We present integral field, far-infrared (FIR) spectroscopy of Mrk 54, a local Lyman continuum emitter, obtained with FIFI-LS on the Stratospheric Observatory for Infrared Astronomy. This is only the second time, after Haro 11, that [C ii] 158 mu m and [O iii] 88 mu m spectroscopy of the known LCEs have been obtained. We find that Mrk 54 has a strong [C ii] emission that accounts for similar to 1% of the total FIR luminosity, whereas it has only moderate [O iii] emission, resulting in the low [O iii]/[C ii] luminosity ratio of 0.22 +/- 0.06. In order to investigate whether [O iii]/[C ii] is a useful tracer of f (esc) (LyC escape fraction), we examine the correlations of [O iii]/[C ii] and (i) the optical line ratio of O-32 equivalent to [O iii] 5007 angstrom/[O ii] 3727 angstrom, (ii) specific star formation rate, (iii) [O iii] 88 mu m/[O i] 63 mu m ratio, (iv) gas-phase metallicity, and (v) dust temperature based on a combined sample of Mrk 54 and the literature data from the Herschel Dwarf Galaxy Survey and the LITTLE THINGS Survey. We find that galaxies with high [O iii]/[C ii] luminosity ratios could be the result of high ionization (traced by O-32), bursty star formation, high ionized-to-neutral gas volume filling factors (traced by [O iii] 88 mu m/[O i] 63 mu m), and low gas-phase metallicities, which is in agreement with theoretical predictions. We present an empirical relation between the [O iii]/[C ii] ratio and f (esc) based on the combination of the [O iii]/[C ii] and O-32 correlation, and the known relation between O-32 and f (esc). The relation implies that high-redshift galaxies with high [O iii]/[C ii] ratios revealed by the Atacama Large Millimeter/submillimeter Array may have f (esc) greater than or similar to 0.1, significantly contributing to the cosmic reionization.

We conduct a comprehensive study on dropout galaxy candidates at z ∼ 9-16 using the first 90 arcmin2 James Webb Space Telescope (JWST) Near Infrared Camera images taken by the early release observations (ERO) and early release science programs. With the JWST simulation images, we find that a number of foreground interlopers are selected with a weak photo-z determination (Δχ 2 > 4). We thus carefully apply a secure photo-z selection criterion (Δχ 2 > 9) and conventional color criteria with confirmations of the ERO Near Infrared Spectrograph spectroscopic redshifts, and obtain a total of 23 dropout galaxies at z ∼ 9-16, including two candidates at z phot = 16.25 − 0.46 + 0.24 and 16.41 − 0.55 + 0.66 . We perform thorough comparisons of dropout galaxies found in our work with recent JWST studies, and conclude that our galaxy sample is reliable enough for statistical analyses. We derive the UV luminosity functions at z ∼ 9-16, and confirm that our UV luminosity functions at z ∼ 9 and 12 agree with those determined by other Hubble Space Telescope and JWST studies. The cosmic star formation rate (SFR) density decreases from z ∼ 9 to 12, and perhaps to 16, but the densities at z ∼ 12-16 are higher than the constant star formation efficiency model. Interestingly, there are six bright galaxy candidates at z ∼ 10-16 with M UV < −19.5 mag and M * ∼ 108−9 M ⊙. Because a majority (∼80%) of these galaxies show no signatures of active galactic nuclei in their morphologies, the high cosmic SFR densities and the existence of these UV-luminous galaxies are explained by the lack of suppression of star formation by the UV background radiation at the pre-reionization epoch and/or an efficient UV radiation production by a top-heavy initial mass function with Population III-like star formation.

This paper presents the third data release of the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP), a wide-field multi-band imaging survey with the Subaru 8.2 m telescope. HSC-SSP has three survey layers (Wide, Deep, and UltraDeep) with different area coverages and depths, designed to address a wide array of astrophysical questions. This third release from HSC-SSP includes data from 278 nights of observing time and covers about 670 deg(2) in all five broad-band filters (grizy) at the full depth (similar to 26 mag at 5 sigma depending on filter) in the Wide layer. If we include partially observed areas, the release covers 1470 deg(2). The Deep and UltraDeep layers have similar to 80% of the originally planned integration times, and are considered done, as we have slightly changed the observing strategy in order to compensate for various time losses. There are a number of updates in the image processing pipeline. Of particular importance is the change in the sky subtraction algorithm; we subtract the sky on small scales before the detection and measurement stages, which has significantly reduced the number of false detections. Thanks to this and other updates, the overall quality of the processed data has improved since the previous release. However, there are limitations in the data (for example, the pipeline is not optimized for crowded fields), and we encourage the user to check the quality assurance plots as well as a list of known issues before exploiting the data. The data release website is < https://hsc-release.mtk.nao.ac.jp >.

Abstract

We present two bright galaxy candidates at z ∼ 12–13 identified in our H-dropout Lyman break selection with 2.3 deg² near-infrared deep imaging data. These galaxy candidates, selected after careful screening of foreground interlopers, have spectral energy distributions showing a sharp discontinuity around 1.7 μm, a flat continuum at 2–5 μm, and nondetections at &lt;1.2 μm in the available photometric data sets, all of which are consistent with a z &gt; 12 galaxy. An ALMA program targeting one of the candidates shows a tentative 4σ [O iii] 88 μm line at z = 13.27, in agreement with its photometric redshift estimate. The number density of the z ∼ 12–13 candidates is comparable to that of bright z ∼ 10 galaxies and is consistent with a recently proposed double-power-law luminosity function rather than the Schechter function, indicating little evolution in the abundance of bright galaxies from z ∼ 4 to 13. Comparisons with theoretical models show that the models cannot reproduce the bright end of rest-frame ultraviolet luminosity functions at z ∼ 10–13. Combined with recent studies reporting similarly bright galaxies at z ∼ 9–11 and mature stellar populations at z ∼ 6–9, our results indicate the existence of a number of star-forming galaxies at z &gt; 10, which will be detected with upcoming space missions such as the James Webb Space Telescope, Nancy Grace Roman Space Telescope, and GREX-PLUS.

