Search

We find multiple Mg II absorption systems at redshift z=1.66, 2.069, and 2.097 in the spatially resolved spectra of the quadruply gravitationally lensed quasar H1413+1143 utilizing the Kyoto tridimensional spectrograph II (Kyoto 3DII) spectrograph on board the Subaru telescope. Here we present the first measurement of differences in Mg II absorption strength of the multiple intervening absorbers, which include ones identified as damped Lyman alpha (DLA) absorption systems. Our detection of the significant Mg II absorptions in the spatially resolved spectra reveals the inhomogeneous chemical enrichment on scales of about 12 kpc within the separation of the four sightlines. For the DLA system at z=1.66, the rest equivalent widths of the Mg II absorption lines between the four spatially resolved lines of sight change by factors of up to about 6, which trace the variations in the H I absorption strength. This suggests that inhomogeneous cold absorbers that give rise to the strong H I/Mg II absorptions dwell on a scale of about 6-12 kpc between the four lines of sight. We also investigate the degree of variation in the equivalent width of the absorption lines between the lines of sight. We find that the systems giving rise to strong absorptions in the spectra of the quadruply lensed quasars tend to have a high degree of variation in absorption strength between the lines of sight toward the lensed quasars., Comment: 21 pages, 13 figures, and 3 tables Accepted for publication in the Astronomical Journal

We report the initial result of an adaptive-optics assisted, optical integral-field-unit observation on IRAS04576+0912, the nearest (z=0.039) active galactic nucleus with a prominent blueshift/tail in [O III] emission from a sample of such objects that we have collected from the literature. We aim at addressing the putative quasar-mode feedback process with Subaru/Kyoto 3D II+AO188. The optical waveband (6400--7500 AA) enables us to measure the gas density via the [S II] doublets, in contrast to earlier Near-IR studies. Since the fast [O III] outflow happens only around rapidly growing central black holes, this object is suitable for investigating the black hole-galaxy coevolution. The obtained data cube exhibits blue tail in the [S II] emission at many lenslets. By fitting the spectrum with the high excess flux at the [S II] blue tail, we find the fast (~ 860 km/s), dense (>3000/cc), wide-angle and offset outflow in central 100-pc scales. Although the large opening angle and the high gas outflow-to-accretion ratio may favour the feedback hypothesis, the inferred kinetic power injection rate of this ionized gas outflow seems insufficient to influence the whole host galaxy. A conventional assumption of a low density must have overestimated the feedback process., 7 pages, 2 figures, Accepted for publication in PASJ

The Prime Focus Spectrograph (PFS) of the Subaru Measurement of Images and Redshifts (SuMIRe) project for Subaru telescope includes four identical spectrograph modules fed by 600 fibers each. This paper presents the integration, alignment and test procedures for the first spectrograph module composed by an optical entrance unit that creates a collimated beam and distributes the light to three channels, two visible and one near infrared. In particular, we present the performance of the single Red channel module. Firstly, we report on the measured optical performance: optical quality and ghost analysis. We also report on the thermal performance of the visible camera cryostat. Finally, we describe the software used to control and monitor the instrument.

The Prime Focus Spectrograph (PFS) is a new optical/near-infrared multi-fiber spectrograph designed for the prime focus of the 8.2m Subaru telescope. PFS will cover a 1.3 degree diameter field with 2394 fibers to complement the imaging capabilities of Hyper SuprimeCam. To retain high throughput, the final positioning accuracy between the fibers and observing targets of PFS is required to be less than 10 μm. The metrology camera system (MCS) serves as the optical encoder of the fiber positioners for the configuring of fibers. MCS provides the fiber positions within a 5 microns error over the 45 cm focal plane. The information from MCS will be fed into the fiber positioner control system for the closed loop control. MCS locates at the Cassegrain focus of Subaru telescope to cover the whole focal plan with one 50M pixel Canon CMOS camera. It is a 380 mm aperture Schmidt type telescope which generates uniform spot size around 10 µm FWHM across the field for reasonable sampling of the point spreading function. An achromatic lens set is designed to remove the possible chromatic error due to the variation of the LED wavelength. Carbon fiber tubes are used to provide stable structure over the operation conditions without focus adjustments. The CMOS sensor can be read in 0.8 s to reduce the overhead for the fiber configuration. The positions of all fibers can be obtained within 0.5 s after the readout of the frame. This enables the overall fiber configuration to be less than 2 minutes. MCS is installed inside a standard Subaru Cassgrain Box. All components generate heat are located inside a glycol cooled cabinet to reduce the possible image motion due to the heat. The integration of MCS started from fall 2017 and it was delivered to Subaru in April 2018. In this report, the performance of MCS after the integration and verification process in ASIAA and the performance after the delivery to Subaru telescope are presented.

