Detections of Water Ice, Hydrocarbons, and 3.3 μm PAH in z ~ 2 ULIRGs (2009)
Sajina, Anna, Spoon, Henrik, Yan, Lin, Imanishi, Masatoshi, Fadda, Dario, Elitzur, Moshe
We present the first detections of the 3 μm water ice and 3.4 μm amorphous hydrocarbon (HAC) absorption features in z ~ 2 ULIRGs. These are based on deep rest-frame 2-8 μm Spitzer Infrared...
Masatoshi Imanishi, Kouichiro Nakanishi, Yoichi Tamura, Nagisa Oi, Kotaro Kohno
We present the results on millimeter interferometric observations of four luminous
Masatoshi Imanishi, Kouichiro Nakanishi, Yoichi Tamura, Chih-han Peng
We report the results of interferometric HCN(1–0) and HCO + (1–0) observations of four luminous infrared galaxies (LIRGs), NGC 2623, Mrk 266, Arp 193, and NGC 1377, as a final sample of our...
Imanishi, Masatoshi, Nakanishi, Kouichiro, Tamura, Yoichi, Peng, Chih-Han
We report the results of interferometric HCN(1-0) and HCO+(1-0) observations of four luminous infrared galaxies (LIRGs), NGC 2623, Mrk 266, Arp 193, and NGC 1377, as a final sample of our systematic...
We present the results of Spitzer IRS infrared 5-35 micron low-resolution spectroscopic energy diagnostics of ultraluminous infrared galaxies (ULIRGs) at z > 0.15, classified optically as...
Imanishi, Masatoshi, Nakagawa, Takao, Ohyama, Yoichi, Shirahata, Mai, Wada, Takehiko, Onaka, Takashi, ...
We report on the results of systematic infrared 2.5-5 micron spectroscopy of 45 nearby ultraluminous infrared galaxies (ULIRGs) at z < 0.3 using IRC onboard the AKARI satellite. This paper...
The SPICA Consortium, Swinyard, Bruce, Nakagawa, Takao, Merken, Patrick, Royer, Pierre, Souverijns, Tim, ...
Watabe, Yasuyuki, Kawakatu, Nozomu, Imanishi, Masatoshi
We investigated the correlation between nuclear/circumnuclear starbursts around the active galactic nuclei (AGNs) and the AGN activities for 43 Seyfert galaxies in the CfA and 12 micron samples. We...
Millimeter Interferometric HCN(1-0) and HCO+(1-0) Observations of Luminous Infrared Galaxies (2007)
Imanishi, Masatoshi, Nakanishi, Kouichiro, Tamura, Yoichi, Oi, Nagisa, Kohno, Kotaro
We present the results on millimeter interferometric observations of four luminous infrared galaxies (LIRGs), Arp 220, Mrk 231, IRAS 08572+3915, and VV 114, and one Wolf-Rayet galaxy, He 2-10, using...
Compact starburst in the central regions of Seyfert galaxies (2007)
Kohno, Kotaro, Nakanishi, Koichiro, Imanishi, Masatoshi
We have conducted a high-resolution ``3D'' imaging survey of the CO(1--0), HCN(1--0), and HCO$^+$(1--0) lines toward the central a few kpc regions of the Seyfert and starburst galaxies in the local...
The Mid-Infrared Emission of M87 (2007)
Perlman, E. S., Mason, R. E., Packham, Christopher, Levenson, N. A., Elitzur, M., Schaefer, Justin J., ...
We discuss Subaru and Spitzer Space Telescope imaging and spectroscopy of M87 in the mid-infrared from 5-35 um. These observations allow us to investigate mid-IR emission mechanisms in the core of...
Kawakatu, Nozomu, Imanishi, Masatoshi, Nagao, Tohru
We discovered a significant anti-correlation between the mass of a supermassive black hole (SMBH), $M_{\rm BH}$, and the luminosity ratio of infrared to active galactic nuclei (AGN) Eddington...
Imanishi, Masatoshi, Dudley, C. C., Maiolino, Roberto, Maloney, Philip R., Nakagawa, Takao, Risaliti, Guido
We present the results of Spitzer IRS low-resolution infrared 5-35 micron spectroscopy of nearby ultraluminous infrared galaxies (ULIRGs) at z < 0.15. We focus on the search for the signatures of...
