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An overview of the Seimei telescope, a 3.8 m optical infrared telescope located on Mt. Chikurinji in the Okayama prefecture of Japan, is presented. Seimei is a segmented-mirror telescope whose primary mirror consists of 18 petal-shaped segments. The telescope tube supporting the thin segmented mirrors is structurally incorporated within large arc-rails providing the elevation axis. The tube has a light-weight homologous structure designed with a genetic algorithm. The total weight of the telescope tube, including 1.4-ton optics, is only 8 tons. By virtue of its light weight, the telescope is able to point at an object anywhere in the observable sky within one minute. The telescope is operated by Kyoto University in collaboration with the National Astronomical Observatory of Japan (NAOJ). Half of the telescope time is used by Kyoto University. The remaining time is open to the Japanese astronomical community. NAOJ is responsible for the management of the open-use time, including handling of the observation proposals. The telescope is now regularly performing scientific observations on the basis of a variety of proposals.

The Fibre Multi-Object Spectrograph (FMOS) is a second-generation common-use instrument of the Subaru telescope. Under an international collaboration scheme of Japan, UK, and Australia, a realistic design of FMOS has been already in completion, and the fabrications of hardware components have been in progress. We present the overall design details together with the special features of FMOS subsystems, such as the prime focus corrector, the prime focus mechanical unit including fibre positioners, and the near-infrared spectrograph, etc.

We investigate the properties (e.g. star formation rate, dust attentuation, stellar mass and metallicity) of a sample of infrared luminous galaxies at z \sim 1 via near-IR spectroscopy with Subaru-FMOS. Our sample consists of Herschel SPIRE and Spitzer MIPS selected sources in the COSMOS field with photometric redshifts in the range 0.7 = 0.51\pm0.27 for = 10^12 Lsol sources at = 1.36. By comparing star formation rates estimated from the IR and from the dust uncorrected H{\alpha} line we find a strong relationship between dust attenuation and star formation rate. This relation is broadly consistent with that previously seen in star-forming galaxies at z ~ 0.1. Finally, we investigate the metallicity via the N2 ratio, finding that z ~ 1 IR-selected sources are indistinguishable from the local mass-metallicity relation. We also find a strong correlation between dust attentuation and metallicity, with the most metal-rich IR-sources experiencing the largest levels of dust attenuation.

Fibre Multi-Object Spectrograph (FMOS) is the first near-infrared instrument with a wide field of view capable of acquiring spectra simultaneously from up to 400 objects. It has been developed as a common-use instrument for the F=2 prime-focus of the Subaru Telescope. The field coverage of 300 diameter is achieved using a new 3-element corrector optimized in the near-infrared (0.9-1.8μm) wavelength range. Due to limited space at the prime-focus, we have had to develop a novel fibre positioner, called " Echidna" , together with two OH-airglow suppressed spectrographs. FMOS consists of three subsystems: the prime focus unit for IR, the fibre positioning system/connector units, and the two spectrographs. After full systems integration, FMOS was installed on the telescope in late 2007. Many aspects of the performance were checked through various test and engineering observations. In this paper, we present the optical and mechanical components of FMOS, and show the results of our on-sky engineering observations to date. © 2010. Astronomical Society of Japan.

FastSound is a galaxy redshift survey using the near-infrared Fiber Multi-Object Spectrograph (FMOS) mounted on the Subaru Telescope, targeting H$\alpha$ emitters at $z \sim 1.18$--$1.54$ down to the sensitivity limit of H$\alpha$ flux $\sim 2 \times 10^{-16} \ \rm erg \ cm^{-2} s^{-1}$. The primary goal of the survey is to detect redshift space distortions (RSD), to test General Relativity by measuring the growth rate of large scale structure and to constrain modified gravity models for the origin of the accelerated expansion of the universe. The target galaxies were selected based on photometric redshifts and H$\alpha$ flux estimates calculated by fitting spectral energy distribution (SED) models to the five optical magnitudes of the Canada France Hawaii Telescope Legacy Survey (CFHTLS) Wide catalog. The survey started in March 2012, and all the observations were completed in July 2014. In total, we achieved $121$ pointings of FMOS (each pointing has a $30$ arcmin diameter circular footprint) covering $20.6$ deg$^2$ by tiling the four fields of the CFHTLS Wide in a hexagonal pattern. Emission lines were detected from $\sim 4,000$ star forming galaxies by an automatic line detection algorithm applied to 2D spectral images. This is the first in a series of papers based on FastSound data, and we describe the details of the survey design, target selection, observations, data reduction, and emission line detections.

