The physical properties and elemental abundances of the interstellar medium in galaxies during co... more The physical properties and elemental abundances of the interstellar medium in galaxies during cosmic reionization are important for understanding the role of galaxies in this process. We report the Atacama Large Millimeter/submillimeter Array detection of an oxygen emission line at a wavelength of 88 micrometers from a galaxy at an epoch about 700 million years after the Big Bang. The oxygen abundance of this galaxy is estimated at about one-tenth that of the Sun. The nondetection of far-infrared continuum emission indicates a deficiency of interstellar dust in the galaxy. A carbon emission line at a wavelength of 158 micrometers is also not detected, implying an unusually small amount of neutral gas. These properties might allow ionizing photons to escape into the intergalactic medium.
Light, Energy and the Environment 2018 (E2, FTS, HISE, SOLAR, SSL)
Atmospheric transmission from Dome A, Antarctica, presents new possibilities in the field of tera... more Atmospheric transmission from Dome A, Antarctica, presents new possibilities in the field of terahertz astronomy, where space telescopes have been the only observational tools until now. Using atmospheric transmission measurements at Dome A with a Fourier transform spectrometer, transmission spectra and their stabilities have been analyzed, which show that important atmospheric windows for terahertz astronomy open for a reasonable length of time in winter season. With large aperture terahertz telescopes and interferometers at Dome A, high angular resolution terahertz observation is foreseen for atomic lines from ionized gas and exoplanet research.
The 8th European Conference on Antennas and Propagation (EuCAP 2014)
Wide field-of-view (FoV) MKID cameras for millimeter and sub millimeter astronomy have been devel... more Wide field-of-view (FoV) MKID cameras for millimeter and sub millimeter astronomy have been developed at the Advanced Technology Center of NAOJ. To observe large scale structure of the universe, thousands of pixels with high sensitive detectors are required. We demonstrate key technologies, such as 700 pixel 220 GHz MKID camera, Si lens array, anti-reflection (AR) coating for Si and Alumina lens, wide FoV cryogenic optics, and read-out circuit for MKID cameras.
With an altitude of 4093m and temperatures as low as -80 celsius degree, Dome A in Antarctic is a... more With an altitude of 4093m and temperatures as low as -80 celsius degree, Dome A in Antarctic is a very attractive site for astronomical observations, especially at frequencies beyond 1THz. Preliminary observation results by a radiometer at 661GHz, which was brought to Dome A in 2008 by Chinese Antarctic expedition team, have demonstrated that Dome A has the lowest PWV among those good THz sites (ALMA site, South Pole and Dome C, for example) on the earth which have been investigated. To have better understanding on the atmospheric condition at Dome A, we have developed a broadband THz FTS to be deployed to the site in Jan. 2010. The FTS will measure atmospheric emission in the frequency range of 0.75-15THz (split in two bands), from which atmospheric transmission is derived using an atmospheric propagation model. Broad spectral coverage helps make this derivation more accurate-this is particularly important at Dome A, where the extremely cold temperatures lie well outside the tested...
Intensity interferometers are extremely important to the field of astronomy as they enable astron... more Intensity interferometers are extremely important to the field of astronomy as they enable astronomers to determine the apparent angular diameter of a radio source or star. Ultimately, they help scientists observe the Universe in significantly improved ways, facilitating relatively detailed observations of stars, galaxies and black holes. Now a team of researchers led by Dr Hiroshi Matsuo and based at the Advanced Technology Center of National Astronomical Observatory of Japan, is investigating a means of developing terahertz (THz) intensity interferometry which will build upon advanced technology and transform our understanding of astrophysical objects.
We performed a mapping observation of the Sunyaev-Zel'dovich effect toward a galaxy cluster, ... more We performed a mapping observation of the Sunyaev-Zel'dovich effect toward a galaxy cluster, CL0016+16, at 43 GHz using a newly developed 6-beam receiver installed in the Nobeyama 45-m telescope. The temperature decrement of the CMB was measured to be δT*A = −0.49 ± 0.06 mK at the center of the cluster. Fitting the isothermal, spherical-symmetrical β -model to the observed temperature decrement distribution, the S-Z effect at the center is inferred to be δTRJ(0) = −1.0 ± 0.1 mK at the Rayleigh-Jeans limit. This suggests that the Hubble constant is H0{q0 = 0.5} = 67+16−11 km s−1 Mpc−1.