The Prime Focus Spectrograph (PFS) is a new optical/near-infrared multi-fiber spectrograph designed for the prime focus of the 8.2m Subaru telescope. PFS will cover a 1.3-degree diameter field with 2394 fibers to complement the imaging capability of Hyper SuprimeCam (HSC). The Fiber Positioning System (FPS) is an automated system that controls the sequences for the operation of the PFS subsystems to achieve accurate positioning of the science fibers for astronomical observations. FPS will be operated continuously for 14 hours a night and accomplish the fiber positioning sequence every 15 minutes. The success rate of each alignment should be 95% or more and FPS should finish the fiber alignment procedure in 105 seconds. A fast centroid algorithm is implemented for measuring 2349 fiber spots within 1 second. In this report, the latest status of the development of FPS system will be given, including the system performance and closed-loop simulations.

PFS (Prime Focus Spectrograph), a next generation facility instrument on the 8.2-meter Subaru Telescope, is a very wide-field, massively multiplexed, optical and near-infrared spectrograph. Exploiting the Subaru prime focus, 2394 reconfigurable fibers will be distributed over the 1.3 deg field of view. The spectrograph has been designed with 3 arms of blue, red, and near-infrared cameras to simultaneously observe spectra from 380nm to 1260nm in one exposure at a resolution of ~ 1.6-2.7Å. An international collaboration is developing this instrument under the initiative of Kavli IPMU. The project recently started undertaking the commissioning process of a subsystem at the Subaru Telescope side, with the integration and test processes of the other subsystems ongoing in parallel. We are aiming to start engineering night-sky operations in 2019, and observations for scientific use in 2021. This article gives an overview of the instrument, current project status and future paths forward.

Hyper Suprime-Cam (HSC) is a wide-field imaging camera on the prime focus of the 8.2m Subaru telescope on the summit of Maunakea in Hawaii. A team of scientists from Japan, Taiwan and Princeton University is using HSC to carry out a 300-night multi-band imaging survey of the high-latitude sky. The survey includes three layers: the Wide layer will cover 1400 deg$^2$ in five broad bands ($grizy$), with a $5\,\sigma$ point-source depth of $r \approx 26$. The Deep layer covers a total of 26~deg$^2$ in four fields, going roughly a magnitude fainter, while the UltraDeep layer goes almost a magnitude fainter still in two pointings of HSC (a total of 3.5 deg$^2$). Here we describe the instrument, the science goals of the survey, and the survey strategy and data processing. This paper serves as an introduction to a special issue of the Publications of the Astronomical Society of Japan, which includes a large number of technical and scientific papers describing results from the early phases of this survey., Comment: 14 pages, 7 figures, 5 tables. Corrected for a typo in the coordinates of HSC-Wide spring equatorial field in Table 5

The Kyoto Tridimensional Spectrograph II (Kyoto 3DII) is an optical integral field spectrograph mounted on the Subaru telescope as a PI-type instrument. Used with AO188, Kyoto 3DII provides us unique opportunities of optical Integral Field Spectroscopy (IFS) with adaptive optics (AO). While AO works better in redder wavelength regions, quantum efficiency of the previous CCD was low there with optimization for a wider wavelength coverage. To optimize Kyoto 3DII to AO observations, we have newly installed the red-sensitive Hamamatsu fully depleted CCD, which enhances the system efficiency by a factor of ~2 in the red wavelength range. Fringes are dramatically reduced, and the readout noise drops to 3:2-3:4e- about two times smaller than previous, due to refrigerator and readout system. With these improvements, we carried out engineering and scientific observations in September 2015, February and March 2016. We measured the system efficiency using a standard star, and confirmed the successful improvement of the system efficiency. We observed galactic nuclei of nearby galaxies in the Natural Guide Star (NGS) and the Laser Guide Star (LGS) modes. We found the spatial resolution of ~0.1′′ FWHM using a 9.5-magnitude NGS, and ~0.2 - 0:4′′ in LGS mode. Together with the AO resolution, improved efficiency opens a new window for Kyoto 3DII to carry out high resolution optical IFS targeting faint objects such as high-redshift galaxies as well as faint lines such as [OI] λ6300° A and absorption lines of nearby objects.

We describe the design and performance of the SuMIRe Prime Focus Spectrograph (PFS) visible camera cryostats. SuMIRe PFS is a massively multi-plexed ground-based spectrograph consisting of four identical spectrograph modules, each receiving roughly 600 fibers from a 2394 fiber robotic positioner at the prime focus. Each spectrograph module has three channels covering wavelength ranges 380~nm -- 640~nm, 640~nm -- 955~nm, and 955~nm -- 1.26~um, with the dispersed light being imaged in each channel by a f/1.07 vacuum Schmidt camera. The cameras are very large, having a clear aperture of 300~mm at the entrance window, and a mass of $\sim$280~kg. In this paper we describe the design of the visible camera cryostats and discuss various aspects of cryostat performance.

