First Results from the Lick AGN Monitoring Project: The Mass of the Black Hole in Arp 151 (2008)
Bentz, Misty C., Walsh, Jonelle L., Barth, Aaron J., Baliber, Nairn, Bennert, Nicola, Canalizo, Gabriela, ...
We have recently completed a 64-night spectroscopic monitoring campaign at the Lick Observatory 3-m Shane telescope with the aim of measuring the masses of the black holes in 13 nearby (z < 0.05)...
Dynamical response to supernova-induced gas removal in spiral galaxies with dark matter halo (2008)
Koyama, Hiroko, Nagashima, Masahiro, Kakehata, Takayuki, Yoshii, Yuzuru
We investigate the dynamical response, in terms of disc size and rotation velocity, to mass loss by supernovae in the evolution of spiral galaxies. A thin baryonic disc having the Kuzmin density...
Measurement of the Spin-Orbit Angle of Exoplanet HAT-P-1b (2008)
Johnson, John A., Winn, Joshua N., Narita, Norio, Enya, Keigo, Williams, Peter K. G., Marcy, Geoffrey W., ...
We present new spectroscopic and photometric observations of the HAT-P-1 planetary system. Spectra obtained during three transits exhibit the Rossiter-McLaughlin effect, allowing us to measure the...
Measurement of the Rossiter--McLaughlin Effect in the Transiting Exoplanetary System TrES-1 (2007)
Narita, Norio, Enya, Keigo, Sato, Bun'ei, Ohta, Yasuhiro, Winn, Joshua N., Suto, Yasushi, ...
We report a measurement of the Rossiter--McLaughlin effect in the transiting extrasolar planetary system TrES-1, via simultaneous spectroscopic and photometric observations with the Subaru and MAGNUM...
NGC 5548 in a Low-Luminosity State: Implications for the Broad-Line Region (2007)
Bentz, Misty C., Denney, Kelly D., Cackett, Edward M., Dietrich, Matthias, Fogel, Jeffrey K. J., Ghosh, Himel, ...
We describe results from a new ground-based monitoring campaign on NGC 5548, the best studied reverberation-mapped AGN. We find that it was in the lowest luminosity state yet recorded during a...
Winn, Joshua N., Holman, Matthew J., Henry, Gregory W., Roussanova, Anna, Enya, Keigo, Yoshii, Yuzuru, ...
We present photometry of HD 189733 during eight transits of its close-in giant planet, and out-of-transit photometry spanning two years. Using the transit photometry, we determine the stellar and...
Tomita, Hiroyuki, Yoshii, Yuzuru, Kobayashi, Yukiyasu, Minezaki, Takeo, Enya, Keigo, Suganuma, Masahiro, ...
We propose a new method of analysing a variable component for type 1 active galactic nuclei (AGNs) in the near-infrared wavelength region. This analysis uses a multiple regression technique and...
The Mass of the Black Hole in the Seyfert 1 Galaxy NGC 4593 from Reverberation Mapping (2006)
Denney, Kelly D., Bentz, Misty C., Peterson, Bradley M., Pogge, Richard W., Cackett, Edward M., Dietrich, Matthias, ...
We present new observations leading to an improved black hole mass estimate for the Seyfert 1 galaxy NGC 4593 as part of a reverberation-mapping campaign conducted at the MDM Observatory....
A Reverberation-Based Mass for the Central Black Hole in NGC 4151 (2006)
Bentz, Misty C., Denney, Kelly D., Cackett, Edward M., Dietrich, Matthias, Fogel, Jeffrey K. J., Ghosh, Himel, ...
We have undertaken a new ground-based monitoring campaign to improve the estimates of the mass of the central black hole in NGC 4151. We measure the lag time of the broad H beta line response...
Fe II Emission in 14 Low-Redshift Quasars: I - Observations (2006)
Tsuzuki, Yumihiko, Kawara, Kimiaki, Yoshii, Yuzuru, Oyabu, Shinki, Tanabe, Toshihiko, Matsuoka, Yoshiki
We present the spectra of 14 quasars with a wide coverage of rest wavelengths from 1000 to 7300 A. The redshift ranges from z = 0.061 to 0.555 and the luminosity from M_{B} = -22.69 to -26.32. We...