Astro-F or IRIS (Infrared Imaging Surveyer) is a Japanese infrared satellite with 70cm liquid Hel... more Astro-F or IRIS (Infrared Imaging Surveyer) is a Japanese infrared satellite with 70cm liquid Helium cooled telescope planned to be launched in 2003. On board are near-infrared and middle-infrared imaging arrays (IRC) and a far-infrared survey instrument (FIS). Both instruments also have spectroscopic capability. During the first half year period, the Astro-F will concentrate on the all sky survey at
The physical properties and elemental abundances of the interstellar medium in galaxies during co... more The physical properties and elemental abundances of the interstellar medium in galaxies during cosmic reionization are important for understanding the role of galaxies in this process. We report the Atacama Large Millimeter/submillimeter Array detection of an oxygen emission line at a wavelength of 88 micrometers from a galaxy at an epoch about 700 million years after the Big Bang. The oxygen abundance of this galaxy is estimated at about one-tenth that of the Sun. The nondetection of far-infrared continuum emission indicates a deficiency of interstellar dust in the galaxy. A carbon emission line at a wavelength of 158 micrometers is also not detected, implying an unusually small amount of neutral gas. These properties might allow ionizing photons to escape into the intergalactic medium.
Light, Energy and the Environment 2018 (E2, FTS, HISE, SOLAR, SSL)
Atmospheric transmission from Dome A, Antarctica, presents new possibilities in the field of tera... more Atmospheric transmission from Dome A, Antarctica, presents new possibilities in the field of terahertz astronomy, where space telescopes have been the only observational tools until now. Using atmospheric transmission measurements at Dome A with a Fourier transform spectrometer, transmission spectra and their stabilities have been analyzed, which show that important atmospheric windows for terahertz astronomy open for a reasonable length of time in winter season. With large aperture terahertz telescopes and interferometers at Dome A, high angular resolution terahertz observation is foreseen for atomic lines from ionized gas and exoplanet research.
The 8th European Conference on Antennas and Propagation (EuCAP 2014)
Wide field-of-view (FoV) MKID cameras for millimeter and sub millimeter astronomy have been devel... more Wide field-of-view (FoV) MKID cameras for millimeter and sub millimeter astronomy have been developed at the Advanced Technology Center of NAOJ. To observe large scale structure of the universe, thousands of pixels with high sensitive detectors are required. We demonstrate key technologies, such as 700 pixel 220 GHz MKID camera, Si lens array, anti-reflection (AR) coating for Si and Alumina lens, wide FoV cryogenic optics, and read-out circuit for MKID cameras.
With an altitude of 4093m and temperatures as low as -80 celsius degree, Dome A in Antarctic is a... more With an altitude of 4093m and temperatures as low as -80 celsius degree, Dome A in Antarctic is a very attractive site for astronomical observations, especially at frequencies beyond 1THz. Preliminary observation results by a radiometer at 661GHz, which was brought to Dome A in 2008 by Chinese Antarctic expedition team, have demonstrated that Dome A has the lowest PWV among those good THz sites (ALMA site, South Pole and Dome C, for example) on the earth which have been investigated. To have better understanding on the atmospheric condition at Dome A, we have developed a broadband THz FTS to be deployed to the site in Jan. 2010. The FTS will measure atmospheric emission in the frequency range of 0.75-15THz (split in two bands), from which atmospheric transmission is derived using an atmospheric propagation model. Broad spectral coverage helps make this derivation more accurate-this is particularly important at Dome A, where the extremely cold temperatures lie well outside the tested...
Intensity interferometers are extremely important to the field of astronomy as they enable astron... more Intensity interferometers are extremely important to the field of astronomy as they enable astronomers to determine the apparent angular diameter of a radio source or star. Ultimately, they help scientists observe the Universe in significantly improved ways, facilitating relatively detailed observations of stars, galaxies and black holes. Now a team of researchers led by Dr Hiroshi Matsuo and based at the Advanced Technology Center of National Astronomical Observatory of Japan, is investigating a means of developing terahertz (THz) intensity interferometry which will build upon advanced technology and transform our understanding of astrophysical objects.
We performed a mapping observation of the Sunyaev-Zel'dovich effect toward a galaxy cluster, ... more We performed a mapping observation of the Sunyaev-Zel'dovich effect toward a galaxy cluster, CL0016+16, at 43 GHz using a newly developed 6-beam receiver installed in the Nobeyama 45-m telescope. The temperature decrement of the CMB was measured to be δT*A = −0.49 ± 0.06 mK at the center of the cluster. Fitting the isothermal, spherical-symmetrical β -model to the observed temperature decrement distribution, the S-Z effect at the center is inferred to be δTRJ(0) = −1.0 ± 0.1 mK at the Rayleigh-Jeans limit. This suggests that the Hubble constant is H0{q0 = 0.5} = 67+16−11 km s−1 Mpc−1.
Astro-F or IRIS (Infrared Imaging Surveyer) is a Japanese infrared satellite with 70cm liquid Hel... more Astro-F or IRIS (Infrared Imaging Surveyer) is a Japanese infrared satellite with 70cm liquid Helium cooled telescope planned to be launched in 2003. On board are near-infrared and middle-infrared imaging arrays (IRC) and a far-infrared survey instrument (FIS). Both instruments also have spectroscopic capability. During the first half year period, the Astro-F will concentrate on the all sky survey at
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Papers by Hiroshi Matsuo