Imanishi, Masatoshi, Nakanishi, Kouichiro
We present ground-based infrared K- (2-2.5 micron) and L-band (2.8-4.1 micron) spectroscopy, as well as interferometric observations at 3mm, for the individual merging components (A, B, and C) of the...
Imanishi, Masatoshi, Nakanishi, Kouichiro, Kohno, Kotaro
We present interferometric observations of three ultraluminous infrared galaxies (ULIRGs; UGC 5101, Mrk 273, and IRAS 17208-0014) in the 3-mm wavelength range, using the Nobeyama Millimeter Array....
We present the results of infrared 2.8-4.1 micron (L-band) spectroscopy of nearby infrared luminous galaxies with possible signatures of dust-obscured active galactic nuclei (AGNs) in data at other...
Imanishi, Masatoshi, Dudley, C. C., Maloney, Philip R.
We present infrared L-band (3-4 micron) nuclear spectra of a large sample of nearby ultraluminous infrared galaxies (ULIRGs).ULIRGs classified optically as non-Seyferts (LINERs, HII-regions, and...
Imanishi, Masatoshi, Wada, Keiichi
We report on infrared K- (2-2.5 micron) and L-band (2.8-4.1 micron) slit spectroscopy of 23 Seyfert 1 galaxies in the CfA and 12 micron samples. A polycyclic aromatic hydrocarbon (PAH) emission...
Imanishi, Masatoshi, Nakanishi, Kouichiro, Kuno, Nario, Kohno, Kotaro
We present near-infrared and millimeter investigations of the nucleus of the infrared luminous galaxy NGC 4418, which previous observations suggest possesses a powerful buried AGN. We found the...
Imanishi, Masatoshi, Alonso-Herrero, Almudena
We present near-infrared K-band slit spectra of the nuclei of 25 Seyfert 2 galaxies in the CfA and 12 micron samples. The strength of the CO absorption features at 2.3-2.4 micron produced by stars is...
Obscured star formation in the central region of the dwarf galaxy NGC5253 (2004)
Alonso-Herrero, Almudena, Takagi, Toshinobu, Baker, Andrew J., Rieke, George H., Rieke, Marcia J., Imanishi, Masatoshi, ...
We present HST/NICMOS observations (1.1-2.2micron) and 1.9-4.1micron spectroscopy of the central region of the dwarf galaxy NGC5253. The HST/NICMOS observations reveal the presence of a nuclear...
Obscured star formation in the central region of the dwarf galaxy NGC 5253 (2004)
Alonso-Herrero, Almudena, Takagi, Toshinobu, Baker, Andrew J., Rieke, George H., Rieke, Marcia J., Imanishi, Masatoshi, ...
Current performance and on-going improvements of the 8.2 m Subaru Telescope (2004)
Iye, Masanori, Karoji, Hiroshi, Ando, Hiroyasu, Kaifu, Norio, Kodaira, Keiichi, Aoki, Kentaro, ...
An overview of the current status of the 8.2m Subaru Telescope constructed and operated at Mauna Kea, Hawaii, by the National Astronomical Observatory of Japan is presented. The basic design concept...
Imanishi, Masatoshi, Terashima, Yuichi
We present X-ray spectra of four ultraluminous infrared galaxies (ULIRGs) with detectable broad near-infrared emission lines produced by active galactic nuclei (AGNs): Mrk 463, PKS 1345+12, IRAS...
X-ray Evidence for a Buried Active Galactic Nucleus in UGC 5101 (2003)
Imanishi, Masatoshi, Terashima, Yuichi, Anabuki, Naohisa, Nakagawa, Takao
We present X-ray observations of the ultraluminous infrared galaxy, UGC 5101, thought to contain a buried active galactic nucleus (AGN) based on observations in other wavebands. We detected an...
Compact Nuclear Starbursts in Seyfert 2 Galaxies from the CfA and 12 Micron Samples (2003)
We present infrared 2.8-4.1 micron slit spectra of 32 Seyfert 2 galaxies in the CfA and 12 micron samples. The 3.3 micron polycyclic aromatic hydrocarbon (PAH) emission feature was used to estimate...