We present the results of deep near-infrared observations searching for very low mass young stellar objects (YSOs) in the massive star-forming region of S106 taken with the Subaru Telescope. The survey, whose limiting magnitude exceeds 20 mag in the JHK' bands, is sensitive enough to provide unprecedented details in the two nebular lobes. In addition, it reveals a census of the stellar population down to objects below the deuterium-burning limit, a fiducial boundary between brown dwarfs and planetary-mass objects. Based on color-color diagrams, nearly 600 embedded YSO candidates with near-infrared excesses have been identified in an area of ~5' ? 5' that are not uniformly distributed but centrally concentrated. Combining the reddening-corrected luminosity of the YSO candidates with the theoretical evolutionary models, we suggest that there exists a substantial substellar population. If we divide the cluster into three subgroups based on stellar and cloud properties, both their luminosity functions and mass functions across the stellar-substellar boundary demonstrate local variation on a subparsec scale. Nevertheless, all the mass functions have distinct characteristics in common: they do not have any turnover and do not decline down to the completeness limits. Furthermore, the mass function for S106 appears to be more abundant in young substellar objects compared to those obtained for other young clusters, such as Trapezium and IC 348. This implies that the substellar mass function for young clusters may have a variation.

To explore various scientific frontiers from nearby substellar objects to large scale structures of the high redshift universe, a Fibre Multi-Object Spectrograph (FMOS) is being developed as the second generation near-infrared measuring instrument for the prime focus of 8.2 m Subaru telescope in Hawaii, which employs a large special Schmidt plate element. The Schmidt plate consists of a large non-axisymmetric aspherical concave plate and a convex plate. This paper introduces its manufacturing process, focusing on its non-axisymmetric aspherical surface machining by utilizing synthetically ELID grinding and arc-enveloped grinding method. A new grinding system capable of fabricating large optical elements was developed with 10 nm resolution. In this ELID arc-enveloped grinding system, a Cast Iron Fibre Bonded (CIFB) diamond wheel was 3D controlled to scan the workpiece to generate required surface. Grinding characteristics such as attainable form accuracy, surface roughness were investigated. Furthermore, some measures to improve form accuracy were discussed and verified.

We present a deep $K^{\prime}$-band (2.12$\mu$m) imaging of 1\arcmin\ $\times$ 1\arcmin Subaru Super Deep Field (SSDF) taken with the Subaru adaptive optics (AO) system. Total integration time of 26.8 hours results in the limiting magnitude of $K^{\prime} \sim 24.7$ (5$\sigma$, 0\farcs2 aperture) for point sources and $K^{\prime} \sim 23.5$ (5$\sigma$, 0\farcs6 aperture) for galaxies, which is the deepest limit ever achieved in the $K^{\prime}$ band. The average stellar FWHM of the co-added image is 0\farcs18. Based on the photometric measurements of detected galaxies, we obtained the differential galaxy number counts, for the first time, down to $K^{\prime} \sim 25$, which is more than 0.5 mag deeper than the previous data. We found that the number count slope $d\log N/dm$ is about 0.15 at $22 < K^{\prime} < 25$, which is flatter than the previous data. Therefore, detected galaxies in the SSDF have only negligible contribution to the near-infrared extragalactic background light (EBL), and the discrepancy claimed so far between the diffuse EBL measurements and the estimated EBL from galaxy count integration has become more serious . The size distribution of detected galaxies was obtained down to the area size of less than 0.1 arcsec$^2$, which is less than a half of the previous data in the $K^{\prime}$ band. We compared the observed size-magnitude relation with a simple pure luminosity evolution model allowing for intrinsic size evolution, and found that a model with no size evolution gives the best fit to the data. It implies that the surface brightness of galaxies at high redshift is not much different from that expected from the size-luminosity relation of present-day galaxies., Comment: 17 pages, 28 figures, 3 tables, Accepted for publication in the Astrophysical Journal

Near-infrared spectra of four QSOs located at $z>6$ are obtained with the OH-airglow suppressor mounted on the Subaru telescope. The FeII/MgII emission-line ratios of these QSOs are examined by the same fitting algorithm as in our previous study of $z6$ QSOs have significant FeII emission in their rest-UV spectra, while the other two have almost no FeII features. We also applied our fitting algorithm to more than 10,000 SDSS QSOs and found two trends in the distribution of FeII/MgII against redshift: (1) the upper envelope of the FeII/MgII distribution at $z>3$ shows a probable declination toward high redshift, and (2) the median distribution settles into lower ratios at $z\sim 1.5$ with small scatter compared to the other redshift. We discuss an Fe/Mg abundance evolution of QSOs with a substantial contribution from the diverse nature of the broad-line regions in high-redshift QSOs., Comment: 12 pages, 2 figures. Accepted for publication in ApJ (10 October 2004, v614)