The Prime Focus Spectrograph (PFS) is a new optical/near-infrared multi-fiber spectrograph designed for the prime focus of the 8.2m Subaru telescope. PFS will cover a 1.3 degree diameter field with 2394 fibers to complement the imaging capabilities of Hyper SuprimeCam. To retain high throughput, the final positioning accuracy between the fibers and observing targets of PFS is required to be less than 10 microns. The metrology camera system (MCS) serves as the optical encoder of the fiber motors for the configuring of fibers. MCS provides the fiber positions within a 5 microns error over the 45 cm focal plane. The information from MCS will be fed into the fiber positioner control system for the closed loop control. MCS will be located at the Cassegrain focus of Subaru telescope in order to cover the whole focal plane with one 50M pixel Canon CMOS camera. It is a 380mm Schmidt type telescope which generates a uniform spot size with a ~10 micron FWHM across the field for reasonable sampling of the point spread function. Carbon fiber tubes are used to provide a stable structure over the operating conditions without focus adjustments. The CMOS sensor can be read in 0.8s to reduce the overhead for the fiber configuration. The positions of all fibers can be obtained within 0.5s after the readout of the frame. This enables the overall fiber configuration to be less than 2 minutes. MCS will be installed inside a standard Subaru Cassgrain Box. All components that generate heat are located inside a glycol cooled cabinet to reduce the possible image motion due to heat. The optics and camera for MCS have been delivered and tested. The mechanical parts and supporting structure are ready as of spring 2016. The integration of MCS will start in the summer of 2016. In this report, the performance of the MCS components, the alignment and testing procedure as well as the status of the PFS MCS will be presented.

We present the test results of science grade substrate-removed 4K×4K HgCdTe H4RG-15 NIR 1.7 μm and SWIR 2.5 μm sensor chip assemblies (SCAs). Teledyne’s 4K×4K, 15 μm pixel pitch infrared array, which was developed for the era of Extremely Large Telescopes, is first being used in new instrumentation on existing telescopes. We report the data on H4RG-15 arrays that have achieved science grade performance: very low dark current ( 97%, total crosstalk 70 ke-, and power dissipation less than 4 mW. These SCAs are substrate-removed HgCdTe which simultaneously detect visible and infrared light, enabling spectrographs to use a single SCA for Visible-IR sensitivity. Larger focal plane arrays can be constructed by assembling mosaics of individual arrays.

PFS (Prime Focus Spectrograph), a next generation facility instrument on the 8.2-meter Subaru Telescope, is a very wide-field, massively multiplexed, optical and near-infrared spectrograph. Exploiting the Subaru prime focus, 2394 reconfigurable fibers will be distributed over the 1.3 deg field of view. The spectrograph has been designed with 3 arms of blue, red, and near-infrared cameras to simultaneously observe spectra from 380nm to 1260nm in one exposure at a resolution of ~1.6-2.7A. An international collaboration is developing this instrument under the initiative of Kavli IPMU. The project is now going into the construction phase aiming at undertaking system integration in 2017-2018 and subsequently carrying out engineering operations in 2018-2019. This article gives an overview of the instrument, current project status and future paths forward., 17 pages, 10 figures. Proceeding of SPIE Astronomical Telescopes and Instrumentation 2016

The Prime Focus Spectrograph (PFS) is a new optical/near-infrared multi-fiber spectrograph design for the prime focus of the 8.2m Subaru telescope. PFS will cover 1.3 degree diameter field with 2394 fibers to complement the imaging capability of Hyper SuprimeCam (HSC). The prime focus unit of PFS called Prime Focus Instrument (PFI) provides the interface with the top structure of Subaru telescope and also accommodates the optical bench in which Cobra fiber positioners are located. In addition, the acquisition and guiding cameras (AGCs), the optical fiber positioner system, the cable wrapper, the fiducial fibers, illuminator, and viewer, the field element, and the telemetry system are located inside the PFI. The mechanical structure of the PFI was designed with special care such that its deflections sufficiently match those of the HSC's Wide Field Corrector (WFC) so the fibers will stay on targets over the course of the observations within the required accuracy. In this report, the latest status of PFI development will be given including the performance of PFI components, the setup and performance of the integration and testing equipment., 9 pages, 8 figures, SPIE proceeding

The Prime Focus Spectrograph (PFS) is a wide-field, multi-object spectrograph accommodating 2394 fibers to observe the sky at the prime focus of the Subaru telescope. The software system to operate a spectroscopic survey is structured by the four packages: Instrument control software, exposure targeting software, data reduction pipeline, and survey planning and tracking software. In addition, we operate a database system where various information such as properties of target objects, instrument configurations, and observation conditions is stored and is organized via a standardized data model for future references to update survey plans and to scientific researches. In this article, we present an overview of the software system and describe the workflows that need to be performed in the PFS operation, with some highlights on the database that organizes various information from sub-processes in the survey operation, and on the process of fiber configuration from the software perspectives., Comment: 9 pages, 5 figures; SPIE (2016) 9913-88

