山田 亨

We present the direct imaging discovery of an extrasolar planet, or possible low-mass brown dwarf, at a projected separation of 55 +/- 2 AU (1 ''.058 +/- 0 ''.007) from the B9-type star kappa And. The planet was detected with Subaru/HiCIAO during the SEEDS survey and confirmed as a bound companion via common proper motion measurements. Observed near-infrared magnitudes of J = 16.3 +/- 0.3, H = 15.2 +/- 0.2, K-s = 14.6 +/- 0.4, and L' = 13.12 +/- 0.09 indicate a temperature of similar to 1700 K. The galactic kinematics of the host star are consistent with membership in the Columba Association, implying a corresponding age of 30(-10)(+20) Myr. The system's age, combined with the companion photometry, points to a model-dependent companion mass similar to 12.8 M-Jup. The host star's estimated mass of 2.4-2.5 M-circle dot places it among the most massive stars ever known to harbor an extrasolar planet or low-mass brown dwarf. While the mass of the companion is close to the deuterium burning limit, its mass ratio, orbital separation, and likely planet-like formation scenario imply that it may be best defined as a "super-Jupiter" with properties similar to other recently discovered companions to massive stars.

We present Subaru/HiCIAO H-band high-contrast images of the debris disk around HIP 79977, whose presence was recently inferred from an infrared excess. Our images resolve the disk for the first time, allowing characterization of its shape, size, and dust grain properties. We use angular differential imaging (ADI) to reveal the disk geometry in unpolarized light out to a radius of similar to 2 '', as well as polarized differential imaging to measure the degree of scattering polarization out to similar to 1 ''.5. In order to strike a favorable balance between suppression of the stellar halo and conservation of disk flux, we explore the application of principal component analysis to both ADI and reference star subtraction. This allows accurate forward modeling of the effects of data reduction on simulated disk images, and thus direct comparison with the imaged disk. The resulting best-fit values and well-fitting intervals for the model parameters are a surface brightness power-law slope of S-out = -3.2[-3.6,-2.9], an inclination of i = 84 degrees[81 degrees, 86 degrees], a high Henyey-Greenstein forward-scattering parameter of g = 0.45[0.35, 0.60], and a nonsignificant disk-star offset of u = 3.0[-1.5, 7.5] AU = 24[-13, 61] mas along the line of nodes. Furthermore, the tangential linear polarization along the disk rises from similar to 10% at 0 ''.5 to similar to 45% at 1 ''.5. These measurements paint a consistent picture of a disk of dust grains produced by collisional cascades and blown out to larger radii by stellar radiation pressure.

We present the first near-IR scattered light detection of the transitional disk associated with the Herbig Ae star MWC 758 using data obtained as part of the Strategic Exploration of Exoplanets and Disks with Subaru, and 1.1 mu m Hubble Space Telescope/NICMOS data. While submillimeter studies suggested there is a dust-depleted cavity with r = 0 ''.35, we find scattered light as close as 0 ''.1 (20-28 AU) from the star, with no visible cavity at H, K', or K-s. We find two small-scaled spiral structures that asymmetrically shadow the outer disk. We model one of the spirals using spiral density wave theory, and derive a disk aspect ratio of h similar to 0.18, indicating a dynamically warm disk. If the spiral pattern is excited by a perturber, we estimate its mass to be 5(-4)(+3) -4 M-J, in the range where planet filtration models predict accretion continuing onto the star. Using a combination of non-redundant aperture masking data at L' and angular differential imaging with Locally Optimized Combination of Images at K' and K-s, we exclude stellar or massive brown dwarf companions within 300 mas of the Herbig Ae star, and all but planetary mass companions exterior to 0 ''.5. We reach 5 sigma contrasts limiting companions to planetary masses, 3-4 MJ at 1 ''.0

Through detailed radiative transfer modeling, we present a disk+cavity model to simultaneously explain both the spectral energy distribution (SED) and SubaruH-band polarized light imaging for the pre-transitional protoplanetary disk PDS 70. In particular, we are able to match not only the radial dependence but also the absolute scale of the surface brightness of the scattered light. Our disk model has a cavity 65AU in radius, which is heavily depleted of sub-micron-sized dust grains, and a small residual inner disk that produces a weak but still optically thick near-IR excess in the SED. To explain the contrast of the cavity's edge in the Subaru image, a factor of similar to 1000 depletion for the sub-micron-sized dust inside the cavity is required. The total dust mass of the disk may be on the order of 10(-4) M-circle dot, only weakly constrained due to the lack of long-wavelength observations and the uncertainties in the dust model. The scale height of the sub-micron-sized dust is similar to 6AU at the cavity edge, and the cavity wall is optically thick in the vertical direction at H-band. PDS 70 is not a member of the class of (pre-) transitional disks identified by Dong et al., whose members only show evidence of the cavity in the millimeter-size dust but not the sub-micron-sized dust in resolved images. The two classes of (pre-) transitional disks may form through different mechanisms, or they may simply be at different evolution stages in the disk-clearing process.

We report high-resolution (0.07 arcsec) near-infrared polarized intensity images of the circumstellar disk around the star 2MASS J16042165-2130284 obtained with HiCIAO mounted on the Subaru 8.2 m telescope. We present our H-band data, which clearly exhibit a resolved, face-on disk with a large inner hole for the first time at infrared wavelengths. We detect the centrosymmetric polarization pattern in the circumstellar material as has been observed in other disks. Elliptical fitting gives the semimajor axis, semiminor axis, and position angle (P.A.) of the disk as 63 AU, 62 AU, and -14 degrees, respectively. The disk is asymmetric, with one dip located at P.A.s of similar to 85 degrees. Our observed disk size agrees well with a previous study of dust and CO emission at submillimeter wavelength with Submillimeter Array. Hence, the near-infrared light is interpreted as scattered light reflected from the inner edge of the disk. Our observations also detect an elongated arc (50 AU) extending over the disk inner hole. It emanates at the inner edge of the western side of the disk, extending inward first, then curving to the northeast. We discuss the possibility that the inner hole, the dip, and the arc that we have observed may be related to the existence of unseen bodies within the disk.

We report that HAT-P-7 has a common proper motion stellar companion. The companion is located at similar to 3.'' 9 to the east and estimated to be an M5.5V dwarf based on its colors. We also confirm the presence of a third companion, which was first reported by Winn et al. (2009, ApJ, 703, L99), based on long-term radial velocity measurements. We revisit the migration mechanism of HAT-P-7b given to the presence of those companions, and propose the sequential Kozai migration as a likely scenario in this system. This scenario may explain the reason for an outlier in the discussion of the spin-orbit alignment timescale for HAT-P-7b by Albrecht et al. (2012, ApJ, 757, 18).

In order to investigate the growth of supermassive black holes (SMBHs), we construct the black hole mass function (BHMF) and Eddington ratio distribution function (ERDF) of X-ray-selected broad-line active galactic nuclei (AGNs) at z similar to 1.4 in the Subaru XMM-Newton Deep Survey (SXDS) field. A significant part of the accretion growth of SMBHs is thought to take place in this redshift range. Black hole masses of X-ray-selected broad-line AGNs are estimated using the width of the broad Mg II line and 3000 angstrom monochromatic luminosity. We supplement the Mg II FWHM values with the H alpha FWHM obtained from our NIR spectroscopic survey. Using the black hole masses of broad-line AGNs at redshifts between 1.18 and 1.68, the binned broad-line AGN BHMFs and ERDFs are calculated using the V-max method. To properly account for selection effects that impact the binned estimates, we derive the corrected broad-line AGN BHMFs and ERDFs by applying the maximum likelihood method, assuming that the ERDF is constant regardless of the black hole mass. We do not correct for the non-negligible uncertainties in virial BH mass estimates. If we compare the corrected broad-line AGN BHMF with that in the local universe, then the corrected BHMF at z = 1.4 has a higher number density above 10(8) M-circle dot but a lower number density below that mass range. The evolution may be indicative of a downsizing trend of accretion activity among the SMBH population. The evolution of broad-line AGN ERDFs from z = 1.4 to 0 indicates that the fraction of broad-line AGNs with accretion rates close to the Eddington limit is higher at higher redshifts.

