed to match their absorption and reduced scattering coefficients (μa and μs’, respectively) with those of biological tissues. The bases of both upper and lower dynamic layers have a slot for laterally sliding a bar that holds an absorber piece. This bar was laterally moved using a programmable stepping motor. The optical properties of dynamic layers were estimated based on the transmittance and reflectance using the Monte Carlo look-up table method. The estimated coefficients for lower and upper dynamic layers approximately coincided with those for biological tissues. We confirmed that the preliminary fNIRS measurement using the fabricated phantom showed that the signals from the brain layer were recovered if those from the dermis layer were completely removed from their mixture, indicating that the phantom is useful for evaluating methods for reducing the contamination of the signals from the scalp.

Functional near-infrared spectroscopy (fNIRS) is suitable for measuring brain functions during neurorehabilitation because of its portability and less motion restriction. However, it is not known whether neural reconstruction can be observed through changes in cerebral hemodynamics. In this study, we modified an fNIRS system for measuring the motor function of awake monkeys to study cerebral hemodynamics during neurorehabilitation. Computer simulation was performed to determine the optimal fNIRS source–detector interval for monkey motor cortex. Accurate digital phantoms were constructed based on anatomical magnetic resonance images. Light propagation based on the diffusion equation was numerically calculated using the finite element method. The source–detector pair was placed on the scalp above the primary motor cortex. Four different interval values (10, 15, 20, 25 mm) were examined. The results showed that the detected intensity decreased and the partial optical path length in gray matter increased with an increase in the source-detector interval. We found that 15 mm is the optimal interval for the fNIRS measurement of monkey motor cortex. The preliminary measurement was performed on a healthy female macaque monkey using fNIRS equipment and custom-made optodes and optode holder. The optodes were attached above bilateral primary motor cortices. Under the awaking condition, 10 to 20 trials of alternated single-sided hand movements for several seconds with intervals of 10 to 30 s were performed. Increases and decreases in oxy- and deoxyhemoglobin concentration were observed in a localized area in the hemisphere contralateral to the moved forelimb.

The difference in signal-to-noise ratio (SNR) within functional near-infrared spectroscopic (fNIRS)-measurement channels makes it difficult to compare the significance of the signal amplitude in an individual channel against the baseline or against signals in other channels. The difference in SNR mainly originates from the difference in light loss due to the hair coverage or the optode–scalp contact. During the initial calibration of most commercial fNIRS equipment, the detected signals in different channels are differently amplified such that the system effectively utilizes a dynamic range for measurement. While different amplification rates among the channels realize almost equal signal intensities, they also differently amplify the detection noises. This results in different apparent noises in the fNIRS signals between channels. In order to level the SNRs in all the measurement channels, the system needs to equalize the light intensities received by the detectors instead of changing the signal amplification rates. To realize this novel procedure for leveling the SNR among the channels, we developed an fNIRS system equipped with an optical attenuator at each source and detector. A systematic procedure for modulating the attenuators to level SNR over all channels was mathematically formulated, and the procedure was examined using an optical phantom with a surface covered with air.

Functional near-infrared spectroscopy (fNIRS) can non-invasively detect hemodynamic changes associated with cerebral neural activation in human subjects. However, its signal is often affected by changes in the optical characteristics of tissues in the head other than brain. To conduct fNIRS measurements precisely and efficiently, the extraction and realtime monitoring of the cerebral functional component is crucial. We previously developed methods for extracting the cerebral functional component—the multidistance optode arrangement (MD) method and the hemodynamic modality separation (HMS) method. In this study, we implemented these methods in a software used with the fNIRS system OEG- 17APD (Spectratech, Japan), and realized a real-time display of the extracted results. When using this system for human subject experiments, the baselines obtained with the MD and HMS methods were highly stabilized, whereas originally, the fNIRS signal fluctuated significantly when the subject moved. Through a functional experiment with repetitive single-sided hand clasping tasks, the extracted signals showed distinctively higher reproducibility than that obtained in the conventional measurements.

