K. Ohta

Publication List Details

Period

1977 - 2008

Number

186

Co-Authors

An extreme EXO: a type 2 QSO at z=1.87 (2008)

Del Moro, A., Watson, M. G., Mateos, S., Akiyama, M., Hashimoto, Y., Tamura, N., ...

We aim to understand the multi-wavelength properties of 2XMM J123204+215255, the source with the most extreme X-ray-to-optical flux ratio amongst a sample of bright X-ray selected EXOs drawn from a...

Model modifications in Schumann resonance intensity caused by a localized ionosphere disturbance over the earthquake epicenter (2008)

Nickolaenko, A. P., Hayakawa, M., Sekiguchi, M., Ando, Y., Ohta, K.

This paper is a further extension of our latest observations and modeling by Hayakawa et al. (2005a), in which we discovered the anomalous behavior of Schumann resonance observed in Japan, in...

Anomalous effect in Schumann resonance phenomena observed in Japan, possibly associated with the Chi-chi earthquake in Taiwan (2008)

Hayakawa, M., Ohta, K., Nickolaenko, A. P., Ando, Y.

The Schumann resonance phenomenon has been monitored at Nakatsugawa (near Nagoya) in Japan since the beginning of 1999, and due to the occurance of a severe earthquake (so-called Chi-chi earthquake)...

Model modifications in Schumann resonance intensity caused by a localized ionosphere disturbance over the earthquake epicenter (2008)

Nickolaenko, A. P., Hayakawa, M., Sekiguchi, M., Ando, Y., Ohta, K.

This paper is a further extension of our latest observations and modeling by Hayakawa et al. (2005a), in which we discovered the anomalous behavior of Schumann resonance observed in Japan, in...

Anomalous effect in Schumann resonance phenomena observed in Japan, possibly associated with the Chi-chi earthquake in Taiwan (2008)

Hayakawa, M., Ohta, K., Nickolaenko, A. P., Ando, Y.

The Schumann resonance phenomenon has been monitored at Nakatsugawa (near Nagoya) in Japan since the beginning of 1999, and due to the occurance of a severe earthquake (so-called Chi-chi earthquake)...

ULF/ELF emissions observed in Japan, possibly associated with the Chi-Chi earthquake in Taiwan (2008)

Ohta, K., Umeda, K., Watanabe, N., Hayakawa, M.

ULF/ELF emission observation has been performed at Nakatsugawa observatory (geographic coordinates; 35.4° N, 137.5° E, Gifu prefecture) since January 1999. The equipment consists of...

ULF/ELF emissions observed in Japan, possibly associated with the Chi-Chi earthquake in Taiwan (2008)

Ohta, K., Umeda, K., Watanabe, N., Hayakawa, M.

ULF/ELF emission observation has been performed at Nakatsugawa observatory (geographic coordinates; 35.4° N, 137.5° E, Gifu prefecture) since January 1999. The equipment consists of...

On the ionospheric perturbation associated with the 2007 Niigata Chuetsu-oki earthquake, as seen from subionospheric VLF/LF network observations (2008)

Hayakawa, M., Horie, T., Yoshida, M., Kasahara, Y., Muto, F., Ohta, K., ...

In order to investigate any precursory effect of ionospheric perturbations associated with the large 2007 Niigata Chuetsu-oki earthquake (16 July 2007) (magnitude, 6.8), we have made full use of our...

VLF-LF radio signals collected at Bari (South Italy): a preliminary analysis on signal anomalies associated with earthquakes (2008)

Biagi, P. F., Piccolo, R., Castellana, L., Maggipinto, T., Ermini, A., Martellucci, S., ...

At the beginning of 2002 an OmniPAL receiver was put into operation at the Department of Physics of Bari University (Southern Italy). The electric field strength of five VLF-LF signals transmitted...

