Goto, Tomotsugu, Hanami, Hitoshi, Im, Myungshin, Imai, Koji, Inami, Hanae, Ishigaki, Tsuyoshi, ...
There is a huge gap between properties of red-sequence selected massive galaxy clusters at z3. It is important to understand when and how the z>3 proto-clusters evolve into passive clusters at z1,...
Asphericity in Supernova Explosions from Late-Time Spectroscopy (2008)
Maeda, Keiichi, Kawabata, Koji, Mazzali, Paolo A., Tanaka, Masaomi, Valenti, Stefano, Nomoto, Ken'ichi, ...
Core-collapse supernovae (CC-SNe) are the explosions that announce the death of massive stars. Some CC-SNe are linked to long-duration gamma-ray bursts (GRBs) and are highly aspherical. One important...
Asphericity in supernova explosions from late-time spectroscopy (2008)
Maeda, Keiichi, Kawabata, Koji, Mazzali, Paolo A., Tanaka, Masaomi, Valenti, Stefano, Nomoto, Ken'ichi, ...
Near-infrared and Mid-infrared Spectroscopy with the Infrared Camera (IRC) for AKARI (2007)
Ohyama, Youichi, Onaka, Takashi, Matsuhara, Hideo, Wada, Takehiko, Kim, Woojung, Fujishiro, Naofumi, ...
The Infrared Camera (IRC) is one of the two instruments on board the AKARI satellite. In addition to deep imaging from 1.8-26.5um for the pointed observation mode of the AKARI, it has a spectroscopic...
Matsuhara, Hideo, Wada, Takehiko, Pearson, Chris P., Oyabu, Shinki, Im, Myungshin, Imai, Koji, ...
We present the results of optical identifications for 257 mid-infrared sources detected with a deep 15um survey over approximately 80 arcmin^2 area in the AKARI performance verification field near...
The Infrared Camera (IRC) deep survey in the performance verification phase (2007)
Wada, Takehiko, Oyabu, Shinki, Ita, Yoshifusa, Matsuhara, Hideo, Pearson, Chris P., Onaka, Takashi, ...
We report the first results of a near- and mid- infrared deep survey with the Infrared Camera (IRC) onboard AKARI in the performance verification phase. Simultaneous observations by the NIR, MIR-S...
AKARI infrared imaging of reflection nebulae IC4954 and IC4955 (2007)
Ishihara, Daisuke, Onaka, Takashi, Kaneda, Hidehiro, Suzuki, Toyoaki, Kataza, Hirokazu, Sakon, Itsuki, ...
We present the observations of the reflection nebulae IC4954 and IC4955 region with the Infrared Camera (IRC) and the Far-Infrared Surveyor (FIS) on board the infrared astronomical satellite AKARI...
Detection of an H-alpha Emission Line on a Quasar, RX J1759.4+6638, at z=4.3 with AKARI (2007)
Oyabu, Shinki, Wada, Takehiko, Ohyama, Youichi, Matsuhara, Hideo, Takagi, Toshinobu, Nakagawa, Takao, ...
We report the detection of an H-alpha emission line in the low resolution spectrum of a quasar, RX J1759.4+6638, at a redshift of 4.3 with the InfraRed Camera (IRC) onboard the AKARI. This is the...
AKARI observations of circumstellar dust in the globular clusters NGC104 and NGC362 (2007)
Ita, Yoshifusa, Tanabe, Toshihiko, Matsunaga, Noriyuki, Nakada, Yoshikazu, Matsuura, Mikako, Onaka, Takashi, ...
We report preliminary results of AKARI observations of two globular clusters, NGC104 and NGC362. Imaging data covering areas of about 10x10 arcmin^2 centered on the two clusters have been obtained...
Lee, Hyung Mok, Im, Myungshin, Wada, Takehiko, Shim, Hyunjin, Kim, Seong Jin, Lee, Myung Gyoon, ...
We present the properties of 11 $\mu$m selected sources detected in the early data of the North Ecliptic Pole Deep (NEP-Deep) Survey of AKARI. The data set covers 6 wavelength bands from 2.5 to 11...
The infrared astronomical mission AKARI (2007)
Murakami, Hiroshi, Baba, Hajime, Barthel, Peter D., Clements, David L., Cohen, Martin, Doi, Yasuo, ...
