Masayuki Akiyama

Publication List Details

Period

1998 - 2009

Number

44

Co-Authors

Stellar Populations of Lyman Alpha Emitters at z = 3 - 4 Based on Deep Large Area Surveys in the Subaru-SXDS/UKIDSS-UDS Field (2009)

Ono, Yoshiaki, Ouchi, Masami, Shimasaku, Kazuhiro, Akiyama, Masayuki, Dunlop, James, Farrah, Duncan, ...

We investigate the stellar populations of Lyman alpha emitters (LAEs) at z=3.1 and 3.7 in 0.65 deg^2 of the Subaru/XMM-Newton Deep Field, based on rest-frame UV-to-optical photometry obtained from...

Lyman Break Galaxies at z~5: Rest-Frame UV Spectra. III (2009)

Kajino, Hiroki, Ohta, Kouji, Iwata, Ikuru, Yabe, Kiyoto, Yuma, Suraphong, Akiyama, Masayuki, ...

We present results of optical spectroscopic observations of candidates of Lyman Break Galaxies (LBGs) at $z \sim 5$ in the region including the GOODS-N and the J0053+1234 region by using GMOS-N and...

Evidence of a link between the evolution of clusters and their AGN fraction (2009)

Van Breukelen, Caroline, Simpson, Chris, Rawlings, Steve, Akiyama, Masayuki, Bonfield, David, Clewley, Lee, ...

We discuss the optical properties, X-ray detections and active galactic nucleus (AGN) populations of four clusters at z ~ 1 in the Subaru–XMM Deep Field (SXDF). The velocity distribution and...

Photometric H alpha and [O II] Luminosity Function of SDF and SXDF Galaxies: Implications for Future Baryon Oscillation Surveys (2009)

Sumiyoshi, Masanao, Totani, Tomonori, Oshige, Shunsuke, Glazebrook, Karl, Akiyama, Masayuki, Morokuma, Tomoki, ...

Efficient selection of emission line galaxies at z > 1 by photometric information in wide field surveys is one of the keys for future spectroscopic surveys to constrain dark energy using the baryon...

Evidence of a link between the evolution of clusters and their AGN fraction (2009)

Van Breukelen, Caroline, Simpson, Chris, Rawlings, Steve, Akiyama, Masayuki, Bonfield, David, Clewley, Lee, ...

We discuss the optical properties, X-ray detections, and Active Galactic Nucleus (AGN) populations of four clusters at z ~ 1 in the Subaru-XMM Deep Field (SXDF). The velocity distribution and...

Photometric H alpha and [O II] luminosity function of SDF and SXDF galaxies: implications for future baryon oscillation surveys (2009)

Sumiyoshi, Masanao, Totani, Tomonori, Oshige, Shunsuke, Glazebrook, Karl, Akiyama, Masayuki, Morokuma, Tomoki, ...

Efficient selection of emission line galaxies at z > 1 by photometric information in wide field surveys is one of the keys for future spectroscopic surveys to constrain dark energy using the baryon...

Photometric H alpha and [O II] luminosity function of SDF and SXDF galaxies: implications for future baryon oscillation surveys (2009)

Sumiyoshi, Masanao, Totani, Tomonori, Oshige, Shunsuke, Glazebrook, Karl, Akiyama, Masayuki, Morokuma, Tomoki, ...

Efficient selection of emission line galaxies at z > 1 by photometric information in wide field surveys is one of the keys for future spectroscopic surveys to constrain dark energy using the baryon...

The Stellar Populations of Lyman Break Galaxies at z~5 (2008)

Yabe, Kiyoto, Ohta, Kouji, Iwata, Ikuru, Sawicki, Marcin, Tamura, Naoyuki, Akiyama, Masayuki, ...

We present the results of Spectral Energy Distribution(SED) fitting analysis for Lyman Break Galaxies(LBGs) at z~5 in the GOODS-N and its flanking fields (the GOODS-FF). With the publicly available...

Discovery of a Giant Lya Emitter Near the Reionization Epoch (2008)

Ouchi, Masami, Ono, Yoshiaki, Egami, Eiichi, Saito, Tomoki, Oguri, Masamune, McCarthy, Patrick J., ...

We report the discovery of a giant Lya emitter (LAE) with a Spitzer/IRAC counterpart near the reionization epoch at z=6.595. The giant LAE is found from the extensive 1 deg^2 Subaru narrow-band...