On the ionospheric perturbation associated with the 2007 Niigata Chuetsu-oki earthquake, as seen from subionospheric VLF/LF network observations (2008)

Hayakawa, M., Horie, T., Yoshida, M., Kasahara, Y., Muto, F., Ohta, K., ...

In order to investigate any precursory effect of ionospheric perturbations associated with the large 2007 Niigata Chuetsu-oki earthquake (16 July 2007) (magnitude, 6.8), we have made full use of our...

VLF-LF radio signals collected at Bari (South Italy): a preliminary analysis on signal anomalies associated with earthquakes (2008)

Biagi, P. F., Piccolo, R., Castellana, L., Maggipinto, T., Ermini, A., Martellucci, S., ...

At the beginning of 2002 an OmniPAL receiver was put into operation at the Department of Physics of Bari University (Southern Italy). The electric field strength of five VLF-LF signals transmitted...

Evolution of Star-forming Galaxies seen from Lyman Break Galaxies at $z\sim5$ (2008)

Ohta, K., Yabe, K., Iwata, I., Sawicki, M., Akiyama, M., Tamura, N., ...

Properties of Lyman Break Galaxies at $z\sim5$ are presented and are compared with those at $z\sim 2-3$ LBGs to see evolution of LBGs from $z\sim5$ to $z \sim3-2$. The LBGs at $z\sim5$ are tend to...

Canonical quantization of gauge fields in static space-times with applications to Rindler spaces (2008)

Lenz, F., Ohta, K., Yazaki, K.

The canonical quantization in Weyl gauge of gauge fields in static space-times is presented. With an appropriate definition of transverse and longitudinal components of gauge fields, the Gauss law...

First Detection of 12CO (1--0) Emission from Two Narrow-Line Seyfert 1 Galaxies (2007)

Kawaguchi, T., Nakanishi, K., Kohno, K., Ohta, K., Aoki, K.

In order to investigate how the growth of galactic bulges progresses with the growth of central black holes (BHs), we observed molecular gas (fuel for the coming star formation) in possibly young...

Adaptive Optics Imaging of Lyman Break Galaxies as Progenitors of Spheroids in the Local Universe (2007)

Akiyama, M., Minowa, Y., Kobayashi, N., Ohta, K., Iwata, I.

In order to reveal the stellar mass distribution of z~3 galaxies, we are conducting deep imaging observations of U-dropout Lyman Break Galaxies (LBGs) with Adaptive Optics (AO) systems in K-band,...

Adaptive Optics Rest-Frame V-band Imaging of Lyman Break Galaxies at z~3: High-surface Density Disk-like Galaxies ? (2007)

Akiyama, M., Minowa, Y., Kobayashi, N., Ohta, K., Ando, M., Iwata, I.

In order to reveal the rest-frame V-band morphology of galaxies at z~3, we conducted AO-assisted K-band imaging observations of z~3 LBGs with Mv*-0.5 to Mv*+3.0 mag. LBGs brighter than Mv* have...

High-Resolution Submillimeter Imaging of the Ly-alpha Blob1 in SSA 22 (2007)

Matsuda, Y., Iono, D., Ohta, K., Yamada, T., Kawabe, R., Hayashino, T., ...

We present ~2" resolution submillimeter observations of the submillimeter luminous giant Ly-alpha blob (LAB1) in the SSA 22 protocluster at redshift z=3.1 with the Submillimeter Array (SMA). Although...

Discotic liquid crystals of transition metal complexes 37: a thermotropic cubic mesophase having Pn3m symmetry exhibited by phthalocyanine-based derivatives (2007)

Ichihara, M, Suzuki, A, Hatsusaka, K, Ohta, K

This is a preprint of an article whose final and definitive form has been published in the LIQUID CRYSTALS © 2007 copyright Taylor & Francis; LIQUID CRYSTALS is available online at:...

