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A Near-infrared (1.18-1.35 micron) high-resolution spectrum of the gravitationally-lensed QSO APM 08279+5255 was obtained with the IRCS mounted on the Subaru Telescope using the AO system. We detected strong NaI D 5891,5897 doublet absorption in high-redshift DLAs at z=1.062 and 1.181, confirming the presence of NaI, which was first reported for the rest-frame UV NaI 3303.3,3303.9 doublet by Petitjean et al. This is the first detection of NaI D absorption in a high-redshift (z>1) DLA. In addition, we detected a new NaI component in the z=1.062 DLA and four new components in the z=1.181 DLA. Using an empirical relationship between NaI and HI column density, we found that all "components" have large HI column density, so that each component is classified as DLA absorption. We also detected strong NaI D absorption associated with a MgII system at z=1.173. Because no other metal absorption lines were detected in this system at the velocity of the NaI absorption in previously reported optical spectra (observed 3.6 years ago), we interpret this NaI absorption cloud probably appeared in the line of sight toward the QSO after the optical observation. This newly found cloud is likely to be a DLA based upon its large estimated HI column density. We found that the N(NaI)/N(CaII) ratios in these DLAs are systematically smaller than those observed in the Galaxy; they are more consistent with the ratios seen in the Large Magellanic Cloud. This is consistent with dust depletion generally being smaller in lower metallicity environments. However, all five clouds of the z=1.181 system have a high N(NaI)/N(CaII) ratio, which is characteristic of cold dense gas. We tentatively suggest that the host galaxy of this system may be the most significant contributor to the gravitational-lens toward APM 08279+5255.

An overview of the current status of the 8.2 m Subaru Telescope constructed and operated at Mauna Kea, Hawaii, by the National Astronomical Observatory of Japan is presented. The basic design concept and the verified performance of the telescope system are described. Also given are the status of the instrument package offered to the astronomical community, the status of operation, and some of the future plans. The status of the telescope reported in a number of SPIE papers as of the summer of 2002 are incorporated with some updates included as of 2004 February. However, readers are encouraged to check the most updated status of the telescope through the home page, http://subarutelescope.org/index.html, and/or the direct contact with the observatory staff., Comment: 18 pages (17 pages in published version), 29 figures (GIF format), This is the version before the galley proof

The design and performance of the Cassegrain Adaptive Optics (AO) system for the 8.2m Subaru Telescope are reported. The system is based on a curvature wavefront sensor with 36 photon-counting avalanche photodiode modules and a bimorph wavefront correcting deformable mirror with 36 driving electrodes. The engineering first light of the AO system took place in 2000 December. The AO system has been in service since 2002 April for two open-use instruments, an infrared camera and spectrograph and a coronagraph imager with adaptive optics. The Strehl ratio in the K-band is around 0.3 for bright guide stars under 0. �� 4 K-band seeing condition. The control loop performs with 2060 corrections per second. High sensitivity of the wavefront sensor allows significant improvement in the image quality, even for faint guide stars down to R = 18mag. The FWHM of stellar images in a globular cluster was measured to derive an estimation of the isoplanatic angle and was found nearly constant out to 30 �� from the guide star, indicating that the height of the effective turbulent layer of that particular night was less than 1.8km. The on-going upgrade plans for a fivefold increase in the number of control elements and for the installation of a laser guide AO system are described.

An H$_2$ emission filament is found in close proximity to the unique object KH 15D using the adaptive optics system of the Subaru Telescope. The morphology of the filament, the presence of spectroscopic outflow signatures observed by Hamilton et al., and the detection of extended H$_2$ emission from KH 15D by Deming, Charbonneau, & Harrington suggest that this filament arises from shocked H$_2$ in an outflow. The filament extends about 15" to the north of KH 15D., 11 pages, 3 figures, 1 table. Astrophysical Journal Letters, in press

The highest angular resolution near-infrared images of the GG Tau A binary system were obtained with the Coronagraphic Imager with Adaptive Optics (CIAO) mounted on the Subaru Telescope. The images show that its circumbinary disk is smooth and does not have 0. 1 scale structures. Asymmetries in the surface brightness as well as a gap are also resolved. Combined with previous measurements of the stellar positions, our data indicate that the central binary is unlikely to have a large eccentricity. The fifth point source toward this double binary system is probably a background star, based on astrometric measurements.

