Taketo Nagasaki
A5052128131- Superconducting and THz Device Technology
- Radio Astronomy Observations and Technology
- Cosmology and Gravitation Theories
- Soil Moisture and Remote Sensing
- Astrophysics and Star Formation Studies
- Precipitation Measurement and Analysis
- Meteorological Phenomena and Simulations
- Advanced Thermodynamic Systems and Engines
- Dark Matter and Cosmic Phenomena
- Adaptive optics and wavefront sensing
- Geophysics and Gravity Measurements
- Atmospheric Ozone and Climate
- Spacecraft Design and Technology
- Molecular Spectroscopy and Structure
- Antenna Design and Optimization
- Inertial Sensor and Navigation
- Galaxies: Formation, Evolution, Phenomena
- Advanced Semiconductor Detectors and Materials
- Cryospheric studies and observations
- Calibration and Measurement Techniques
- Arctic and Antarctic ice dynamics
- Astrophysics and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- Solar and Space Plasma Dynamics
- GNSS positioning and interference
High Energy Accelerator Research Organization
2015-2024
The Graduate University for Advanced Studies, SOKENDAI
2024
Tohoku University
2024
Sapienza University of Rome
2020
RIKEN
2020
Université Paris-Sud
2020
Centre National de la Recherche Scientifique
2020
Institut d'Astrophysique Spatiale
2020
University of Tsukuba
2013-2015
Misato Observatory
2015
Abstract Understanding telescope pointing (i.e. line of sight) is important for observing the cosmic microwave background (CMB) and astronomical objects. The Moon a candidate source calibration. Although visible size (30′) larger than that planets, we can frequently observe once month with high signal-to-noise ratio. We developed method performing calibration using observational data from Moon. considered tilts axes as well encoder collimation offsets In addition, evaluated effects...
We have mapped the Orion-A Giant Molecular Cloud in CO (J=4-3) line with Tsukuba 30-cm submillimeter telescope.The map covered a 7.125 deg^2 area 9' resolution, including main components of cloud such as Orion Nebula, OMC-2/3, and L1641-N. The most intense emission was detected toward KL region. integrated intensity ratio between (J=1-0) derived using data from Columbia-Univ. de Chile survey, which carried out comparable angular resolution. r_{4-3/1-0} ~ 0.2 southern region 0.4-0.8 at star...
GroundBIRD is a ground-based cosmic microwave background (CMB) experiment for observing the polarization pattern imprinted on large angular scales (ℓ > 6 ) from Teide Observatory in Tenerife, Spain. Our primary scientific objective precise measurement of optical depth τ (σ(τ ∼ 0.01) to reionization epoch Universe cross-check systematic effects measurements made by previous experiments. observes wide sky area Northern Hemisphere (∼ 40% full sky) while continuously rotating telescope at high...
Polarized patterns in the cosmic microwave background (CMB) radiation contains rich knowledge for early stage of universe. In particular their odd-parity at large angular scale (> 1°), primordial B-modes, are smoking-gun evidence inflation. The GroundBIRD experiment aims to detect these B-modes with a ground-based apparatus that includes several novel devices: high-speed rotational scan system, cold optics, and kinetic inductance detectors (MKIDs). We plan start observations Canary Islands...
We have developed a transportable 30-cm submillimeter-wave telescope to operate at the Dome Fuji station in Antarctic plateau. Transportability is an important requirement design; can be divided into several subsystems by hands. The maximum weight of restricted below 60 kg, so that assembled without lifting machine. A small 4 K mechanical cryocooler used for cooling down SIS mixer. Total power consumption was designed less than 2.5 kW. optical system satisfy frequency independent matching...
We search for hidden-photon cold dark matter (HP-CDM) using a spectroscopic system in K-band frequency range. Our comprises planar metal plate and cryogenic receiver. This is the first time receiver has been used HP-CDM. Such use helps reduce thermal noise. recorded data 9.3 hours an effective aperture area of 14.8 cm$^2$. No signal was found data. set upper limits parameter mixing between photon HP-CDM mass range from 115.79 to 115.85 $\mu$eV, $\chi < 1.8$-$4.3 \times 10^{-10}$, at 95%...
We have developed a 30-cm submillimeter-wave telescope intended to survey the Milky Way in 500 GHz emission lines at Dome Fuji station Antarctic plateau. Transportability and low power consumption are required while keeping system noise temperature for operation Antarctica. The is designed be divided into five components operate with less than 2.5 kW of electric power. Its receiver 85 K SSB 461 492 GHz. succeeded operating -30◦C laboratory that typical summer.
Understanding telescope pointing (i.e., line of sight) is important for observing the cosmic microwave background (CMB) and astronomical objects. The Moon a candidate source calibration. Although visible size ($\ang{;30}$) larger than that planets, we can frequently observe once month with high signal-to-noise ratio. We developed method performing calibration using observational data from Moon. considered tilts axes as well encoder collimation offsets In addition, evaluated effects...
We have developed a state-of-the-art microwave radiometer named KUMODeS (KEK Universal Moisture and Oxygen Detection System) using millimeter-wave spectroscopy to monitor water vapor behavior. carried out comparative measurements of precipitable (PWV) investigate the potential KUMODeS/PWV measurements. Although further investigation is required evaluate performance quantitatively, preliminary results PWV comparisons imply that technology will be useful for retrieving accurate behavior with...
&lt;p&gt;We have started to develop a next-generation microwave radiometer be used in millimeter-wave spectroscopy for the high-resolution and high-precision monitoring of water vapor behavior. The new will suitable not only space geodetic techniques such as VLBI GNSS, but also field measurements monitor, example, volcanic activities cumulonimbus cloud generation. planned front-end system our has wide bandwidth feed 20&amp;#8211;60 GHz. A signal from is separated into two linear...