The zCOSMOS 10k-Bright Spectroscopic Sample (2009)
Lilly, Simon J., Le Brun, Vincent, Maier, Christian, Mainieri, Vincenzo, Mignoli, Marco, Scodeggio, Marco, ...
We present spectroscopic redshifts of a large sample of galaxies with I_(AB) < 22.5 in the COSMOS field, measured from spectra of 10,644 objects that have been obtained in the first two years of...
The Chandra COSMOS Survey. I. Overview and Point Source Catalog (2009)
Elvis, Martin, Civano, Francesca, Vignali, Cristian, Puccetti, Simonetta, Fiore, Fabrizio, Cappelluti, Nico, ...
The Chandra COSMOS Survey (C-COSMOS) is a large, 1.8 Ms, Chandra program that has imaged the central 0.5 deg^2 of the COSMOS field (centered at 10 ^h , +02 ^o ) with an effective exposure of ~160 ks,...
Chemical Evolution of High-Redshift Radio Galaxies (2009)
Matsuoka, Kenta, Nagao, Tohru, Maiolino, Roberto, Marconi, Alessandro, Taniguchi, Yoshiaki
We present new deep optical spectra of 9 high-z radio galaxies (HzRGs) at z > 2.7 obtained with FORS2 on VLT. These rest-frame ultraviolet spectra are used to infer the metallicity of the narrow-line...
The Chandra COSMOS Survey, I: Overview and Point Source Catalog (2009)
Elvis, Martin, Civano, Francesca, Vignali, Cristian, Puccetti, Simonetta, Fiore, Fabrizio, Cappelluti, Nico, ...
The Chandra COSMOS Survey (C-COSMOS) is a large, 1.8 Ms, Chandra} program that has imaged the central 0.5 sq.deg of the COSMOS field (centered at 10h, +02deg) with an effective exposure of ~160ksec,...
The Chandra COSMOS survey - I. Overview and point source catalog (2009)
Elvis, Martin, Civano, Francesca, Vignali, Christian, Puccetti, Simonetta, Fiore, Fabrizio, Cappelluti, Nico, ...
A Traveling Wave based Communication Mechanism for Wireless Sensor Networks (2008)
Yoshiaki Taniguchi, Naoki Wakamiya, Masayuki Murata
Abstract — In this paper, we propose and evaluate a selforganizing communication mechanism for wireless sensor networks where a large number of sensor nodes are deployed. To accomplish...
Nakajima, Aki, Shioya, Yasuhiro, Nagao, Tohru, Saito, Tomoki, Murayama, Takashi, Sasaki, Shunji S., ...
We present our analysis on the clustering properties of star-forming galaxies selected by narrow-band excesses in the Subaru Deep Field. Specifically we focus on Halpha emitting galaxies at z = 0.24...
Star-Forming Galaxies at z=0.24 in the Subaru Deep Field and the Sloan Digital Sky Survey (2008)
Morioka, Taichi, Nakajima, Aki, Taniguchi, Yoshiaki, Shioya, Yasuhiro, Murayama, Takashi, Sasaki, Shunji S.
We make a search for Halpha emitting galaxies at z=0.24 in the Subaru Deep Field (SDF) using the archival data set obtained with the Subaru Telescope. We carefully select Halpha emitters in the...
Yoshiaki Taniguchi, Naoki Wakamiya, Masayuki Murata
The proxy mechanism widely used in WWW systems offers low-delay and scalable delivery of data by means of a “proxy server”. By applying proxy mechanism to video streaming systems, high-quality...
Nagao, Tohru, Sasaki, Shunji, Maiolino, Roberto, Grady, Celestine, Kashikawa, Nobunari, Ly, Chun, ...
We present a new photometric search for high-z galaxies hosting Population III (PopIII) stars based on deep intermediate-band imaging observations obtained in the Subaru Deep Field (SDF), by using...
Nagao, Tohru, Murayama, Takashi, Maiolino, Roberto, Marconi, Alessandro, Kashikawa, Nobunari, Ajiki, Masaru, ...
We report new follow-up spectroscopy of i-dropout galaxies with an NB921-band depression found in the Subaru Deep Field. The NB921-depressed i-dropout selection method is expected to select galaxies...