We describe observations of a galaxy in the field of the $z=2.483$ radio galaxy 4C 23.56, photometrically selected to have a spectral-energy distribution consistent with an old stellar population at the redshift of the radio galaxy. Exploration of redshift--stellar-population-reddening constraints from the photometry indicates that the galaxy is indeed at a redshift close to that of 4C23.56, that the age of the most recent significant star formation is roughly >~2 Gyr, and that reddening is fairly modest, with more reddening required for the younger end of stellar age range. From analysis of a deep adaptive-optics image of the galaxy, we find that an r^1/4-law profile, common for local spheroidal galaxies, can be excluded quite strongly. On the other hand, a pure exponential profile fits remarkably well, while the best fit is given by a Sersic profile with index n=1.49. Reconstruction of the two-dimensional form of the galaxy from the best-fit model is consistent with a disk galaxy with neither a significant bulge component nor gross azimuthal structure. The assembly of roughly 2L* of old stars into such a configuration this early in the history of the universe is not easily explainable by any of the currently popular scenarios for galaxy formation. A galaxy with these properties would seem to require smooth but rapid infall of the large mass of gas involved, followed by a burst of extremely vigorous and efficient star formation in the resulting disk., 8 pages, 6 figures, emulateapj.sty, accepted for publication in The Astrophysical Journal

By using ASCA and Chandra, we discovered a bright X-ray source M82 X-1 in the starburst galaxy M82. The peak luminosity of ∼ 1 x 10 4 1 ergs sec - 1 and the location of off-center position of M82 in the starburst galaxy M82 suggest that M82 X-1 is a new type of black hole, intermediate massive black hole (IMBH). We also found an expanding molecular super bubble (EMSB) surrounding the IMBH. We propose a hypothesis that the IMBH was formed in the starburst activity 10 6 ∼ 10 7 yrs ago. We review the course of the discovery and show recent progress on studies of the X-ray spectrum and the position of M82 X-1.

Near-infrared spectra of 15 high-redshift radio galaxies (HzRGs) located at 2 < z < 2.6 were obtained by the OH Airglow Suppressor spectrograph mounted on the Subaru telescope. The UV-optical line ratio diagnostic diagrams indicate that half of the observed HzRGs have extended emission-line regions with low metal abundance, photoionized by a flat-continuum active galactic nucleus such as a quasar. We also found two probable correlations between radio and rest-optical parameters: (1) HzRGs with massive hosts tend to have a redder rest-optical continuum, and (2) HzRGs with smaller radio sizes also show a redder optical continuum. On the basis of the correlations, the nature of HzRGs at 2 < z < 2.6 is discussed.

We have constructed a very deep K'-selected multicolor BVRIz'JK' sample of 439 field galaxies. Photometric redshifts for sample galaxies were estimated. The overall redshift distribution N(z) for the K'2. The photometric redshift and the best-fit SED model evaluations allow the derivation of the rest-frame K', B, and UV(2000A) luminosity functions (LFs) and their evolutions. The rest-K' LF shows almost no evolution up to z=3, while the rest B LF shows mild luminosity evolution, and the rest UV LF shows strong luminosity evolution. This trend corresponds to the evolution of the rest UV-K' color, which gets bluer with increasing redshift. We also found that more massive galaxies are redder in this rest-frame color in every epoch. The rest-UV LF of our K'-selected galaxies shows a much shallower faint end slope at z=3 than that of previous estimations for rest-UV selected Lyman break galaxies. As a consequence, the contribution to the global star formation rate of our K'-selected galaxies is about 42% of that derived from the integration of LF of Lyman break galaxies at z=3. This result suggests that a large fraction of the star formation rate density at z>1.5 comes from the contribution from the faint (M_2000A>-20) blue galaxy population at high redshift universe that have not yet obviously been identified. (abridged), 35 pages, 9 figures, Accepted for publication in AJ

We report the discovery of a redshift z = 6.56 galaxy lying behind the cluster Abell 370. The object HCM 6A was found in a narrowband imaging survey using a 118 A bandpass filter centered at 9152 A in the Low-Resolution Imaging Spectrograph (LRIS) camera on the 10 m Keck II telescope. Candidate Lyα emitters were identified by the equivalent width of the emission and the absence of lower wavelength flux in ultradeep broadband images. HCM 6A is the first galaxy to be confirmed at redshift z > 6 and has Wλ(observed) = 190 A, flux = 2.7 × 10-17 ergs cm-2 s-1. Spectra obtained with LRIS confirm the emission line and the continuum break across the line and show an asymmetric line profile with steep falloff on the blue side. Deep Subaru near-infrared Cooled Infrared Spectrograph and Camera for OHS images in J, H, and K' that extend the sampled continuum to longer wavelengths give a consistent estimate of the continuum flux density in these line-free regions of × 10-30 ergs cm-2 s-1 Hz-1. The line width and strength, asymmetric profile, and very deep spectral break are only consistent with the interpretation of the line as a redshifted Lyα feature. From the detailed lensing model of this cluster, we estimate a lensing amplification of 4.5 for this galaxy, which is located slightly over an arcminute from the center of the cluster, for an unlensed flux of 6.5 × 10-18 ergs cm-2 s-1. The presence of such a galaxy suggests that the reionizing epoch is beyond z = 6.6.

