Search Publications
Cosmology from cosmic shear power spectra with Subaru Hyper Suprime-Cam first-year data
Strauss, Michael A.; Wang, Shiang-Yu; Sifón, Cristóbal +34 more
We measure cosmic weak lensing shear power spectra with the Subaru Hyper Suprime-Cam (HSC) survey first-year shear catalog covering 137 deg2 of the sky. Thanks to the high effective galaxy number density of ∼17 arcmin-2, even after conservative cuts such as a magnitude cut of i < 24.5 and photometric redshift cut of 0.3 ≤ …
Big Three Dragons: A z = 7.15 Lyman-break galaxy detected in [O III] 88 µm, [C II] 158 µm, and dust continuum with ALMA
Ono, Yoshiaki; Ouchi, Masami; Harikane, Yuichi +18 more
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, MUV ≈ -22.4, and has been spectroscopically identified in Lyα with a small rest-frame equivalent width of ≈4 Å. A previous Hubble Space TElescope (HST) image has shown th…
Boötes. IV. A new Milky Way satellite discovered in the Subaru Hyper Suprime-Cam Survey and implications for the missing satellite problem
Strauss, Michael A.; Wang, Shiang-Yu; Ishigaki, Miho N. +13 more
We report on the discovery of a new Milky Way (MW) satellite in Boötes based on data from the ongoing Hyper Suprime-Cam (HSC) Subaru Strategic Program (SSP). This satellite, named Boötes IV, is the third ultra-faint dwarf that we have discovered in the HSC-SSP. We have identified a statistically significant (32.3σ) overdensity of stars with charac…
Environmental impacts on molecular gas in protocluster galaxies at z ∼ 2
Tamura, Yoichi; Kohno, Kotaro; Suzuki, Tomoko L. +12 more
We present the results from ALMA CO(3-2) observations of 66 Hα-selected galaxies in three protoclusters around radio galaxies: PKS 1138-262 (z = 2.16), USS 1558-003 (z = 2.53), and 4C 23.56 (z = 2.49). The pointing areas have an overdensity of ∼100 compared to the mean surface number density of galaxies in field environments. We detect the CO emis…
Fluctuation of the background sky in the Hubble Extremely Deep Field (XDF) and its origin
Matsumoto, Toshio; Tsumura, Kohji
We performed a fluctuation analysis of the Hubble Extremely Deep Field (XDF) at four optical wavelength bands and found large fluctuations that are significantly brighter than those expected for ordinary galaxies. Good cross-correlations with flat spectra are found down to {0{^''.}2}, indicating the existence of a spatial structure even…
The UV spectral slope β and stellar population of most active star-forming galaxies at z ∼ 4
Yamada, Toru; Yamanaka, Satoshi
We investigate a stellar population of star-forming galaxies at z ∼ 4 by focusing on the slope of their rest-frame ultraviolet (UV) continuum, β, where fλ ∝ λβ. We investigate a sample of bright Lyman break galaxies (LBGs) with i' ≤ 26.0 in the Subaru/XMM-Newton Deep Survey field by using a spectral energy distribution fittin…
Extended star-forming regions within galaxies in a dense proto-cluster core at z = 2.53
Suzuki, Tomoko L.; Minowa, Yosuke; Koyama, Yusei +5 more
At z ∼ 2, star formation activity is thought to be high even in high-density environments such as galaxy clusters and proto-clusters. One of the critical but outstanding issues is if the structural growth of star-forming galaxies can differ depending on their surrounding environments. In order to investigate how galaxies grow their structures and …
Searches for Population III pair-instability supernovae: Impact of gravitational lensing magnification
Oguri, Masamune; Koyama, Yusei; Nomoto, Ken'ichi +3 more
Superluminous supernovae have been proposed to arise from Population III progenitors that explode as pair-instability supernovae (PISNe). Population III stars are the first generation of stars in the Universe, and are thought to have formed as late as z ∼ 6. Future near-infrared imaging facilities such as ULTIMATE-Subaru will potentially be able t…
Ground-based Paα narrow-band imaging of local luminous infrared galaxies. II. Bulge structure and star formation activity
Komugi, Shinya; Takahashi, Hidenori; Doi, Mamoru +8 more
We present properties of two types of bulges (classical and pseudobulges) in 20 luminous infrared galaxies observed in the near infrared of the H, Ks, and 1.91µm narrow-band targeting of the hydrogen Paα emission line by the University of Tokyo Atacama Observatory 1 m telescope. To classify the two types of bulges, we first perfor…