Syntheses, structures, and mesomorphism of a series of Cu(II) salen complexes with 4-substituted long alkoxy chains (2007)

Abe, Y, Nakazima, N, Tanase, T, Katano, S, Mukai, H, Ohta, K

This is a preprint of an article whose final and definitive form has been published in the MOLECULAR CRYSTALS AND LIQUID CRYSTALS © 2007 copyright Taylor & Francis; MOLECULAR CRYSTALS AND LIQUID...

Discotic Liquid Crystals of Transition Metal Complexes 37†: A Thermotropic Cubic Mesophase having Pn3m Symmetry of Phthalocyanine-based Derivatives (2007)

Ichihara, M, Suzuki, A, Hatsusaka, K, Ohta, K

This is an electronic version of an article published in Liquid Crystals 34(5): 555-567 (2007). Liquid Crystals is available online at informaworldTM with...

MITSuME--Multicolor Imaging Telescopes for Survey and Monstrous Explosions (2007)

Kotani, T., Kawai, N., Yanagisawa, K., Watanabe, J., Arimoto, M., Fukushima, H., ...

Development of MITSuME is reported. Two 50-cm optical telescopes have been built at Akeno in Yamanashi prefecture and at Okayama Astrophysical Observatory (OAO) in Okayama prefecture. Three CCD...

Differential Evolution of the UV Luminosity Function of Lyman Break Galaxies from z~5 to 3 (2007)

Iwata, I., Ohta, K., Tamura, N., Akiyama, M., Aoki, K., Ando, M., ...

(abridged) We report the UV luminosity function (LF) of Lyman break galaxies at z~5 derived from a deep and wide survey using the Subaru/Suprime-Cam. Target fields consist of two blank regions of the...

The Cosmic Evolution Survey (COSMOS): Subaru observations of the HST cosmos field (2007)

Taniguchi, Y., Scoville, N., Murayama, T., Sanders, D. B., Mobasher, B., Aussel, H., ...

We present deep optical imaging observations of 2 square degree area, covered by the Cosmic Evolution Survey (COSMOS), made by the prime-focus camera (Supreme-Cam) on the 8.2 m Subaru Telescope....

A potential galaxy threshing system in the COSMOS field (2007)

Sasaki, S. S., Taniguchi, Y., Scoville, N., Mobasher, B., Aussel, H., Sanders, D. B., ...

We report on the discovery of a new potential galaxy threshing system in the COSMOS 2 square degree field using the prime-focus camera, Suprime-Cam, on the 8.2 m Subaru Telescope. This system...

Different disk structures in the hexagonal columnar mesophases of 2,3-dicyano-6,7,10,11-tetraalkoxy-1,4-diazatriphenylenes and 2,3-dicyano-6,7,10,11-tetraalkoxytriphenylenes (2007)

Ichihara, M, Suzuki, H, Mohr, B, Ohta, K

This is an electronic version of an article published in Liquid Crystals. 34(3): 401-410 (2007). "Liquid Crystals" is available online at:...

A Potential Galaxy Threshing System in the Cosmos Field (2006)

Sasaki, S. S., Taniguchi, Y., Scoville, N., Mobasher, B., Aussel, H., Sanders, D. B., ...

We report on the discovery of a new potential galaxy threshing system in the COSMOS 2 square degree field using the prime-focus camera, Suprime-Cam, on the 8.2 m Subaru Telescope. This system...

Balmer Absorption Lines in FeLoBALs (2006)

Aoki, K., Iwata, I., Ohta, K., Tamura, N., Ando, M., Akiyama, M., ...

We discovered non-stellar Balmer absorption lines in two many-narrow-trough FeLoBALs (mntBALs) by the near-infrared spectroscopy with Subaru/CISCO. Presence of the non-stellar Balmer absorption lines...

Search for the host galaxy of GRB 050904 at z=6.3 (2006)

Aoki, K., Furusawa, H., Ohta, K., Yamada, T., Kawai, N.