Near-infrared spectra of 13 QSOs located between 4.4 < z < 5.3 were obtained by the OH-airglow suppression spectrograph mounted on the Subaru telescope. The Fe II/Mg II emission-line ratios of the QSOs at various redshifts were examined by applying the same fitting algorithm to the present data together with published or archived spectra. We found a trend of a decreasing Fe II/Mg II ratio from z ~ 5 to 1.5, almost independent of their luminosities. We also confirmed the Baldwin effect on the Mg II emission line.

We present a stellar mass-metallicity relation at z~1.4 with an unprecedentedly large sample of ~340 star-forming galaxies obtained with FMOS on the Subaru Telescope. We observed K-band selected galaxies at 1.2 < z_{ph} < 1.6 in the SXDS/UDS fields with M_{*} > 10^{9.5} M_{\sun}, and expected F(H\alpha) > 5 \times 10^{-17} erg s^{-1} cm^{-2}. Among the observed ~1200 targets, 343 objects show significant H\alpha emission lines. The gas-phase metallicity is obtained from [NII]\lambda 6584/H\alpha line ratio, after excluding possible active galactic nuclei (AGNs). Due to the faintness of the [NII]\lambda 6584 lines, we apply the stacking analysis and derive the mass-metallicity relation at z~1.4. Our results are compared to past results at different redshifts in the literature. The mass-metallicity relation at z~1.4 is located between those at z~0.8 and z~2.2; it is found that the metallicity increases with decreasing redshift from z~3 to z~0 at fixed stellar mass. Thanks to the large size of the sample, we can study the dependence of the mass-metallicity relation on various galaxy physical properties. The average metallicity from the stacked spectra is close to the local FMR in the higher metallicity part but >0.1 dex higher in metallicity than the FMR in the lower metallicity part. We find that galaxies with larger E(B-V), B-R, and R-H colours tend to show higher metallicity by ~0.05 dex at fixed stellar mass. We also find relatively clearer size dependence that objects with smaller half light radius tend to show higher metallicity by ~0.1 dex at fixed stellar mass, especially in the low mass part., Comment: 18 pages, 13 figures, 3 tables, MNRAS accepted

We present the results of deep K � -a ndJ-band imaging of the field of a proto-cluster region near the radio galaxy 53W002 at z =2 .390 with the Subaru Telescope. The data were analyzed together with deep optical and nearinfrared (NIR) images taken with the Hubble Space Telescope to investigate the properties of ten optically compact emission-line galaxies and candidates. Excluding the three objects which may contain active galactic nuclei, many are faint or undetected at K � (λrest ≈6000 u A), and are therefore revealed to be intrinsically small starbursting objects. On the other hand, we detect few objects with colors and magnitudes expected for quiescent massive galaxies at z =2 . 4i n the f ield.

We present spectroscopic observations of MWC 297 with medium spectral resolution in the 2.1-4.1 μ m region, that show the unusual emission band at 3.53 μ m as well as gaseous emission lines of the Brackett, Pfund and Humphrey series of hydrogen. A unique aspect of the measured 3.53 μ m emission band is the fact that, within our detection limit, it is not accompanied by the 3.3 and 3.4 μ m emission band. We suggest that the 3.53 μ m feature could be emitted by highly dehydrogenized carbonaceous dust particles that were processed under the influence of the strong radiation field of the central star.

Deep narrow- and broad-band near-infrared imaging observations of the central 2 � ×2 � region of the SSA 22 field were made with the near-infrared camera (CISCO) attached to the Subaru Telescope. Using a narrow-band filter centered at 2.033 µm, [O III] λ 5007 emitters at z ∼ 3.06 ±0.02 were searched to examine star-forming activities in an over-density region where a clustering of Lyman Break Galaxies (LBGs) and Lyman α emitter candidates around z =3 .09 was reported, though the targeted redshift is slightly different from that of the peak of the over-density region. Although one emitter candidate at z =3 .06 was detected, it is likely to be located at a redshift of between 1 and 2 judged based on multi-band photometry. Another emission-line object was detected in another narrowband filter (“off band” filter) centered at 2.120 µm, which is identified with a galaxy at z =0 .132 (the emission line is Paschen α). The K � -band imaging data revealed the presence of 12 Extremely Red Objects (EROs) with I814 −K � ≥4. The distribution of the EROs does not seem to coincide with that of Lyman Break Galaxies or Lyman α emitters at z ∼3. The magnitudes and colors of the EROs are not consistent with those of passively evolving massive elliptical galaxies at z ∼ 3. Candidates for counterparts of the submm sources detected with SCUBA are found; no EROs around the submm sources are found in our magnitude limit.