The HI content of star-forming galaxies at z = 0.24 (2007)
Lah, Philip, Chengalur, Jayaram N., Briggs, Frank H., Colless, Matthew, De Propris, Roberto, Pracy, Michael B., ...
We use observations from the Giant Metrewave Radio Telescope (GMRT) to measure the atomic hydrogen gas content of star-forming galaxies at z = 0.24 (i.e. a look-backtime of ~3 Gyr). The sample of...
Ajiki, Masaru, Taniguchi, Yoshiaki, Murayama, Takashi, Shioya, Yasuhiro, Nagao, Tohru, Sasaki, Shunji S., ...
Recently, Zheng et al. (2005) found evidence for an overdensity of galaxies around a radio-loud quasar, SDSS J0836+0054, at z=5.8 (a five arcmin$^2$ region). We have examined our deep optical imaging...
Ajiki, Masaru, Shioya, Yasuhiro, Taniguchi, Yoshiaki, Murayama, Takashi, Nagao, Tohru, Sasaki, Shunji S., ...
We discuss observational properties of strong emission-line galaxies at low redshift found by our deep imaging survey for high-redshift Ly alpha emitters. In our surveys, we used the narrowband...
An Intermediate-band imaging survey for high-redshift Lyman Alpha Emitters: The Mahoroba-11 (2005)
Yamada, Sanae F., Sasaki, Shunji S., Sumiya, Ryoko, Umeda, Kazuyoshi, Shioya, Yasuhiro, Ajiki, Masaru, ...
We present results of our intermediate-band optical imaging survey for high-$z$ Ly$\alpha$ emitters (LAEs) using the prime focus camera, Suprime-Cam, on the 8.2m Subaru Telescope. In our survey, we...
Narrow-Band Survey of the GOODS Fields: Search for Lyman-Alpha Emitters at z = 5.7 (2005)
Ajiki, Masaru, Mobasher, Bahram, Taniguchi, Yoshiaki, Shioya, Yasuhiro, Nagao, Tohru, Murayama, Takashi, ...
We present results from optical narrow-band lambda_c = 8150A ~ and Delta lambda = 120A) observations of the Great Observatories Origins Deep Survey (GOODS) fields, using Suprime-Cam on the Subaru...
Nagao, Tohru, Motohara, Kentaro, Maiolino, Roberto, Marconi, Alessandro, Taniguchi, Yoshiaki, Aoki, Kentaro, ...
We present a very deep near-infrared spectroscopic observation of a strong Ly_alpha emitter at z=6.33, SDF J132440.6+273607, which we used to search for HeII 1640. This emission line is expected if...
A survey of NB921 dropouts in the Subaru Deep Field (2005)
Shioya, Yasuhiro, Taniguchi, Yoshiaki, Ajiki, Masaru, Nagao, Tohru, Murayama, Takashi, Sasaki, Shunji S., ...
In order to search for high-redshift galaxies beyond $z = 6.6$ in the Subaru Deep Field, we have investigated NB921-dropout galaxies where NB921 is the narrowband filter centered at 919.6 nm with...
New High-Redshift Galaxies at $z$ = 5.8 - 6.5 in the Subaru Deep Field (2005)
Shioya, Yasuhiro, Taniguchi, Yoshiaki, Ajiki, Masaru, Nagao, Tohru, Murayama, Takashi, Sasaki, Shunji, ...
In order to search for high-redshift galaxies around $z \sim 6$ in the Subaru Deep Field, we have investigated NB816-dropout galaxies where NB816 is the narrowband filter centered at 815nm with FWHM...
The HST Cosmos Project: Contribution from the Subaru Telescope (2005)
Taniguchi, Yoshiaki, Scoville, N. Z., Sanders, D. B., Mobasher, B., Aussel, H., Capak, P., ...
The Cosmic Evolution Survey (COSMOS) is a Hubble Space Telescope (HST) treasury project.The COSMOS aims to perform a 2 square degree imaging survey of an equatorial field in $I$(F814W) band, using...
The Intermediate-band Dropout Method: A New Method to Search for High-Redshift Galaxies (2005)
Shioya, Yasuhiro, Taniguchi, Yoshiaki, Ajiki, Masaru, Nagao, Tohru, Murayama, Takashi, Sasaki, Shunji, ...