We present the results of deep imaging of the field of GRB 050904 with Suprime-Cam on the Subaru 8.2m telescope. We have obtained a narrow-band (130 A) image centered at 9200 A (NB921) and an i'-band...

The Cosmic Evolution Survey (COSMOS): Subaru Observations of the HST COSMOS Field (2006)

Taniguchi, Y., Scoville, N., Murayama, T., Sanders, D. B., Mobasher, B., Aussel, H., ...

We present deep optical imaging observations of 2 square degree area, covered by the Cosmic Evolution Survey (COSMOS), made by the prime-focus Camera (Supreme-Cam) on the 8.2m Subaru Telescope....

Luminosity Dependent Evolution of Lyman Break Galaxies from redshift 5 to 3 (2006)

Iwata, I., Ohta, K., Tamura, N., Akiyama, M., Aoki, K., Ando, M., ...

In this contribution we briefly describe our recent results on the properties of Lyman break galaxies at z~5 obtained from deep and wide blank field surveys using Subaru telescope, and through the...

The End of the Reionization Epoch Probed by Ly-alpha Emitters at z=6.5 in the Subaru Deep Field (2006)

Kashikawa, N., Shimasaku, K., Malkan, M. A., Doi, M., Matsuda, Y., Ouchi, M., ...

We report an extensive search for Lyman-alpha emitters (LAEs) at z=6.5 in the Subaru Deep Field. Subsequent spectroscopy with Subaru and Keck identified eight more LAEs, giving a total of 17...

Ly Alpha Emitters at z=5.7 in the Subaru Deep Field (2006)

Shimasaku, K., Kashikawa, N., Doi, M., Ly, C., Malkan, M. A., Matsuda, Y., ...

We present the properties of Ly Alpha emitters (LAEs) at z = 5.7 in the Subaru Deep Field. A photometric sample of 89 LAE candidates is constructed from narrow-band (NB816) data down to NB816 = 26.0...

Afterglow spectrum of a gamma-ray burst with the highest known redshift z=6.295 (2005)

Kawai, N., Kosugi, G., Aoki, K., Yamada, T., Totani, T., Ohta, K., ...

Gamma-ray bursts (GRBs) and their afterglows have been proposed as an excellent probe to study the evolution of cosmic star formation, the reionization of the intergalactic medium, and the metal...

Evolution of Lyman Break Galaxies From z=5 to 3 (2005)

Iwata, I., Ohta, K., Ando, M., Kiuchi, G., Tamura, N., Akiyama, M., ...

We report the updated UV luminosity function (LF) of Lyman break galaxies (LBGs) at z~5. Combining with lower redshift data, we found that the evolution of UV LF is differential depending on the UV...

Deep Spectroscopic Survey of Lyman Break Galaxies at z~5 (2005)

Ando, M., Ohta, K., Iwata, I., Akiyama, M., Aoki, K., Tamura, N.

We report results of deep optical spectroscopy with Subaru/FOCAS for Lyman Break Galaxy (LBG) candidates at z~5. So far, we made spectroscopic observations for 24 LBG candidates among ~200 bright...

Large-scale Filamentary Structure around the Protocluster at Redshift z=3.1 (2005)

Matsuda, Y., Yamada, T., Hayashino, T., Tamura, H., Yamauchi, R., Murayama, T., ...

We report the discovery of a large-scale coherent filamentary structure of Lyman alpha emitters in a redshift space at z=3.1. We carried out spectroscopic observations to map the three dimensional...

A wide area survey for high-redshift massive galaxies. I. Number counts and clustering of BzKs and EROs (2005)

Kong, X., Daddi, E., Arimoto, N., Renzini, A., Broadhurst, T., Cimatti, A., ...

We have combined deep BRIz' imaging over 2x940 arcmin^2 fields obtained with the Suprime-Cam on the Subaru telescope with JKs imaging with the SOFI camera at the New Technology Telescope to search...