Deep optical and near-infrared galaxy counts are utilized to estimate the extragalactic background light (EBL) coming from normal galactic light in the universe. Although the slope of number-magnitude relation of the faintest counts is flat enough for the count integration to converge, considerable fraction of EBL from galaxies could still have been missed in deep galaxy surveys because of various selection effects including the cosmological dimming of surface brightness of galaxies. Here we give an estimate of EBL from galaxy counts, in which these selection effects are quantitatively taken into account for the first time, based on reasonable models of galaxy evolution which are consistent with all available data of galaxy counts, size, and redshift distributions. We show that the EBL from galaxies is best resolved into discrete galaxies in the near-infrared bands (J, K) by using the latest data of the Subaru Deep Field; more than 80-90% of EBL from galaxies has been resolved in these bands. Our result indicates that the contribution by missing galaxies cannot account for the discrepancy between the count integration and recent tentative detections of diffuse EBL in the K-band (2.2 micron), and there may be a very diffuse component of EBL which has left no imprints in known galaxy populations., ApJ Letters in press. Two new reports on the diffuse EBL at 1.25 and 2.2 microns are added to the reference list and Table 1

Deep near-infrared images of a blank 2'x2' section of sky near the Galactic north pole taken by Subaru Telescope are presented. The total integration times of the J and K' bands are 12.1 hours and 9.7 hours, resulting in 5-sigma limiting magnitudes of 25.1 and 23.5 mag, respectively. The numbers of sources within these limiting magnitudes found with an automated detection procedure are 385 in the J band and 350 in K'. Based on photometric measurements of these sources, we present number count vs. magnitude relations, color vs. magnitude diagrams, size vs. color relationships, etc. The slope of the galaxy number count plotted against the AB magnitude scale is about 0.23 in the 22 to 26 AB magnitude range of both bands. The spatial number density of galaxies as well as the slopes in the faint-end region given by the Subaru Deep Field (SDF) survey is consistent with those given by HST-NICMOS surveys as expressed on the AB magnitude diagram. Several sources having very large J-K' color are found including a few K' objects without detection at J. In addition, a number of faint Galactic stars are also detected, most of which are assigned to M-subdwarfs, together with a few brown dwarf candidates., 11 pages, 14 figures, to appear in Publ.Astr.Soc.Japan. The full ps file can be retrieved at ftp://ftp-cr.scphys.kyoto-u.ac.jp/pub/crmember/maihara/sdf/sdf.ps.gz

We construct infrared star count models of the Galaxy applicable at faint magnitudes. In addition to dwarfs and subdwarfs, we also take into account L dwarfs, T dwarfs, and white dwarfs of both disk and halo. As a test case of the models, we analyze the infrared imaging data at J and K' obtained during the Subaru Deep Field Survey to study stellar objects. Infrared star count models we have obtained predict that the Next Generation Space Telescope will primarily see T dwarfs, M subdwarfs, and old halo white dwarfs at faint magnitudes., 20 pages, 3 figures. To be published in the November 2000 issue of the Astronomical Journal

We present the results of the near-infrared spectroscopy of the Pluto-Charon system, conducted in the K band at two different sub-Earth longitudes. The spatially resolved images resulted in separated spectra with a spectral resolution of approximately 530. The spectrum of Charon showed a broad absorption feature at 2 /im during both orbital phases, suggesting a uniform distribution of water ice. In the separated spectrum of Pluto obtained in June, we confirmed the absorption bands of solid methane, carbon monoxide, and nitrogen ices. Additional weak dips have been found at 2.28, 2.32, and 2.40 /xm in the spectrum of the opposite side observed in May. In order to examine the carrier of these dips, we performed model calculations of the reflectance of Pluto using Hapke's bidirectional reflectance model for icy intimate mixtures. By adding a small amount of solid ethane into the mixture, we successfully reproduced the dips at 2.28 and 2.315 /im, but the absorption at 2.40 /xm is more distinct than that in the observed spectrum.