We present H-band polarimetric imagery of UX Tau A taken with HiCIAO/AO188 on the Subaru Telescope. UX Tau A has been classified as a pre-transitional disk object, with a gap structure separating its inner and outer disks. Our imagery taken with the 0 ''.15 (21 AU) radius coronagraphic mask has revealed a strongly polarized circumstellar disk surrounding UX Tau A, which extends to 120 AU, at a spatial resolution of 0 ''.1 (14 AU). It is inclined by 46 degrees +/- 2 degrees, since the west side is nearest. Although SED modeling and sub-millimeter imagery have suggested the presence of a gap in the disk, with the inner edge of the outer disk estimated to be located at 25-30 AU, we detect no evidence of a gap at the limit of our inner working angle (23 AU) at the near-infrared wavelength. We attribute the observed strong polarization (up to 66%) to light scattering by dust grains in the disk. However, neither polarization models of the circumstellar disk based on Rayleigh-scattering nor Mie-scattering approximations were consistent with the observed azimuthal profile of the polarization degrees of the disk. Instead, a geometric optics model of the disk with nonspherical grains with radii of 30 mu m is consistent with the observed profile. We suggest that the dust grains have experienced frequent collisional coagulations, and have grown in the circumstellar disk of UX Tau A.

We present the results of our wide-field narrowband imaging of the field around the radio galaxy 53W002 at z = 2.390 with Subaru/Suprime-Cam. A custom-made filter, NB413, centered at 4140 angstrom with a width of 83 angstrom is used to observe the 31' x 24' area around the radio galaxy. We detected 204 Ly alpha emitters (LAEs) at z = 2.4 with a rest-frame equivalent width larger than 25 angstrom to the depth of 26 AB mag (in NB413). The entire LAE population in the 53W002 field has an average number density and distributions of equivalent width and size that are similar to those of other fields at z similar to 2. We identify a significant high-density region (53W002F-HDR) that spreads over approximate to 5' x 4' near 53W002, where the LAE number density is nearly four times as large as the average of the entire field. Using the probability distribution function of density fluctuation, we evaluate the rareness probability of 53W002F-HDR to be 0.9(-0.62)(+2.4)%, which corresponds to a moderately rich structure. No notable environmental dependency at the comoving scale of 10 Mpc is found for the distributions of the Ly alpha equivalent width and luminosity in the field. We also detected four Ly alpha blobs, one of which is newly discovered. They are all located in the rims of high-density regions. The biased location and unique morphologies in Ly alpha suggest that galaxy interaction plays a key role in their formation.

We present high-resolution H-band polarized intensity (FWHM = 0.'' 1:14 AU) and L'-band imaging data (FWHM = 0.'' 11:15 AU) of the circumstellar disk around the weak-lined T Tauri star PDS 70 in Centaurus at a radial distance of 28 AU (0.'' 2) up to 210 AU (1.'' 5). In both images, a giant inner gap is clearly resolved for the first time, and the radius of the gap is similar to 70 AU. Our data show that the geometric center of the disk shifts by similar to 6 AU toward the minor axis. We confirm that the brown dwarf companion candidate to the north of PDS 70 is a background star based on its proper motion. As a result of spectral energy distribution fitting by Monte Carlo radiative transfer modeling, we infer the existence of an optically thick inner disk at a few AU. Combining our observations and modeling, we classify the disk of PDS 70 as a pre-transitional disk. Furthermore, based on the analysis of L'-band imaging data, we put an upper limit of similar to 30 to similar to 50 M-J on the mass of companions within the gap. Taking into account the presence of the large and sharp gap, we suggest that the gap could be formed by dynamical interactions of sub-stellar companions or multiple unseen giant planets in the gap.

Using stacks of Lya images of 2128 Lya emitters (LAEs) and 24 proto-cluster UV-selected galaxies (LBGs) at z = 3.1, we examine the surface brightness profiles of Lya haloes around high-z galaxies as a function of environment and UV luminosity. We find that the slopes of the Lya radial profiles become flatter as the Mpc-scale LAE surface density increases, but that they are almost independent of the central UV luminosity. The characteristic exponential scalelength of the Lya haloes appears to be proportional to the square of the LAE surface density (r Ly a?S LAE 2). Including the diffuse, extended Lya haloes, the rest-frame Lya equivalent width of the LAEs in the densest regions approaches EW0 similar to 200 angstrom, the maximum value expected for young (<107?yr) galaxies. This suggests that Lya photons formed via shock compression by gas outflows or cooling radiation by gravitational gas inflows may partly contribute to the illumination of Lya haloes; however, most of their Lya luminosity can be explained by photoionization by or by scattering of Lya photons produced from H?ii regions in and around the central galaxies. Regardless of the source of Lya photons, if the Lya haloes trace the overall gaseous structure, following the dark matter distribution, it is not surprising that the Lya spatial extent depends more strongly on the surrounding Mpc-scale environment than on the activity of the central galaxies.

One of the key predictions of modeling from the IR excess of Herbig Ae stars is that for protoplanetary disks, where significant grain growth and settling has occurred, the dust disk has flattened to the point that it can be partially or largely shadowed by the innermost material at or near the dust sublimation radius. When the self-shadowing has already started, the outer disk is expected to be detected in scattered light only in the exceptional cases when the scale height of the dust disk at the sublimation radius is smaller than usual. High-contrast imaging combined with the IR spectral energy distribution allow us to measure the degree of flattening of the disk, as well as to determine the properties of the outer disk. We present polarimetric differential imaging in the H band obtained with Subaru/HiCIAO of one such system, MWC 480. The HiCIAO data were obtained at a historic minimum of the NIR excess. The disk is detected in scattered light from 0.'' 2 to 1.'' 0 (27.4-137AU). Together with the marginal detection of the disk from 1998 February 24 by Hubble Space Telescope/NICMOS, our data constrain the opening half-angle for the disk to lie between 1.degrees 3 <= theta <= 2 degrees.2. When compared with similar measures in CO for the gas disk from the literature, the dust disk subtends only similar to 30% of the gas disk scale height (H/R similar to 0.03). Such a dust disk is a factor of 5-7 flatter than transitional disks, which have structural signatures that giant planets have formed.

Transitional circumstellar disks around young stellar objects have a distinctive infrared deficit around 10 mu m in their spectral energy distributions, recently measured by the Spitzer Infrared Spectrograph (IRS), suggesting dust depletion in the inner regions. These disks have been confirmed to have giant central cavities by imaging of the submillimeter continuum emission using the Submillimeter Array (SMA). However, the polarized near-infrared scattered light images for most objects in a systematic IRS/SMA cross sample, obtained by HiCIAO on the Subaru telescope, show no evidence for the cavity, in clear contrast with SMA and Spitzer observations. Radiative transfer modeling indicates that many of these scattered light images are consistent with a smooth spatial distribution for mu m-sized grains, with little discontinuity in the surface density of the mu m-sized grains at the cavity edge. Here we present a generic disk model that can simultaneously account for the general features in IRS, SMA, and Subaru observations. Particularly, the scattered light images for this model are computed, which agree with the general trend seen in Subaru data. Decoupling between the spatial distributions of the mu m-sized dust and mm-sized dust inside the cavity is suggested by the model, which, if confirmed, necessitates a mechanism, such as dust filtration, for differentiating the small and big dust in the cavity clearing process. Our model also suggests an inwardly increasing gas-to-dust ratio in the inner disk, and different spatial distributions for the small dust inside and outside the cavity, echoing the predictions in grain coagulation and growth models.

We present the results of the observations of the Ly alpha line profiles of 91 emission-line galaxies at z = 3.1 with a spectral resolution of lambda/d lambda (FWHM) approximate to 1700 or 180 km s(-1). A significant fraction of similar to 50% of the observed objects show the characteristic double peaks in their Ly alpha profile. The red peak is much stronger than the blue one for most of the cases. The red peaks themselves also show weak but significant asymmetry and their widths are correlated with the velocity separation of the red and the blue peaks. This implies that the peaks are not isolated multiple components with different velocities but parts of a single line that are modified by the absorption and/or scattering by the associated neutral hydrogen gas. The characteristic profile can be naturally explained by scattering in the expanding shell of the neutral hydrogen surrounding the Ly alpha emitting region while the attenuation by the intergalactic medium should also be considered. Our results suggest that the star formation in these Ly alpha emitters are dominated by young burst-like events that produce the intrinsic Ly alpha emission as well as the gas outflow.