We propose a new method to search for high-redshift galaxies that is based on an intermediate-band dropout technique rather than the usual broad-band dropout one. In this method, we use an...
Subaru Deep Spectroscopy of a Star-forming Companion Galaxy of BR 1202-0725 at $z=4.7$ (2004)
Ohyama, Youichi, Taniguchi, Yoshiaki, Shioya, Yasuhiro
We present deep spatially-resolved optical spectroscopy of the NW companion galaxy of the quasar BR 1202-0725 at $z=4.7$. Its rest-frame UV spectrum shows star-forming activity in the nuclear region....
Nagao, Tohru, Kawabata, Koji S., Murayama, Takashi, Ohyama, Youichi, Taniguchi, Yoshiaki, Shioya, Yasuhiro, ...
We report on the result of our high quality spectropolarimetric observation for the narrow-line region in a nearby Seyfert 2 galaxy, Mrk 573, by the Subaru Telescope. The polarized flux spectrum of...
A Subaru Search for Lyman-Alpha Emitters at z=5.8 with an Intermediate-Band Filter (2004)
Ajiki, Masaru, Taniguchi, Yoshiaki, Fujita, Shinobu S., Shioya, Yasuhiro, Nagao, Tohru, Murayama, Takashi, ...
We present the results of a survey for Ly-alpha emitters at z ~ 5.8 using a new intermediate-band filter centered at lambda_c = 8275 AA with Delta-lambda_FWHM = 340 AA (i.e., the spectroscopic...
Starburst-AGN Connection: A Lesson from High-z Powerful Radio Galaxies (2004)
Powerful radio galaxies at high redshift are highly useful in studies of early evolution of AGN-hosting galaxies because their observed optical and near infrared light are dominated by their stellar...
Detection of Polarized Broad Emission in the Seyfert 2 Galaxy Mrk 573 (2004)
Nagao, Tohru, Kawabata, Koji S., Murayama, Takashi, Ohyama, Youichi, Taniguchi, Yoshiaki, Sumiya, Ryoko, ...
We report the discovery of the scattered emission from a hidden broad-line region (BLR) in a Seyfert 2 galaxy, Mrk 573, based on our recent spectropolarimetric observation performed at the Subaru...
Faint 6.7 micron galaxies and their contributions to the stellar mass density in the universe (2004)
Sato, Yasunori, Cowie, Lennox L., Kawara, Kimiaki, Matsuhara, Hideo, Okuda, Haruyuki, Sanders, David B., ...
Ohyama, Youichi, Taniguchi, Yoshiaki
We report results of our new spatially-resolved, optical spectroscopy of the giant Ly$\alpha$ nebula around a powerful radio galaxy 1243+036 (4C+03.24) at $z=3.57$. The nebula is extended over $\sim...
Faint 6.7um Galaxies and their Contributions to the Stellar Mass Density in the Universe (2003)
Sato, Yasunori, Cowie, Lennox L., Kawara, Kimiaki, Matsuhara, Hideo, Okuda, Haruyuki, Sanders, David B., ...
We discuss the nature of faint 6.7um galaxies detected with the mid-infrared camera ISOCAM on board the Infrared Space Observatory (ISO). The 23 hour integration on the Hawaii Deep Field SSA13 has...
The Halpha Luminosity Function of the Galaxy Cluster Abell 521 at z = 0.25 (2003)
Umeda, Kazuyoshi, Yagi, Masafumi, Yamada, Sanae F., Taniguchi, Yoshiaki, Shioya, Yasuhiro, Murayama, Takashi, ...
We present an optical multicolor-imaging study of the galaxy cluster Abell 521 at $z = 0.25$, using Suprime-Cam on the Subaru Telescope, covering an area of $32 \times 20$ arcmin$^2$ ($9.4 \times 5.8...
A Subaru Search for Lyman$\alpha$ Emitters at Redshift 5.7 (2003)
Ajiki, Masaru, Taniguchi, Yoshiaki, Fujita, Shinobu S., Shioya, Yasuhiro, Nagao, Tohru, Murayama, Takashi, ...
We present the results of a survey for Ly$\alpha$ emitters at $z\approx 5.7$ based on optical narrow-band ($\lambda_{\rm c} = 8150$ \AA ~ and $\Delta\lambda = 120$ \AA), and broad-band ($B$, $R_{\rm...