We present near-infrared spectroscopy of low-mass companions in a nearby triple system HD 130948 (Gliese 564, HR 5534). Adaptive optics on the Subaru Telescope allowed spectroscopy of the individual components of the 0".13 binary system. Based on a direct comparison with a series of template spectra, we determined the spectral types of HD 130948B and C to be L4 +- 1. If we take the young age of the primary star into account (0.3-0.8 Gyr), HD 130948B and C most likely are a binary brown dwarf system.

We have developed 1-GHz bandwidth digital spectro-correlator system for the Nobeyama Millimeter Array (NMA). It consists of 2Gsample/sec-2bit analog-to-digital (A/D) converters and an ultra-wide band digital correlator. We developed two kinds of special-purpose LSI having functions of delay compensation and correlation, respectively. With these LSIs, the ultra-wide band digital correlator realizes 1024-MHz bandwidth spectroscopy with 128-channel resolution for 15-correlation data. This system allows us to observe radio continuum emission with about a two-times better signal-to-noise ratio than that of the previous correlator system. We started common-use observations with this new system from 1997 March; the system has been extended in order to obtain 21-correlation data for a 7-element "Rainbow" (NMA + 45-m telescope) interferometer system.

We present high spatial resolution images of the gravitational-lens system PG 1115+080 taken with the near-infrared camera (CISCO) on the Subaru telescope. The FWHM of the combined image is $0.''32$ in the $K'$-band, yielding spatial resolution of $0.''14$ after a deconvolution procedure. This is a first detection of an extended emission adjacent to the A1/A2 components, indicating the presence of a fairly bright emission region with a characteristic angular radius of $\sim$ 5 mas (40 pc). The near-infrared image of the Einstein ring was extracted in both the $J$ and $K'$ bands. The $J-K'$ color is found to be significantly redder than that of a synthetic model galaxy with an age of 3 Gyr, the age of the universe at the quasar redshift., 11 pages, 6 figures. Accepted for publication in PASJ(2000)

We present new measurements of the diameter of o Cet (Mira) as a function of wavelength in the 2.2 micron atmospheric window using the adaptive optics system and the infrared camera and spectrograph mounted on the Subaru Telescope. We found that the angular size of the star at the wavelengths of CO and H2O absorption lines were up to twice as large as the continuum photosphere. This size difference is attributable to the optically thick CO and H2O molecular layers surrounding the photosphere. This measurement is the first direct differential spectroscopic imaging of stellar extension that resolves individual molecular lines with high spectral-resolution observations. This observation technique is extremely sensitive to differences in spatial profiles at different wavelengths; we show that a difference in diameter much smaller than the point spread function can be measured., 6 pages, 3 figures, accepted for publication in PASJ

The authors have developed the tracking control system of astronomical objects in the Nobeyama millimeter array. A system was studied which can accomplish sufficient tracking accuracy for an interferometer, such as delay tracking, phase tracking, and fine delay correction. It was found that the location error of an astronomical object can be made less than 1 percent of the maximum spatial resolution on a synthesized map and the radio intensity degradation less than 0.1 percent if the phase tracking is executed at an interval of about 10 s and the fine delay correction at 1 - 2 s. Further, from the actual observation results, it was confirmed that this system has realized an extremely high tracking accuracy.

The Subaru Telescope has been operated smoothly for eight years after its first light. With the advent of instruments with high spatial resolution such as the adaptive optics, elongation of images has been noticed towards specific azimuth (AZ) and elevation (EL). With accelerometers with high time resolution, we detected vibrations of the telescope and could attribute the elongation of images to the vibrations. The detected vibrations are at 3.6 Hz and at 7-9 Hz in AZ direction and at 5-6 Hz in EL direction. Image motion due to these vibrations is 0.4 arcsec peak-to-peak at maximum, which is not negligible compared to image motion of 0.063 arcsec rms in quiescent state. The motion, which can not be canceled with the auto guider, results in elongation of images. The 3.6 Hz vibration in AZ direction is only excited while culmination EL of above 80 degrees. The 7-9 Hz vibration in AZ direction and the 5-6 Hz vibration in EL direction are excited by periodic errors in incremental encoders which are used to measure velocity of telescope rotation. We investigated possibilities to reduce the vibrations with tuning control loops of the AZ and EL axes.© (2006) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The Subaru telescope had its astronomical first light in January 1999 and has been stably operated since the common use started in December 2000. The telescope is mounted on an alt-azimuth structure. The structure of 550 tons is supported by six hydrostatic oil pads which lift the structure by 50 microns. The azimuth (Az) and elevation (El) axes are driven by direct-drive linear motors, ensuring very smooth pointing and tracking operations. The Az rail consists of eight circular arc pieces. They were installed in January 1997 with a peak-to-peak level of within 0.1mm. However at a later time, vertical undulations of the Az rail were found to be more than 0.2 mm peak-to-peak at some locations where the telescope structure in the rest position applies load. Open-loop tracking accuracy of the telescope, which was about 2 arcsec RMS on the sky, was found to be due to the undulations of the Az rail. We made a table to correct telescope pointings due to the undulations. It has made open-loop tracking accuracy better than 0.2arcsec RMS. Since then, we have been monitoring the flatness of the Az rail. So far the undulations have not changed.