We present the results of wide-field deep JHK imaging of the SSA22 field using the MOIRCS instrument equipped with the Subaru telescope. The observed field is 112 arcmin(2) in area, which covers the z = 3.1 protocluster characterized by the overdensities of Ly alpha emitters (LAEs) and Ly alpha blobs (LABs). The 5 sigma limiting magnitude is K-AB = 24.3. We extract the potential protocluster members from the K-selected sample by using the multi-band photometric-redshift selection as well as the simple color cut for distant red galaxies (DRGs; J - K-AB > 1.4). The surface number density of DRGs in our observed fields shows clear excess compared with those in the blank fields, and the location of the densest area whose projected overdensity is twice the average coincides with the large-scale density peak of LAEs. We also found that K-band counterparts with z(phot) similar or equal to 3.1 are detected for 75% (15/20) of the LABs within their Ly alpha halo, and the 40% (8/20) of LABs have multiple components, which gives a direct evidence of the hierarchical multiple merging in galaxy formation. The stellar mass of LABs correlates with their luminosity, isophotal area, and the Ly alpha velocity widths, implying that the physical scale and the dynamical motion of Ly alpha emission are closely related to their previous star formation activities. Highly dust-obscured galaxies such as hyper extremely red objects (J - K-AB > 2.1) and plausible K-band counterparts of submillimeter sources are also populated in the high-density region.

We present high-resolution, H-band imaging observations, collected with Subaru/HiCIAO, of the scattered light from the transitional disk around SAO 206462 (HD 135344B). Although previous sub-mm imagery suggested the existence of a dust-depleted cavity at r <= 46 AU, our observations reveal the presence of scattered light components as close as 0 ''.2 (similar to 28 AU) from the star. Moreover, we have discovered two small-scale spiral structures lying within 0.'' 5 (similar to 70 AU). We present models for the spiral structures using the spiral density wave theory, and derive a disk aspect ratio of h similar to 0.1, which is consistent with previous sub-mm observations. This model can potentially give estimates of the temperature and rotation profiles of the disk based on dynamical processes, independently from sub-mm observations. It also predicts the evolution of the spiral structures, which can be observable on timescales of 10-20 years, providing conclusive tests of the model. While we cannot uniquely identify the origin of these spirals, planets embedded in the disk may be capable of exciting the observed morphology. Assuming that this is the case, we can make predictions on the locations and, possibly, the masses of the unseen planets. Such planets may be detected by future multi-wavelength observations.

We present the results of the extensive narrowband survey of Ly alpha emission-line objects at z = 3.1 in the 1.38 deg(2) area surrounding the high-density region of star-forming galaxies at z = 3.09 in the SSA22 field, as well as in the 1.04 deg(2) area of the three separated general blank fields. In total, of 2161 Lya emitters, there are 1394 in the SSA22 fields and 767 in the general fields detected at the narrowband AB magnitude limit of 25.73, which corresponds to the line flux of approximate to 1.8 x 10(-17) erg s(-1) cm(-2) or the luminosity of approximate to 1.5 x 10(42) erg s(-1) at z = 3.1, above the observed equivalent-width threshold, approximate to 190 angstrom. The average surface number density of the emitters at z = 3.1 in the general fields above the thresholds is 0.20 +/- 0.01 arcmin(-2). The SSA22 high-density region at z = 3.09, whose peak local density is six times that of the average, is found to be the most prominent outstanding structure in the whole surveyed area and is firmly identified as a robust "protocluster." We also compared the overdensity of the 100 arcmin(2) and 700 arcmin(2) areas which contain the protocluster with the expected fluctuation of the dark matter as well as those of the model galaxies in cosmological simulations. We found that the peak height values of the overdensity are 8-10 and 3-4 times the expected standard deviations for the counts of Lya emitters at z = 3.1 in the corresponding volume, respectively. We conclude that the structure at z = 3.09 in the SSA22 field is a very significant and rare density peak up to the scale of approximate to 60 Mpc.

In order to constrain the bolometric luminosities, dust properties, and molecular gas content of giant Ly alpha nebulae, the so-called Lya blobs, we have carried out a study of dust continuum and CO line emission in two well-studied representatives of this population at z similar to 3: an Lya blob discovered by its strong Spitzer Multiband Infrared Photometer 24 mu m detection (LABd05) and the Steidel blob 1 (SSA22-LAB01). We find that the spectral energy distribution of LABd05 is well described by an active-galactic-nucleus-starburst composite template with L-FIR = (4.0 +/- 0.5) x 10(12) L-circle dot, comparable to high-z submillimeter galaxies and ultraluminous infrared galaxies. New Large APEX Bolometer Camera 870 mu m measurements rule out the reported Submillimeter Common-User Bolometer Array detection of the SSA22-LAB01 (S-850 mu m = 16.8 mJy) at the >4 sigma level. Consistent with this, ultradeep Plateau de Bure Interferometer observations with similar to 2 '' spatial resolution also fail to detect any 1.2 mm continuum source down to approximate to 0.45 mJy beam(-1) (3 sigma). Combined with the existing (sub) millimeter observations in the literature, we conclude that the FIR luminosity of SSA22-LAB01 remains uncertain. No CO line is detected in either case down to integrated flux limits of S-v Delta V less than or similar to 0.25-1.0 Jy km s(-1), indicating a modest molecular gas reservoir, M(H-2) < (1-3) x 10(10) M-circle dot. The non-detections exclude, with high significance (12 sigma), the previous tentative detection of a CO J = 4-3 line in the SSA22-LAB01. The increased sensitivity afforded by the Atacama Large Millimeter/submillimeter Array will be critical in studying molecular gas and dust in these interesting systems.

WISH, Wide-field Imaging Surveyor for High-redshiftt, is a space mission concept to conduct very deep and wide-field surveys at near infrared wavelength at 1-5 mu m to study the properties of galaxies at very high redshift beyond the epoch of cosmic reionization. The concept has been developed and studied since 2008 to be proposed for future JAXA/ISAS mission. WISH has a 1.5m-diameter primary mirror and a wide-field imager covering 850 arcmin(2) The pixel scale is 0.155 arcsec for 18 mu m pitch, which properly samples the diffraction-limited image at 1.5 mu m. The main program is Ultra Deep Survey (UDS) covering 100 deg(2) down to 28AB mag at least in five broad bands We expect to detect >10(4) galaxies at z=8-9, 10(3)-10(4) galaxies at z=11-12, and 50-100 galaxies at z>14, many of which can be feasible targets for deep spectroscopy with Extremely Large Telescopes. With recurrent deep observations, detection and light curve monitoring for type-Ia SNe in rest-frame infrared wavelength is also conducted, which is another main science goal of the mission. During the in-orbit 5 years observations, we expect to detect and monitor >2000 type-Ia SNe up to z similar to 2. WISH also conducts Ultra Wide Survey, covering 1000deg(2) down to 24-25AB mag as well as Extreme Survey, covering a limited number of fields of view down to 29-30AB mag. We here report the progress of the WISH project including the basic telescope and satellite design as well as the results of the test for a proto-model of the flip-type filter exchanger which works robustly near 100K.