Are Two z~6 Quasars Gravitationally Lensed ? (2003)
Yamada, Sanae F., Shioya, Yasuhiro, Taniguchi, Yoshiaki, Murayama, Takashi, Ajiki, Masaru, Nagao, Tohru, ...
Several high-z (z > 5.7) quasars have been found in the course of Sloan Digital Sky Survey. The presence of such very high-z quasars is expected to give constraints on early structure formation. On...
Lyman$\alpha$ Emitters beyond Redshift 5:The Dawn of Galaxy Formation (2003)
Taniguchi, Yoshiaki, Shioya, Yasuhiro, Fujita, Shinobu S., Nagao, Tohru, Murayamaoya, Takashi, Ajiki, Masaru
The 8m class telescopes in the ground-based optical astronomy together with help from the ultra-sharp eye of the Hubble Space Telescope have enabled us to observe forming galaxies beyond redshift...
Subaru High-Dispersion Spectroscopy of Narrow-Line Region in the Seyfert Galaxy NGC 4151 (2003)
Nagao, Tohru, Murayama, Takashi, Shioya, Yasuhiro, Taniguchi, Yoshiaki
We report on a study of forbidden emission-line spectrum of nearby Seyfert 1.5 galaxy NGC 4151 based on the high-resolution (R ~ 45,000) optical spectrum obtained by using the High Dispersion...
The discovery of a very narrow line star-forming object at a redshift of 5.66 (2003)
Taniguchi, Yoshiaki, Ajiki, Masaru, Murayama, Takashi, Nagao, Tohru, Veilleux, Sylvain, Sanders, David B., ...
Yoshiaki Taniguchi, Atsushi Ueoka, Naoki Wakamiya, Masayuki Murata
With the increase in computing power and the proliferation of the Internet, video streaming services have become widely deployed. In this paper, we propose, design, implement, and evaluate a proxy...
Nagao, Tohru, Murayama, Takashi, Shioya, Yasuhiro, Taniguchi, Yoshiaki
In order to examine whether or not high-ionization nuclear emission-line regions (HINERs) in narrow-line regions of active galactic nuclei are dusty, we focus on two high-ionization forbidden...
SDSSp J104433.04$-$012502.2 at $z=5.74$ is Gravitationally Magnified by an Intervening Galaxy (2002)
Shioya, Yasuhiro, Taniguchi, Yoshiaki, Murayama, Takashi, Ajki, Masaru, Nagao, Tohru, Fujita, Shinobu S., ...
During the course of our optical deep survey program on L$\alpha$ emitters at $z \approx 5.7$ in the sky area surrounding the quasar SDSSp J104433.04$-$012502.2 at $z=5.74$, we found that a faint...
Starburst-AGN Connection from High Redshift to the Present Day (2002)
We give a review on possible starburst-AGN (active galactic nuclei) connections from high redshift to the present day. First, we give a historical review on some basic ideas related to the...
A Search for Lyman alpha Emitters at Redshift 3.7 (2002)
Fujita, Shinobu S., Ajiki, Masaru, Shioya, Yasuhiro, Nagao, Tohru, Murayama, Takashi, Taniguchi, Yoshiaki, ...
We present the results of a survey for emission-line objects based on optical intermediate-band ($\lambda_{\rm c}$ = 5736 \AA ~ and $\Delta\lambda$ = 280 \AA) and broad-band ($B$, $V$, $R$, and...
Decomposition of the Superwind in M82 (2002)
Ohyama, Youichi, Taniguchi, Yoshiaki, Iye, Masanori, Yoshida, Michitoshi, Sekiguchi, Kazuhiro, Takata, Tadafumi, ...
We present new optical images ($B$, $V$, and H$\alpha$) of the archetypical starburst/superwind galaxy M82 obtained with the 8.2 m Subaru Telescope to reveal new detailed structures of the...
Effects of a burst of formation of first-generation stars on the evolution of galaxies (2002)
Shioya, Yasuhiro, Taniguchi, Yoshiaki, Murayama, Takashi, Nishiura, Shingo, Nagao, Tohru, Kakazu, Yuko
First-generation (Population III) stars in the universe play an important role inearly enrichment of heavy elements in galaxies and intergalactic medium and thus affect the history of galaxies. The...