We present 3 um spectroscopy of the carbon-rich proto-planetary nebulae IRAS 04296+3429 and IRAS 05341+0852 conducted with the adaptive optics system at the Subaru Telescope. We utilize the nearly diffraction-limited spectroscopy to probe the spatial extent of the hydrocarbon dust emitting zone. We find a hydrocarbon emission core extending up to 100--160 mas from the center of IRAS 04296+3429, corresponding to a physical diameter of 400--640 AU, assuming a distance of 4 kpc. On the other hand, we find that IRAS 05341+0852 is not spatially resolved with this instrumentation. The physical extent of these proto-planetary nebulae, along with the reanalyzed data of IRAS 22272+5435 published previously, suggests a correlation between the physical extent of the hydrocarbon dust emission and the spectral evolution of the aliphatic to aromatic features in these post-AGB stars. These measurements represent the first direct test of the proposed chemical synthesis route of carbonaceous dust in the circumstellar environment of evolved stars., Comment: 6 pages, 4 figures, Accepted for publication in the Astrophysical Journal

A wide-band FFT spectrum analyzer, called FX, is in operation at the Nobeyama Radio Observatory for spectroscopy of radio waves from the molecules in the gas clouds which are the cradles of stars. It processes input of six 320MHz bandwidth data streams into the output of fifteen cross-power spectrums of 1024 frequency channels each. This processing speed is 105times as high as usual computers. Its highly parallel pipeline architecture made it possible to achieve the above speed. The FX is made up of about 4500 LSI chips of CMOS gate arrays. They are designed using CAD and have 3900 or 2000 gates/chip, operate at 10 MHz clock rate, and consume 100 mW/chip or less. The SNR (signal-to-noise ratio) is better than 10 dB, which is adequate to the astronomical uses.

We present the development status of the laser system for Subaru Laser Guide Star Adaptive Optics System. We are manufacturing the quasi-continuous-wave sum frequency laser as a prototype. The optical efficiency of sum frequency generation normalized by the mode-locked fundamental YAG (1064 nm) laser output power is achieved to be 14 % using the non-linear crystal, periodically poled potassium titanyl phosphate (PPKTP). Output power at sodium D2 line was about 260 mW. The optical relay fiber and the laser launching telescope are also described in this paper. For the optical relay fiber, we are testing an index guided photonic crystal fiber (PCF), whose core material is filled by fused silica, and whose clad has close-packed air holes in two dimension. The coupling efficiency was evaluated as about 80 % using 1mW He-Ne laser. We introduce the design of laser launching telescope (LLT), which is a copy of VLT laser launching telescope, and the interface to the Subaru Telescope.

The Subaru Telescope has been stably operated with high image quality since common use began in December2000. We have updated the following items in order to achieve further improvement of observation eciency,image quality, and tracking. 1. High re”ectivity of mirrors. The re”ectivity of the primary mirror has beenmaintained, yielding 84% at 670 nm by regular CO 2 cleaning (every two to three weeks). We successfully carriedout the silver coating of the Infrared secondary mirror in April 2003 without over-coating. The re”ectivity hasbeen maintained at greater 98% at 1,300 nm. 2. Image Quality. Subaru telescope delivers exceptional imagequality a median image size of 0.6 arc-second FWHM in the R -band as taken by Auto-Guider Cameras atall four foci; Prime, Cassegrain, and two Nasmyth. We optimized parameters of the servo control system ofthe Elevation servo, reducing the amplitude of 3 8 Hz vibration mode of the telescope and improving imagequality when using the Adaptive Optics (AO) system. 3. Acquisition Guiding. Dithering time was shortened byupdating the control software. The slit viewer camera for HDS and the “ber bundle for FMOS are available foracquisition guiding in addition to Auto-Guider Cameras. 4. New instruments. We are developing a new primefocus unit for FMOS and will start functional tests in 2005. Moreover, we have started to prepare new interfacesand facilities for FMOS and the new 188 element AO natural/laser guide star system. The focus switching timewill be shortened by updating the hardware of the IR and Cassegrain Optical secondary mirrors from September2004, reducing it to 10 minutes to switch the focus between Cassegrain and Nasmyth foci.Keywords: Subaru Telescope, Ground based Large Telescope, Astronomy