We have investigated the optical and near-infrared colors of K'-selected galaxies in clusters at z ~ 1.2 near to the radio galaxy 3C 324 using images obtained with the Subaru telescope and archival HST data. The distribution of colors of the galaxies in the cluster region is found to be fairly broad, and it may imply significant scatter in their star-formation histories, although the effect of contamination of field galaxies is uncertain. The red sequence of galaxies whose R-K colors are consistent with passive evolution models for old galaxies is found to be truncated at K' ~ 20 mag, and there are few fainter galaxies with similar red colors in the cluster region. We find that the bulge-dominated galaxies selected by quantitative morphological classification form a broad sequence in the color-magnitude diagram, whose slope is much steeper than that expected from metallicity variations within a passively evolving coeval galaxy population. We argue that the observed color-magnitude sequence can be explained by metallicity and age variations, and the fainter galaxies with K' > 20 mag may be 1-2 Gyr younger than the brighter galaxies. Some spatial segregation of the color and K'-band luminosity is seen in the sky distribution; the redder and the brighter objects tend to be located near 3C 324., 16 pages, 10 figures, accepted for publication in PASJ

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 the 2.12~$\mu$m narrow-band image of the Hubble Deep Field North taken with the near-infrared camera (CISCO) on the Subaru telescope. Among five targets whose H$\alpha$ or [O~{\sc iii}] emission lines are redshifted into our narrow-band range expected from their spectroscopic redshift, four of them have strong emission lines, especially for the two [O~{\sc iii}] emission-line objects. The remaining one target shows no H$\alpha$ emission in spite of its bright rest-UV luminosity, indicating that this object is already under the post-starburst phase. The volume-averaged $SFR$ derived from the detected two H$\alpha$ emission is roughly consistent with that evaluated from the rest-UV continuum., Comment: 12 pages, 7 figures. Accepted for publication in PASJ(2000)

We investigate the spectroscopic alteration through thermal annealing on the quenched carbonaceous composite (QCC) produced from hydrocarbon plasma. The emission and absorption spectra of QCC samples annealed at various temperatures indicate that the proportion of aliphatic C-H bonds in QCC decreases relative to aromatic C-H bonds with increase of annealing temperature. By comparing the spectra of annealed QCC with observed emission spectra of proto-planetary nebulae, similarity between the spectral sequence obtained in the laboratory and that in the observational data is clearly noticed. On this basis, we discuss a simple evolutional scenario of carbon dust in circumstellar environment around cool evolved stars.

We present the results of spectroscopic studies of Mrk 231 and NGC 4151 in the 3 /im region. In the spectrum of Mrk 231, the strengths of the 3.3 /im emission feature and the 3.4 /im carbonaceous absorption feature are smaller than expected. The weakness of the 3.3 /im emission feature implies that large fractions of extended H2 emission detected by Krabbe et al. (1997, AAA 67.158.058) are excited by SMBH-driven activities, and/or the 3.3 /im emission carriers in the circumnuclear starburst region are destroyed by being exposed to energetic radiation from SMBH-driven activities. The weakness of the 3.4 /im carbonaceous absorption feature may be due to the destruction of C-H stretching bonds in dust grains and/or lower abundance of C relative to Si, O, and Mg than that in our Galaxy, consistent to the fact that Mrk 231 is now undergoing starburst activities. In the spectrum of NGC 4151, we detect the broad Bra emission line, but do not detect the 3.3 /im emission feature nor the 3.4 /im carbonaceous absorption feature. The nondetection of the 3.3 /im emission feature implies that nuclear starburst activities just outside the obscuring torus are weak (LFIR < 3.7 x 10 9 L@).

We have developed a special grating capable of producing an echellogram (a spectrum arranged in raster form) in the 30th or even higher order in the near-infrared wavelength region. The grating substrate is made of an aluminum alloy that has been carved mechanically with a high-precision shaving machine. The optical efficiency, measured with a special spectrophotometer at about 2 μm, is ~70%. The diffuse light component, possibly attributable to scattering on the grating surface, has been estimated to be at most ~5% when the grating is incorporated in an actual spectrograph system. The measured efficiency of the fabricated grating is compared with that given by a numerical analysis. The comparison shows remarkable agreement in both the optical efficiency and the distribution of energy diffracted to various orders.

A 3.8 m segmented telescope is planned to be built at the Okayama Astrophysical Observatory by the joint program among Kyoto university, Nagoya university, NAOJ, and Nano-Optonics Energy Inc. This is the world’s first optical-infrared telescope whose primary mirror is composed of “petal-shaped” segment mirrors. To investigate the best layout of the displacement sensors as well as to study the control algorithm, we have developed a simulation software for the segmented petaloid mirrors. This simulator calculates the vertical position differences between the segments at the 60 displacement sensors based on the three-dimensional movements of the 54 actuators, and enables us to test the control algorithms under various conditions including random noise on the displacement sensors, random movement errors of the actuators, and unexpected lateral shifts of the segments. The outputs of the simulator are not only the phase error of the primary mirror but also the PSF image, taking the structure function of the optical surfaces into account. Using a singular value decomposition method, we found that the 18 petal-shaped segments are controllable within the required displacement errors of 15 nm under the following three conditions: 1) the displacement measurement sensors are placed in staggered fashion between segments, 2) the displacement measurement sensors are axisymmetrically placed with respect to the optical axis, and 3) the relative lateral shift and rotation of each segment are less than 500 μm and 0.05 degree, respectively. In this report, the control algorithm, requirements for the layout of the displacement measurement sensors, and the simulated performance will be presented.