The Optical/Near-Infrared Light Curves of SN 2002ap for the First 1.5 Years after Discovery (2006)
Tomita, Hiroyuki, Deng, Jinsong, Maeda, Keiichi, Yoshii, Yuzuru, Nomoto, Ken'ichi, Mazzali, Paolo A., ...
Late-time BVRIJHK photometry of the peculiar Type Ic SN 2002ap, taken between 2002 June 12 and 2003 August 29 with the MAGNUM telescope, is presented. The light curve decline rate is derived in each...
The optical/near-infrared light curves of SN 2002ap for the first 1.5 years after discovery (2006)
Tomita, Hiroyuki, Deng, Jinsong, Maeda, Keiichi, Yoshii, Yuzuru, Nomoto, Ken'ichi, Mazzali, Paolo A., ...
Nagashima, Masahiro, Yahagi, Hideki, Enoki, Motohiro, Yoshii, Yuzuru, Gouda, Naoteru
We construct the Numerical Galaxy Catalog ($\nu$GC), based on a semi-analytic model of galaxy formation combined with high-resolution N-body simulations in a $\Lambda$-dominated flat cold dark matter...
OI Line Emission in the Quasar PG 1116+215 (2005)
Matsuoka, Yoshiki, Oyabu, Shinki, Tsuzuki, Yumihiko, Kawara, Kimiaki, Yoshii, Yuzuru
By observing the near-infrared spectrum of the quasar PG 1116+215 at z = 0.176 and combining with the HST/FOS spectrum, we obtained the relative strengths of three permitted OI lines ({lambda}1304,...
Subaru Super Deep Field with Adaptive Optics I. Observations and First Implications (2005)
Minowa, Yosuke, Kobayashi, Naoto, Yoshii, Yuzuru, Totani, Tomonori, Maihara, Toshinori, Iwamuro, Fumihide, ...
We present a deep $K^{\prime}$-band (2.12$\mu$m) imaging of 1\arcmin\ $\times$ 1\arcmin Subaru Super Deep Field (SSDF) taken with the Subaru adaptive optics (AO) system. Total integration time of...
Nucleosynthetic signatures of the first stars (2005)
Frebel, Anna, Aoki, Wako, Christlieb, Norbert, Ando, Hiroyasu, Asplund, Martin, Barklem, Paul S., ...
The chemically most primitive stars provide constraints on the nature of the first stellar objects that formed in the Universe; elements other than hydrogen, helium and traces of lithium within these...
Hierarchical Formation of Galaxies with Dynamical Response to Supernova-Induced Gas removal (2004)
Nagashima, Masahiro, Yoshii, Yuzuru
We reanalyze the formation and evolution of galaxies in the hierarchical clustering scenario. Using a semi-analytic model (SAM) of galaxy formation described in this paper, which we hereafter call...
Mass Function of Low Mass Dark Halos (2004)
Yahagi, Hideki, Nagashima, Masahiro, Yoshii, Yuzuru
The mass function of dark halos in a Lambda-dominated cold dark matter (LambdaCDM) universe is investigated. 529 output files from five runs of N-body simulations are analyzed using the...
Excavation of the first stars (2003)
Shigeyama, Toshikazu, Tsujimoto, Takuji, Yoshii, Yuzuru
The external pollution of the first stars in the Galaxy is investigated. The first stars were born in clouds composed of the pristine gas without heavy elements. These stars accreted gas polluted...
Dynamical response to supernova-induced gas removal in two-component spherical galaxies (2002)
Nagashima, Masahiro, Yoshii, Yuzuru
We investigate dynamical response on size and velocity dispersion to mass loss by supernovae in formation of two-component spherical galaxies composed of baryon and dark matter. Three-dimensional...
JHK' Imaging Photometry of Seyfert 1 AGNs and Quasars I: Multi-Aperture Photometry (2002)
Enya, Keigo, Yoshii, Yuzuru, Kobayashi, Yukiyasu, Minezaki, Takeo, Tomita, Hiroyuki, Peterson, Bruce A.
Near-infrared $JHK'$ imaging photometry was obtained of 331 AGNs consisting mainly of Seyfert 1 AGNs and quasars (QSOs). This sample was selected to cover a range of radio emission strength, redshift...