By using the Integral Field Spectroscopy mode of the Kyoto Tri-dimensional Spectrograph II we have mapped the two-dimensional distribution of kinematics in a wide variety of emission lines in the narrow-line region of NGC 4151. We decomposed the emission lines and defined two components: a narrow component and a broad component. The narrow component has smaller FWHM values, and is spatially more extended than the broad component. We applied a simple model to each component, a rotation in the galactic plane for the narrow component and a biconical outflow model for the broad one. The two-dimensional velocity distributions of the narrow component was well-fitted to a normal rotation in the galactic plane, with the best-fit parameters being similar among the emission lines. We found that the residual maps show similar large positive values at a knot around 6 00 southwest form the nucleus. For the central region, excluding the knot, the velocity field was fitted better, and the residual was small as the relative wavelength-calibration accuracy of the instrument among lenslets. We modeled the broad component with a simple biconical outflow axisymmetrical with respect to its axis by assuming a constant outflowing velocity, a constant FWHM value, and the emission line strength declining according to a power law with the distance from the nucleus. The best-fit model suggests that PA for the axis of the biconical outflow is close to the direction of the [O III] line emission elongation. Our line of sight was included within the outflowing bicone, which had filled cones.

In order to investigate physical conditions of ionized gas in galaxies, as well as its kinematics, we have developed the Kyoto tridimensional spectrograph II. It is a multimode optical instrument, including integral field spectrograph (IFS) and Fabry-Perot imager modes. We have designed it compact so that we can mount it on 2 m class telescopes as well as on the 8.2 m Subaru telescope. Special care was taken to obtain high-quality calibrations in the IFS mode. In order to remove the chromatic aberration of micropupil images produced by a lenslet array, we have introduced a corrector lens system behind the lenslet array. The internal calibration system simulates the telescope optics so that the system provides micropupil images identical to those produced by the telescope. The rigidness of the instrument provides the positional stability of micropupil images. We have succeeded in test observations of all the modes on Subaru and the University of Hawaii 88 in (UH88) telescopes and have verified the performance of the instrument. This includes the instrument efficiencies as well as the effective sky background subtraction and the minimization of crosstalk effects in the IFS mode. In the IFS mode a spatial resolution of 0.4'' was obtained in good seeing conditions. Each of 37 × 37 lenslets subtends 0.1'' in Subaru's case. This samples the image size well. A wider field of view is emphasized in the case of UH88.

We have performed a two-dimensional spectroscopy of three nearby E+A (post-starburst) galaxies with the Kyoto3DII integral field spectrograph. In all the cases, Hdelta absorption is stronger at the centre of the galaxies, but significantly extended in a few kpc scale. For one galaxy (J1656), we found a close companion galaxy at the same redshift. The galaxy turned out to be a star-forming galaxy with a strong emission in Hgamma. For the other two galaxies, we have found that the central post-starburst regions possibly extend toward the direction of the tidal tails. Our results are consistent with the merger/interaction origin of E+A galaxies, where the infalling-gas possibly caused by a galaxy-galaxy merging creates a central-starburst, succeeded by a post-starburst (E+A) phase once the gas is depleted.

We have observed the quadruply lensed quasar 1RXS J1131-1231 with the integral field spectrograph mode of the Kyoto Tridimensional Spectrograph II mounted on the Subaru telescope. Its field of view has covered simultaneously the three brighter lensed images A, B, and C, which are known to exhibit anomalous flux ratios in their continuum emission. We have found that the [OIII] line flux ratios among these lensed images are consistent with those predicted by smooth-lens models. The absence of both microlensing and millilensing effects on this [OIII] narrow line region sets important limits on the mass of any substructures along the line of sight, which is expressed as M_E < 10^5 M_solar for the mass inside an Einstein radius. In contrast, the H_beta line emission, which originates from the broad line region, shows an anomaly in the flux ratio between images B and C, i.e., a factor two smaller C/B ratio than predicted by smooth-lens models. The ratio of A/B in the H_beta line is well reproduced. We show that the anomalous C/B ratio for the H_beta line is caused most likely by micro/milli-lensing of image C. This is because other effects, such as the differential dust extinction and/or arrival time difference between images B and C, or the simultaneous lensing of another pair of images A and B, are all unlikely. In addition, we have found that the broad H_beta line of image A shows a slight asymmetry in its profile compared with those in the other images, which suggests the presence of a small microlensing effect on this line emitting region of image A., 21 pages, 7 figures, 1 table, ApJ accepted

The Kyoto tridimensional spectrograph II is a multimode spectrograph. It is so far the only spectrograph with Fabry–Perot and/or integral field spectrograph (IFS) modes that is mounted on the Subaru Telescope. Its pixel/lenslet sampling matches Subaru’s excellent image quality. This compact spectrograph is also used at the UH 88-inch telescope. Possible merits of lenslet IFS’s are discussed.

