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37 papers
First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way
The Event Horizon Telescope Collaboration
We present the first Event Horizon Telescope (EHT) observations of Sagittarius A* (Sgr A), the Galactic center source associated with a supermassive black hole. These observati…
Development of a new wideband heterodyne receiver system for the Osaka 1.85-m mm-submm telescope -- Corrugated horn & Optics covering 210-375 GHz band
Yasumasa Yamasaki, Sho Masui, Hideo Ogawa +21
The corrugated horn is a high performance feed often used in radio telescopes. There has been a growing demand for wideband optics and corrugated horns in millimeter and submillime…
Development of a new wideband heterodyne receiver system for the Osaka 1.85-m mm-submm telescope -- Receiver development & the first light of simultaneous observation in 230GHz and 345GHz bands with an SIS-mixer with 4-21GHz IF output
Sho Masui, Yasumasa Yamasaki, Hideo Ogawa +22
We have developed a wideband receiver system for simultaneous observations in CO lines of J = 2-1 and J = 3-2 transitions using the Osaka 1.85-m mm-submm telescope. As a frequency…
Observational demonstration of a low-cost fast Fourier transform spectrometer with a delay-line-based ramp-compare ADC implemented on FPGA
Atsushi Nishimura, Takeru Matsumoto, Teppei Yonetsu +5
In this study, a novel type of Fourier transform radio spectrometer (termed as all-digital radio spectrometer; ADRS) has been developed in which all functionalities comprising a ra…
Wavefront sensor for millimeter/submillimeter-wave adaptive optics based on aperture-plane interferometry
Yoichi Tamura, Ryohei Kawabe, Yuhei Fukasaku +20
We present a concept of a millimeter wavefront sensor that allows real-time sensing of the surface of a ground-based millimeter/submillimeter telescope. It is becoming important fo…
Overview of the Medium and High Frequency Telescopes of the LiteBIRD satellite mission
L. Montier, B. Mot, P. de Bernardis +232
LiteBIRD is a JAXA-led Strategic Large-Class mission designed to search for the existence of the primordial gravitational waves produced during the inflationary phase of the Univer…
LiteBIRD: JAXA's new strategic L-class mission for all-sky surveys of cosmic microwave background polarization
M. Hazumi, P. A. R. Ade, A. Adler +233
LiteBIRD, the Lite (Light) satellite for the study of B-mode polarization and Inflation from cosmic background Radiation Detection, is a space mission for primordial cosmology and…
Concept Design of Low Frequency Telescope for CMB B-mode Polarization satellite LiteBIRD
Y. Sekimoto, P. A. R. Ade, A. Adler +232
LiteBIRD has been selected as JAXA's strategic large mission in the 2020s, to observe the cosmic microwave background (CMB) -mode polarization over the full sky at large angular…
Current status and future plan of Osaka Prefecture University 1.85-m mm-submm telescope project
Atsushi Nishimura, Kazuki Tokuda, Ryohei Harada +25
We report the current status of the 1.85-m mm-submm telescope installed at the Nobeyama Radio Observatory (altitude 1400 m) and the future plan. The scientific goal is to reveal th…
Development of the new multi-beam receiver and telescope control system for NASCO
Atsushi Nishimura, Akio Ohama, Kimihiro Kimura +59
We report the current status of the NASCO (NAnten2 Super CO survey as legacy) project which aims to provide all-sky CO data cube of southern hemisphere using the NANTEN2 4-m submil…
Wind- and Operation-Induced Vibration Measurements of the Main Reflector of the Nobeyama 45 m Radio Telescope
Ikumi Hashimoto, Masakatsu Chiba, Nozomi Okada +5
As deformations of the main reflector of a radio telescope directly affect the observations, the evaluation of the deformation is extremely important. Dynamic characteristics of th…
Updated design of the CMB polarization experiment satellite LiteBIRD
H. Sugai, P. A. R. Ade, Y. Akiba +216