<title>ABSTRACT</title>
We present results from a new cosmological hydrodynamics simulation campaign of protocluster (PC) regions, FOREVER22: FORmation and EVolution of galaxies in Extremely overdense Regions motivated by SSA22. The simulations cover a wide range of cosmological scales using three different zoom set-ups in a parent volume of $(714.2~\rm cMpc)^{3}$: PCR (Proto-Cluster Region; V = (28.6 cMpc)3, SPH particle mass, mSPH = 4.1 × 106 M⊙, and final redshift, zend = 2.0), BCG (Brightest proto-Cluster Galaxy; V ∼ (10 cMpc)3, mSPH = 5.0 × 105 M⊙ and zend = 4.0), and First (V ∼ (3 cMpc)3, mSPH = 7.9 × 103 M⊙ and zend = 9.5) runs, that allow us to focus on different aspects of galaxy formation. In the PCR runs, we follow 10 PCs, each harbouring 1–4 SMBHs with ${\rm M_{\rm BH } }\ge 10^{9}~{\rm M_{\odot } }$. One of the PC cores shows a spatially close arrangement of seven starburst galaxies with ${\rm SFR} \gtrsim 100~{\rm {\rm M_{\odot } }~{\rm yr^{-1 } } }$ each, that are dust-obscured and would appear as submillimetre galaxies with flux ≳1 mJy at $1.1~ \rm mm$ in observations. The BCG runs show that the total SFRs of haloes hosting BCGs are affected by AGN feedback, but exceed $1000~{\rm {\rm M_{\odot } }~{\rm yr^{-1 } } }$ at z ≲ 6. The First runs resolve mini-haloes hosting population (Pop) III stars and we show that, in PC regions, the dominant stellar population changes from Pop III to Pop II at z ≳ 20, and the first galaxies with ${\rm SFR} \gtrsim 18~{\rm {\rm M_{\odot } }~{\rm yr^{-1 } } }$ form at z ∼ 10. These can be prime targets for future observations with the James Webb Space Telescope. Our simulations successfully reproduce the global star formation activities in observed PCs and suggest that PCs can kickstart cosmic reionization.

<italic>Context.</italic> Characterizing the galaxy population in the early Universe holds the key to understanding the evolution of these objects and the role they played in cosmic reionization. However, there have been very few observations at the very highest redshifts to date.


<italic>Aims.</italic> In order to shed light on the properties of galaxies in the high-redshift Universe and their interstellar media, we observe the Lyman-<italic>α</italic> emitting galaxy <ext-link ext-link-type="aoi">z7_GSD_3811</ext-link> at <italic>z</italic> = 7.664 with bands 6 and 8 at the Atacama Large Millimeter/submillimeter Array (ALMA).


<italic>Methods.</italic> We target the far-infrared [O <sc>III</sc>] 88 <italic>μ</italic>m and [C <sc>II</sc>] 158 <italic>μ</italic>m emission lines and dust continuum in the star-forming galaxy z7_GSD_3811 with ALMA. We combine these measurements with earlier observations in the rest-frame ultraviolet (UV) in order to characterize the object and compare the results to those of earlier studies that observed [O <sc>III</sc>] and [C <sc>II</sc>] emission in high-redshift galaxies.


<italic>Results.</italic> The [O <sc>III</sc>] 88 <italic>μ</italic>m and [C <sc>II</sc>] 158 <italic>μ</italic>m emission lines are undetected at the position of z7_GSD_3811, with 3<italic>σ</italic> upper limits of 1.6  ×  10⁸ <italic>L</italic>_⊙ and 4.0  ×  10⁷ <italic>L</italic>_⊙, respectively. We do not detect any dust continuum in band 6 nor band 8. The measured rms in the band 8 and band 6 continua are 26 and 9.9 <italic>μ</italic>Jy beam⁻¹, respectively. Similar to several other high-redshift galaxies, z7_GSD_3811 exhibits low [C <sc>II</sc>] emission for its star formation rate compared to local galaxies. Furthermore, our upper limit on the [O <sc>III</sc>] line luminosity is lower than the previously observed [O <sc>III</sc>] lines in high-redshift galaxies with similar UV luminosities. Our ALMA band 6 and 8 dust continuum observations imply that z7_GSD_3811 likely has a low dust content, and our non-detections of the [O <sc>III</sc>] and [C <sc>II</sc>] lines could indicate that z7_GSD_3811 has a low metallicity (<italic>Z</italic> ≲ 0.1 <italic>Z</italic>_⊙).