Nagao, Tohru, Murayama, Takashi, Shioya, Yasuhiro, Taniguchi, Yoshiaki
We investigate gas metallicity of narrow-line regions in narrow-line Seyfert 1 galaxies (NLS1s) and broad-line ones (BLS1s) in order to examine whether or not there is a difference in the gas...
Implementation and Evaluation of Proxy Caching Mechanisms with Video Quality Adjustment (2002)
Masahiro Sasabe, Yoshiaki Taniguchi, Naoki Wakamiya, Masayuki Murata, Hideo Miyahara
The proxy mechanism widely used in WWW systems o#ers low-delay data delivery by means of "proxy server". By applying the proxy mechanisms to the video streaming system, we expect that...
Proxy Caching Mechanisms with Quality Adjustment for Video Streaming Services (2002)
Masahiro Sasabe, Student Member, Yoshiaki Taniguchi, Naoki Wakamiya, Masayuki Murata, Hideo Miyahara
this paper, we propose proxy caching mechanisms to accomplish high-quality and low-delay video streaming services. In our proposed system, a video stream is divided into blocks for e#- cient use of...
Discovery of Active Galactic Nuclei in Mid- and Far-Infrared Deep Surveys with ISO (2001)
We present a summary on the discovery of active galactic nuclei in mid- and far-infrared deep surveys with use of the Infrared Space Observatory.
Nagao, Tohru, Murayama, Takashi, Shioya, Yasuhiro, Taniguchi, Yoshiaki
In order to examine the prediction that the broad-line radio galaxies (BLRGs) with double-peaked Balmer lines harbor an accretion disk characterized by an advection-dominated accretion flow (ADAF) in...
Taniguchi, Yoshiaki, Shioya, Yasuhiro, Kakazu, Yuko
The most remarkable class of high-redshift objects observed so far is extended Ly$\alpha$ emission-line blobs found in an over-density region at redshift 3.1. They may be either a dust-enshrouded,...
A Shock-Induced Pair of Superbubbles in the High-Redshift Powerful Radio Galaxy MRC 0406-244 (2001)
Taniguchi, Yoshiaki, Ohyama, Youichi, Murayama, Takashi, Yoshida, Michitoshi, Kashikawa, Nobunari, Iye, Masanori, ...
We present new optical spectroscopy of the high-redshift powerful radio galaxy MRC 0406$-$244 at redshift of 2.429. We find that the two extensions toward NW and SE probed in the rest-frame...
Nagao, Tohru, Murayama, Takashi, Taniguchi, Yoshiaki
In order to examine how narrow emission-line flux ratios depend on the Seyfert type, we compiled various narrow emission-line flux ratios of 355 Seyfert galaxies from the literature. We present in...
The [O III]4363 Emitting Region Obscured by Dusty Tori (2001)
Nagao, Tohru, Murayama, Takashi, Taniguchi, Yoshiaki
The emission-line flux ratio of [O III]4363/[O III]5007 is a useful diagnostic for the ionization mechanism and physical properties of narrow-line regions in active galactic nuclei. However, it is...
Submillimeter CO emission from shock-heated gas in the L1157 outflow (2001)
Hirano, Naomi, Taniguchi, Yoshiaki
We present the CO J=6-5, 4-3, and 3-2 spectra from the blueshifted gas of the outflow driven by the low-mass class 0 protostar in the L1157 dark cloud. Strong submillimeter CO emission lines with...
On the Hidden Nuclear Starburst in Arp 220 (2000)
Shioya, Yasuhiro, Trentham, Neil, Taniguchi, Yoshiaki
We construct a starburst model for the hidden starbursts in Arp 220 based on the new Starburst99 models of Leitherer et al. Comparing these stellar population synthesis models with observations, we...
Where is the [O III]4363 emitting region in active galactic nuclei? (2000)
Nagao, Tohru, Murayama, Takashi, Taniguchi, Yoshiaki
The emission-line flux ratio of [O III]4363/[O III]5007 (R_OIII)is a useful diagnostic for the ionization mechanism and physical properties of emission-line regions in active galactic nuclei (AGNs)....