The SUBARU Telescope has four focal positions to allow different types of astronomical instrument. At present, there are four different Top Units; three types of secondary mirrors and one primary focus unit. IR secondary mirror which is one of the three units, has silver coated surface. Other secondary mirrors are coated by aluminum for observations at visible wavelength. The silver coating for IR secondary mirror was first carried out in 1999 at the medium size (1.6 m) vacuum evaporation chamber in Mitaka campus of NAOJ at Tokyo JAPAN. Since then the reflectivity had deteriorated over the years. Then, we made a plan to recoat IR secondary mirror in 2003 using the SUBARU’s large-size vacuum evaporation chamber at the summit facility on Mauna Kea, Hawaii. Some tests were performed for silver vacuum evaporation at the base facility, and then the IR secondary mirror was recoated at the summit. The reflectivity achieves 97.6% and 99.3% at the wavelength of 500 nm and 2000 nm, respectively. Degradation of the coat has not been seen 8 months after recoating. We also performed the recoating of the aluminum surface of the primary mirror in 2003. This year we made effort to simplify the procedure. The reflectivity is 91.2% and 97.4% at the wavelength of 500 nm and 2000 nm, respectively.

We have measured near-infrared colors of the binary Kuiper Belt object (KBO) 1998 WW31 using the Subaru Telescope with adaptive optics. The satellite was detected near its perigee and apogee (0.18″ and 1.2″ apart from the primary). The primary and the satellite have similar H-K colors, while the satellite is redder than the primary in J-H. Combined with the R band magnitude previously published by Veillet et al., 2002, the color of the primary is consistent with that of optically red KBOs. The satellite’s R-, J-, H-colors suggest the presence of ~1μm absorption band due to rock-forming minerals. If the surface of the satellite is mainly composed by olivine, the satellite’s albedo is higher value than the canonically assumed value of 4%.

Adaptive optics imaging of the bright visual T Tauri binary AS 353 with the Subaru Telescope shows that it is a hierarchical triple system. The secondary component, located 5.6" south of AS 353A, is resolved into a subarcsecond binary, AS 353Ba and Bb, separated by 0.24". Resolved spectroscopy of the two close components shows that both have nearly identical spectral types of about M1.5. Whereas AS 353A and Ba show clear evidence for an infrared excess, AS 353Bb does not. We discuss the possible role of multiplicity in launching the large Herbig-Haro flow associated with AS 353A., AASTeXv5.0, 21 pages, 5 figures, Astronomical Journal, in press

I will report on the deformation of the Subaru Telescope primary mirror surface due to wind pressure. The 261 actuators, controlled precisely down to 0.01 N level, together with 3 fixed points maintains the optical figure of the primary mirror. The extra-force exerted by wind pressure, however, pushes the actuator pistons to cause their displacement while not affecting the fixed points. This results in an overall deformation of the primary mirror, which we measured. We first measured the difference in the actuator force of the sensors with and without wind pressure, i.e., with the dome shutter opened and closed. The force were then converted to the displacement of the 261 actuator pistons. The experiment was made under the wind speed of 5m/s with the telescope pointing toward the wind at elevations 30 and 60 degrees. The deformation pattern at EL=30 was triangular with three fixed points protruding, while that at EL=60 was saddle with the left and right pushed back. The value of deformation was ~2um. The patterns were interpreted that the wind pushes the entire mirror surface at EL=30 while it lifts the bottom part up at EL=60.