Differential Evolution of Lyman Break Galaxies from $z$=5 to 3 (2008)

Iwata, Ikuru, Ohta, Kouji, Sawicki, Marcin, Tamura, Naoyuki, Akiyama, Masayuki, Aoki, Kentaro

We briefly summarize our findings from the unbiased surveys for $z$$\sim$5 LBGs based on Subaru/Suprime-Cam and follow-up optical spectroscopy.

The Stellar Populations of Lyman Break Galaxies at $z\sim5$ (2008)

Yabe, Kiyoto, Ohta, Kouji, Iwata, Ikuru, Sawicki, Marcin, Tamura, Naoyuki, Akiyama, Masayuki, ...

We present the results of Spectral Energy Distribution (SED) fitting analysis for Lyman Break Galaxies (LBGs) at $z\sim5$ in the GOODS-N and its flanking fields. From the SED fitting for $\sim100$...

The Subaru/XMM-Newton Deep Survey (SXDS): III. X-Ray Data (2008)

Ueda, Yoshihiro, Watson, Michael G., Stewart, Ian M., Akiyama, Masayuki, Schwope, Axel D., Lamer, Georg, ...

We present the X-ray source catalog in the Subaru/XMM-Newton deep survey. A continuous area of 1.14 deg^2 centered at R.A. = 02h18m and Dec. = -05d is mapped by seven pointings with XMM-Newton...

Subaru/MOIRCS Near-Infrared Imaging in the Proto-Cluster Region at z=3.1 (2008)

Uchimoto, Yuka Katsuno, Suzuki, Ryuji, Tokoku, Chihiro, Ichikawa, Takashi, Konishi, Masahiro, Yoshikawa, Tomohiro, ...

We present the results of deep near-infrared imaging observations of the z=3.1 proto-cluster region in the SSA22a field taken by MOIRCS mounted on the Subaru Telescope. We observed a 21.7 arcmin^2...

The Subaru/XMM-Newton Deep Survey (SXDS) - VI. Properties of Active Galactic Nuclei Selected by Optical Variability (2007)

Morokuma, Tomoki, Doi, Mamoru, Yasuda, Naoki, Akiyama, Masayuki, Sekiguchi, Kazuhiro, Furusawa, Hisanori, ...

We present the properties of active galactic nuclei (AGN) selected by optical variability in the Subaru/XMM-Newton Deep Field (SXDF). Based on the locations of variable components and light curves,...

The Subaru/XMM-Newton Deep Survey (SXDS) - V. Optically Faint Variable Object Survey (2007)

Morokuma, Tomoki, Doi, Mamoru, Yasuda, Naoki, Akiyama, Masayuki, Sekiguchi, Kazuhiro, Furusawa, Hisanori, ...

We present our survey for optically faint variable objects using multi-epoch (8-10 epochs over 2-4 years) $i'$-band imaging data obtained with Subaru Suprime-Cam over 0.918 deg$^2$ in the...

The Subaru/XMM-Newton Deep Survey (SXDS). IV. Evolution of Lya Emitters from z=3.1 to 5.7 in the 1 deg^2 Field: Luminosity Functions and AGN (2007)

Ouchi, Masami, Shimasaku, Kazuhiro, Akiyama, Masayuki, Simpson, Chris, Saito, Tomoki, Ueda, Yoshihiro, ...

We present luminosity functions (LFs) and various properties of Lya emitters (LAEs) at z=3.1, 3.7, and 5.7, in a 1 deg^2 sky of the Subaru/XMM-Newton Deep Survey (SXDS) Field. We obtain a photometric...

Deep Spectroscopy of Systematically Surveyed Extended Lyman-alpha Sources at z~3-5 (2007)

Saito, Tomoki, Shimasaku, Kazuhiro, Okamura, Sadanori, Ouchi, Masami, Akiyama, Masayuki, Yoshida, Michitoshi, ...

Spatially extended Ly-alpha sources that are faint and/or compact in coninuum are candidates for extremely young (~< 10^7 yrs) galaxies at high redshifts. We present medium-resolution (R~2000)...

Lyman Break Galaxies at z~5: Rest-frame UV Spectra II (2007)

Ando, Masataka, Ohta, Kouji, Iwata, Ikuru, Akiyama, Masayuki, Aoki, Kentaro, Tamura, Naoyuki

We present the results of spectroscopy of Lyman Break Galaxies (LBGs) at z~5 in the J0053+1234 field with the Faint Object Camera and Spectrograph on the Subaru telescope. Among 5 bright candidates...

CO Observations of a FeLoBAL Quasar with an H alpha Absorption Line at z=2.3 (2007)

Ohta, Kouji, Kiuchi, Gaku, Nakanishi, Kouichiro, Aoki, Kentaro, Iwata, Ikuru, Akiyama, Masayuki, ...