LRG J0239-0134: A Ring Galaxy or a Pair of Superbubbles at z=1 ? (2000)
Taniguchi, Yoshiaki, Murayama, Takashi
The unusual morphology of LRG J0239$-$0134 at $z$ =1.062 has been interpreted as a ring galaxy. Here we propose an alternative idea that the ring-like morphology is attributed to a pair of...
SiO Emission in the Multi-Lobe Outflow associated with IRAS 16293-2422 (2000)
Hirano, Naomi, Mikami, Hitomi, Umemoto, Tomofumi, Yamamoto, Satoshi, Taniguchi, Yoshiaki
We have mapped the thermal emission line of SiO (v = 0; J = 2-1) associated with the quadrupolar molecular outflow driven by the very cold far-infrared source IRAS 16293-2422. The SiO emission is...
A New interpretation of chain galaxies at high redshift (2000)
Taniguchi, Yoshiaki, Shioya, Yasuhiro
We propose a possible new model for the formation of chain galaxies at high redshift. Our model is summarized as follows. Step I: Successive merging of subgalactic gas clumps results in the formation...
Photometric Properties of the Arp 220 Super Star Clusters (2000)
Shioya, Yasuhiro, Taniguchi, Yoshiaki, Trentham, Neil
We investigate the photometric properties of six super stellar clusters (SSCs) seen in both the optical and near-infrared Hubble Space Telescope images of the local ultraluminous starburst galaxy Arp...
X-ray emission from Seyfert 2 galaxies with optical polarized broad lines (2000)
Awaki, Hisamitsu, Ueno, Shiro, Taniguchi, Yoshiaki, Weaver, Kimberly A.
We analyze the 0.5-10 keV spectra of six Seyfert 2 galaxies observed with the X-ray satellite ASCA: Mrk 3, Mrk 348, Mrk 1210, Mrk 477, NGC 7212, and Was 49b. These galaxies were selected based on...
Poststarburst Models of LINERs (2000)
Taniguchi, Yoshiaki, Shioya, Yasuhiro, Murayama, Takashi
Since the discovery of low-ionization nuclear emission-line regions in many galaxies (LINERs), it has been recognized that they constitute a class of active galactic nuclei (AGNs) which are thought...
The High-Ionization Nuclear Emission-Line Region of Seyfert Galaxies (2000)
Nagao, Tohru, Taniguchi, Yoshiaki, Murayama, Takashi
Recently Murayama & Taniguchi proposed that a significant part of the high-ionization nuclear emission-line region (HINER) in Seyfert nuclei arises from the inner wall of dusty tori because type 1...
The Nuclear Activity of the Galaxies in the Hickson Compact Groups (2000)
Shimada, Masashi, Ohyama, Youichi, Nishiura, Shingo, Murayama, Takashi, Taniguchi, Yoshiaki
In order to investigate the nuclear activity of galaxies residing in compact groups of galaxies, we present results of our optical spectroscopic program made at Okayama Astrophysical Observatory. We...
Formation of intermediate-mass black holes in circumnuclear regions of galaxies (2000)
Taniguchi, Yoshiaki, Shioya, Yasuhiro, Tsuru, Takeshi G., Ikeuchi, Satoru
Recent high-resolution X-ray imaging studies have discovered possible candidates of intermediate-mass black holes with masses of $M_\bullet \sim 10^{2-4} \MO$ in circumnuclear regions of many (disk)...
Superwind model of extended Lyman alpha emitters at high redshift (2000)
Taniguchi, Yoshiaki, Shioya, Yasuhiro
We propose a new model for the extended Ly alpha blobs found recently at high redshift z ~ 3. The observational properties of these blobs are; 1) the observed Ly alpha luminosities are ~ 10^{43}...
Dusty Tori of Seyfert Nuclei (2000)
Taniguchi, Yoshiaki, Murayama, Takashi, Mouri, Hideaki
Dusty tori around active galactic nuclei (AGNs) play an important role in the classification of Seyfert galaxies. Therefore, physical properties of dusty tori are of great interest. We briefly...
Discovery of a Low Surface Brightness Object near Seyfert's Sextet (2000)
Murayama, Takashi, Nishiura, Shingo, Nagao, Tohru, Sato, Yasunori, Taniguchi, Yoshiaki, Sanders, D. B.