<title>Abstract</title>
To determine the dominant sources for cosmic reionization, the evolution history of the global ionizing fraction, and the topology of the ionized regions, we have conducted a deep imaging survey using four narrow-band (NB) and one intermediate-band (IB) filters on the Subaru/Hyper Suprime-Cam (HSC), called Cosmic HydrOgen Reionization Unveiled with Subaru (CHORUS). The central wavelengths and full-widths-at-half-maximum of the CHORUS filters are, respectively, 386.2 nm and 5.5 nm for NB387, 526.0 nm and 7.9 nm for NB527, 717.1 nm and 11.1 nm for NB718, 946.2 nm and 33.0 nm for IB945, and 971.2 nm and 11.2 nm for NB973. This combination, including NB921 (921.5 nm and 13.5 nm) from the Subaru Strategic Program with HSC (HSC SSP), is carefully designed, as if they were playing a chorus, to observe multiple spectral features simultaneously, such as Lyman continuum, Lyα, C iv, and He ii for $z$ = 2–7. The observing field is the same as that of the deepest footprint of the HSC SSP in the COSMOS field and its effective area is about 1.6 deg2. We present an overview of the CHORUS project, which includes descriptions of the filter design philosophy, observations and data reduction, multiband photometric catalogs, assessments of the imaging quality, measurements of the number counts, and example use cases for the data. All the imaging data, photometric catalogs, masked pixel images, data of limiting magnitudes and point spread functions, results of completeness simulations, and source number counts are publicly available through the HSC SSP database.

Using a sample of galaxies at z approximate to 3 with detected Lyman Continuum (LyC) leakage in the SSA22 field, we attempt to verify a proposed indirect method for identifying cases with high LyC escape fraction f(esc) based on measurements of the H beta equivalent width (EW) and the beta slope of the UV continuum. To this end, we present Keck/MOSFIRE H beta emission line flux measurements of LyC galaxies (LCGs) at spectroscopic redshifts z(spec) similar to 3.3, Lyman break galaxies (LBGs) at photometric redshifts z(phot) = 2.7-3.7, and Ly alpha emitters at z(phot) = 3.1. We also reconfirm the spectroscopic redshifts and measure the H beta emission-line fluxes from two LCGs and six LBGs. For the LCG in our sample with the most extreme f(esc), as revealed by the direct detection of LyC photons, we find that the EW(H beta)-beta method gives a broadly consistent estimate for f(esc), although the error bars remain very large. We also discuss how a combination of f(esc) measurements based on direct and indirect methods can shed light on the LyC escape mechanism and the anisotropy of the leakage.

We present an IGM HI tomography map in a survey volume of $16 \times 19<br />
\times 131 \ h^{-3} {\rm comoving \ Mpc}^{3}$ (cMpc$^3$) centered at MAMMOTH-1<br />
nebula and three neighbouring quasars at $z=2.3$. MAMMOTH-1 nebula is an<br />
enormous Ly$\alpha$ nebula (ELAN), hosted by a type-II quasar dubbed<br />
MAMMOTH1-QSO, that extends over $1\ h^{-1}$ cMpc with not fully clear physical<br />
origin. Here we investigate the HI-gas distribution around MAMMOTH1-QSO with<br />
the ELAN and three neighbouring type-I quasars, making the IGM HI tomography<br />
map with a spatial resolution of $2.6\ h^{-1}$ cMpc. Our HI tomography map is<br />
reconstructed with HI Ly$\alpha$ forest absorption of bright background objects<br />
at $z=2.4-2.9$: one eBOSS quasar and 16 Keck/LRIS galaxy spectra. We estimate<br />
the radial profile of HI flux overdensity for MAMMOTH1-QSO, and find that<br />
MAMMOTH1-QSO resides in a volume with significantly weak HI absorption. This<br />
suggests that MAMMOTH1-QSO has a proximity zone where quasar illuminates and<br />
photo-ionizes the surrounding HI gas and suppresses HI absorption, and that the<br />
ELAN is probably a photo-ionized cloud embedded in the cosmic web. The HI<br />
radial profile of MAMMOTH1-QSO is very similar to those of three neighbouring<br />
type-I quasars at $z=2.3$, which is compatible with the AGN unification model.<br />
We compare the distributions of the HI absorption and star-forming galaxies in<br />
our survey volume, and identify a spatial offset between density peaks of<br />
star-forming galaxies and HI gas. This segregation may suggest anisotropic UV<br />
background radiation created by star-forming galaxy density fluctuations.

We report on the detection of the [CII] 157.7 $\mu$m emission from the Lyman
break galaxy (LBG) MACS0416_Y1 at z = 8.3113, by using the Atacama Large
Millimeter/submillimeter Array (ALMA). The luminosity ratio of [OIII] 88 $\mu$m
(from previous campaigns) to [CII] is 9.31 $\pm$ 2.6, indicative of hard
interstellar radiation fields and/or a low covering fraction of
photo-dissociation regions. The emission of [CII] is cospatial to the 850
$\mu$m dust emission (90 $\mu$m rest-frame, from previous campaigns), however
the peak [CII] emission does not agree with the peak [OIII] emission,
suggesting that the lines originate from different conditions in the
interstellar medium. We fail to detect continuum emission at 1.5 mm (160 $\mu$m
rest-frame) down to 18 $\mu$Jy (3$\sigma$). This nondetection places a strong
limit on the dust spectrum, considering the 137 $\pm$ 26 $\mu$Jy continuum
emission at 850 $\mu$m. This suggests an unusually warm dust component (T $>$
80 K, 90% confidence limit), and/or a steep dust-emissivity index ($\beta_{\rm
dust}$ $>$ 2), compared to galaxy-wide dust emission found at lower redshifts
(typically T $\sim$ 30 - 50 K, $\beta_{\rm dust}$ $\sim$ 1 - 2). If such
temperatures are common, this would reduce the required dust mass and relax the
dust production problem at the highest redshifts. We therefore warn against the
use of only single-wavelength information to derive physical properties,
recommend a more thorough examination of dust temperatures in the early
Universe, and stress the need for instrumentation that probes the peak of warm
dust in the Epoch of Reionization.