We conducted the aluminization campaign of the primary mirror of the Subaru Telescope in September 2001. This was the third time with the Subaru's coating facility. The witness samples coated at the same time show reflectance above 91% at 500 nm, the highest of the three coating campaigns. We continue to pursue the film which has high reflectance, high adhesion nature to the glass substratum, and durability with little degradation in time. As part of the effort, we started to compare various evaluation methods of the coating films. The emphasis is on the physical property side, using XPS (X-ray Photoelectron Spectroscopy), SIMS (Secondary Ion Mass Spectrometry), and SEM (Scanning Electron Microscope). We hope to use the findings to improve our coating processes for the Subaru's mirrors and other mirrors. First thing we confirmed is that three oxidization layers exist in the aluminum coatings itself and between the aluminum and the glass substratum. This is caused by the three stage firing in the Subaru's 9 m chamber. The extent of such layers seems to contribute to the adhesion of the film to the glass. Next, we compared the film produced by the conventional evaporation (using 1.6 m chamber at Mitaka, Tokyo) and by the sputtering (using the Tohoku University equipment). The contamination and defects in the film seem to be responsible for the exfoliation, and the reflectance. We will use these physical property evaluations also to optimize the coating process of other coating materials that is suited for the infrared observations.

We present an overview of Subaru Cassegrain adaptive optics system and its performance verified at the engineering run. The system is based on a curvature wavefront sensor with 36-element sub-apertures and a bimorph deformable mirror with identical number of elements. We had the first light in Dec. 2000. The AO system has been in service for two instruments, IRCS; infrared camera and spectrograph, and CIAO; coronagraph imager with adaptive optics. The Strehl ratio at the K band is around 0.30 under 0.4- 0.5 arcsec K-band seeing condition for bright guide stars. The sensitivity of the wavefront sensor is so high that we have significant improvement of image quality even for a faint guide star down to R=18 th magnitude. The measurement of stars in a globular cluster suggests an isoplanatic angle, about 40 arcsec, wider than that expected from the equivalent turbulence layer assumed at the height of 6.5 km. The system has been offered for common use since Apr. 2002. Some scientific results using this AO system are shown in this paper.

We would like to present the procedure of how to prepare the primary mirror of Subaru Telescope for the realuminization. The equipment for the coating and its preparation are located at the ground floor of the telescope enclosure. There are two trolleys for carrying the mirror cell and the mirror itself, a mirror lifting jig, a washing facility for the primary mirror (PMWF), the water purification system, the coating chamber and the waste water pit. The PMWF can provide the tap water for initial rinsing, the chemical for stripping the old coating, and the deionized water for final cleaning. It has two pairs of arms that deploy horizontally above the mirror and have nozzles to spray. The arms spin around its center where the rotary joints are connected to the plumbing from storage tanks. Deck above the water arms serve as platform for personnel for the inspection or for scrubbing work. We use hydrochloric acid mixture to remove the old aluminum coating. For rinsing and final cleaning, we use the water through the purification system. The water supply from the nozzles and the rotation of the arms can be controlled from a panel separated from the washing machine itself. After several experiments and improvements in the washing, we have carried out the coating of the 8.3 m primary mirror in September last year. This was the third time, and the reflectivity of the new coating show satisfactory result.

The SUBARU Telescope has four focal positions to allow different types of instruments. At present, there are four different Top Units; three types of secondary mirrors and one primary focus unit. These units have the weight of about 3 tons, and they need to be installed or changed high above in the air, with the telescope in its rest position, namely, pointed to the zenith. In order to carry out this exchange work safely and securely, in already a difficult working condition of high altitude place like Mauna Kea, we developed an automatic exchanger with remote control, called Top Unit Exchanger (TUE).

We present the first spectroimagery of extended molecular atmosphere of Mira spatially resolved by adaptive optics system. We found the molecular atmosphere of H2O, CO and CO2 is extended to about 40 mas. The presence of extended molecular layer has been revealed by recent infrared spectroscopic studies with space borne telescope ISO. The physical extent in our observation is consistent with their studies. The new technique that resolves objects in wavelength and in space simultaneously is proved to be very sensitive to the extended component respect to the continuum photosphere, because the time variable seeing effect is mostly canceled by relative measurement of the image size

We describe the silver coating of 1.3-m secondary nirror being used for infrared observations at Subaru Telescope. This was the first successful in-house runof silve coating on thelarge moern astronimical mirror. Silver was desposited over the chromium bondange layer, using a 1.6-m vacuum coating chamber at the Advanced technology Center of the National Astronomical Obervatoryof Japan in March 1998. The reflectnc eand scatter performnce are measured by micrScan at 670 nm and 1300 nm. Monitor over 17 month shows the silve coated mirror continues to maintain high refleciton.