We present the H$\alpha$ intensity map of the host galaxy of the repeating fast radio burst FRB 121102 at a redshift of z=0.193 obtained with the AO-assisted Kyoto 3DII optical integral-field unit mounted on the 8.2-m Subaru Telescope. We detected a compact H$\alpha$-emitting (i.e., star-forming) region in the galaxy, which has a much smaller angular size [$< 0".57$ (1.9 kpc) at full width at half maximum (FWHM)] than the extended stellar continuum emission region determined by the Gemini/GMOS z'-band image [$\simeq 1".4$ (4.6 kpc) at FWHM with ellipticity b/a=0.45]. The spatial offset between the centroid of the H$\alpha$ emission region and the position of the radio bursts is $0".08 \pm 0".02$ ($0.26 \pm 0.07$ kpc), indicating that FRB 121102 is located within the star-forming region. This close spatial association of FRB 121102 with the star-forming region is consistent with expectations from young pulsar/magnetar models for FRB 121102, and it also suggests that the observed H$\alpha$ emission region can make a major dispersion measure (DM) contribution to the host galaxy DM component of FRB 121102. Nevertheless, the largest possible value of the DM contribution from the H$\alpha$ emission region inferred from our observations still requires a significant amount of ionized baryons in intergalactic medium (the so-called `missing' baryons) as the DM source of FRB 121102, and we obtain a 90\% confidence level lower limit on the cosmic baryon density in the intergalactic medium in the low-redshift universe as $\Omega_{IGM} > 0.012$., Comment: 11 pages, 5 figures, and 1 table, accepted for publication in the Astrophysical Journal 2017 June 20

The Prime Focus Spectrograph (PFS) is an optical/near-infrared multi-fiber spectrograph with 2394 science fibers, which are distributed in 1.3 degree diameter field of view at Subaru 8.2-meter telescope. The simultaneous wide wavelength coverage from 0.38 um to 1.26 um, with the resolving power of 3000, strengthens its ability to target three main survey programs: cosmology, Galactic archaeology, and galaxy/AGN evolution. A medium resolution mode with resolving power of 5000 for 0.71 um to 0.89 um also will be available by simply exchanging dispersers. PFS takes the role for the spectroscopic part of the Subaru Measurement of Images and Redshifts project, while Hyper Suprime-Cam works on the imaging part. To transform the telescope plus WFC focal ratio, a 3-mm thick broad-band coated glass-molded microlens is glued to each fiber tip. A higher transmission fiber is selected for the longest part of cable system, while one with a better FRD performance is selected for the fiber-positioner and fiber-slit components, given the more frequent fiber movements and tightly curved structure. Each Fiber positioner consists of two stages of piezo-electric rotary motors. Its engineering model has been produced and tested. Fiber positioning will be performed iteratively by taking an image of artificially back-illuminated fibers with the Metrology camera located in the Cassegrain container. The camera is carefully designed so that fiber position measurements are unaffected by small amounts of high special-frequency inaccuracies in WFC lens surface shapes. Target light carried through the fiber system reaches one of four identical fast-Schmidt spectrograph modules, each with three arms. Prototype VPH gratings have been optically tested. CCD production is complete, with standard fully-depleted CCDs for red arms and more-challenging thinner fully-depleted CCDs with blue-optimized coating for blue arms., 14 pages, 12 figures, submitted to "Ground-based and Airborne Instrumentation for Astronomy V, Suzanne K. Ramsay, Ian S. McLean, Hideki Takami, Editors, Proc. SPIE 9147 (2014)"

We present the detailed design of the near infrared camera for the SuMIRe (Subaru Measurement of Images and Redshifts) Prime Focus Spectrograph (PFS) being developed for the Subaru Telescope. The PFS spectrograph is designed to collect spectra from 2394 objects simultaneously, covering wavelengths that extend from 380 nm - 1.26 um. The spectrograph is comprised of four identical spectrograph modules, with each module collecting roughly 600 spectra from a robotic fiber positioner at the telescope prime focus. Each spectrograph module will have two visible channels covering wavelength ranges 380 nm - 640 nm and 640 nm - 955 nm, and one near infrared (NIR) channel with a wavelength range 955 nm - 1.26 um. Dispersed light in each channel is imaged by a 300 mm focal length, f/1.07, vacuum Schmidt camera onto a 4k x 4k, 15 um pixel, detector format. For the NIR channel a HgCdTe substrate-removed Teledyne 1.7 um cutoff device is used. In the visible channels, CCDs from Hamamatsu are used. These cameras are large, having a clear aperture of 300 mm at the entrance window, and a mass of ~ 250 kg. Like the two visible channel cameras, the NIR camera contains just four optical elements: a two-element refractive corrector, a Mangin mirror, and a field flattening lens. This simple design produces very good imaging performance considering the wide field and wavelength range, and it does so in large part due to the use of a Mangin mirror (a lens with a reflecting rear surface) for the Schmidt primary. In the case of the NIR camera, the rear reflecting surface is a dichroic, which reflects in-band wavelengths and transmits wavelengths beyond 1.26 um. This, combined with a thermal rejection filter coating on the rear surface of the second corrector element, greatly reduces the out-of-band thermal radiation that reaches the detector., Submitted to the 2014 SPIE Astronomical Telescopes + Instrumentation conference, Montreal, Quebec, Canada