We present high-contrast images of HR 4796 A taken with Subaru/HiCIAO in the H band, resolving the debris disk in scattered light. The application of specialized angular differential imaging methods allows us to trace the inner edge of the disk with high precision and reveals a pair of "streamers" extending radially outward from the ansae. Using a simple disk model with a power-law surface brightness profile, we demonstrate that the observed streamers can be understood as part of the smoothly tapered outer boundary of the debris disk, which is most visible at the ansae. Our observations are consistent with the expected result of a narrow planetesimal ring being ground up in a collisional cascade, yielding dust with a wide range of grain sizes. Radiation forces leave large grains in the ring and push smaller grains onto elliptical or even hyperbolic trajectories. We measure and characterize the disk's surface brightness profile, and confirm the previously suspected offset of the disk's center from the star's position along the ring's major axis. Furthermore, we present first evidence for an offset along the minor axis. Such offsets are commonly viewed as signposts for the presence of unseen planets within a disk's cavity. Our images also offer new constraints on the presence of companions down to the planetary mass regime (similar to 9 M-Jup at 0.'' 5, similar to 3 M-Jup at 1 '').

We present the results of a narrow-band (H(2)S1, lambda(c) = 2.121 mu m, delta lambda = 0.021 mu m) imaging search with Wide Field Camera/United Kingdom Infrared Telescope for Ha emitters (HAEs) around several potential signposts of rare (similar to 10(-7)-10(-8) comoving Mpc(-3)) overdense regions at z = 2.23: an overdensity of quasi-stellar objects [QSOs; 2dF QSO Redshift Survey (2QZ) cluster], a powerful, high-redshift radio galaxy (HzRG) and a concentration of submillimetre galaxies (SMGs) and optically faint radio galaxies (OFRGs). In total, we detect 137 narrowband emitter candidates down to emission-line fluxes of 0.5-1 x 10(-16) erg s(-1) cm(-2), across a total area of 0.56 deg(2) (2.1 x 10(5) comoving Mpc(3) at z = 2.23) in these fields. The BzK colours of the emitters suggest that at least 80 per cent of our sample are likely to be HAEs at z = 2.23. This is one of the largest HAE samples known at z greater than or similar to 2. Although there is no evidence for large-scale (20 comoving Mpc) overdensities of the emitters around the targets, we find modest (similar to 3 sigma) local overdensities associated with all three targets on smaller scales (5-10 comoving Mpc). In the 2QZ cluster field, the structure appears to be connecting the QSOs, while in the HzRG and SMG/OFRG fields, the structures are seen only in the vicinities of the targets. Our results suggest that these rare targets are located in local overdensities of galaxies, rather than average density regions, although it is not clear whether these structures are likely to evolve into rare, rich clusters. The K-band magnitudes and the Ha equivalent widths of the emitters are weakly correlated with the overdensities of the emitters: emitters in overdense regions are more evolved systems compared to those in underdense regions at z = 2.23. We find several examples of extended HAEs near to the targets, including a striking example with a spatial extent of 7.5 arcsec (60 kpc at z = 2.23) in the 2QZ cluster field, suggesting that these are relatively common in overdense regions. We conclude that narrow-band Ha surveys are efficient routes to map overdense regions at high redshifts and thus to understand the relation between the growth of galaxies and their surrounding large-scale structures.

The measurement of the light scattered from extrasolar planets informs atmospheric and formation models. With the discovery of many hot Jupiter planets orbiting nearby stars, this motivates the development of robust methods of characterization from follow-up observations. In this paper, we discuss two methods for determining the planetary albedo in transiting systems. First, the most widely used method for measuring the light scattered by hot Jupiters is investigated for application for typical echelle spectra of a transiting planet system, showing that a detection requires high-signal-to-noise-ratio data of bright planets. Secondly, a new Fourier analysis method is also presented, which is model-independent and utilizes the benefits of the reduced number of unknown parameters in transiting systems. This approach involves solving for the planet and stellar spectra in Fourier space by least squares. The sensitivities of the methods are determined via Monte Carlo simulations for a range of planet-to-star flux ratios. We find the Fourier analysis method to be better suited to the ideal case of typical observations of a well-constrained transiting system than the Collier Cameron et al. method. To guide future observations of transiting planets with ground-based capabilities, the expected sensitivity to the planet-to-star flux ratio is quantified as a function of the signal-to-noise ratio and wavelength range. We apply the Fourier analysis method for extracting the light scattered by transiting hot Jupiters from high-resolution spectra to echelle spectra of HD 209458 and HD 189733. Unfortunately, we are unable to improve on the previous upper limit of the planet-to-star flux ratio for HD 209458b set by space-based observations. A 1 sigma upper limit on the planet-to-star flux ratio of HD 189733b is measured in the wavelength range of 558.83-599.56 nm yielding epsilon < 4.5 x 10(-4). This limit is not sufficiently strong to constrain models. Improvement in the measurement of the upper limit of the planet-to-star flux ratio of this system, with ground-based capabilities, requires data with a higher signal-to-noise ratio and increased stability of the telescope.

Based on the ultraviolet to far-infrared photometry already compiled and presented in a companion paper (Paper I), we present a detailed spectral energy distribution (SED) analysis of nearly 80,000 IRAC 3.6 + 4.5 mu m selected galaxies in the Extended Groth Strip. We estimate photometric redshifts, stellar masses, and star formation rates (SFRs) separately for each galaxy in this large sample. The catalog includes 76,936 sources with [3.6] <= 23.75 (85% completeness level of the IRAC survey) over 0.48 deg(2). The typical photometric redshift accuracy is Delta z/(1 + z) = 0.034, with a catastrophic outlier fraction of just 2%. We quantify the systematics introduced by the use of different stellar population synthesis libraries and initial mass functions in the calculation of stellar masses. We find systematic offsets ranging from 0.1 to 0.4 dex, with a typical scatter of 0.3 dex. We also provide UV- and IR-based SFRs for all sample galaxies, based on several sets of dust emission templates and SFR indicators. We evaluate the systematic differences and goodness of the different SFR estimations using the deep FIDEL 70 mu m data available in the Extended Groth Strip. Typical random uncertainties of the IR-bases SFRs are a factor of two, with non-negligible systematic effects at z greater than or similar to 1.5 observed when only MIPS 24 mu m data are available. All data products (SEDs, postage stamps from imaging data, and different estimations of the photometric redshifts, stellar masses, and SFRs of each galaxy) described in this and the companion paper are publicly available, and they can be accessed through our the Web interface utility Rainbow-navigator.

We present an IRAC 3.6+4.5 mu m selected catalog in the Extended Groth Strip (EGS) containing photometry from the ultraviolet to the far-infrared and stellar parameters derived from the analysis of the multi-wavelength data. In this paper, we describe the method used to build coherent spectral energy distributions (SEDs) for all the sources. In a forthcoming companion paper, we analyze those SEDs to obtain robust estimations of stellar parameters such as photometric redshifts, stellar masses, and star formation rates. The catalog comprises 76,936 sources with [3.6] <= 23.75 mag (85% completeness level of the IRAC survey in the EGS) over 0.48 deg(2). For approximately 16% of this sample, we are able to deconvolve the IRAC data to obtain robust fluxes for the multiple counterparts found in ground-based optical images. Typically, the SEDs of the IRAC sources in our catalog count with more than 15 photometric data points, spanning from the ultraviolet wavelengths probed by GALEX to the far-infrared observed by Spitzer, and going through ground-and space-based optical and near-infrared data taken with 2-8 m class telescopes. Approximately 95% and 90% of all IRAC sources are detected in the deepest optical and near-infrared bands. These fractions are reduced to 85% and 70% for S/N > 5 detections in each band. Only 10% of the sources in the catalog have optical spectroscopy and redshift estimations. Almost 20% and 2% of the sources are detected by MIPS at 24 and 70 mu m, respectively. We also cross-correlate our catalog with public X-ray and radio catalogs. Finally, we present the Rainbow Navigator public Web interface utility, designed to browse all the data products resulting from this work, including images, spectra, photometry, and stellar parameters.

We report high-resolution 1.6 mu m polarized intensity (PI) images of the circumstellar disk around the Herbig Ae star AB Aur at a radial distance of 22 AU (0 ''.15) up to 554 AU (3 ''.85), which have been obtained by the high-contrast instrument HiCIAO with the dual-beam polarimetry. We revealed complicated and asymmetrical structures in the inner part (less than or similar to 140 AU) of the disk while confirming the previously reported outer (r greater than or similar to 200 AU) spiral structure. We have imaged a double ring structure at similar to 40 and similar to 100 AU and a ring-like gap between the two. We found a significant discrepancy of inclination angles between two rings, which may indicate that the disk of AB Aur is warped. Furthermore, we found seven dips (the typical size is similar to 45 AU or less) within two rings, as well as three prominent PI peaks at similar to 40 AU. The observed structures, including a bumpy double ring, a ring-like gap, and a warped disk in the innermost regions, provide essential information for understanding the formation mechanism of recently detected wide-orbit (r > 20 AU) planets.