Imanishi, Masatoshi, Maloney, Philip R.
Ground-based 2.8--4.1 $\mu$m slit spectra of the nuclei of seven ultraluminous infrared galaxies (ULIRGs) that are classified optically as LINERs and have cool far-infrared colors are presented. All...
ERO R1 in CL0939+4713 field - Evidence for an S0-like galaxy at z \sim 1.5 (2002)
Iye, Masanori, Shimasaku, Kazuhiro, Miyazaki, Satoshi, Imanishi, Masatoshi, Kashikawa, Nobunari, Kodama, Tadayuki, ...
We present further observations of the extremely red object ERO J094258+4659.2, identified by \citet{iye00} as ERO R1 in their deep images of the cluster A851. We estimate its redshift independently...
We report on 3--4 $\mu$m slit spectroscopy of 13 Seyfert 2 nuclei. The 3.3 $\mu$m polycyclic aromatic hydrocarbon (PAH) emission is used to estimate the magnitudes of compact ($
Imanishi, Masatoshi, Dudley, C. C., Maloney, Philip R.
We report on the results of 3--4 $\mu$m spectroscopy of the ultra-luminous infrared galaxy (ULIRG) UGC 5101. It has a cool far-infrared color and a LINER-type optical spectrum, and so, based on a...
Thermal Infrared 3--5 $\mu$m Colors of Obscured and Unobscured Active Galactic Nuclei (2001)
Thermal infrared photometry in the $L$- and $M'$-band and $L - M'$ colors of type-1 and type-2 active galactic nuclei (AGNs) are presented. After combining our observations with photometric data at...
Energy Diagnoses of Nine Infrared Luminous Galaxies Based on 3--4 Micron Spectra (2000)
Imanishi, Masatoshi, Dudley, C. C.
The energy sources of nine infrared luminous galaxies (IRLGs) are diagnosed based on their ground-based 3--4 $\mu$m spectra. Both the equivalent width of the 3.3 $\mu$m polycyclic aromatic...
The 3.4 micron absorption feature towards three obscured active galactic nuclei (2000)
The results of 3-4 $\mu$m spectroscopy towards the nuclei of NGC 3094, NGC 7172, and NGC 7479 are reported. In ground-based 8-13 $\mu$m spectra, all the sources have strong absorption-like features...
Yamada, Toru, Kajisawa, Masaru, Tanaka, Ichi, Maihara, Toshinori, Iwamuro, Fumihide, Terada, Hiroshi, ...
We have obtained high-resolution K'-band images of the powerful z=1.206 radio galaxy 3C 324 with the Subaru telescope under seeing conditions of 0.3--0.4 arcsec. We clearly resolved the galaxy and...
Kajisawa, Masaru, Yamada, Toru, Tanaka, Ichi, Maihara, Toshinori, Iwamuro, Fumihide, Terada, Hiroshi, ...
We investigate the $K$-band luminosity distribution of galaxies in the region of clusters at $z\sim1.2$ near to the radio galaxy 3C 324. The imaging data were obtained during the commissioning period...
Color-Magnitude Sequence in the Clusters at z$\sim$1.2 near the Radio Galaxy 3C 324 (2000)
Kajisawa, Masaru, Yamada, Toru, Tanaka, Ichi, Maihara, Toshinori, Iwamuro, Fumihide, Terada, Hiroshi, ...
We have investigated the optical and near-infrared colors of K'-selected galaxies in clusters at z ~ 1.2 near to the radio galaxy 3C 324 using images obtained with the Subaru telescope and archival...
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...
Imanishi, Masatoshi, Ueno, Shiro
We report the detection of a 9.7 $\mu$m silicate dust absorption feature toward the Cygnus A nucleus. Its optical depth is, however, significantly smaller than that expected from the dust extinction...
Imanishi, Masatoshi, Ueno, Shiro
We report the results of hard X-ray observations of four multinuclei merging infrared luminous galaxies (IRLGs). We selected these four sources for their excess of radio to far-infrared luminosity...