A submm survey of Lyman-alpha haloes in the SA22 protocluster at z=3.1 (2005)

Geach, J. E., Matsuda, Y., Smail, Ian, Chapman, S. C., Yamada, T., Ivison, R. J., ...

We present the results from a submm survey of a sample of 23 giant Lya emitting nebulae in the overdensity at z=3.09 in the SA22 field. These objects, which have become known as Lya Blobs (LABs) have...

Spectroscopy of i-Dropout Galaxies with an NB921-Band Depression in the Subaru Deep Field (2005)

Nagao, T., Kashikawa, N., Malkan, M. A., Murayama, T., Taniguchi, Y., Shimasaku, K., ...

We report new spectroscopy of two star-forming galaxies with strong Ly_alpha emission at z=6.03 and z=6.04 in the Subaru Deep Field. These two objects are originally selected as i'-dropouts (i'-z' >...

The Growth of the Local Void and the Origin of the Local Velocity Anomaly (2005)

Iwata, I., Ohta, K., Nakanishi, K., Chamaraux, P., Roman, A. T.

The Local Void is the nearest void from us and is thought to be playing an important role in the kinematics of the local universe, especially as one of the suspected source of the motion of the Local...

Nobeyama Millimeter Array Observations of GRB 030329: a Decay of Afterglow with Bumps and Molecular Gas in the Host Galaxy (2004)

Kohno, K., Tosaki, T., Okuda, T., Nakanishi, K., Kamazaki, T., Muraoka, K., ...

Nobeyama Millimeter Array was used to observe millimeter-wave afterglow of GRB 030329 at 93 GHz and 141 GHz from 2003 April 6 to 2003 May 30. A sensitive search for CO(J=1-0) emission/absorption from...

The Subaru Deep Field: The Optical Imaging Data (2004)

Kashikawa, N., Shimasaku, K., Yasuda, N., Ajiki, M., Akiyama, M., Ando, H., ...

The Subaru Deep Field (SDF) project is a program of Subaru Observatory to carry out a deep galaxy survey over a blank field as large as 34'x27'. The program consists of very deep multi-band optical...

Dynamic aspect of the chiral phase transition in the mode coupling theory (2004)

Ohnishi, K., Fukushima, K., Ohta, K.

We analyze the dynamic aspect of the chiral phase transition. We apply the mode coupling theory to the linear sigma model and derive the kinetic equation for the chiral phase transition. We challenge...

Tsukushi functions as an organizer inducer by inhibition of BMP activity in cooperation with chordin (2004)

Ohta, K., Lupo, G., Kuriyama, S., Keynes, R., Holt, C.E., Harris, W.A., ...

During chick gastrulation, inhibition of BMP signaling is required for primitive streak formation and induction of Hensen's node. We have identified a unique secreted protein, Tsukushi (TSK), which...

A Strong Lyman-alpha Emitter at z=6.33 in the Subaru Deep Field Selected as an i' Dropout (2004)

Nagao, T., Taniguchi, Y., Kashikawa, N., Kodaira, K., Kaifu, N., Ando, H., ...

We report on the discovery of a star-forming galaxy at z=6.33 in the Subaru Deep Field. This object is selected as a candidate of an i'-dropout, high-redshift galaxy around z=6 because of its red...

A Subaru Search for Ly-alpha Blobs in and around the Proto-cluster Region at Redshift z=3.1 (2004)

Matsuda, Y., Yamada, T., Hayashino, T., Tamura, H., Yamauchi, R., Ajiki, M., ...

We report the properties of the 35 robust candidates of Ly-alpha blobs (LABs), which are larger than 16 arcsec^2 in isophotal area and brighter than 0.7 x 10^-16 ergs s^-1 cm^-2, searched in and...

Growth of massive black holes by super-Eddington accretion (2004)

Kawaguchi, T., Aoki, K., Ohta, K., Collin, S.