Deep narrow-band (NB359) imaging with Subaru telescope by Iwata et al. has detected a surprisingly strong Lyman continuum (LyC; similar to 900 A in the rest frame) from some Lyman alpha emitters (LAEs) at z = 3.1. However, the possibility of a redshift misidentification by the previous spectroscopic studies due to a narrow wavelength coverage cannot be rejected. Here we present the results of a new technique, the deep spectroscopy, in which we covered 4000-7000 A with VLT/VIMOS and Subaru/FOCAS for the eight LAEs detected in NB359. All the eight objects have only one detectable emission line around 4970 A, which is most likely to be Ly alpha at z = 3.1, and thus, the objects are certainly LAEs at the redshift. However, five of them show a similar to 0.8 arcsec spatial offset between the Ly alpha emission and the source detected in NB359. No indications of the redshifts of the NB359 sources are found although it is statistically difficult that all the five LAEs have a foreground object accounting for the NB359 flux. The rest three LAEs show no significant offset from the NB359 position. Therefore, we conclude that they are truly LyC-emitting LAEs at z = 3.1. We also examine the stellar population which simultaneously accounts for the strength of the LyC and the spectral slope of non-ionizing ultraviolet of the LAEs. We consider the latest statistics of Lyman limit systems to estimate the LyC optical depth in the intergalactic medium (IGM) and an additional contribution of the bound-free LyC from photoionized nebulae to the LyC emissivity. As a result, we find that stellar populations with metallicity Z >= 1/50 Z(circle dot) can explain the observed LyC strength only with a very top-heavy initial mass function (IMF; << m >> similar to 50 M-circle dot). However, the critical metallicity for such an IMF is expected to be much lower. A very young (similar to 1 Myr) and massive (similar to 100 M-circle dot) extremely metal-poor (Z < 5 x 10-4 Z(circle dot)) or metal-free (so-called Population III) stellar population can reproduce the observed LyC strength. The required mass fraction of such 'primordial' stellar population is similar to 1-10 per cent in total stellar mass of the LAEs. We also present a possible evolutionary scenario of galaxies emitting strong LyC and implications of the primordial stars at z similar to 3 for the metal enrichment in the intergalactic medium and for the ionizing background and reionization.

We have developed high-dispersion VPH (volume phase holographic) grisms with zinc selenide (ZnSe) prisms for the cryogenic optical system of MOIRCS (Multi-Object near-InfraRed Camera and Spectrograph) for Y-, J-, H-, and K-band observations. We fabricated VPH gratings using a hologram resin. After several heat cycles at between room temperature and 120 K, the VPH gratings were assembled to grisms by gluing with two ZnSe prisms. Several heat cycles were also carried out for the grisms before being installed into MOIRCS. We measured the efficiencies of the VPH grisms in a laboratory, and found them to be 70%-82%. The performances obtained by observations of MOIRCS with the 8.2 m Subaru Telescope have been found to be very consistent with the results in the laboratory test. This is the first astronomical application of cryogenic VPH grisms.

We present deep J-, H-, and K-s-band imaging data of the MOIRCS Deep Survey (MODS), which was carried out with the Multi-Object Infrared Camera and Spectrograph (MOIRCS) mounted on the Subaru Telescope in the GOODS-North region. The data reach 5 sigma total limiting magnitudes for point sources of J = 23.9, H = 22.8, and K-s = 22.8 (Vega magnitude) over 103 arcmin(2) (wide field). In 28 arcmin(2) of the survey area, which is an ultra-deep field of the MODS (deep field), the data reach 5 sigma depths of J = 24.8, H = 23.4, and K-s = 23.8. The spatial resolutions of the combined images are FWHM similar to 0.'' 6 and 0.'' 5 for the wide and deep fields in all bands, respectively. Combining the MODS data with the multi-wavelength public data taken with the HST, Spitzer, and other ground-based telescopes in the GOODS field, we constructed a multi-wavelength photometric catalog of K-s-selected sources. Using the catalog, we present K-s-band number counts and near-infrared color distribution of the detected objects; we also demonstrate some selection techniques with the NIR colors for high redshift galaxies. These data and catalog are publicly available via Internet.

We studied the evolution of quiescent galaxies at 0.5 < z < 2.5 as a function of the stellar mass, using very deep NIR imaging data from the MOIRCS Deep Survey in the GOODS-North region. The deep NIR data allowed us to construct a stellar mass-limited sample of quiescent galaxies down to similar to 10(10) M-circle dot even at z similar to 2, for the first time. We selected quiescent galaxies with age /tau > 6 by performing a SED fitting of the multi broad-band photometry from the U to Spitzer 5.8 mu m bands with the population synthesis model of Bruzual and Chariot (2003, MNRAS, 344, 1000), where exponentially decaying star-formation histories are assumed. The number density of quiescent galaxies increases by a factor of similar to 3 from 1.0 < z < 1.5 to 0.5 < z < 1.0, and by a factor of similar to 10 from 1.5 < z < 2.5 to 0.5 < z < 1.0, while that of star-forming galaxies with age/tau < 4 increases only by factors of similar to 2 and similar to 3 in the same redshift ranges. At 0.5 < z < 2.5, the low-mass slope of the stellar mass function of quiescent galaxies is alpha similar to 0-0.6, which is significantly flatter than those of star-forming galaxies (alpha similar to -1.3--1.5). As a result, the fraction of quiescent galaxies in the overall galaxy population increases with stellar mass in the redshift range. The fraction of quiescent galaxies at 10(11)-10(11.5) M-circle dot increases from similar to 20%-30% at z similar to 2 to similar to 40%-60% at z similar to 0.75, while that at 10(10)-10(10.5) M-circle dot increases from less than or similar to 5% to similar to 15% in the same redshift range. These results could suggest that the quenching of star formation had been more effective in more massive galaxies at 1 less than or similar to z less than or similar to 2. Such a mass-dependent quenching could explain the rapid increase in the number density of similar to M* galaxies relative to lower-mass galaxies at z greater than or similar to 1-1.5.

We investigated rest-frame near-infrared (NIR) morphologies of a sample of 139 galaxies with M-s >= 1 x 10(10) M-circle dot at z = 0.8-1.2 in the GOODS-North field using our deep NIR imaging data (MOIRCS Deep Survey, MODS). We focused on Luminous Infrared Galaxies (LIRGs), which dominate a high star formation rate (SFR) density at z similar to 1, in a sample identified by cross-correlating with the Spitzer/MIPS 24 mu m source catalog. We performed two-dimensional light profile fittings of z similar to 1 galaxies in the K-s-band (rest-frame J-band) with a single-component Sersic model. We found that at z similar to 1, similar to 90% of the LIRGs have low Sersic indices (n < 2.5, similar to disk-like galaxies) in the K-s-band, and that those disk-like LIRGs consist of similar to 60% of the whole disk-like sample above M-s >= 3 x 10(10) M-circle dot. The z similar to 1 disk-like LIRGs are comparable to or similar to 20% smaller at the maximum in size compared to local disk-like galaxies in the same stellar mass range. When we examined rest-frame UV-optical morphologies using the HST/ACS images, the rest-frame B-band sizes of the z similar to 1 disk-like galaxies were found to be comparable to those of the local disk-like galaxies, as reported by previous studies on the size evolution of disk-like galaxies in the rest-frame optical band. By measuring color gradients (galaxy sizes as a function of wavelength) of the z similar to 1 and local disk-like galaxies, we found that the z similar to 1 disk-like galaxies have a 3-5 times steeper color gradient than the local ones. Our results indicate that (i) more than a half of the relatively massive disk-like galaxies at z similar to 1 are in violent star-formation epochs observed as LIRGs, and also (ii) that most of those LIRGs are constructing their fundamental disk structure vigorously. The high SFR density in the universe at z similar to 1 may be dominated by such star formation in the disk region in massive galaxies.

