Takeo Minezaki

The Lick AGN Monitoring Project: Photometric Light Curves and Optical Variability Characteristics (2009)

Walsh, Jonelle L., Minezaki, Takeo, Bentz, Misty C., Barth, Aaron J., Baliber, Nairn, Li, Weidong, ...

The Lick AGN Monitoring Project targeted 13 nearby Seyfert 1 galaxies with the intent of measuring the masses of their central black holes using reverberation mapping. The sample includes 12 galaxies...

The Lick AGN Monitoring Project: Broad-Line Region Radii and Black Hole Masses from Reverberation Mapping of Hbeta (2009)

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 12 nearby (z < 0.05)...

Variation of Inner Radius of Dust Torus in NGC4151 (2009)

Koshida, Shintaro, Yoshii, Yuzuru, Kobayashi, Yukiyasu, Minezaki, Takeo, Sakata, Yu, Sugawara, Shota, ...

The long-term optical and near infrared monitoring observations for a type 1 act ive galactic nucleus NGC 4151 were carried out for six years from 2001 to 2006 b y using the MAGNUM telescope, and...

Nebular Phase Observations of the Type Ib Supernova 2008D/X-ray Transient 080109: Side-Viewed Bipolar Explosion (2009)

Tanaka, Masaomi, Yamanaka, Masayuki, Maeda, Keiichi, Kawabata, Koji S., Hattori, Takashi, Minezaki, Takeo, ...

We present optical spectroscopic and photometric observations of supernova (SN) 2008D, associated with the luminous X-ray transient 080109, at >300 days after the explosion (nebular phases). We also...

Subaru Mid-infrared Imaging of the Quadruple Lenses. II. Unveiling Lens Structure of MG0414+0534 and Q2237+030 (2009)

Minezaki, Takeo, Chiba, Masashi, Kashikawa, Nobunari, Inoue, Kaiki Taro, Kataza, Hirokazu

We present mid-infrared imaging at 11.7 $\mu$m for the quadruple lens systems, MG0414+0534 and Q2237+030, using the cooled mid-infrared camera and spectrometer (COMICS) attached on the Subaru...

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)...

Dark Matter Substructure in Lensing Galaxies (2008)

Chiba, Masashi, Minezaki, Takeo, Inoue, Kaiki T., Kashikawa, Nobunari, Kataza, Hirokazu, Sugai, Hajime

To set useful limits on the abundance of small-scale dark matter halos (subhalos) in a galaxy scale, we have carried out mid-infrared imaging and integral-field spectroscopy for a sample of quadruple...

SN 2006aj Associated with XRF 060218 At Late Phases: Nucleosynthesis-Signature of A Neutron Star-Driven Explosion (2007)

Maeda, Keiichi, Kawabata, Koji, Tanaka, Masaomi, Nomoto, Ken'ichi, Tominaga, Nozomu, Hattori, Takashi, ...

Optical spectroscopy and photometry of SN 2006aj have been performed with the Subaru telescope at t > 200 days after GRB060218, the X-ray Flash with which it was associated. Strong nebular...

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...

Multiple Regression Analysis of the Variable Component in the Near-Infrared Region for Type 1 AGN MCG+08-11-011 (2006)

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...

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...

Subaru Mid-infrared Imaging of the Quadruple Lenses PG1115+080 and B1422+231: Limits on Substructure Lensing (2005)

Chiba, Masashi, Minezaki, Takeo, Kashikawa, Nobunari, Kataza, Hirokazu, Inoue, Kaiki Taro

We present mid-infrared imaging at 11.7 mu m for the quadruple lens systems, PG1115+080 and B1422+231, using the cooled mid-infrared camera and spectrometer (COMICS) attached on the Subaru telescope....

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...

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...

$JHK'$ Imaging Photometry of Seyfert 1 AGNs and Quasars II: Observation of Long-Term Variability (2002)

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...

$JHK'$ Imaging Photometry of Seyfert 1 AGNs and Quasars III: Variability of Radio Quiet and Radio Loud AGNs (2002)

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...

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...