Fiber Multi Object Spectrograph \FMOS" on Subaru Telescope is capable of con guring 400 bers on the 30-arcmin diameter eld of view at the prime focus for near-infrared (0.9{1.8 m) spectroscopy, and this instrumenthas been open as a common-use instrument since May 2010. In this article, an overview of the instrument isgiven rst, and then the typical operational sequence in science observation and a few notable features of theinstrument are explained. In x 5, the instrument performance in terms of ber positioning, auto guiding, andsensitivity to emission lines are highlighted. Recently (since March 2012) a Subaru Strategic Program (SSP)has started with FMOS to conduct a wide- eld galaxy survey for a cosmological experiment. Upgrading bercon guration by using a \metrology camera" has also been under discussion, which will enable to measure thepositions of the 400 bers quickly and shorten the ber con guration time signi cantly. We will also report thestatus of these recent activities.Keywords: Subaru Telescope, multiobject spectroscopy, optical bers, near infrared

Accepted: 1993-08-13, 資料番号: SA1001315000

Interstellar [CII] and [OI] lines have been observed by the Balloon-Borne Infrared Telescope (BIRT) in corporation with a Fabry-Perot spectrometer. Two balloon flights were successfully made from Palestine, Texas in May/June 1988. With a new method of “frequency switching”, diffuse [CII] line emission was efficiently detected and mapped in extended regions around HII/molecular cloud complexes and in a wide area of the Galactic plane. It has been shown that the [CII] emission is very strong and ubiquitously distributed in interstellar space in the Galaxy.

We evaluated depth of subsurface damage on a ground surface of the ultra low expansion glass-ceramics CLEARCERAMR®-Z HS (CC-Z HS) by Ohara Inc., which is one of the candidates for material for segmented mirrors of the Thirty Meter Telescope. We made polishing spots of Magnetorheological Finishing on the ground surface of CC-Z HS and measured exposed subsurface damage features on the spot surface. We also studied on hydrofluoric acid etching of the CC-Z HS ground surface, which is expected to be an effective method to remove a subsurface damage layer compared with time-consuming polishing. We etched small ground surfaces of CC-Z HS and evaluated its uniformity.

The Fibre Multi-Object Spectrograph for Subaru Telescope (FMOS) is a near-infrared instrument with 400 fibres in a 30' filed of view at F/2 prime focus. To observe 400 objects simultaneously, we have developed a fibre positioner called "Echidna" using a tube piezo actuator. We have also developed two OH-airglow suppressed and refrigerated spectrographs. Each spectrograph has two spectral resolution modes: the low-resolution mode and the high-resolution mode. The low-resolution mode covers the complete wavelength range of 0.9 - 1.8 μm with one exposure, while the high-resolution mode requires four exposures at different camera positions to cover the full wavelength range. The first light was accomplished in May 2008. The science observations and the open-use observations begin in May 2010. © 2010 Copyright SPIE - The International Society for Optical Engineering.

Accepted: 1991-07-28, 資料番号: SA1001345000

Accepted: 1990-12-11, 資料番号: SA1001308000

Fibre Multi-Object Spectrograph (FMOS) is the next common-use instrument of Subaru Telescope. FMOS consists of three subsystems; the Prime focus unit for Infrared (PIR), the fibre positioning system/connector units, and the two infrared spectrographs. The PIR was transferred to the Subaru Observatory in the spring of 2005 to check the optical performance on the telescope. As a result of the test observation, we found that the adjustment of the optical axis between PIR and the primary mirror was difficult with the initial design of the corrector alignment stage. Furthermore, the optical axis of the telescope moved over a little owing to an earthquake in Hawaii Island in Oct. 2006. Therefore we decided to modify mechanical structure of PIR, the corrector alignment stage as well as the cable wrapping system. This modification was completed in the summer of 2007. In this proceeding, we report the mechanical structure of the new PIR and the results of the engineering observations.