GJ 758 B is a cold (similar to 600 K) companion to a Sun-like star at 29 AU projected separation, which was recently detected with high-contrast imaging. Here, we present photometry of the companion in seven photometric bands from Subaru/HiCIAO, Gemini/NIRI, and Keck/NIRC2, providing a rich sampling of the spectral energy distribution in the 1-5 mu m wavelength range. A clear detection at 1.58 mu m combined with an upper limit at 1.69 mu m shows methane absorption in the atmosphere of the companion. The mass of the companion remains uncertain, but an updated age estimate indicates that the most likely mass range is similar to 30-40 M-jup. In addition, we present an updated astrometric analysis that imposes tighter constraints on GJ 758 B's orbit and identifies the proposed second candidate companion, "GJ 758 C," as a background star.

We present results of a survey for giant Ly alpha blobs (LABs) at z = 3 with Subaru/Suprime-Cam. We obtained Ly alpha imaging at z = 3.09 +/- 0.03 around the SSA22 protocluster and in several blank fields. The total survey area is 2.1 deg(2), corresponding to a comoving volume of 1.6 x 10(6) Mpc(3). Using a uniform detection threshold of 1.4 x 10(-18) erg s(-1) cm(-2) arcsec(-2) for the Ly alpha images, we construct a sample of 14 LAB candidates with major-axis diameters larger than 100 kpc, including five previously known blobs and two known quasars. This survey triples the number of known LABs over 100 kpc. The giant LAB sample shows a possible 'morphology-density relation': filamentary LABs reside in average density environments as derived from compact Ly alpha emitters, while circular LABs reside in both average density and overdense environments. Although it is hard to examine the formation mechanisms of LABs only from the Ly alpha morphologies, more filamentary LABs may relate to cold gas accretion from the surrounding intergalactic medium (IGM) and more circular LABs may relate to large-scale gas outflows, which are driven by intense starbursts and/or by active galactic nucleus activities. Our survey highlights the potential usefulness of giant LABs to investigate the interactions between galaxies and the surrounding IGM from the field to overdense environments at high redshift.

We present results from Submillimeter Array (SMA) 860 mu m subarcsecond astrometry and multiwavelength observations of the brightest millimeter (S-1.1mm = 8.4 mJy) source, SSA22-AzTEC1, found near the core of the SSA22 protocluster that is traced by Ly alpha-emitting galaxies at z = 3.09. We identify a 860 mu m counterpart with a flux density of S-860 mu m = 12.2 +/- 2.3 mJy and absolute positional accuracy that is better than 0 ''.3. At the SMA position, we find radio-to-mid-infrared counterparts, whilst no object is found in Subaru optical and near-infrared deep images at wavelengths <= 1 mu m (J > 25.4 in AB, 2 sigma). The photometric redshift estimate, using flux densities at >= 24 mu m, indicates z(phot) = 3.19(-0.35)(+0.26) , consistent with the protocluster redshift. We then model the near-to-mid-infrared spectral energy distribution (SED) of SSA22-AzTEC1, and find that the SED modeling requires a large extinction (A(V) approximate to 3.4 mag) of starlight from a stellar component with M-star similar to 10(10.9) M-circle dot, assuming z = 3.1. Additionally, we find a significant X-ray counterpart with a very hard spectrum (Gamma(eff) = -0.34(-0.61)(+0.57)), strongly suggesting that SSA22-AzTEC1 harbors a luminous active galactic nuclei (AGNs; L-X approximate to 3 x 10(44) erg s(-1)) behind a large hydrogen column (N-H similar to 10(24) cm(-2)). The AGN, however, is responsible for only similar to 10% of the bolometric luminosity of the host galaxy, and therefore the star formation activity likely dominates the submillimeter emission. It is possible that SSA22-AzTEC1 is the first example of a protoquasar growing at the bottom of the gravitational potential underlying the SSA22 protocluster.

We study the evolution of star formation activity of galaxies at 0.5 < z < 3.5 as a function of stellar mass, using very deep NIR data taken with the Multi-Object Infrared Camera and Spectrograph on the Subaru telescope in the GOODS-North region. The NIR imaging data reach K similar to 23-24 Vega magnitude and they allow us to construct a nearly stellar-mass-limited sample down to similar to 10(9.5-10) M-circle dot even at z similar to 3. We estimated star formation rates (SFRs) of the sample with two indicators, namely, the Spitzer/MIPS 24 mu m flux and the rest-frame 2800 angstrom luminosity. The SFR distribution at a fixed M-star shifts to higher values with increasing redshift at 0.5 < z < 3.5. More massive galaxies show stronger evolution of SFR at z greater than or similar to 1. We found galaxies at 2.5 < z < 3.5 show a bimodality in their SSFR distribution, which can be divided into two populations by a constant SSFR of similar to 2 Gyr(-1). Galaxies in the low-SSFR group have SSFRs of similar to 0.5-1.0 Gyr(-1), while the high-SSFR population shows similar to 10 Gyr(-1). The cosmic SFR density (SFRD) is dominated by galaxies with M-star = 10(10-11) M-circle dot at 0.5 < z < 3.5, while the contribution of massive galaxies with M-star = 10(11-11.5) M-circle dot shows a strong evolution at z > 1 and becomes significant at z similar to 3, especially in the case with the SFR based on MIPS 24 mu m. In galaxies with M-star = 10(10-11.5) M-circle dot, those with a relatively narrow range of SSFR (less than or similar to 1 dex) dominates the cosmic SFRD at 0.5 < z < 3.5. The SSFR of galaxies that dominate the SFRD systematically increases with redshift. At 2.5 < z < 3.5, the high-SSFR population, which is relatively small in number, dominates the SFRD. Major star formation in the universe at higher redshift seems to be associated with a more rapid growth of stellar mass of galaxies.

We present the Ly alpha luminosity function (LF), clustering measurements, and Ly alpha line profiles based on the largest sample to date of 207 Ly alpha emitters (LAEs) at z = 6.6 on the 1 deg(2) sky of Subaru/XMM-Newton Deep Survey field. Our z = 6.6 Ly alpha LF including cosmic variance estimates yields the best-fit Schechter parameters of phi* = 8.5(-2.2)(+3.0) x 10(-4) Mpc(-3) and L*(Ly alpha) = 4.4(-0.6)(+0.6) x 10(42) erg s(-1) with a fixed alpha = -1.5, and indicates a decrease from z = 5.7 at the greater than or similar to 90% confidence level. However, this decrease is not large, only similar or equal to 30% in Ly alpha luminosity, which is too small to have been identified in the previous studies. A clustering signal of z = 6.6 LAEs is detected for the first time. We obtain the correlation length of r(0) = 2-5 h(100)(-1) Mpc and a bias of b = 3-6, and find no significant boost of clustering amplitude by reionization at z = 6.6. The average hosting dark halo mass inferred from clustering is 10(10)-10(11) M-circle dot, and a duty cycle of LAE population is roughly similar to 1%, albeit with large uncertainties. The average of our high-quality Keck/DEIMOS spectra shows an FWHM velocity width of 251 +/- 16 km s(-1). We find no large evolution of the Ly alpha line profile from z = 5.7 to 6.6, and no anti-correlation between Ly alpha luminosity and line width at z = 6.6. The combination of various reionization models and our observational results about the LF, clustering, and line profile indicates that there would exist a small decrease of the intergalactic medium's (IGM's) Ly alpha transmission owing to reionization, but that the hydrogen IGM is not highly neutral at z = 6.6. Our neutral-hydrogen fraction constraint implies that the major reionization process took place at z greater than or similar to 7.