FOCCoS, Fiber Optical Cable and Connector System, has the main function of capturing the direct light from the focal plane of Subaru Telescope using optical fibers, each one with a microlens in its tip, and conducting this light through a route containing connectors to a set of four spectrographs. The optical fiber cable is divided in 3 different segments called Cable A, Cable B and Cable C. Multi-fibers connectors assure precise connection among all optical fibers of the segments, providing flexibility for instrument changes. To assure strong and accurate connection, these sets are arranged inside two types of assemblies: the Tower Connector, for connection between Cable C and Cable B; and the Gang Connector, for connection between Cable B and Cable A. Throughput tests were made to evaluate the efficiency of the connections. A lifetime test connection is in progress. Cable C is installed inside the PFI, Prime Focus Instrument, where each fiber tip with a microlens is bonded to the end of the shaft of a 2-stage piezo-electric rotatory motor positioner; this assembly allows each fiber to be placed anywhere within its patrol region, which is 9.5mm diameter.. Each positioner uses a fiber arm to support the ferrule, the microlens, and the optical fiber. 2400 of these assemblies are arranged on a motor bench plate in a hexagonal-closed-packed disposition., 11 pages, 20 figures

The Prime Focus Spectrograph (PFS) is a new optical/near-infrared multi-fiber spectrograph design for the prime focus of the 8.2m Subaru telescope. PFS will cover 1.3 degree diameter field with 2394 fibers to complement the imaging capability of Hyper SuprimeCam (HSC). The prime focus unit of PFS called Prime Focus Instrument (PFI) provides the interface with the top structure of Subaru telescope and also accommodates the optical bench in which Cobra fiber positioners are located. In addition, the acquisition and guiding (A&G) cameras, the optical fiber positioner system, the cable wrapper, the fiducial fibers, illuminator, and viewer, the field element, and the telemetry system are located inside the PFI. The mechanical structure of the PFI was designed with special care such that its deflections sufficiently match those of the HSC Wide Field Corrector (WFC) so the fibers will stay on targets over the course of the observations within the required accuracy., 9 pages, 7 figures, SPIE Astronomical Telescopes and Instrumentation 2014

The Prime Focus Spectrograph (PFS) is a new optical/near-infrared multi-fiber spectrograph designed for the prime focus of the 8.2m Subaru telescope. The metrology camera system of PFS serves as the optical encoder of the COBRA fiber motors for the configuring of fibers. The 380mm diameter aperture metrology camera will locate at the Cassegrain focus of Subaru telescope to cover the whole focal plane with one 50M pixel Canon CMOS sensor. The metrology camera is designed to provide the fiber position information within 5{\mu}m error over the 45cm focal plane. The positions of all fibers can be obtained within 1s after the exposure is finished. This enables the overall fiber configuration to be less than 2 minutes., Comment: 10 pages, 12 figures, SPIE Astronomical Telescopes and Instrumentation 2014

The PFS is a multi-object spectrograph fed by 2394 fibers at the prime focus of Subaru telescope. Since the F/# at the prime focus is too fast for the spectrograph, we designed a small concave-plano negative lens to be attached to the tip of each fiber that converts the telescope beam (F/2.2) to F/2.8. We optimized the lens to maximize the number of rays that can be confined inside F/2.8 while maintaining a 1.28 magnification. The microlenses are manufactured by glass molding, and an ultra-broadband AR coating (, 7 pages, 8 figures, SPIE2014

Adaptive optics (AO) enables us to observe objects with high spatial resolution, which is important in most astrophysical observations. Most AO systems are operational at near-infrared wavelengths but not in the optical range, because optical observations require a much higher performance to obtain the same Strehl ratio as near-infrared observations. Therefore, to enable AO-assisted observations at optical wavelengths, we connected the Kyoto Tridimensional Spectrograph II (Kyoto 3DII), which can perform integral field spectroscopy, to the second generation AO system of the Subaru Telescope (AO188). We developed a new beam-splitter that reflects light below 594 nm for the wavefront sensors of AO188 and transmits above 644 nm for Kyoto 3DII. We also developed a Kyoto 3DII mount at the Nasmyth focus of the Subaru Telescope. In test observations, the spatial resolution of the combined AO188–Kyoto 3DII was higher than that in natural seeing conditions, even at 6500 A. The full width at half maximum of an undersampled (1.5 spaxels) bright guide star (7.0 mag in the V-band) was 012.