SDSS J083942.11+380526.3 is an Iron Low-ionization Broad Absorption Line (FeLoBAL) quasar at z = 2.3, and Aoki et al. (2006) recently found the presence of an H alpha absorption line in the broad H...

MOIRCS Deep Survey. II. Clustering Properties of K-band Selected Galaxies in GOODS-North Region (2007)

Ichikawa, Takashi, Suzuki, Ryuji, Tokoku, Chihiro, Katsuno-Uchimoto, Yuka, Konishi, Masahiro, Yoshikawa, Tomohiro, ...

We present the first measurement of clustering properties of low mass galaxies with a stellar mass down to M_*~10^9 Msun at 1

The Long Faint Tail of the High-Redshift Galaxy Population (2006)

Sawicki, Marcin, Iwata, Ikuru, Ohta, Kouji, Thompson, David, Tamura, Naoyuki, Akiyama, Masayuki, ...

We study the properties of very faint, sub-L* Lyman break galaxies at z~2-5 - thus far a largely neglected but numerically and energetically very important population. We find that the LBG luminosity...

MOIRCS Deep Survey. I: DRG Number Counts (2006)

Kajisawa, Masaru, Konishi, Masahiro, Suzuki, Ryuji, Tokoku, Chihiro, Uchimoto, Yuka Katsuno, Yoshikawa, Tomohiro, ...

We use very deep near-infrared imaging data taken with Multi-Object InfraRed Camera and Spectrograph (MOIRCS) on the Subaru Telescope to investigate the number counts of Distant Red Galaxies (DRGs)....

Radio imaging of the Subaru/XMM-Newton Deep Field - I. The 100-microJy catalogue, optical identifications, and the nature of the faint radio source population (2006)

Simpson, Chris, Martinez-Sansigre, Alejo, Rawlings, Steve, Ivison, Rob, Akiyama, Masayuki, Sekiguchi, Kazuhiro, ...

We describe deep radio imaging at 1.4-GHz of the 1.3 square degree Subaru/XMM-Newton Deep Field (SXDF), made with the Very Large Array in B and C configurations. We present a radio map of the entire...

Discovery of H alpha absorption in the unusual broad absorption line quasar SDSS J083942.11+380526.3 (2006)

Aoki, Kentaro, Iwata, Ikuru, Ohta, Kouji, Ando, Masataka, Akiyama, Masayuki, Tamura, Naoyuki

We discovered an H alpha absorption in a broad H alpha emission line of an unusual broad absorption line quasar, SDSS J083942.11+380526.3 at z=2.318, by near-infrared spectroscopy with the Cooled...

Systematic Survey of Extended Lyman-alpha Sources over z~3-5 (2006)

Saito, Tomoki, Shimasaku, Kazuhiro, Okamura, Sadanori, Ouchi, Masami, Akiyama, Masayuki, Yoshida, Michitoshi

Spatially extended Ly-alpha sources which are faint and compact in coninuum are candidates for extremely young galaxies (age of ~

Deficiency of large equivalent width Lyman-alpha emission in luminous Lyman break galaxies at z~5-6? (2006)

Ando, Masataka, Ohta, Kouji, Iwata, Ikuru, Akiyama, Masayuki, Aoki, Kentaro, Tamura, Naoyuki

We report a deficiency of luminous Lyman break galaxies (LBGs) with a large rest-frame equivalent width (EW_rest) of Lyman-alpha emission at z~5-6. Combining our spectroscopic sample of LBGs at z~5...

Host Galaxies of Hard X-ray Selected Type-2 Active Galactic Nuclei at Intermediate Redshifts (2006)

Kiuchi, Gaku, Ohta, Kouji, Akiyama, Masayuki, Aoki, Kentaro, Ueda, Yoshihiro

We study properties of the host galaxies of 15 hard X-ray selected type-2 active galactic nuclei (AGNs) at intermediate redshifts (0.05$

The Number Density of Old Passively-Evolving Galaxies at z=1 in the Subaru/XMM-Newton Deep Survey Field (2005)

Yamada, Toru, Kodama, Tadayuki, Akiyama, Masayuki, Furusawa, Hisanori, Iwata, Ikuru, Kajisawa, Masaru, ...

We obtained the number counts and the rest-frame B-band luminosity function of the color-selected old passively-evolving galaxies (OPEGs) at z=1 with very high statistical accuracy using a large and...