Enya, Keigo, Yoshii, Yuzuru, Kobayashi, Yukiyasu, Minezaki, Takeo, Tomita, Hiroyuki, Peterson, Bruce A.
Observations of 226 AGNs in the near-infrared $J$, $H$, and $K'$ bands are presented along with the analysis of the observations for variability. Our sample consists mainly of Seyfert 1 AGNs and...
Enya, Keigo, Yoshii, Yuzuru, Kobayashi, Yukiyasu, Minezaki, Takeo, Tomita, Hiroyuki, Peterson, Bruce A.
Variability of 226 AGNs in the near-infrared $J$, $H$, and $K'$ bands is analyzed and discussed. An ensemble average for measured variabilities was obtained for various samples of the AGNs divided by...
Chemical Evolution of Odd Elements in an Inhomogeneous Early Galaxy (2001)
Tsujimoto, Takuji, Shigeyama, Toshikazu, Yoshii, Yuzuru
We investigate the chemical evolution of odd-numbered elements such as sodium (Na) and aluminum (Al) during the early epochs of the Galactic halo with the use of a model that reproduces the observed...
Totani, Tomonori, Yoshii, Yuzuru, Iwamuro, Fumihide, Maihara, Toshinori, Motohara, Kentaro
We report observational analyses and theoretical interpretations of unusually red galaxies in the Subaru Deep Field (SDF). A careful analysis of the SDF data revealed a population with unusually red...
N-Body Code with Adaptive Mesh Refinement (2001)
Yahagi, Hideki, Yoshii, Yuzuru
We have developed a simulation code with the techniques which enhance both spatial and time resolution of the PM method for which the spatial resolution is restricted by the spacing of structured...
A New Model for the Evolution of Light Elements in an Inhomogeneous Galactic Halo (2000)
Suzuki, Takeru Ken, Yoshii, Yuzuru
We present predictions of the evolution of the light elements, Li, Be, and B, in the early epochs of the Galactic halo, using a model of supernova-induced chemical evolution based on contributions...
Totani, Tomonori, Yoshii, Yuzuru
(Abridged) We present a detailed analysis of the number count and photometric redshift distribution of faint galaxies in the Hubble Deep Field (HDF), paying a special attention to the selection...
Suzuki, Takeru Ken, Yoshii, Yuzuru, Beers, Timothy C.
We have refined the estimate of the primordial level of $^7$Li abundance to an accuracy better than 10%, based on high-precision Li abundances for metal-poor halo stars, and a recent model of...
The Light Elements Be and B as Stellar Chronometers in the Early Galaxy (2000)
Beers, Timothy C., Suzuki, Takeru K., Yoshii, Yuzuru
Recent detailed simulations of Galactic Chemical Evolution have shown that the heavy elements, in particular [Fe/H], are expected to exhibit a weak, or absent, correlation with stellar ages in the...
Tsujimoto, Takuji, Shigeyama, Toshikazu, Yoshii, Yuzuru
We suggest that if the astrophysical site for r-process nucleosynthesis in the early Galaxy is confined to a narrow mass range of Type II supernova (SN II) progenitors, with a lower mass limit of Mms...
Evolution of Beryllium and Boron in the Inhomogeneous Early Galaxy (1999)
Suzuki, Takeru Ken, Yoshii, Yuzuru, Kajino, Toshitaka
A model of supernova-driven chemical evolution of the Galactic halo, recently proposed by Tsujimoto, Shigeyama, & Yoshii (1999, ApJL, 519, 64), is extended in order to investigate the evolution of...
Tsujimoto, Takuji, Shigeyama, Toshikazu, Yoshii, Yuzuru
A model for Galactic chemical evolution, driven by supernova-induced star formation, is formulated and used to examine the nature of the Galactic halo at early epochs. In this model, new stars are...
The Forest Method as a New Parallel Tree Method with the Sectional Voronoi Tessellation (1999)
Hideki Yahagi, Masao Mori, Yuzuru Yoshii
We have developed a new parallel tree method which will be called the forest method hereafter. This new method uses the sectional Voronoi tessellation (SVT) for the domain decomposition. The SVT...