We report the discovery of a low surface brightness (LSB) object serendipitously found during deep CCD imaging of a compact group of galaxies, Seyfert's Sextet, in VR and I bands. The LSB object is...
Extended High-Ionization Nuclear Emission-Line Region in the Seyfert Galaxy NGC 4051 (1999)
Nagao, Tohru, Murayama, Takashi, Taniguchi, Yoshiaki, Yoshida, Michitoshi
We present an optical spectroscopic analysis of the well-known Seyfert galaxy NGC 4051. The high-ionization nuclear emission-line region (HINER) traced by [Fe X]6374 is found to be spatially extended...
Taniguchi, Yoshiaki, Murayama, Takashi, Nagao, Tohru
Recently growing evidence has been accumulated that the NLS1s are viewed from nearly pole-on viewing angles. However, there has been no theoretical model which explains the following important...
Globular cluster formation triggered by the initial starburst in galaxy formation (1999)
Taniguchi, Yoshiaki, Trentham, Neil, Ikeuchi, Satoru
We propose and investigate a new formation mechanism for globular clusters in which they form within molecular clouds that are formed in the shocked regions created by galactic winds driven by...
New Mid-Infrared Diagnostic of the Dusty Torus Model for Seyfert Nuclei (1999)
Murayama, Takashi, Mouri, Hideaki, Taniguchi, Yoshiaki
We propose a new diagnostic of the ``dusty torus'' model for Seyfert nuclei. Dust grains in the torus are heated by the nuclear continuum, and reradiate mostly in the mid-infrared wavelengths. From...
The Electron Scattering Region in Seyfert Nuclei (1999)
Taniguchi, Yoshiaki, Anabuki, Naohisa
The electron scattering region (ESR) is one of important ingredients in Seyfert nuclei because it makes possible to observe the hidden broad line region (hereafter HBLR) in some type 2 Seyfert nuclei...
Seyfert nuclei are typical active galactic nuclei (AGNs) in the local universe, which are thought to be powered by gas accretion onto a supermassive black hole (SMBH). The dynamical effect exerted...
13CO(J=1-0) Depression in Luminous Starburst Mergers, Revisited (1999)
Taniguchi, Yoshiaki, Ohyama, Youichi, Sanders, D. B.
It is known that merging galaxies with luminous starbursts and high far-infrared luminosities tend to have higher $R_{1-0} =^{12}CO(J=1-0)/^{13}CO(J=1-0)$ integrated line intensity ratios ($R_{1-0}...
Ohyama, Youichi, Taniguchi, Yoshiaki, Hibbard, J. E., Vacca, William D.
We present redshift measurements of four faint galaxies around the archetypal ultraluminous infrared galaxy Arp 220. These galaxies have significantly higher redshifts ($z \sim$ 0.036 -- 0.091) than...
Formation of Quasar Nuclei in the Heart of Ultraluminous Infrared Galaxies (1999)
Taniguchi, Yoshiaki, Shioya, Yasuhiro
We investigate whether or not a supermassive black hole (SMBH) with mass $\gtrsim 10^8 M_\odot$ can be made in the heart of ultraluminous infrared galaxies (ULIGs) during the course of mergers...
What Controls the Star Formation in Luminous Starburst Mergers ? (1998)
Taniguchi, Yoshiaki, Ohyama, Youichi
In order to understand what controls the star formation process in luminous starburst mergers (e.g., NGC 6240, Arp 220, and so on), we investigate observational properties of two samples of...
Optical Versus Mid-Infrared Spectroscopic Classification of Ultraluminous Infrared Galaxies (1998)
Taniguchi, Yoshiaki, Yoshino, Akira, Ohyama, Youichi, Nishiura, Shingo
The origin of huge infrared luminosities of ultraluminous infrared galaxies (ULIGs) is still in question. Recently, Genzel et al. made mid-infrared (MIR) spectroscopy of a large number of ULIGs and...
An Origin of the Huge Far-Infrared Luminosity of Starburst Mergers (1998)
Taniguchi, Yoshiaki, Ohyama, Youichi
Recently Taniguchi and Ohyama found that the higher $^{12}$CO to $^{13}$CO integrated intensity ratios at a transition $J$=1--0, $R = I(^{12}$CO)$/I(^{13}$CO) $\gtrsim 20$, in a sample of starburst...