Host Galaxies of the High-redshift AGNs in the GOODS Fields (2005)

Akiyama, Masayuki

The star-formation rates and the stellar masses of the host galaxies of AGNs at high-redshifts are keys to understanding the evolution of the relation between the mass of the spheroidal component of...

Lyman Break Galaxies at $z\sim5$: Rest-Frame UV Spectra (2004)

Ando, Masataka, Ohta, Kouji, Iwata, Ikuru, Watanabe, Chisato, Tamura, Naoyuki, Akiyama, Masayuki, ...

We report initial results for spectroscopic observations of candidates of Lyman Break Galaxies (LBGs) at $z\sim5$ in a region centered on the Hubble Deep Field-North by using the Faint Object Camera...

Near-Infrared Colors of Hard X-ray Selected Active Galactic Nuclei (2004)

Watanabe, Chisato, Ohta, Kouji, Akiyama, Masayuki, Ueda, Yoshihiro

We present results of near-infrared photometry (J, H, K_S) for a sample of active galactic nuclei (AGNs) obtained from hard X-ray surveys with ASCA. The sample covers the AGNs at z=0.1-1 with...

Cosmological Evolution of the Hard X-ray AGN Luminosity Function and the Origin of the Hard X-ray Background (2003)

Ueda, Yoshihiro, Akiyama, Masayuki, Ohta, Kouji, Miyaji, Takamitsu

We investigate the cosmological evolution of the hard X-ray luminosity function (HXLF) of Active Galactic Nuclei (AGN) in the 2-10 keV luminosity range of 10^{41.5} - 10^{46.5} erg s^-1 as a function...

Optical Identification of the ASCA Lynx Deep Survey: An Association of QSOs and a Supercluster at z=1.3? (2003)

Ohta, Kouji, Akiyama, Masayuki, Ueda, Yoshihiro, Yamada, Toru, Nakanishi, Kouichiro, Dalton, Gavin B., ...

Results of optical identification of the ASCA Lynx deep survey are presented. Six X-ray sources are detected in the 2-7 keV band using the SIS in a 20'x20' field of view with fluxes larger than...

Optical Identification of the ASCA Medium Sensitivity Survey in the Northern Sky: Nature of Hard X-ray-selected Luminous Active Galactic Nuclei (2003)

Akiyama, Masayuki, Ueda, Yoshihiro, Ohta, Kouji, Takahashi, Tadayuki, Yamada, Toru

We present the results of optical spectroscopic identifications of a bright subsample of 2-10keV hard X-ray selected sources from the ASCA Medium Sensitivity Survey in the northern sky. The flux...

Chandra Observations and Optical Identification of Hard X-ray Sources Discovered with ASCA (2002)

Watanabe, Shin, Akiyama, Masayuki, Ueda, Yoshihiro, Ohta, Kouji, Mushotzky, Richard, Takahashi, Tadayuki, ...

We present the first results of the Chandra and optical follow-up observations of hard X-ray sources detected in the ASCA Medium Sensitivity Survey (AMSS). Optical identifications are made for five...

A candidate of a type-2 QSO at z=0.9: Large X-ray absorption with a strong broad-H-alpha emission line (2001)

Akiyama, Masayuki, Ohta, Kouji, Ueda, Yoshihiro

Deep hard X-ray and near infrared observations of a type-2 radio-quiet QSO candidate at z=0.9, AXJ08494+4454, are reported. The 0.5-10keV Chandra X-ray Observatory spectrum of AXJ08494+4454 is hard,...

AGN Population at 10^-13 erg s-1 cm-2: Results from Optical Identification of ASCA Surveys (2001)

Akiyama, Masayuki

In this paper, results of optical identification of ASCA surveys are summarized. To understand luminous AGNs in the z

An Extremely Red Nucleus in an Absorbed QSO at z=0.65 (2000)

Akiyama, Masayuki, Ohta, Kouji

The results of K-band-imaging observations of a candidate of an absorbed QSO at z=0.653, AX J131831+3341, are presented. The B-K color of the object is 4.85 mag, which is much redder than...

The hardest X-ray source in the ASCA Large Sky Survey: Discovery of a new type 2 Seyfert (1998)

Sakano, Masaaki, Koyama, Katsuji, Tsuru, Takeshi, Awaki, Hisamitsu, Ueda, Yoshihiro, Takahashi, Tadayuki, ...

We present results of ASCA deep exposure observations of the hardest X-ray source discovered in the ASCA Large Sky Survey (LSS) project, designated as AX J131501+3141. We extract its accurate X-ray...