Mori, Masao, Yoshii, Yuzuru, Nomoto, Ken'ichi
We simulate the dynamical, chemical, and spectro-photometric evolution of dwarf and normal elliptical galaxies embedded in a dark matter halo, using a three-dimensional N-body/SPH simulation code....
The Evolution Of Dwarf Galaxies With Star Formation In Outward Propagating Super Shell (1998)
Masao Mori, Yuzuru Yoshii, Takuji Tsujimoto
We simulate the dynamical and chemical evolution of a dwarf galaxy embedded in a dark matter halo, using a three-dimensional N-body/SPH simulation code combined with stellar population synthesis. The...
Age Dating of a High-Redshift QSO B1422+231 at Z=3.62 and its Cosmological Implications (1998)
Yoshii, Yuzuru, Tsujimoto, Takuji, Kawara, Kimiaki
The observed Fe II(UV+optical)/Mg II lambda lambda 2796,2804 flux ratio from a gravitationally lensed quasar B1422+231 at z=3.62 is interpreted in terms of detailed modeling of photoionization and...
New limits on a cosmological constant from statistics of gravitational lensing (1998)
Chiba, Masashi, Yoshii, Yuzuru
We present new limits on cosmological parameters from the statistics of gravitational lensing, based on the recently revised knowledge of the luminosity function and internal dynamics of E/S0...
Does the Number Density of Elliptical Galaxies Change at z (1998)
Totani, Tomonori, Yoshii, Yuzuru
We have performed a detailed V/Vmax test for a sample of the Canada-France Redshift Survey (CFRS) for the purpose of examining whether the comoving number density of field galaxies changes...
The Absolute Magnitude of RR Lyrae Stars Derived from the Hipparcos Catalogue (1997)
Tsujimoto, Takuji, Miyamoto, Masanori, Yoshii, Yuzuru
The present determination of the absolute magnitude $M_V(RR)$ of RR Lyrae stars is twofold, relying upon Hipparcos proper motions and trigonometric parallaxes separately. First, applying the...
Three-dimensional orbits of metal-poor halo stars and the formation of the Galaxy (1997)
Chiba, Masashi, Yoshii, Yuzuru
We present the three-dimensional orbital motions of metal-poor stars in conjunction with their metal abundances, for the purpose of getting insight into the formation process of the Galaxy. Our...
A New Approach to Determine the Initial Mass Function in the Solar Neighborhood (1997)
Tsujimoto, Takuji, Yoshii, Yuzuru, Nomoto, Ken'ichi, Matteucci, Francesca, Thielemann, Friedrich-Karl, Hashimoto, Masaaki
Oxygen to iron abundance ratios of metal-poor stars provide information on nucleosynthesis yields from massive stars which end in Type II supernova explosions. Using a standard model of chemical...
The Evolution of Dwarf Galaxies with Star Formation in Outward Propagating Super Shell (1997)
Mori, Masao, Yoshii, Yuzuru, Tsujimoto, Takuji, Nomoto, Ken'ichi
We simulate the dynamical and chemical evolution of a dwarf galaxy embedded in a dark matter halo, using a three-dimensional N-body/SPH simulation code combined with stellar population synthesis. The...
A Group of Galaxies at Redshift 2.38 (1995)
Francis, Paul, Woodgate, Bruce, Warren, Steve, Moller, Palle, Mazzolini, Marg, Bunker, Andy, ...
We report the discovery of a group of galaxies at redshift 2.38. We imaged about 10% of a claimed supercluster of QSO absorption-lines at z=2.38 (Francis & Hewett 1993). In this small field (2 arcmin...
Spectrum of the Supernova Relic Neutrino Background and Evolution of Galaxies (1995)
Totani, Tomonori, Sato, Katsuhiko, Yoshii, Yuzuru
The spectrum of the supernova relic neutrino background (SRN) from collapse-driven supernovae ever occurred in the universe is calculated by using a realistic, time-dependent supernova rate derived...
A Technique Fof Determining the Extragalactic Distance Scale (1994)
Chiba, Masashi, Yoshii, Yuzuru
We propose a method of distance determination based on the internal structure and dynamics of disk galaxies. The method relies on the universal luminosity profile of a stellar disk represented by an...