Similar to blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI), functional nearinfrared spectroscopy (fNIRS) observes regional hemodynamic responses associated with neuronal activation. However, the conventional criteria for detecting true positive fNIRS and fMRI signals appear to be based on different understandings of cerebral hemodynamics. Considerable numbers of fNIRS studies have ascribed the increase in oxygenated hemoglobin to a typical sign of functional activation, whereas the corresponding BOLD signal in fMRI directly correlates with a decrease in deoxygenated hemoglobin. This inconsistency requires solution through the simultaneous measurements of fNIRS and fMRI. In practice, however, there remain several technical problems associated with conducting simultaneous measurements with high reproducibility. One issue is the precise spatial registration of NIRS optodes in MR images. We prepared marker containers of an annular shape that can be coaxially fixed to the optode. Liquid paraffin with α-tocopheryl acetate, which exhibits a bright contrast in T1-weighted MR images of human heads, was solidified in each container by adding higher fatty acid. A subject wearing the marker-fixed optodes at parietal area participated in preliminary fNIRS and fMRI experiments; the subject was instructed to execute single-sided hand finger tapping. The positions showed that deoxygenated hemoglobin decreases in fNIRS coincided with the BOLD-positive region in fMRI. The prepared marker is chemically stable and repetitively usable. We believe that this simple method contributes precision to the co-registration of fNIRS and fMRI.

While most commercially available functional near-infrared spectroscopy (fNIRS) systems employ optical fibers for both the measurement optode and the transmission cable for optical signals, their material inflexibility presents some problems in stable optode fixation to the head surface and adequate cable lining to the main system. In practice, mechanical fluctuations of optical fibers in fNIRS measurement often lead to motion artifacts in the signals. A few fiberless fNIRS systems are available and equipped with light sources and detectors that directly adhere to the scalp surface. However, their shapes and detection sensitivities are not suitable for usage on a hair-covered head. Based on the commercial fiber-less fNIRS system OEG-16 (Spectratech Inc., Japan), we developed a new source-detector unit that was designed with LEDs for enhanced illumination, avalanche photodiodes instead of photodiodes, and a new holder system. The electrical circuits of the system were modified after the design. By simultaneous implementation of multidistance fNIRS measurement and hemodynamic modality separation on conventional fNIRS data at the bilateral parietal area during single-sided motor tasks, significant functional signals were observed only at the position contralateral to the side of movement. This is the first report describing a fiber-less fNIRS system that can detect functional signals on a hair-covered head. We believe this fiber-less system will improve the utility of fNIRS, particularly in less restraining conditions.

WISH, Wide-field Imaging Surveyor for High-redshiftt, is a space mission concept to conduct very deep and widefield surveys at near infrared wavelength at 1-5μm to study the properties of galaxies at very high redshift beyond the epoch of cosmic reionization. The concept has been developed and studied since 2008 to be proposed for future JAXA/ISAS mission. WISH has a 1.5m-diameter primary mirror and a wide-field imager covering 850 arcmin 2 . The pixel scale is 0.155 arcsec for 18μm pitch, which properly samples the diffraction-limited image at 1.5μm. The main program is Ultra Deep Survey (UDS) covering 100 deg 2 down to 28AB mag at least in five broad bands. We expect to detect 4 galaxies at z=8-9, 10 3 -10 4 galaxies at z=11-12, and 50-100 galaxies at z