Deep extragalactic surveys around the Ecliptic Poles with AKARI (ASTRO-F) (2006)
Matsuhara, Hideo, Wada, Takehiko, Matsuura, Shuji, Nakagawa, Takao, Kawada, Mitsunobu, Ohyama, Youichi, ...
AKARI (formerly ASTRO-F) is an infrared space telescope designed for an all-sky survey at 10-180 mum, and deep pointed surveys of selected areas at 2-180 mum. The deep pointed surveys with AKARI will...
Kawabata, Koji S., Ohyama, Youichi, Ebizuka, Noboru, Takata, Tadafumi, Yoshida, Michitoshi, Isogai, Mizuki, ...
We present low-resolution ($R\sim 90$) and medium-resolution ($R\sim 2500$) spectropolarimetry of Nova V475 Sct with the HBS instrument, mounted on the 0.91-m telescope at the Okayama Astrophysical...
Misawa, Toru, Kashikawa, Nobunari, Ohyama, Youichi, Hashimoto, Tetsuya, Iye, Masanori
We carried out a Subaru and UKIRT near infrared imaging survey for H-alpha emitting galaxies around two pair quasar systems (Q0301-005/Q0302-003 and Q2343+125/Q2344+125), and a triple quasar system...
Dark and stellar matter in strong lensing galaxies from a joint lensing and stellar dynamics (2005)
Hamana, Takashi, Ohyama, Youichi, Chiba, Masashi, Kashikawa, Nobunari
We present Subaru spectroscopy of the early-type lensing galaxies in the lens systems HST14113+5211 (z=0.464) and B2045+265 (z=0.868), being aimed at measuring the velocity dispersion of the lensing...
An asymmetric energetic type Ic supernova viewed off-axis, and a link to gamma ray bursts (2005)
Mazzali, Paolo A., Kawabata, Koji S., Maeda, Keiichi, Nomoto, Ken'ichi, Filippenko, Alexei V., Ramirez-Ruiz, Enrico, ...
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...
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...
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 $\sim...
Dusty ERO Search behind Two Massive Clusters (2003)
Takata, Tadafumi, Kashikawa, Nobunari, Nakanishi, Kouichiro, Aoki, Kentaro, Asai, Ryo, Ebizuka, Noboru, ...
We performed deep K'-band imaging observations of 2 massive clusters, MS 0451.6-0305 at z = 0.55 and MS 0440.5+0204 at z = 0.19, for searching counterparts of the faint sub-mm sources behind these...
Ohyama, Youichi, Yoshida, Michitoshi, Takata, Tadafumi
We report on our new analysis of the spatial and kinematical distribution of warm and cold molecular gas in NGC 6240, which was undertaken to explore the origin of its unusually luminous H$_2$...
SDSSp J104433.04$-$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...
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...
Kashikawa, Nobunari, Takata, Tadafumi, Ohyama, Youichi, Yoshida, Michitoshi, Maihara, Toshinori, Iwamuro, Fumihide, ...
We have constructed a very deep K'-selected multicolor BVRIz'JK' sample of 439 field galaxies. Photometric redshifts for sample galaxies were estimated. The overall redshift distribution N(z) for the...
Ohyama, Youichi, Hamana, Takashi, Kashikawa, Nobunari, Chiba, Masashi, Futamase, Toshifumi, Iye, Masanori, ...
We present new optical spectroscopy of the lens elliptical galax in the ``Einstein Cross'' lens system HST 14176+5226, using the Faint Object Camera and Spectrograph (FOCAS) of the Subaru t Our...
Discovery of Very Extended Emission-Line Region around the Seyfert 2 Galaxy NGC 4388 (2001)
Yoshida, Michitoshi, Yagi, Masafumi, Okamura, Sadanori, Aoki, Kentaro, Ohyama, Youichi, Komiyama, Yutaka, ...
We found a very large, 35 kpc, emission-line region around the Seyfert type 2 galaxy NGC 4388, using deep narrow-band imaging with the prime focus camera (Suprime-Cam) of the Subaru telescope. This...
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...
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...
Superwind-Driven Intense H_2 Emission in NGC 6240 (2000)
Ohyama, Youichi, Yoshida, Michitoshi, Takata, Tadafumi, Imanishi, Masatoshi, Usuda, Tomonori, Saito, Yoshihiko, ...
We have performed a long-slit K band spectroscopic observation of the luminous infrared galaxy NGC 6240. The peak position of the H_2 v=1-0 S(1) emission in the slit is located ~0.3" - 0.4" north of...
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...
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...
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...