FMOS: the Fiber Multiple-Object Spectrograph is the next common-use instrument of the Subaru Telescope, having a capability of 400 targets multiplicity in the near-infrared 0.9-1.8μm wavelength range with a field coverage of 30- diameter. FMOS consists of three units: 1) the prime focus unit including the corrector lenses, the Echidna fiber positioner, and the instrument-bay to adjust the instrument focus and shift the axis of the corrector lens system, 2) the fiber bundle unit equipping two fiber slits on one end and a fiber connector box with the back-illumination mechanism on the other end on the bundle, 3) the two infrared spectrographs (IRS1 and IRS2) to obtain 2×200 spectra simultaneously. After all the components were installed in the telescope at the end of 2007, the total performance was checked through various tests and engineering observations. We report the results of these tests and demonstrate the performance of FMOS.

We present the results of NICMOS imaging of two massive galaxies photometrically selected to have old stellar populations at z ~ 2.5. Both galaxies are dominated by apparent disks of old stars, although one of them also has a small bulge comprising about 1/3 of the light at rest-frame 4800 A. The presence of massive disks of old stars at high redshift means that at least some massive galaxies in the early universe have formed directly from the dissipative collapse of a large mass of gas. The stars formed in disks like these may have made significant contributions to the stellar populations of massive spheroids at the present epoch., Accepted by ApJ; 8 pages, 8 figures, emulateapj format; replaced Fig. 6 with correct version

We have examined in detail the morphologies of seven z~1.5 passively evolving luminous red galaxies using high resolution HST NICMOS and ACS imaging data. Almost all of these galaxies appear to be relaxed systems, with smooth morphologies at both rest-frame UV and visible wavelengths. Previous results from spectral synthesis modeling favor a single burst of star formation more than 1 Gyr before the observed epoch. The prevalence of old stellar populations, however, does not correlate exclusively with early-type morphologies as it does in the local universe; the light profiles for some of these galaxies appear to be dominated by massive exponential disks. This evidence for massive old disks, along with the apparent uniformity of stellar age across the disk, suggests formation by a mechanism better described as a form of monolithic collapse than as a hierarchical merger. These galaxies could not have undergone a single major merging event since the bulk of their stars were formed, more than 1 Gyr earlier. There is at least one case, however, that appears to be undergoing a "dry merger", which may be an example of the process that converts these unusual galaxies into the familiar spheroids that dominate galaxies comprising old stellar populations at the present epoch., Comment: 16 pages, 9 figures (8 in color), accepted for publication in ApJ

Fibre Multi-Object Spectrograph (FMOS) is one of the second-generation instruments of Subaru Telescope. FMOS is consisted of a number of subsystems; the Prime focus unit for IR (called PIR), the fibre positioning system/connector units, and the two spectrographs. The PIR and one spectrograph were made in Kyoto University, and were brought to the Subaru telescope last spring. The PIR attached to the telescope and stellar images were obtained for optical alignment in July and October last year. We report on these engineering run in this proceeding.

The Fiber Multiple-Object Spectrograph for Subaru Telescope (FMOS) is quite large instrument composed of the prime focus unit, the fiber bundle unit, and the two infrared spectrographs. Among these units, a part of the prime focus unit and one of the spectrograph were transported from Kyoto University to the Subaru Observatory in the middle of 2005. We present the optical and the mechanical components of the spectrograph, which was reassembled on the new floor of the Subaru dome. We also show the preliminary results of the optical alignment and the cooling test of the instrument at the summit of Mauna Kea.

We have carried out near-infrared JHK spectroscopy of a gravitationally lensed submillimeter galaxy SMM J14011+0252 at z=2.565, using OHS and CISCO on the Subaru telescope. This object consists of two optical components, J1 and J2, which are lensed by the cluster Abell 1835. J1 suffers additional strong lensing by a foreground galaxy at z=0.25 in the cluster. The rest-optical H-alpha, H-beta, and [O II]3727 lines are detected in both J1 and J2, and [N II]6548,6583 lines are also detected in J1. A diagnosis of emission-line ratios shows that the excitation source of J1 is stellar origin, consistent with previous X-ray observations. The continua of J1 and J2 show breaks at rest 4000A, indicating relatively young age. Combined with optical photometry, we have carried out model spectrum fitting of J2 and find that it is a very young (~50 Myr) galaxy of rather small mass (~10e8 M_sol) which suffers some amount of dust extinction. A new gravitational lensing model is constructed to assess both magnification factor and contamination from the lensing galaxy of the component J1, using HST-F702W image. We have found that J1 suffers strong lensing with magnification of ~30, and its stellar mass is estimated to be < 10e9 M_sol. These results suggest that SMM J14011+0252 is a major merger system at high redshift that undergoes intense star formation, but not a formation site of a giant elliptical. Still having plenty of gas, it will transform most of the gas into stars and will evolve into a galaxy of < 10e10 M_sol. Therefore, this system is possibly an ancestor of a less massive galaxy such as a mid-sized elliptical or a spiral at the present., 21 pages, 11 figures. Accepted for publication in Astronomical Journal