The Prime Focus Spectrograph (PFS) is a new multi-fiber spectrograph on Subaru telescope. PFS will cover around 1.4 degree diameter field with ~2400 fibers. To ensure precise positioning of the fibers, a metrology camera is designed to provide the fiber position information within 5 {\mu}m error. The final positioning accuracy of PFS is targeted to be better than 10 {\mu}m. The metrology camera will locate at the Cassegrain focus of Subaru telescope to cover the whole focal plane. The PFS metrology camera will also serve for the existing multi-fiber infrared spectrograph FMOS., Comment: 7 pages, 5 figures; Ground-based and Airborne Instrumentation for Astronomy IV, Proc. SPIE 8446 (2012)

The Prime Focus Spectrograph (PFS) is a wide field multi-fiber spectrograph using the prime focus of the Subaru telescope, which is capable of observing up to 2400 astronomical objects simultaneously. The instrument control software will manage the observation procedure communicateing with subsystems such as the fiber positioner "COBRA", the metrology camera system, and the spectrograph and camera systems. Before an exposure starts, the instrument control system needs to access to a database where target lists provided by observers are stored in advance, and accurately position fibers onto astronomical targets as requested therein. This fiber positioning will be carried out interacting with the metrology system which measures the fiber positions. In parallel, the control system can issue a command to point the telescope to the target position and to rotate the instrument rotator. Finally the telescope pointing and the rotator angle will be checked by imaging bright stars and checking their positions on the auto-guide and acquisition cameras. After the exposure finishes, the data are collected from the detector systems and are finalized as FITS files to archive with necessary information. The observation preparation software is required, given target lists and a sequence of observation, to find optimal fiber allocations with maximizing the number of guide stars. To carry out these operations efficiently, the control system will be integrated seamlessly with a database system which will store information necessary for observation execution such as fiber configurations. In this article, the conceptual system design of the observation preparation software and the instrument control software will be presented., Comment: 8 pages, 4 figures; Proc. SPIE 8451 (2012)

The Prime Focus Spectrograph (PFS) of the Subaru Measurement of Images and Redshifts (SuMIRe) project has been endorsed by Japanese community as one of the main future instruments of the Subaru 8.2-meter telescope at Mauna Kea, Hawaii. This optical/near-infrared multi-fiber spectrograph targets cosmology with galaxy surveys, Galactic archaeology, and studies of galaxy/AGN evolution. Taking advantage of Subaru's wide field of view, which is further extended with the recently completed Wide Field Corrector, PFS will enable us to carry out multi-fiber spectroscopy of 2400 targets within 1.3 degree diameter. A microlens is attached at each fiber entrance for F-ratio transformation into a larger one so that difficulties of spectrograph design are eased. Fibers are accurately placed onto target positions by positioners, each of which consists of two stages of piezo-electric rotary motors, through iterations by using back-illuminated fiber position measurements with a wide-field metrology camera. Fibers then carry light to a set of four identical fast-Schmidt spectrographs with three color arms each: the wavelength ranges from 0.38 {\mu}m to 1.3 {\mu}m will be simultaneously observed with an average resolving power of 3000. Before and during the era of extremely large telescopes, PFS will provide the unique capability of obtaining spectra of 2400 cosmological/astrophysical targets simultaneously with an 8-10 meter class telescope. The PFS collaboration, led by IPMU, consists of USP/LNA in Brazil, Caltech/JPL, Princeton, & JHU in USA, LAM in France, ASIAA in Taiwan, and NAOJ/Subaru., Comment: 13 pages, 11 figures, submitted to "Ground-based and Airborne Instrumentation for Astronomy IV, Ian S. McLean, Suzanne K. Ramsay, Hideki Takami, Editors, Proc. SPIE 8446 (2012)"

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.

The Fiber Optical Cable and Connector System (FOCCoS), provides optical connection between 2400 positioners and a set of spectrographs by an optical fibers cable as part of Subaru PFS instrument. Each positioner retains one fiber entrance attached at a microlens, which is responsible for the F-ratio transformation into a larger one so that difficulties of spectrograph design are eased. The optical fibers cable will be segmented in 3 parts at long of the way, cable A, cable B and cable C, connected by a set of multi-fibers connectors. Cable B will be permanently attached at the Subaru telescope. The first set of multi-fibers connectors will connect the cable A to the cable C from the spectrograph system at the Nasmith platform. The cable A, is an extension of a pseudo-slit device obtained with the linear disposition of the extremities of the optical fibers and fixed by epoxy at a base of composite substrate. The second set of multi-fibers connectors will connect the other extremity of cable A to the cable B, which is part of the positioner's device structure. The optical fiber under study for this project is the Polymicro FBP120170190, which has shown very encouraging results. The kind of test involves FRD measurements caused by stress induced by rotation and twist of the fiber extremity, similar conditions to those produced by positioners of the PFS instrument. The multi-fibers connector under study is produced by USCONEC Company and may connect 32 optical fibers. The tests involve throughput of light and stability after many connections and disconnections. This paper will review the general design of the FOCCoS subsystem, methods used to fabricate the devices involved and the tests results necessary to evaluate the total efficiency of the set., Comment: 14 pages, 27 figures, SPIE