We search for galaxies with a strong Balmer break (Balmer Break Galaxies;<br />
BBGs) at $z \sim 6$ over a 0.41 deg$^2$ effective area in the COSMOS field.<br />
Based on rich imaging data, including data obtained with the Atacama Large<br />
Millimeter/submillimeter Array (ALMA), three candidates are identified by their<br />
extremely red $K - [3.6]$ colors as well as by non-detection in X-ray, optical,<br />
far-infrared (FIR), and radio bands. The non-detection in the deep ALMA<br />
observations suggests that they are not dusty galaxies but BBGs at $z \sim 6$,<br />
although contamination from Active Galactic Nuclei (AGNs) at $z \sim 0$ cannot<br />
be completely ruled out for the moment. Our spectral energy distribution (SED)<br />
analyses reveal that the BBG candidates at $z \sim 6$ have stellar masses of<br />
$\approx 5 \times 10^{10} M_{\odot}$ dominated by old stellar populations with<br />
ages of $\gtrsim 700$ Myr. Assuming that all the three candidates are real BBGs<br />
at $z \sim 6$, we estimate the stellar mass density (SMD) to be<br />
$2.4^{+2.3}_{-1.3} \times 10^{4} M_{\odot}$ Mpc$^{-3}$. This is consistent with<br />
an extrapolation from the lower redshift measurements. The onset of star<br />
formation in the three BBG candidates is expected to be several hundred million<br />
years before the observed epoch of $z \sim 6$. We estimate the star-formation<br />
rate density (SFRD) contributed by progenitors of the BBGs to be 2.4 -- 12<br />
$\times 10^{-5} M_{\odot}$ yr$^{-1} $Mpc$^{-3}$ at $z &gt; 14$ (99.7\% confidence<br />
range). Our result suggests a smooth evolution of the SFRD beyond $z = 8$.

We present improved results of the measurement of the correlation between<br />
galaxies and the intergalactic medium (IGM) transmission at the end of<br />
reionisation. We have gathered a sample of $13$ spectroscopically confirmed<br />
Lyman-break galaxies (LBGs) and $21$ Lyman-$\alpha$ emitters (LAEs) at angular<br />
separations $20&#039;&#039; \lesssim \theta \lesssim 10&#039;$ ($\sim 0.1-4$ pMpc at $z\sim<br />
6$) from the sightlines to $8$ background $z\gtrsim 6$ quasars. We report for<br />
the first time the detection of an excess of Lyman-$\alpha$ transmission spikes<br />
at $\sim 10-60$ cMpc from LAEs ($3.6\sigma$) and LBGs ($3.1\sigma$). We<br />
interpret the data with an improved model of the galaxy-Lyman-$\alpha$<br />
transmission and two-point cross-correlations which includes the enhanced<br />
photoionisation due to clustered faint sources, enhanced gas densities around<br />
the central bright objects and spatial variations of the mean free path. The<br />
observed LAE(LBG)-Lyman-$\alpha$ transmission spike two-point cross-correlation<br />
function (2PCCF) constrains the luminosity-averaged escape fraction of all<br />
galaxies contributing to reionisation to $\langle f_{\rm esc} \rangle_{M_{\rm<br />
UV}&lt;-12} = 0.10_{-0.05}^{+0.17}\,(0.18_{-0.06}^{+0.52})$. We investigate if the<br />
2PCCF measurement can determine whether bright or faint galaxies are the<br />
dominant contributors to reionisation. Our results show that a contribution<br />
from faint galaxies ($M_{\rm UV} &gt; -20 \, (2\sigma)$) is necessary to reproduce<br />
the observed 2PCCF and that reionisation might be driven by different<br />
sub-populations around LBGs and LAEs at $z\sim 6$.

<title>Abstract</title>We have developed a new SED fitting tool specialized for frontier redshift galaxies. It is a common case for high-<italic>z</italic> galaxies that the available data are restricted to rich optical to near-infrared photometry and few far-infrared (FIR) data deep enough to detect the faint object (e.g., <italic>HST</italic>/WFC3 + <italic>Spitzer</italic>/IRAC + ALMA). In such situation, one cannot perform a complicated modeling of dust emission in FIR regime. We then adopt simple treatment for the dust emission using empirical LIRG templates. Instead, we adopt a sophisticated and physically motivated modeling for stellar and nebular emission parts in rest-frame UV-to-optical regime. Our new code fits not only broad band photometry but also spectral emission line flux. There is an option to fit observed SED with two templates with different physical properties. Our new code, PANHIT, is now in public, and was already applied to some high-<italic>z</italic> frontier galaxies.

<title>Abstract</title>We present a 4.7σ detection of the [OIII] 88 <italic>μ</italic>m line in a gravitationally-lensed Lyman break galaxy, RXC J2248-ID3, using the Atacama Large Millimeter/submillimeter Array (ALMA). We did not detect [CII] 158 <italic>μ</italic>m and rest-frame 90 <italic>μ</italic>m dust continuum emission, suggesting that the bulk of the interstellar medium (ISM) is ionized. Our two-component SED model combining the previous Hubble Space Telescope (HST) data and new photometry obtained from Very Large Telescope (VLT), Spitzer and ALMA suggests the presence of young (∼2 Myr) and mature (∼600 Myr) stellar components with the metallicity of <italic>Z</italic> = 0.2Z_⊙. Our findings are in contrast with previous results claiming a very young, metal-poor stellar component.