After the initial coating of the 8.3-m primary mirror of the Subaru Telescope in November 1998, we have conducted the first re-aluminization in August 1999. The primary mirror washing fixture worked efficiently for stripping the old coating and for washing the surface. Dry process is still to be improved. Suite of secondary and tertiary mirrors are being tested at the telescope, two of which were coated in- house, one in silver for the infrared observations and the other in aluminum for the optical observations, respectively. Evaluation of the coating film is conducted in two methods. Using a portable microScan, the reflectivity and the BRDF numbers of the primary mirror is monitored. Reflectivity over a wide range of the wavelength is measured in the witness mirrors. The preliminary data shows reasonably good number for the telescope optics. The in-situ cleaning of the primary mirror with solid and gaseous CO2 sprinkle arms is operating once every month. Next step for the coating chamber commissioning is to improve the heating capacity for silver coating of the infrared secondary and tertiary mirrors, and the experiment for silver coating is going.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Prototype laser guide star system for Subaru telescope has been developed at Communications Research Laboratory (CRL). The laser system comprises two commercially available lasers: a modified continuous wave (CW) dye laser and a 10 W all-solid CW laser of 532 nm wavelength for pumping the dye laser. The natural guide star adaptive optics system for Subaru telescope on Cassegrain focus will be upgraded to a laser guide star adaptive optics system using this laser system. The experiment of transmitting laser beam to the sodium layer is performed at CRL using a 1.5 m telescope. The laser beam is emitted from a 20 cm telescope mounted next to the 1.5 m telescope. A laser guide star is observed by a cooled CCD camera, which is equipped on the Nasmyth platform. We report the preliminary results of the experiment of observing a sodium laser guide star.

We investigate the $K$-band luminosity distribution of galaxies in the region of clusters at $z\sim1.2$ near to the radio galaxy 3C 324. The imaging data were obtained during the commissioning period of the Subaru telescope. There is a significant excess of the surface number density of the galaxies with $K =$ 17--20 mag in the region within $\sim$ 40'' from 3C 324. At this bright end, the measured luminosity distribution shows a drop, which can be represented by the exponential cut off of the Schechter-function formula; the best-fitted value of the characteristic magnitude, $K^{*}$, is $\sim 18.4\pm0.8$. This measurement follows the evolutionary trend of the $K^*$ of the rich clusters observed at an intermediate redshift, which is consistent with passive evolution models with a formation redshift $z_f \gtsim 2$. At $K \gtsim 20$ mag, however, the excess of the galaxy surface density in the region of the clusters decreases abruptly, which may imply that the luminosity function of the cluster galaxies has a negative slope at the faint end. This may imply strong luminosity segregation between the inner and outer parts of the clusters, or some deficit of faint galaxies in the cluster central region of the cluster., 12 pages, 9 figures, accepted for publication in PASJ

The adaptive optics system for Subaru 8.2m telescope of the National Astronomical Observatory Japan has been developed for the Cassegrain ear-IR instruments, CIAO and IRCS. The system consists of a wavefront curvature sensor with 36 subaperture photon-counting avalanche photodiode modules and a bimorph deformable mirror with 36 electrodes. The expected Strehl ratio at K band exceeds 0.4 for objects that are located close enough to a bright guide star as faint as R equals 16 mag at the median seeing of 0.45 arcsec at Mauna Kea. The system will be in operation in 1999 as a natural guide star system, and will eventually be upgraded to a laser guide star system in cooperating an IR wavefront tilt sensor to provide nearly full sky. The construction of this common use system to Subaru telescope is now underway in our laboratory in Tokyo. Prior to starting the fabrication of this common use system, a full size prototype system was constructed and tested with the 1.6 m IR telescope at our observatory in Tokyo. This system has the identical optical design, deformable mirror, loop control computer to those for the Subaru system, while the wavefront sensing detectors were less-sensitive analog APDs. We succeeded in getting closed loop images of stars in K band with diffraction limited core. The Strehl ratio was around 0.5 and the factor of improvement was about 20 at K-band under the average seeing of 2 arcsec during the observation. The loop sped of the system was 2 K corrections per second.