Recent developments of transition-edge sensors (TESs), based on extensive experience in ground-based experiments, have been making the sensor techniques mature enough for their app…
High-mass star formation in Orion B triggered by cloud-cloud collision: Merging molecular clouds in NGC 2024
Rei Enokiya, Akio Ohama, Rin Yamada +13
We performed new comprehensive CO(=2--1) observations toward NGC 2024, the most active star forming region in Orion B, with an angular resolution of 100'' obtained…
First M87 Event Horizon Telescope Results. II. Array and Instrumentation
The Event Horizon Telescope Collaboration
The Event Horizon Telescope (EHT) is a very long baseline interferometry (VLBI) array that comprises millimeter- and submillimeter-wavelength telescopes separated by distances comp…
A Balloon-Borne Very Long Baseline Interferometry Experiment in the Stratosphere: Systems Design and Developments
Akihiro Doi, Yusuke Kono, Kimihiro Kimura +33
The balloon-borne very long baseline interferometry (VLBI) experiment is a technical feasibility study for performing radio interferometry in the stratosphere. The flight model has…
Electronics Instrumentation for the Greenland Telescope
Derek Kubo, Chih-Chiang Han, Hiroaki Nishioka +37
The Greenland Telescope project has recently participated in an experiment to image the supermassive black hole shadow at the center of M87 using Very Long Baseline Interferometry…
Detailed CO ( = 1--0, 2--1 and 3--2) observations toward an H{\sc ii} region RCW~32 in the Vela Molecular Ridge
Rei Enokiya, Hidetoshi Sano, Katsuhiro Hayashi +9
We made CO ( = 1--0, 2--1, and 3--2) observations toward an H{\sc ii} region RCW~32 in the Vela Molecular Ridge. The CO gas distribution associated with the H{\sc ii} region was…
A new view of the giant molecular cloud M16 (Eagle Nebula) in 12CO J=1-0 and 2-1 transitions with NANTEN2
Atsushi Nishimura, Jean Costes, Tetsuta Inaba +11
M16, the Eagle Nebula, is an outstanding HII region where extensive high-mass star formation is taking place in the Sagittarius Arm, and hosts the remarkable "pillars" observed wit…
High-mass star formation possibly triggered by cloud-cloud collision in the HII region RCW 34
Katsuhiro Hayashi, Hidetoshi Sano, Rei Enokiya +12
We report a possibility that the high-mass star located in the HII region RCW 34 was formed by a triggering induced by a collision of molecular clouds. Molecular gas distributions…
RCW 36 in the Vela Molecular Ridge: Evidence for a high-mass star cluster formation triggered by Cloud-Cloud Collision
Hidetoshi Sano, Rei Enokiya, Katsuhiro Hayashi +21
A collision between two molecular clouds is one possible candidate for high-mass star formation. The HII region RCW 36, located in the Vela molecular ridge, contains a young star c…
High-mass star formation in Orion possibly triggered by cloud-cloud collision III, NGC2068 and NGC2071
Shinji Fujita, Daichi Tsutsumi, Akio Ohama +12
Using the NANTEN2 Observatory, we carried out a molecular line study of high-mass star forming regions with reflection nebulae, NGC 2068 and NGC 2071, in Orion in the 13CO(J=2-1) t…
Z45: A New 45-GHz Band Dual-Polarization HEMT Receiver for the NRO 45-m Radio Telescope
Fumitaka Nakamura, Hideo Ogawa, Yoshinori Yonekura +20
We developed a dual-linear-polarization HEMT (High Electron Mobility Transistor) amplifier receiver system of the 45-GHz band (hereafter Z45), and installed it in the Nobeyama 45-m…
Revealing the physical properties of molecular gas in Orion with a large scale survey in J=2-1 lines of 12CO, 13CO and C18O
Atsushi Nishimura, Kazuki Tokuda, Kimihiro Kimura +8
We present fully sampled ~3' resolution images of the 12CO(J=2-1), 13CO(J=2-1), and C18O(J=2-1) emission taken with the newly developed 1.85-m mm-submm telescope toward the entire…
Cluster Formation Triggered by Filament Collisions in Serpens South
Fumitaka Nakamura, Koji Sugitani, Tomohiro Tanaka +24
The Serpens South infrared dark cloud consists of several filamentary ridges, some of which fragment into dense clumps. On the basis of CCS (), HCN (), N$_2…