<title>Abstract</title>Recently huge amount of dust <italic>M</italic>_dust ≃ 10⁶⁻⁷<italic>M</italic>_⊙ in galaxies at <italic>z</italic> = 7–8 has been discovered by ALMA observations. The suggested timescale of the dust production was a few–several×10⁸ yr, while the stellar mass was several × 10⁹<italic>M</italic>_⊙. This amount of dust cannot be easily explained only by a supply from supernovae if we consider the dust destruction by reverse shocks. We propose that these values can be consistently explained if we take into account the grain growth in the interstellar medium (ISM). This scenario successfully reproduces the evolution of the dust mass, as well as the SFR, and stellar mass simultaneously. We conclude that even at such an early epoch of the Universe, the dust grain growth in the ISM plays a significant role in galaxies.

The scatter in the relationship between the strength of [C II] 158 μm emission and the star formation rate at high redshift has been the source of much recent interest. Although the relationship is well established locally, several intensely star-forming galaxies have been found whose [C II] 158 μm emission is either weak, absent, or spatially offset from the young stars. Here we present new ALMA data for the two most distant gravitationally lensed and spectroscopically confirmed galaxies, A2744_YD4 at z = 8.38 and MACS1149_JD1 at z = 9.11, both of which reveal intense [O III] 88 μm emission. In both cases we provide stringent upper limits on the presence of [C II] 158 μm with respect to [O III] 88 μm. We review possible explanations for this apparent redshift-dependent [C II] deficit in the context of our recent hydrodynamical simulations. Our results highlight the importance of using several emission line diagnostics with ALMA to investigate the nature of the interstellar medium in early galaxies....

We present results of the cross-correlation Lya intensity mapping with<br />
Subaru/Hyper Suprime-Cam (HSC) ultra-deep narrowband images and Lya emitters<br />
(LAEs) at $z=5.7$ and $6.6$ in a total area of $4$ deg$^2$. Although<br />
overwhelming amount of data quality controls have been performed for the<br />
narrowband images and the LAE samples, we further conduct extensive analysis<br />
evaluating systematics of large-scale point spread function wings, sky<br />
subtractions, and unknown errors on the basis of physically uncorrelated<br />
signals and sources found in real HSC images and object catalogs, respectively.<br />
Removing the systematics, we carefully calculate cross-correlations between Lya<br />
intensity of the narrowband images and the LAEs. We identify very diffuse Lya<br />
emission with the $3\sigma$ ($2\sigma$) significance at $&gt;150$ comoving kpc<br />
(ckpc) far from the LAEs at $z = 5.7$ ($6.6$), beyond a virial radius of<br />
star-forming galaxies with $M_\mathrm{h} \sim 10^{11} M_\odot$. The diffuse Lya<br />
emission possibly extends up to $1,000$ ckpc with the surface brightness of<br />
$10^{-20}-10^{-19}$ erg s$^{-1}$ cm$^{-2}$ arcsec$^{-2}$. We confirm that the<br />
small-scale ($&lt;150$ ckpc) Lya radial profiles of LAEs in our Lya intensity maps<br />
are consistent with those obtained by recent MUSE observations (Leclercq et al.<br />
2017). Comparisons with numerical simulations suggest that the large-scale<br />
($\sim 150-1,000$ ckpc) Lya emission are not explained by unresolved faint<br />
sources of neighboring galaxies including satellites, but by a combination of<br />
Lya photons emitted from the central LAE and other unknown sources, such as a<br />
cold-gas stream and galactic outflow. We find no evolution in the Lya radial<br />
profiles of our LAEs from $z=5.7$ to $6.6$, where theoretical models predict a<br />
flattening of the profile slope made by cosmic reionization, albeit with our<br />
moderately large observational errors.

We present very faint dropout galaxies at z~6-9 with a stellar mass M* down<br />
to M*~10^6Mo that are found in deep optical/near-infrared (NIR) images of the<br />
full data sets of the Hubble Frontier Fields (HFF) program in conjunction with<br />
deep ground-based and Spitzer images and gravitational lensing magnification<br />
effects. We investigate stellar populations of the HFF dropout galaxies with<br />
the optical/NIR photometry and BEAGLE models made of self-consistent stellar<br />
population synthesis and photoionization models, carefully including strong<br />
nebular emission impacting on the photometry. We identify 357 galaxies with<br />
M*~10^6-10^9Mo, and find that a stellar mass to UV luminosity L_UV ratio<br />
M*/L_UV is nearly constant at M*~10^6-10^9Mo. Our best-estimate M*/L_UV<br />
function is comparable to a model of star-formation duration time of 100 Myr,<br />
but 2-7 times higher than the one of 10 Myr assumed in a previous study (at the<br />
5sigma level) that would probably underestimate M* of faint galaxies. We derive<br />
the galaxy stellar mass functions (GSMFs) at z~6-9 that agree with those<br />
obtained by previous studies with no M*/L_UV assumptions at M*&gt;~10^8Mo, and<br />
that extends to M*~10^6Mo. Estimating the stellar mass densities rho* with the<br />
GSMFs, we find that rho* smoothly increases from log(rho*/[Mo Mpc^(-3)])=5.91<br />
+0.75/-0.65 at z~9 to 6.21 +0.39/-0.37 at z~6-7, which is consistent with the<br />
one estimated from star-formation rate density measurements. In conjunction<br />
with the estimates of the galaxy effective radii R_e on the source plane, we<br />
have pinpointed two objects with low stellar masses (M*&lt;=10^7Mo) and very<br />
compact morphologies (R_e&lt;=40 physical pc) that are comparable with those of<br />
globular clusters (GCs) in the Milky Way today. These objects are candidates of<br />
star clusters that should be a part or a dominant component of high-redshift<br />
low-mass galaxy, some of which may be related to GCs today.