We have conducted a series of coating experiments using the newly installed 1.6 m evaporation chamber at the Advanced Technology Center (ATC) of the National Astronomical Observatory of Japan. The main task of this chamber is to re-aluminize the 1.6 m mirror of the Infrared Simulator at the ATC. The design concept of the 1.6 m chamber is basically the same with the 8.3 m coating facility for Subaru Telescope. Therefore, we could utilize this chamber to evaluate the fundamental performance of the larger chamber. The extensive coating experiments were done in the spring, autumn of 1996, and autumn of 1997. Reduction of the number of the filaments has lead to the increase in their size, which caused difficulty in the annealing process. Attempts are focused on securing the sufficient metal loads on the filaments. Then the filaments are fired to measure the spray pattern of a single filament exposure, or the uniformity pattern resulted from the full setup of filament arrays. Using small slide glasses, the important parameters of the resultant reflecting film that are the thickness, the uniformity of the thickness, and the spectroscopic reflectance are measured. The absolute value of the reflectivity is estimated to be around 91% immediately after opening the chamber. In order to cover a wide range of observing wavelengths for the Infrared Simulator, and eventually for the optical-IR Subaru Telescope, it is necessary to seek after a higher evaporation rate with these chambers.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The system overview and the current status of an adaptive optics system for the Cassegrain focus of Subaru 8.2 m telescope under construction atop Mauna Kea is presented. The system is composed of a wavefront curvature sensor with 36 elements photon-counting APD modules and a 36-element bimorph deformable mirror. We aim to get the Strehl ratio of greater than 0.6 at the K band (2.2 micron) using natural guide stars as wavefront reference under the average seeing condition (approximately 0.45 arcsec) at Mauna Kea. It is scheduled to be in operation in 1998. Expected performance, especially the sky coverage when employing natural guide stars are also presented. currently we are testing prototype system with basically identical specifications as those of the final system. We present here the optical system, deformable mirror, wavefront sensor, control system of the final system, and simple introduction and experimental results of the prototype system.

New developments for upgrading the Nobeyama Millimeter Array(NMA, Ishiguro et al., 1984) and the recent results from millimeter-wave spectral-line observations are presented.

A wide-band FFT spectrum analyzer, which we call FX, has been in operation since 1983 at the Nobeyama Radio Observatory for spectroscopy of radio waves from interstellar molecules. It processes an input of six 320-MHz-bandwidth data streams to produce the output of fifteen cross-power spectra of 1024 frequency channels each. Its highly parallel pipeline architecture made it possible to achieve the above speed, 1010butterfly operations per second, which is 105times that of usual mainframe computers. The FX incorporates about 4500 newly developed CMOS LSI chips. They are designed using CAD (computer-aided design) and have 3900 or 2000 gates/chip, operate at a clock rate of 10 MHz, and consume 100 mW/chip or less. For 80-MHz bandwidth signal at an optimum input level, the SNR (signal-power to noise-power ratio) of the FX is better than 10 dB, which is adequate for astronomical use.

The ∼20 pc square region around the continuum peak, (α(1950.0) = 17h44m 10.6s, δ(1950.0) = −28°22′05″) of Sgr B2 was observed using the 45-m telescope of Nobeyama Radio Observatory. The observed molecules are H2O, NH3, CH3OH, SiO, H13CN, H13CO+, CO, HNCO, HC3N, and so on.

Aperture synthesis observations of the central 1.5 kpc region of the spiral galaxy Maffei 2 have been made in CO(J = 1-0) line. A central narrow ridge of molecular gas with a size 1000 pc x 200 pc and a ringlike feature with a large noncircular motion (60 km/s) with a size 500 pc x 240 pc have been found. The narrow ridge is interpreted as a bar of molecular gas in shocks generated at the leading edges in the bar potential. The observational results suggest that the ring is an expanding and rotating ring of molecular gas in the plane of the galaxy. The ring may have been formed by a starburst induced by the efficient gas supply in the bar potential. 38 refs.

NH{sub 3} and H{sub 2}O maser observations of the 20 km/s molecular cloud M-0.13-0.08 in the Sgr A complex region are reported. NH{sub 3} (1,1) and (2,2) lines were observed simultaneously, and the molecular gas temperature and density are estimated. The NH{sub 3} emission is elongated in the same direction of the entire M-0.13-0.08 cloud and has a large velocity gradient along its major axis. Strong NH{sub 3} emission is located in the northern part of the cloud, where a perturbed velocity field and broad line widths are observed. In addition, a new H{sub 2}O maser spot was detected near one of the nonthermal continuum sources. These observational results suggest the physical association between a part of the M-0.13-0.08 molecular cloud and the nonthermal continuum sources in the Sgr A complex. 39 refs.