Narrow-Line Seyfert 1 galaxies (NLS1s) and Narrow-Line quasars (NLQs) seem to amount to ~ 10-30 % of active galactic nuclei (AGNs) in the local universe. Together with their average accretion rate,...

Chiral Symmetry in Light-Cone Field Theory (2004)

Lenz, F., Ohta, K., Thies, M., Yazaki, K.

An analysis of spontaneously broken chiral symmetry in light-cone field theory is presented. The non-locality inherent to light-cone field theory requires revision of the standard procedure in the...

Large Cosmic Variance in the Clustering Properties of Lyman Alpha Emitters at z~5 (2004)

Shimasaku, K., Hayashino, T., Matsuda, Y., Ouchi, M., Ohta, K., Okamura, S., ...

We reported in a previous paper the discovery of large-scale structure of Lyman Alpha emitters (LAEs) at z=4.86+-0.03 with a projected size of 20 Mpc x 50 Mpc in narrow-band data of a 25' x 45' area...

The synthesis of 7-deazaguanines as potential inhibitors of guanosine triphosphate cyclohydrolase 1 (2004)

Gibson, C.L., La Rosa, S., Ohta, K., Boyle, P.H., Leurquin, F., Lemaçon, A., ...

Variously substituted 7-deazaguanines are of interest as inhibitors of GTP cyclohydrolase I, the first enzyme in the biosynthetic pathway leading to dihydrofolate and tetrahydrobiopterin. Methods are...

The synthesis of 7-deazaguanines as potential inhibitors of guanosine triphosphate cyclohydrolase 1 (2004)

Gibson, C.L., La Rosa, S., Ohta, K., Boyle, P.H., Leurquin, F., Lemaçon, A., ...

Variously substituted 7-deazaguanines are of interest as inhibitors of GTP cyclohydrolase I, the first enzyme in the biosynthetic pathway leading to dihydrofolate and tetrahydrobiopterin. Methods are...

VLF-LF radio signals collected at Bari (South Italy): a preliminary analysis on signal anomalies associated with earthquakes (2004)

P. F. Biagi, R. Piccolo, L. Castellana, T. Maggipinto, A. Ermini, S. Martellucci, ...

At the beginning of 2002 an OmniPAL receiver was put into operation at the Department of Physics of Bari University (Southern Italy). The electric field strength of five VLF-LF signals transmitted...

Subaru Deep Survey. IV. Discovery of a Large-Scale Structure at Redshift \simeq 5 (2003)

Shimasaku, K., Ouchi, M., Okamura, S., Kashikawa, N., Doi, M., Furusawa, H., ...

We report the discovery of a large-scale structure of Lyman alpha emitters (LAEs) at z=4.86 based on wide-field imaging with the prime-focus camera (Suprime-Cam) on the Subaru telescope. We observed...

Lyman Break Galaxies at z~5: Luminosity Function (2003)

Iwata, I., Ohta, K., Tamura, N., Ando, M., Wada, S., Watanabe, C., ...

(abridged) We present results of a search for Lyman break galaxies (LBGs) at z ~ 5 in a 618 square-arcmin field including the HDF-N taken by Subaru Prime Focus Camera. Utilizing the published...

High-resolution imaging of molecular line emission from high- redshift QSOs (2002)

Carilli, C. L., Kohno, K., Kawabe, R., Ohta, K., Henkel, C., Menten, K. M., ...

We present moderate-(1") and high-resolution (0."2) observations of the CO (2-1) emission at 43 GHz and radio continuum emission at 1.47 GHz from the z = 4.7 QSO BRI 1202- 0725 and the z = 4.4 QSO...

High resolution imaging of molecular line emission from high redshift QSOs (2001)

Carilli, C. L., Kohno, K., Kawabe, R., Ohta, K., Henkel, C., Menten, K., ...

We present moderate (1'') and high resolution (0.2'') observations of the CO(2-1) emission at 43 GHz, and radio continuum emission at 1.47 GHz, from the z=4.7 QSO BRI