$^{13}CO(J = 1 -- 0)$ Depression in Luminous Starburst Mergers (1998)
Taniguchi, Yoshiaki, Ohyama, Youichi
It is known that the class of luminous starburst galaxies tends to have higher $R =^{12}CO(J=1--0)/^{13}CO(J=1--0)$ integrated line intensity ratios ($R>20$) than normal spiral galaxies ($R \sim...
Starburst-driven Starbursts in the Heart of Ultraluminous Infrared Galaxies (1998)
Taniguchi, Yoshiaki, Trentham, Neil, Shioya, Yasuhiro
There is increasing evidence for the presence of blue super star clusters in the central regions of ultraluminous infrared galaxies like Arp 220. Ultraluminous galaxies are thought to be triggered by...
Murayama, Takashi, Taniguchi, Yoshiaki
Having found that type 1 Seyfert nuclei have excess [FeVII]6087 emission with respect to type 2s, Murayama & Taniguchi have proposed that the high-ionization nuclear emission-line region (HINER)...
A Multiple Merger Model for the Origin of Ultraluminous Infrared Galaxies (1998)
Taniguchi, Yoshiaki, Shioya, Yasuhiro
It has been often considered that the dissipative collapse caused by a merger of two gas-rich galaxies is responsible for the intense nuclear starbursts or the nonthermal quasar activity in...
Taniguchi, Yoshiaki, Murayama, Takashi
Geometrical and physical properties of dusty tori of Seyfert nuclei probed by the water vapor maser emission at 22 GHz are discussed. We assume that the dusty torus has a simple cylindrical form and...
Near-Infrared Spectroscopy of the High Redshift Quasar S4 0636+68 at z=3.2 (1998)
Murayama, Takashi, Taniguchi, Yoshiaki, Evans, Aaron S., Sanders, D. B., Ohyama, Youichi, Kawara, Kimiaki, ...
We present near-infrared (observed frame) spectra of the high-redshift quasar S4 0636+68 at z=3.2 which was previously thought to be one of a group of ``strong'' Fe II emitters [i.e., F(Fe II...
Where is the coronal line region in active galactic nuclei? (1998)
Murayama, Takashi, Taniguchi, Yoshiaki
We report the new finding that type 1 Seyfert nuclei (S1s) have excess [FeVII]6087 emission with respect to type 2s (S2s). The S1s exhibit broad emission lines which are attributed to ionized gas...
Why Can We Detect Quasar BR1202$-$0725 in Co ? (1997)
Ikuta, Chisato, Arimoto, Nobuo, Sofue, Yoshiaki, Taniguchi, Yoshiaki
We present CO luminosity evolution of both elliptical and spiral galaxies based on a galactic wind model and a bulge-disk model, respectively. We have found that the CO luminosity peaks around the...
Does the Radiative Avalanche Fueling Work in Any Active Galactic Nuclei ? (1997)
Recently Umemura, Fukue, & Mineshige (1997) proposed the radiative avalanche fueling to active galactic nuclei; gas accretion is driven by radiation drag exerted by stellar radiation from...
The Epoch of Major Star Formation in High-z Quasar Hosts (1997)
Taniguchi, Yoshiaki, Arimoto, Nobuo, Murayama, Takashi, Evans, Aaron S., Sanders, David B., Kawara, Kimiaki
We present the results of our observing program on near infrared spectroscopy of high-redshift quasars which have been undertaken both at Kitt Peak National Observatory and at Mauna Kea Observatory,...
The most Distant [OIII]-emitting Quasar PKS 1937-101 at redshift 3.8 (1997)
Taniguchi, Yoshiaki, Murayama, Takashi, Kawara, Kimiaki, Arimoto, Nobuo
We report the discovery of a high-z quasar with unambiguous [OIII]5007 emission; PKS 1937-101 at redshift 3.8. This quasar, however, shows little evidence for rest-frame ultraviolet and optical FeII...
Why Does NGC 1068 Have a More Powerful Active Galactic Nucleus than NGC 4258 ? (1997)
Murayama, Takashi, Taniguchi, Yoshiaki
The nuclear gas kinematics probed by water vapor maser emission has shown that two nearby active galaxies, NGC 1068 and NGC 4258, have a supermassive object in their nuclei and their masses are...