Recently, spectroscopic detections of O[III] 88 μm and Ly-α emission lines from the z 9.1 galaxy MACS1149-JD1 have been presented, and with these, some interesting properties of this galaxy were uncovered. One such property is that MACS1149-JD1 exhibits a significant Balmer break at around rest-frame 4000 Å, which may indicate that the galaxy has experienced large variations in star formation rate prior to z ∼ 9, with a rather long period of low star formation activity. While some simulations predict large variations in star formation activity in high-redshift galaxies, it is unclear whether the simulations can reproduce the kind of variations seen in MACS1149-JD1. Here, we utilize synthetic spectra of simulated galaxies from two simulation suites in order to study to what extent these can accurately reproduce the spectral features (specifically the Balmer break) observed in MACS1149-JD1. We show that while the simulations used in this study produce galaxies with varying star formation histories, galaxies such as MACS1149-JD1 would be very rare in the simulations. In principle, future observations with the James Webb Space Telescope may tell us if MACS1149-JD1 represents something rare, or if such galaxies are more common than predicted by current simulations.

Photometric observations of the spectroscopically confirmed z ≈ 9.1 galaxy MACS1149-JD1 have indicated the presence of a prominent Balmer break in its spectral energy distribution, which may be interpreted as due to very large fluctuations in its past star formation activity. In this paper, we investigate to what extent contemporary simulations of high-redshift galaxies produce star formation rate variations sufficiently large to reproduce the observed Balmer break of MACS1149-JD1. We find that several independent galaxy simulations are unable to account for Balmer breaks of the inferred size, suggesting that MACS1149-JD1 either must be a very rare type of object or that our simulations are missing some key ingredient. We present predictions of spectroscopic Balmer break strength distributions for z ≈ 7-9 galaxies that may be tested through observations with the upcoming James Webb Space Telescope and also discuss the impact that various assumptions on dust reddening, Lyman continuum leakage, and deviations from a standard stellar initial mass function would have on the results.

We present the Atacama Large Millimeter/submillimeter Array (ALMA) detection
of the [O III] 88 $\mu$m line and rest-frame 90 $\mu$m dust continuum emission
in a Y-dropout Lyman break galaxy (LBG), MACS0416_Y1, lying behind the Frontier
Field cluster MACS J0416.1-2403. This [O III] detection confirms the LBG with a
spectroscopic redshift of $z = 8.3118 \pm 0.0003$, making this object one of
the furthest galaxies ever identified spectroscopically. The observed 850
$\mu$m flux density of $137 \pm 26$ $\mu$Jy corresponds to a de-lensed total
infrared (IR) luminosity of $L_{\rm IR} = (1.7 \pm 0.3) \times 10^{11}
L_{\odot}$ if assuming a dust temperature of $T_{\rm dust} = 50$ K and an
emissivity index of $\beta = 1.5$, yielding a large dust mass of $4 \times 10^6
M_{\odot}$. The ultraviolet-to-far IR spectral energy distribution modeling
where the [O III] emissivity model is incorporated suggests the presence of a
young ($\tau_{\rm age} \approx 4$ Myr), star-forming (SFR $\approx 60
M_{\odot}$ yr$^{-1}$), moderately metal-polluted ($Z \approx 0.2 Z_{\odot}$)
stellar component with a mass of $M_{\rm star} = 3 \times 10^8 M_{\odot}$. An
analytic dust mass evolution model with a single episode of star-formation does
not reproduce the metallicity and dust mass in $\tau_{\rm age} \approx 4$ Myr,
suggesting a pre-existing evolved stellar component with $M_{\rm star} \sim 3
\times 10^9 M_{\odot}$ and $\tau_{\rm age} \sim 0.3$ Gyr as the origin of the
dust mass.

We present new ALMA observations and physical properties of a Lyman Break
Galaxy at z=7.15. Our target, B14-65666, has a bright ultra-violet (UV)
absolute magnitude, $M_{\rm UV}\approx-22.4$, and has been spectroscopically
identified in Ly$\alpha$ with a small rest-frame equivalent width of $\approx4$
\AA. Previous HST image has shown that the target is comprised of two spatially
separated clumps in the rest-frame UV. With ALMA, we have newly detected
spatially resolved [OIII] 88 $\mu$m, [CII] 158 $\mu$m, and their underlying
dust continuum emission. In the whole system of B14-65666, the [OIII] and [CII]
lines have consistent redshifts of $7.1520\pm0.0003$, and the [OIII]
luminosity, $(34.4\pm4.1)\times10^{8}L_{\rm \odot}$, is about three times
higher than the [CII] luminosity, $(11.0\pm1.4)\times10^{8}L_{\rm \odot}$. With
our two continuum flux densities, the dust temperature is constrained to be
$T_{\rm d}\approx50-60$ K under the assumption of the dust emissivity index of
$\beta_{\rm d}=2.0-1.5$, leading to a large total infrared luminosity of
$L_{\rm TIR}\approx1\times10^{12}L_{\rm \odot}$. Owing to our high spatial
resolution data, we show that the [OIII] and [CII] emission can be spatially
decomposed into two clumps associated with the two rest-frame UV clumps whose
spectra are kinematically separated by $\approx200$ km s$^{-1}$. We also find
these two clumps have comparable UV, infrared, [OIII], and [CII] luminosities.
Based on these results, we argue that B14-65666 is a starburst galaxy induced
by a major-merger. The merger interpretation is also supported by the large
specific star-formation rate (defined as the star-formation rate per unit
stellar mass), sSFR$=260^{+119}_{-57}$ Gyr$^{-1}$, inferred from our SED
fitting. Probably, a strong UV radiation field caused by intense star formation
contributes to its high dust temperature and the [OIII]-to-[CII] luminosity
ratio.

