Tadashi Nakajima

Overdensity of i'-Dropout Galaxies in the Subaru Deep Field: A Candidate Protocluster at z ~ 6 (2008)

Ota, Kazuaki, Kashikawa, Nobunari, Malkan, Matthew A., Iye, Masanori, Nakajima, Tadashi, Nagao, Tohru, ...

We investigate the sky distribution of z ~ 6 Lyman break galaxies selected as i'-dropouts having i' - z' > 1.45 down to z' < 26.5 in the Subaru Deep Field (SDF). We discover 37 i'-dropouts clustered...

Received; accepted Submitted to Astrophys. J. (2007)

Tadashi Nakajima

A conceptual design for a fringe-tracking interferometric array is presented. Unlike the conventional design which splits N beams of an N aperture array and combines them into N(N01)/2 fringes, only...

An Interpretation of Flat Density Cores of Clusters of Galaxies by Degeneracy Pressure of Fermionic Dark Matter: A Case Study of Abell 1689 (2006)

Nakajima, Tadashi, Morikawa, Masahiro

Flat density cores have been obtained for a limited number of clusters of galaxies by strong gravitational lensing. This paper explores the possibility that the degeneracy pressure of fermionic dark...

Zenith-Distance Dependence of Chromatic Shear Effect: A Limiting Factor for an Extreme Adaptive Optics System (2006)

Nakajima, Tadashi

Consider a perfect AO system with a very fine wavefront sampling interval and a very small actuator interval. If this AO system senses wavefront at a wavelength, lambda_{WFS}, and does science...

Dynamical Stability of Cusps and Cores: Implication to the Centers of Galaxies and Cluster of Galaxies (2006)

Nakajima, Tadashi

We study the stability of a spherically symmetric density profile. We analyze the case of a collisionless system with a power-law profile given by rho propto r^-alpha, in the Newtonian regime using...

Fully Degenerate Self-Gravitating Fermionic Dark Matter: Implications to the Density Profile of the Cluster of Galaxies A1689, and the Mass Hierarchy of Black Holes (2005)

Nakajima, Tadashi, Morikawa, Masahiro

Equilibrium configurations of weakly interacting fully degenerate fermionic dark matter are considered at various scales in the Universe. We treat the general situations for the gravity from...

Spectral Classification and Effective Temperatures of L and T Dwarfs Based of Near-Infrared Spectra (2004)

Nakajima, Tadashi, Tsuji, Takashi, Yanagisawa, Kenshi

We have obtained near-infrared spectra of L dwarfs, L/T transition objects and T dwarfs using Subaru. Resulting spectra are examined in detail to see their dependence on the spectral types. We have...

Dust in the Photospheric Environment II. Effect on the Near Infrared Spectra of L and T Dwarfs (2004)

Tsuji, Takashi, Nakajima, Tadashi, Yanagisawa, Kenshi

We report an attempt to interpret the spectra of L and T dwarfs with the use of the Unified Cloudy Model (UCM). For this purpose, we extend the grid of the UCMs to the cases of log g = 4.5 and 5.5....

Transition from L to T Dwarfs on the Color-Magnitude Diagram (2003)

Tsuji, Takashi, Nakajima, Tadashi

The color-magnitude (CM) diagram of cool dwarfs and brown dwarfs based on the recent astrometry data is compared with the CM diagram transformed from the theoretical evolutionary tracks via the...

H and K Band Methane Features in an L Dwarf, 2MASS 0920+35 (2001)

Nakajima, Tadashi, Tsuji, Takashi, Yanagisawa, Kenshi

We have obtained near-infrared spectra of three L dwarfs discovered by 2MASS, 1506+13 (L3), 1507-16 (L5), and 0920+35 (L6.5). From the comparison of the H and K band spectra of these L dwarfs, we...

Sensitivity of a Ground-Based Infrared Interferometer for Aperture Synthesis Imaging (2001)

Nakajima, Tadashi

Sensitivity limits of ground-based infrared interferometers using aperture synthesis are presented. The motivation of this analysis is to compare an interferometer composed of multiple large...

Sensitivity of an Imaging Space Infrared Interferometer (2000)

Nakajima, Tadashi, Matsuhara, Hideo

We study the sensitivities of space infrared interferometers. We formulate the signal-to-noise ratios of infrared images obtained by aperture synthesis in the presence of source shot noise,...

Near-Infrared Spectroscopy of the Cool Brown Dwarf, SDSS 1624+00 (1999)

Nakajima, Tadashi, Tsuji, Takashi, Maihara, Toshinori, Iwamuro, Fumihide, Motohara, Ken-taro, Taguchi, Tomoyuki, ...

Using the Subaru Telescope, we have obtained multiple near-infrared spectra of the cool brown dwarf, SDSS 1624+00, in search of spectral variability in an 80 minute time span. We have found the...

Voltage-shift of the current activation in HERG S4 mutation (R534C) in LQT2 (1999)

Nakajima, Tadashi, Furukawa, Tetsushi, Hirano, Yuji, Tanaka, Toshihiro, Sakurada, Harumizu, Takahashi, Tamana, ...

Objective: Recently, a novel missense mutation (R534C) in the S4 region of human ether-a-go-go-related gene (HERG) was identified in one Japanese LQT2 family. The S4 region presumably functions as a...

Signal-to-noise ratio of the bispectral analysis of speckle interferometry (1988)

Nakajima, Tadashi

Monte Carlo simulations of an atmospheric phase screen, based on a Kolmogorov spectrum of phase fluctuations, were performed. Speckle patterns produced from the phase screens were used to derive...

Paleomagnetism of Miocene Rocks in the Western Area of Baragoi, Northern Kenya (1987)

NAKAJIMA, Tadashi, TORII, Masayuki

A total of 22 reliable paleomagnetic data has been obtained from Miocene rocks in this area. The magnetic polarity sequence is divided into six magneto-zones, which are tentatively correlated with...

Compound-specific Na+ channel pore conformational changes induced by local anaesthetics

Fukuda, Koji, Nakajima, Tadashi, Viswanathan, Prakash C, Balser, Jeffrey R

Upon prolonged depolarizations, voltage-dependent Na+ channels open and subsequently inactivate, occupying fast and slow inactivated conformational states. Like C-type inactivation in K+ channels,...

Compound-specific Na+ channel pore conformational changes induced by local anaesthetics

Fukuda, Koji, Nakajima, Tadashi, Viswanathan, Prakash C, Balser, Jeffrey R

Upon prolonged depolarizations, voltage-dependent Na+ channels open and subsequently inactivate, occupying fast and slow inactivated conformational states. Like C-type inactivation in K+ channels,...