We present optical and near-infrared observations of Swift GRB 080325 classified as a "dark gamma-ray burst (GRB)." Near-infrared observations with Subaru/MOIRCS provided a clear detection of afterglow in the K-s band, although no optical counterpart was reported. The flux ratio of rest-wavelength optical to X-ray bands of the afterglow indicates that the dust extinction along the line of sight to the afterglow is AV = 2.7-10 mag. This large extinction is probably the major reason for the optical faintness of GRB 080325. The J - K-s color of the host galaxy, (J - K-s = 1.3 in AB magnitude), is significantly redder than those for typical GRB hosts previously identified. In addition to J and Ks bands, optical images in B, R-c, i', and z' bands with Subaru/SuprimeCam were obtained at about 1 year after the burst, and a photometric redshift of the host is estimated to be z(photo) = 1.9. The host luminosity is comparable to L* at z similar to 2 in contrast to the sub-L* property of typical GRB hosts at lower redshifts. The best-fit stellar population synthesis model for the host shows that the red nature of the host is attributed to a large dust extinction (A(V) = 0.8 mag), and that the host galaxy is massive (M* = 7.0 x 10(10) M-circle dot), which makes it one of the most massive GRB hosts yet identified. By assuming that the mass-metallicity relation for star-forming galaxies at z similar to 2 is applicable for the GRB host, this large stellar mass suggests the high-metallicity environment around GRB 080325, consistent with inferred large extinction.

We present H- and K-s-band imaging data resolving the gap in the transitional disk around LkCa 15, revealing the surrounding nebulosity. We detect sharp elliptical contours delimiting the nebulosity on the inside as well as the outside, consistent with the shape, size, ellipticity, and orientation of starlight reflected from the far-side disk wall, whereas the near-side wall is shielded from view by the disk's optically thick bulk. We note that forward scattering of starlight on the near-side disk surface could provide an alternate interpretation of the nebulosity. In either case, this discovery provides confirmation of the disk geometry that has been proposed to explain the spectral energy distributions of such systems, comprising an optically thick disk with an inner truncation radius of similar to 46 AU enclosing a largely evacuated gap. Our data show an offset of the nebulosity contours along the major axis, likely corresponding to a physical pericenter offset of the disk gap. This reinforces the leading theory that dynamical clearing by at least one orbiting body is the cause of the gap. Based on evolutionary models, our high-contrast imagery imposes an upper limit of 21 M-Jup on companions at separations outside of 0 ''.1 and of 13 M-Jup outside of 0 ''.2. Thus, we find that a planetary system around LkCa 15 is the most likely explanation for the disk architecture.

We present the results of near-infrared multi-object spectroscopic observations for 37 BzK-color-selected star-forming galaxies conducted with MOIRCS on the Subaru Telescope. The sample is drawn from the K-s-bandselected catalog of the MOIRCS Deep Survey in the GOODS-N region. About half of our samples are selected from the publicly available 24 mu m-source catalog of the Multiband Imaging Photometer for Spitzer on board the Spitzer Space Telescope. Ha emission lines are detected from 23 galaxies, of which the median redshift is 2.12. We derived the star formation rates (SFRs) from extinction-corrected Ha luminosities. The extinction correction is estimated from the spectral energy distribution (SED) fitting of multiband photometric data covering UV to near-infrared wavelengths. The Balmer decrement of the stacked emission lines shows that the amount of extinction for the ionized gas is larger than that for the stellar continuum. From a comparison of the extinction-corrected Ha luminosity and other SFR indicators, we found that the relation between the dust properties of stellar continuum and ionized gas is different depending on the intrinsic SFR (differential extinction). We compared SFRs estimated from extinction-corrected Ha luminosities with stellar masses estimated from SED fitting. The comparison shows no correlation between SFR and stellar mass. Some galaxies with stellar mass smaller than similar to 10(10) M-circle dot show SFRs higher than similar to 100 M-circle dot yr(-1). The specific SFRs (SSFRs) of these galaxies are remarkably high; galaxies which have SSFR higher than similar to 10(-8) yr(-1) are found in eight of the present sample. From the best-fit parameters of SED fitting for these high-SSFR galaxies, we find that the average age of the stellar population is younger than 100 Myr, which is consistent with the implied high SSFR. The large SFR implies the possibility that the high-SSFR galaxies significantly contribute to the cosmic SFR density of the universe at z similar to 2. When we apply the larger extinction correction for the ionized gas or the differential extinction correction, the total SFR density estimated from the H alpha-emission-line galaxies is 0.089-0.136 M-circle dot yr(-1) Mpc(-3), which is consistent with the total SFR densities in the literature. The metallicity of the high-SSFR galaxies, which is estimated from the N2 index, is larger than that expected from the mass-metallicity relation of UV-selected galaxies at z similar to 2 by Erb et al.

We present results of direct imaging observations for HAT-P-7 taken with the Subaru HiCIAO and the Calar Alto AstraLux. Since the close-in transiting planet HAT-P-7b was reported to have a highly tilted orbit, massive bodies such as giant planets, brown dwarfs, and a binary star are expected to exist in the outer region of this system. We show that there are indeed two candidates for distant faint stellar companions around HAT-P-7. We discuss how such companions can play a role on the orbital evolution of HAT-P-7b. We conclude that since there is a third body in the system, as reported by Winn et al. (2009, ApJ, 763, L99), Kozai migration is less likely, while planet-planet scattering is possible.

We present an 880 mu m Submillimeter Array (SMA) detection of the submillimeter galaxy SXDF 850.6. SXDF 850.6 is a bright source (S-850 mu m = 8 mJy) detected in the SCUBA Half Degree Extragalactic Survey and has multiple possible radio counterparts in its deep radio image obtained at the VLA. Our new SMA detection finds that the submillimeter emission coincides with the brightest radio emission that is found similar to 8 '' north of the coordinates determined from SCUBA. Despite the lack of detectable counterparts in deep UV/optical images, we find a source at the SMA position in near-infrared and longer wavelength images. We perform spectral energy distribution (SED) model fits to UV-optical-IR photometry (u, B, V, R, i', z', J, H, K, 3.6 mu m, 4.5 mu m, 5.8 mu m, and 8.0 mu m) and to submillimeter-radio photometry (850 mu m, 880 mu m, 1100 mu m, and 21 cm) independently, and we find both are well described by starburst templates at a redshift of z similar or equal to 2.2 +/- 0.3. The best-fit parameters from the UV-optical-IR SED fit are a redshift of z = 1.87(-0.07)(+0.15), a stellar mass of M-star = 2.5(-0.3)(+2.2) x 10(11)M(circle dot), an extinction of Lambda(V) = 3.0(-1.0)(+0.3) mag, and an age of 720(-210)(+1880) Myr. The submillimeter-radio SED fit provides a consistent redshift of z similar to 1.8-2.5, an IR luminosity of L-IR = (7-26) x 10(12) L-circle dot, and a star formation rate of 1300-4500 M-circle dot yr(-1). These results suggest that SXDF 850.6 is a mature system already having a massive amount of old stellar population constructed before its submillimeter bright phase and is experiencing a dusty starburst, possibly induced by major mergers.

We present the discovery of a large-scale structure of emission-line galaxies at redshift z = 4.86 behind a massive cluster of galaxies, A1689. Previous spectroscopic observations of a galaxy, A1689-7.1 at z = 4.87, near this structure, revealed a possible overdense region of intergalactic medium (IGM) around the galaxy, which extends at least similar to 80 comoving Mpc along the line of sight. In order to investigate whether this z similar to 5 IGM overdense region contains a galaxy overdensity, we undertook narrow- and broad-band imaging observations around A1689-7.1 with Subaru/Suprime-Cam. We detected 51 candidates as Ly alpha emitters at redshift z = 4.86 +/- 0.03 in the 32 x 24 arcmin2 field of view. After correction for lensing by the foreground cluster, we found a large-scale (similar to 20 x 60 comoving Mpc) overdense region of galaxies around A1689-7.1 in the source plane at z = 4.86. The densest peak in this region has an overdensity of delta similar to 4, suggesting that this structure is probably a good candidate for a protocluster which may evolve into a massive cluster of galaxies in the present-day Universe. A1689-7.1 is located at the edge of this region, where the local galaxy density is similar to 1.6 times the mean density and is close to the density contrast in the IGM along the line of sight to A1689-7.1 estimated from the optical depth. The overdensities of galaxies we have found may suggest that at least some parts of the IGM overdense region have already started to form galaxies and moreover they relate to the formation of a protocluster. Although we lack information on the three-dimensional distributions of both IGM and galaxy overdense regions, the similarity of the scales of both regions may suggest that the two are parts of a single large-scale structure, which would be an large edge-on sheet along the line of sight with a size of similar to 20 x 60 x 80 comoving Mpc.