We have observed the central region of the nearby starburst galaxy NGC 253 with the Kyoto Tridimensional Spectrograph II (Kyoto3DII) Fabry-Perot mode in order to investigate the properties of its galactic wind. Since this galaxy has a large inclination, it is easy to observe its galactic wind. We produced the Ha, [N II]6583, and [S II]6716,6731 images, as well as those line ratio maps. The [N II]/Ha ratio in the galactic wind region is larger than those in H II regions in the galactic disk. The [N II]/Ha ratio in the southeastern filament, a part of the galactic wind, is the largest and reaches about 1.5. These large [N II]/Ha ratios are explained by shock ionization/excitation. Using the [S II]/Ha ratio map, we spatially separate the galactic wind region from the starburst region. The kinetic energy of the galactic wind can be sufficiently supplied by supernovae in a starburst region in the galactic center. The shape of the galactic wind and the line ratio maps are non-axisymmetric about the galactic minor axis, which is also seen in M82. In the [N II]6583/[S II]6716,6731 map, the positions with large ratios coincide with the positions of star clusters found in the Hubble Space Telescope (HST) observation. This means that intense star formation causes strong nitrogen enrichment in these regions. Our unique data of the line ratio maps including [S II] lines have demonstrated their effectiveness for clearly distinguishing between shocked gas regions and starburst regions, determining the extent of galactic wind and its mass and kinetic energy, and discovering regions with enhanced nitrogen abundance., 22 pages, 5 figures, 1 table, accepted for publication in ApJ

In order to investigate the physical conditions of ionized gas in galaxies, as well as its kinematics, we have developed the Kyoto tridimensional spectrograph II (3DII). It is a multi-mode instrument designed for Cassegrain focus, including integral field spectrograph (IFS) and Fabry-Perot imager modes. We have designed it compact so that we can mount it at 2-m class telescopes as well as at 8-m Subaru telescope. We have succeeded in test observations of the 3DII. In the IFS mode the spatial resolution of ~ 0".5 and 0".4 was obtained in 30-minute exposures at University of Hawaii 88-inch (UH88) and Subaru, respectively, in relatively good weather conditions. Each of 37 × 37 microlenses subtends ~ 0".1 in Subaru's case. This samples well the image size. A wider field of view is emphasized in the case of UH88. Because our micropupil spectroscopy is free from a slit effect, we have reached the accuracy of an order of one tenth of a pixel for deriving velocity fields in terms of velocity center while the full width at half maximum of the instrumental profile corresponds to two pixels. At Subaru we have used a container designed in a collaboration with National Astronomical Observatory, Japan: it fits with a robotic instrument exchanger. The containerincludes two heat exchangers to keep its surface cool and void degrading the image quality. We have established effective observational equences by realizing a software interface with Subaru operating system. ome results from target observations are shown.

The M82 `cap' is a gas cloud at a projected radius of 11.6 kpc along the minor axis of this well known superwind source. The cap has been detected in optical line emission and X-ray emission and therefore provides an important probe of the wind energetics. In order to investigate the ionization source of the cap, we observed it with the Kyoto3DII Fabry-Perot instrument mounted on the Subaru Telescope. Deep continuum, Ha, [NII]6583/Ha, and [SII]6716,6731/Ha maps were obtained with sub-arcsecond resolution. The superior spatial resolution compared to earlier studies reveals a number of bright Ha emitting clouds within the cap. The emission line widths (< 100 km s^-1 FWHM) and line ratios in the newly identified knots are most reasonably explained by slow to moderate shocks velocities (v_shock = 40--80 km s^-1) driven by a fast wind into dense clouds. The momentum input from the M82 nuclear starburst region is enough to produce the observed shock. Consequently, earlier claims of photoionization by the central starburst are ruled out because they cannot explain the observed fluxes of the densest knots unless the UV escape fraction is very high (f_esc > 60%), i.e., an order of magnitude higher than observed in dwarf galaxies to date. Using these results, we discuss the evolutionary history of the M82 superwind. Future UV/X-ray surveys are expected to confirm that the temperature of the gas is consistent with our moderate shock model., 7 pages, 5 figures, 2 tables; Accepted for publication in ApJ

In order to investigate the evolution of E+A galaxies, we observed a galaxy SDSS J160241.00+521426.9, a possible E+A progenitor which shows both emission and strong Balmer absorptions, and its neighbor galaxy. We used the integral field spectroscopic mode of the Kyoto Tridimensional Spectrograph (Kyoto3DII), mounted on the University of Hawaii 88-inch telescope located on Mauna Kea, and the slit-spectroscopic mode of the Faint Object Camera and Spectrograph (FOCAS) on the Subaru Telescope. We found a strong Balmer absorption region in the center of the galaxy and an emission-line region located 2 kpc from the center, in the direction of its neighbor galaxy. The recession velocities of the galaxy and its neighbor galaxy differ only by 100 km s^-1, which suggests that they are a physical pair and would have been interacting. Comparing observed Lick indices of Balmer lines and color indices with those predicted from stellar population synthesis models, we find that a suddenly quenched star-formation scenario is plausible for the star-formation history of the central region. We consider that star formation started in the galaxy due to galaxy interactions and was quenched in the central region, whereas star formation in a region offset from the center still continues or has begun recently. This work is the first study of a possible E+A progenitor using spatially resolved spectroscopy., 39 pages, 10 figures and 10 tables, accepted to ApJ