WISH is a new space science mission concept whose primary goal is to study the first galaxies in the early universe. We will launch a 1.5m telescope equipped with 1000 arcmin2 wide-field NIR camera by late 2010's in order to conduct unique ultra-deep and wide-area sky surveys at 1-5 micron. The primary science goal of WISH mission is pushing the high-redshift frontier beyond the epoch of reionization by utilizing its unique imaging capability and the dedicated survey strategy. We expect to detect ~10 4 galaxies at z=8-9, ~3-6x10 3 galaxies at z=11-12, and ~50-100 galaxies at z=14-17 within about 5 years of the planned mission life time. It is worth mentioning that a large fraction of these objects may be bright enough for the spectroscopic observations with the extremely large telescopes. By adopting the optimized strategy for the recurrent observations to reach the depth, we also use the surveys to detect transient objects. Type Ia Supernova cosmology is thus another important primary goal of WISH. A unique optical layout has been developed to achieve the diffraction-limited imaging at 1-5micron over the required large area. Cooling the mirror and telescope to ~100K is needed to achieve the zodiacal light limited imaging and WISH will achieve the required temperature by passive cooling in the stable thermal environment at the orbit near Sun-Earth L2. We are conducting the conceptual studies and development for the important components of WISH including the exchange mechanism for the wide-field filters as well as the primary mirror fixation.

We provide theoretical validation of the brain-functional detection using multidistance probe arrangement based on Monte Carlo simulations of five-layered model in which both scattering and absorption changes occur. It shows that optimized multidistance probe arrangement can be effective in removing interferences by scattering and absorption changes in upper layers and extracting absorption change in the gray matter layer. Using newly designed probes and their holder system, both conventional and proposed fNIRS measurements were implemented with non-functional (body and head movements and respiratory change) and functional (finger opposition) tasks. Artifacts, even if it correlate with task sequence, were well reduced. Functional signals were well localized at lateralized cerebral functional area.

Functional near-infrared spectroscopy (fNIRS) has the potential of easily detecting cerebral activity. However, in practical fNIRS measurements, a subject's physical or physiological changes such as body movements have often caused serious problems. If such a change is evoked by the tasks being monitored, it strongly correlates with the task sequence, and its interference in fNIRS cannot be eliminated using conventional signal filtering techniques. Hence, further improvement is necessary to eliminate such interference if we intend to use fNIRS on subjects with little or no physical restraint such as infants. We introduced an additional detector (d 2 ) between the source and detector (d 1 ) positioned in a conventional arrangement. The distances from the source to the detector d 1 and d 2 were set at 30 mm and 20 mm, respectively. Concentration changes of oxygenated and deoxygenated hemoglobin (ΔHbO and ΔHbR) were calculated using the linear combination of absorbance changes at d1 and d 2 . Then tasks such as the upper-body tilting, the head nodding, the breath holding, and the finger opposition were performed by the participant. The statistical significance of the difference in concentration changes of ΔHbO and ΔHbR between task and rest periods was examined using the paired t-test. The results showed that interference due to upper-body tilting, head nodding, and breath holding was reduced by this method. Moreover, in the finger opposition task, a simultaneous increase of ΔHbO and decrease of ΔHbR was observed and these were significantly localized in the activation area by this method.

Subaru Telescope has recently replaced most equipment of Subaru Telescope Network II with the new equipment which includes 124TB of RAID system for data archive. Switching the data storage from tape to RAID enables users to access the data faster. The STN-III dropped some important components of STN-II, such as supercomputers, development & testing subsystem for Subaru Observation Control System, or data processing subsystem. On the other hand, we invested more computers to the remote operation system. Thanks to IT innovations, our LAN as well as the network between Hilo and summit were upgraded to gigabit network at the similar or even reduced cost from the previous system. As the result of the redesigning of the computer system by more focusing on the observatory operation, we greatly reduced the total cost for computer rental, purchase and maintenance.

The High-Contrast Coronographic Imager for Adaptive Optics (HiCIAO), is a coronographic simultaneous differential imager for the new 188-actuator AO system at the Subaru Telescope Nasmyth focus. It is designed primarily to search for faint companions, brown dwarves and young giant planets around nearby stars, but will also allow observations of disks around young stars and of emission line regions near other bright central sources. HiCIAO will work in conjunction with the new Subaru Telescope 188-actuator adaptive optics system. It is designed as a flexible, experimental instrument that will grow from the initial, simple coronographic system into more complex, innovative optics as these technologies become available. The main component of HiCIAO is an infrared camera optimized for spectral simultaneous differential imaging that uses a Teledyne 2.5 μm HAWAII-2RG detector array operated by a Sidecar ASIC. This paper reports on the assembly, testing, and "first light" observations at the Subaru Telescope.