We present a universal linear correlation between the stellar mass and surface brightness (SB) of galaxies at 0.3 < z < 3, using a deep K-band-selected catalog in the GOODS-North region. The correlation has a nearly constant slope, independent of redshift and color of galaxies in the rest-z frame. Considering unresolved compact galaxies, the tight correlation gives a lower boundary of SB for a given stellar mass; lower SB galaxies are prohibited over the boundary. The universal slope suggests that the stellar mass in galaxies was built up over their cosmic histories in a similar manner irrelevant to galaxy mass, as opposed to the scenario that massive galaxies mainly accumulated their stellar mass by major merging. In contrast, SB shows a strong dependence on redshift for a given stellar mass. It evolves as similar to(1+ z)(-2.0 similar to- 0.8), in addition to dimming as (1+z)(4) by the cosmological expansion effect. The brightening depends on galaxy color and stellar mass. The blue population (rest-frame U - V < 0), which is dominated by young and star-forming galaxies, evolves as similar to(1 + z)(-0.8 +/- 0.3) in the rest-V band. On the other hand, the red population (U - V > 0) and the massive galaxies (M(*) > 10(10) M(circle dot)) show stronger brightening, (1 + z)(-1.5 +/- 0.1). By comparison with galaxy evolution models, the phenomena are well understood by the pure luminosity evolution of galaxies out to z similar to 3.

We developed the VPH grism for NIR spectroscopy with the Subaru Telescope. After some cryogenic tests in the laboratory, we confirmed its on-sky performance.

WISH is a new space science mission concept whose primary goal is to study the first galaxies in the early universe. We will launch a 1.5m telescope equipped with 1000 arcmin(2) wide-field NIR camera by late 2010's in order to conduct unique ultra-deep and wide-area sky surveys at 1-5 micron. The primary science goal of WISH mission is pushing the high-redshift frontier beyond the epoch of reionization by utilizing its unique imaging capability and the dedicated survey strategy. We expect to detect similar to 10(4) galaxies at z=8-9, similar to 3-6x10(3) galaxies at z=11-12, and similar to 50-100 galaxies at z=14-17 within about 5 years of the planned mission life time. It is worth mentioning that a large fraction of these objects may be bright enough for the spectroscopic observations with the extremely large telescopes. By adopting the optimized strategy for the recurrent observations to reach the depth, we also use the surveys to detect transient objects. Type Ia Supernova cosmology is thus another important primary goal of WISH. A unique optical layout has been developed to achieve the diffraction-limited imaging at 1-5micron over the required large area. Cooling the mirror and telescope to similar to 100K is needed to achieve the zodiacal light limited imaging and WISH will achieve the required temperature by passive cooling in the stable thermal environment at the orbit near Sun-Earth L2. We are conducting the conceptual studies and development for the important components of WISH including the exchange mechanism for the wide-field filters as well as the primary mirror fixation.

We present the discovery of a candidate of giant radio-quiet Ly alpha blob (RQLAB) in a large-scale structure around a high-redshift radio galaxy (HzRG) lying in a giant Ly alpha halo B3 J2330+3927 at redshift z = 3.087. We obtained narrow- and broad-band imaging around B3 J2330+3927 with Subaru/Suprime-Cam to search for Ly alpha emitters (LAEs) and absorbers (LAAs) at redshift z = 3.09 +/- 0.03. We detected candidate 127 LAEs and 26 LAAs in the field of view of 31 x 24 arcmin(2) (58 x 44 comoving Mpc). We found that B3 J2330+3927 is surrounded by a 130 kpc Ly alpha halo and a large-scale (similar to 60 x 20 comoving Mpc) filamentary structure. The large-scale structure contains one prominent local density peak with an overdensity of greater than 5, which is 8 arcmin (15 comoving Mpc) away from B3 J2330+3927. In this peak, we discovered a candidate 100 kpc RQLAB. The existence of both types of Ly alpha nebulae in the same large-scale structure suggests that giant Ly alpha nebulae need special large-scale environments to form. On smaller scales, however, the location of B3 J2330+3927 is not a significant local density peak in this structure, in contrast to the RQLAB. There are two possible interpretations of the difference of the local environments of these two Ly alpha nebulae. First, RQLAB may need a prominent (delta similar to 5) density peak of galaxies to form through intense starbursts due to frequent galaxy interactions/mergers and/or continuous gas accretion in an overdense environment. On the other hand, Ly alpha halo around HzRG may not always need a prominent density peak to form if the surrounding Ly alpha halo is mainly powered by its radio and active galactic nucleus activities. Alternatively, both RQLAB and Ly alpha halo around HzRG may need prominent density peaks to form but we could not completely trace the density of galaxies because we missed evolved and dusty galaxies in this survey.

We present an improved measurement of the Rossiter-McLaughlin effect for the exoplanetary system HD 17156, based on radial-velocity data gathered with the Subaru 8.2-m telescope throughout the planetary transit of UT 2008 November 7. The data allow for a precise and independent determination of the projected spin-orbit angle of this system: lambda = 10 degrees.0 +/- 5 degrees.1. This result supersedes the previous claim of lambda = 62 degrees +/- 25 degrees by Narita et al. (2008, PASJ, 60, L1), which was based on lower-precision data with poor statistics. Thus the stellar spin and planetary orbital axes of the HD 17156 system are likely to be well-aligned, despite the planet's large orbital eccentricity suggesting a history of strong dynamical interactions.

We have obtained deep images in the BVRIJHKs bands of the field centered on QSO 1508+5714 (z(em) = 4.28) with the Suprime-Cam, FOCAS, and MOIRCS cameras on Subaru telescope. We report here on the detection of a B-dropout galaxy, which is 3.'' 5 north-west of the QSO sightline. A photometric redshift analysis is presented to complement the color selection. Given the photometric properties of this object (M = -22.2, making L approximate to 3 L*, if placed at its photometric redshift, z similar to 3.5), as well as the Sersic index (n similar to 1) derived from a 2-D imaging decomposition of the HST WFPC2 image taken with the I-F814 filter, the identified system is consistent with a massive disk galaxy at z > 3. If confirmed, it would be one of the most distant massive disk galaxies known so far.

We use very deep near-infrared (NIR) imaging data obtained in MOIRCS Deep Survey (MODS) to investigate the evolution of the galaxy stellar mass function back to z similar to 3. The MODS data reach J = 24.2, H = 23.1, and K = 23.1 (5 sigma, Vega magnitude) over 10(3) arcmin(2) (wide) and J = 25.1, H = 23.7, and K = 24.1 over 28 arcmin(2) (deep) in the GOODS-North region. The wide and very deep NIR data allow us to measure the number density of galaxies down to low stellar mass (10(9)-10(10) M-circle dot) even at high redshift with high statistical accuracy. The normalization of the mass function decreases with redshift, and the integrated stellar mass density becomes similar to 8%-18% of the local value at z similar to 2 and similar to 4%-9% at z similar to 3, which are consistent with results of previous studies in general fields. Furthermore, we found that the low-mass slope becomes steeper with redshift from alpha similar to -1.3 at z similar to 1 to alpha similar to -1.6 at z similar to 3 and that the evolution of the number density of low-mass (10(9)-10(10) M-circle dot) galaxies is weaker than that of M* (similar to 10(11) M-circle dot) galaxies. This indicates that the contribution of low-mass galaxies to the total stellar mass density has been significant at high redshift. The steepening of the low-mass slope with redshift is an opposite trend expected from the stellar mass dependence of the specific star formation rate reported in previous studies. The present result suggests that the hierarchical merging process overwhelmed the effect of the stellar mass growth by star formation and was very important for the stellar mass assembly of these galaxies at 1 less than or similar to z less than or similar to 3.