We present the Ly$\alpha$ luminosity function (LF) derived from 34 Ly$\alpha$<br />
emitters (LAEs) at $z=7.0$ on the sky of $3.1$ deg$^2$, the largest sample<br />
compared to those in the literature obtained at a redshift $z\gtrsim7$. The LAE<br />
sample is made by deep large-area Subaru narrowband observations conducted by<br />
the Cosmic HydrOgen Reionization Unveiled with Subaru (CHORUS) project. The<br />
$z=7.0$ Ly$\alpha$ LF of our project is consistent with those of the previous<br />
DECam and Subaru studies at the bright and faint ends, respectively, while our<br />
$z=7.0$ Ly$\alpha$ LF has uncertainties significantly smaller than those of the<br />
previous study results. Exploiting the small errors of our measurements, we<br />
investigate the shape of the faint to bright-end Ly$\alpha$ LF. We find that<br />
the $z=7.0$ Ly$\alpha$ LF shape can be explained by the steep slope of $\alpha<br />
\simeq -2.5$ suggested at $z=6.6$, and that there is no clear signature of a<br />
bright-end excess at $z\simeq 7$ claimed by the previous work, which was<br />
thought to be made by the ionized bubbles around bright LAEs whose Ly$\alpha$<br />
photons could easily escape from the partly neutral IGM at $z \simeq 7$. We<br />
estimate the Ly$\alpha$ luminosity densities (LDs) with Ly$\alpha$ LFs at<br />
$z\simeq 6-8$ given by our and the previous studies, and compare the evolution<br />
of the UV-continuum LD estimated with dropouts. The Ly$\alpha$ LD monotonically<br />
decreases from $z\sim 6$ to $8$, and evolves stronger than the UV-continuum LD,<br />
indicative of the Ly$\alpha$ damping wing absorption of the IGM towards the<br />
heart of the reionization epoch.

Using galaxies as background light sources to map intervening Ly a absorption is a novel approach to study the interplay among galaxies, the circumgalactic medium (CGM) and the intergalactic medium. Introducing a new measure of z = 3.1 HI Ly alpha absorption relative to the cosmic mean, Delta NB497, estimated from photometric data of star-forming galaxies at 3.3 less than or similar to z less than or similar to 3.5, we have made two-dimensional Delta NB497 maps in the z = 3.1 SSA22 protocluster region and two control fields (Subaru/XMM-Newton Deep Survey; Great Observatory Optical Deep Survey North) with a spatial resolution of similar to 5 comoving Mpc. The Delta NB497 measurements in the SSA22 field are systematically larger than those in the control fields, and this HI absorption enhancement extends more than 50 comovingMpc. The field-averaged (i. e. similar to 50 comovingMpc scale) Delta NB497 and the overdensity of Ly alpha emitters (LAEs) seem to be correlated, while there is no clear dependency of the Delta NB497 on the local LAE overdensity in a few comoving Mpc scale. These results suggest that diffuse HI gas spreads out in/around the SSA22 protocluster. We have also found an enhancement of Delta NB497 at a projected distance &lt; 100 physical kpc from the nearest z = 3.1 galaxies at least in the SSA22 field, which is probably due to HI gas associated with the CGM of individual galaxies. The HI absorption enhancement in the CGM-scale tends to be weaker around galaxies with stronger Ly alpha emission, which suggests that the Ly alpha escape fraction from galaxies depends on hydrogen neutrality in the CGM.

The physical properties and elemental abundances of the interstellar medium
in galaxies during cosmic reionization are important for understanding the role
of galaxies in this process. We report the Atacama Large
Millimeter/submillimeter Array detection of an oxygen emission line at a
wavelength of 88 micrometers from a galaxy at an epoch about 700 million years
after the Big Bang. The oxygen abundance of this galaxy is estimated at about
one-tenth that of the Sun. The non-detection of far-infrared continuum emission
indicates a deficiency of interstellar dust in the galaxy. A carbon emission
line at a wavelength of 158 micrometers is also not detected, implying an
unusually small amount of neutral gas. These properties might allow ionizing
photons to escape into the intergalactic medium.