MOIRCS is a new Cassegrain instrument of Subaru telescope, dedicated for wide field imaging and multi-object spectroscopy in near-infrared. MOIRCS has been constructed jointly by Tohoku University and the Subaru Telescope and saw the first light in Sep, 2004. The commissioning observations to study both imaging and spectroscopic performance were conducted for about one year. MOIRCS mounts two 2048 × 2048 HAWAII2 arrays and provides a field of view of 4 � × 7 � with a pixel scale of 0. �� 117. All-lens optical design is optimized for 0.8 to 2.5 µm with no practical chromatic aberration. Observations confirm the high image quality over the field of view without any perceptible degradation even at the field edge. The best seeing we have obtained so far is FWHM= 0. �� 18. A novel design of MOIRCS enables us to perform multi-object spectroscopy with aluminum slit masks, which are housed in a carrousel dewar and cooled to ∼ 110 K. When choosing MOS mode, a manipulator pulls out a slit mask from the carrousel into the MOIRCS main dewar and sets it properly at the Cassegrain focus. The carrousel is shuttered by a gate valve, so that it can be warmed and cooled independently to exchange slit-mask sets during daytime. We have tested various configurations of 30 or more multi-slit positions in various sky fields and found that targets are dropped at the centers of slits or guide holes within a dispersion of about 0.3 pixels (0. �� 03). MOIRCS has been open to common use specifically for imaging observations since Feb. 2006.

MOIRCS (Multi-Object InfraRed Camera and Spectrograph) is one of the second generation instruments for the Subaru Telescope. This instrument is under construction by the National Astronomical Observatory of Japan and Tohoku University. It has imaging and multi-object spectroscopy (MOS) capabilities in the wavelength range from 0.85 µ mt o 2.5µ mw ith 4 � × 7 � F.O.V. The focal plane is imaged onto two 2048 × 2048 pixel HAWAII-2 HgCdTe arrays with a pixel scale of 0. �� 12 pixel −1 through two independent optical trains. The optical design is optimized to maximize K band performance. Unique design of MOIRCS allows multi-object spectroscopy out to K band with cooled multi-slit masks. Twenty-four masks are stored in a mask dewar and are exchanged in the cryogenic environment. The mask dewar has its own vacuum pump and cryogenic cooler, and the masks can be accessed without breaking the vacuum of the main dewar. The two-channel optics and arrays are mounted back-to-back of a single optical bench plate. A PC-Linux based infrared array control system has been prepared to operate HAWAII-2. The first light of MOIRCS is planned in the spring of 2003.

We conducted deep NIR and optical imaging observations in general fields as well as the fields of cluster of galaxies and candidates at z > 1. In the observed rich cluster environment, massive galaxies have been well developed by z =1.2-1.3. However, in a general field, HDF-N, we see conspicuous and sudden decrease of comoving number density of early-type galaxies above z =1. There are few galaxies as massive as present-day L * galaxies at z=2-4 in HDF-N. Their rest-frame optical light is dominated by very young stellar population and their morphology also does not show any clear sequence. Thus formation/evolution of galaxies seems to strongly depend on their density environment and in general fields massive galaxies which form present-day Hubble sequence might have been formed between 1 z < 2 while early type galaxies in clusters formed earlier epoch.

A new type of polarizing undulator proposed and developed in the Electrotechnical Laboratory which produces high brilliant, quasi-monochromatic, wavelength-variable from the soft x-ray to infrared region, and polarized synchrotron radiation of any ellipticity was installed in the electron storage ring TERAS and NIJI-II. The synchrotron radiations emitted from these polarizing undulators were used for various research fields. In this review we report the radiation properties of the polarizing undulator, the development of magnetic circular dichroism instrument in VUV region for magnetic materials, the development of polarizing microscope for circular differential imaging, the absolute asymmetric synthesis study, and the others.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.