We report on the identification of the old stellar population galaxy candidates at z greater than or similar to 5. We developed a new infrared color selection scheme to isolate galaxies with the strong Balmer breaks at z greater than or similar to 5, and applied it to the ultra-deep and wide infrared survey data from the Spitzer Extended Deep Survey (SEDS) and the UKIRT Infrared Deep Sky Survey. The eight objects satisfying K - [3.6] &gt; 1.3 and K - [3.6] &gt; 2.4([3.6] - [4.5]) + 0.6 are selected in the 0.34 deg(2) SEDS Ultra Deep Survey field. Rich multi-wavelength imaging data from optical to far-infrared are also used to reject blending sources and strong nebular line emitters, and we finally obtained the three most likely evolved galaxies at z greater than or similar to 5. Their stacked spectral energy distribution is fitted well with the old stellar population template with M-* = (7.5 +/- 1.5) x 10(10) M-circle dot, star formation rate = 0.9 +/- 0.2M(circle dot) yr(-1), dust A(V) &lt; 1, and age = 0.7 +/- 0.4 Gyr at z = 5.7 +/- 0.6, where the dusty star-forming galaxies at z similar to 2.8 are disfavored because of the faintness in the 24 mu m. The stellar mass density of these evolved galaxy candidates, (6 +/- 4) x 10(4) M-circle dot Mpc(-3), is much lower than that of star-forming galaxies, but the non-zero fraction suggests that initial star-formation and quenching have been completed by z similar to 6.

Using galaxies as background light sources to map the Ly alpha absorption lines is a novel approach to study Damped Ly alpha Absorbers (DLAs). We report the discovery of an intervening z = 3.335 +/- 0.007 DLA along a galaxy sight-line identified among 80 Lyman Break Galaxy (LBG) spectra obtained with our Very Large Telescope/Visible Multi-Object Spectrograph survey in the SSA22 field. The measured DLA neutral hydrogen (H-I) column density is log(N-H I/cm(-2)) = 21.68 +/- 0.17. The DLA covering fraction over the extended background LBG is &gt;70% (2 sigma), yielding a conservative constraint on the DLA area of greater than or similar to 1 kpc(2). Our search for a counterpart galaxy hosting this DLA concludes that there is no counterpart galaxy with star formation rate larger than a few M-circle dot yr(-1), ruling out an unobscured violent star formation in the DLA gas cloud. We also rule out the possibility that the host galaxy of the DLA is a passive galaxy with M-* greater than or similar to 5 x 10(10) M-circle dot or a heavily dust-obscured galaxy with E(B - V) greater than or similar to 2. The DLA may coincide with a large-scale overdensity of the spectroscopic LBGs. The occurrence rate of the DLA is compatible with that of DLAs found in QSO sight-lines.

SPT-CL J2040-4451-spectroscopically confirmed at z = 1.478-is the highest-redshift galaxy cluster yet discovered via the Sunyaev-Zel'dovich effect. SPT-CL J2040-4451 was a candidate galaxy cluster identified in the first 720 deg(2) of the South Pole Telescope Sunyaev-Zel'dovich (SPT-SZ) survey, and has been confirmed in follow-up imaging and spectroscopy. From multi-object spectroscopy with Magellan-I/Baade+ IMACS we measure spectroscopic redshifts for 15 cluster member galaxies, all of which have strong [O Pi]lambda lambda 3727 emission. SPT-CL J2040-4451 has an SZ-measured mass of M-500,(SZ) = 3.2 +/- 0.8 x 10(14)M(circle dot) h(-1) 70, corresponding to M-200,M- (SZ) = 5.8 +/- 1.4 x 10(14)M(circle dot) h(70-)(1.) The velocity dispersion measured entirely from blue star-forming members is sv = 1500 +/- 520 km s(-1). The prevalence of star-forming cluster members (galaxies with &gt; 1.5M(circle dot) yr(-1)) implies that this massive, high-redshift cluster is experiencing a phase of active star formation, and supports recent results showing a marked increase in star formation occurring in galaxy clusters at z greater than or similar to 1.4. We also compute the probability of finding a cluster as rare as this in the SPT-SZ survey to be &gt; 99%, indicating that its discovery is not in tension with the concordance Lambda CDM cosmological model.

We present the results of our wide-field narrow band imaging of the field<br />
around the radio galaxy 53W002 at z = 2.390 with Subaru/Suprime-Cam. A custom<br />
made filter NB413 centered at 4140 \AA\ with the width of 83 \AA\ is used to<br />
observe the 31&#039; x 24&#039; area around the radio galaxy. We detected 204 Ly\alpha<br />
emitters (LAEs) at z = 2.4 with a rest frame equivalent width larger than 25<br />
\AA\ to the depth of 26 AB mag (in NB413). The entire LAE population in the<br />
53W002 field has an average number density and distributions of equivalent<br />
width and size that are similar to those of other fields at z ~ 2. We identify<br />
a significant high density region (53W002F-HDR) that spreads over ~ 5&#039; x 4&#039;<br />
near 53W002 where the LAE number density is nearly four times as large as the<br />
average of the entire field. Using the probability distribution function of<br />
density fluctuation, we evaluate the rareness probability of the 53W002F-HDR to<br />
be 0.9^{+2.4}_{-0.62}%, which corresponds to a moderately rich structure. No<br />
notable environmental dependency at the comoving scale of 10 Mpc is found for<br />
the distributions of the Ly\alpha equivalent width and luminosity in the field.<br />
We also detected 4 Ly\alpha blobs (LABs), one of which is newly discovered.<br />
They are all found to be located in the rims of high density regions. The<br />
biased location and unique morphologies in Ly\alpha suggest that galaxy<br />
interaction play a key role in their formation.

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 &gt;10(4) galaxies at z=8-9, 10(3)-10(4) galaxies at z=11-12, and 50-100 galaxies at z&gt;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 &gt;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 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.