176 citations · 1.1k across the 20 of their papers we have counts for
20 papers
Magnetic Field Structure of Orion Source I
Tomoya Hirota, Richard L. Plambeck, Melvyn C. H. Wright +6
We observed polarization of the SiO rotational transitions from Orion Source I (SrcI) to probe the magnetic field in bipolar outflows from this high mass protostar. Both 43 GHz …
Multiple outflows in the high-mass cluster forming region, G25.82-0.17
Jungha Kim, Mi Kyoung Kim, Tomoya Hirota +14
We present results of continuum and spectral line observations with ALMA and 22 GHz water (HO) maser observations using KaVA and VERA toward a high-mass star-forming region, G2…
The First VERA Astrometry Catalog
VERA collaboration, Tomoya Hirota, Takumi Nagayama +59
We present the first astrometry catalog from the Japanese VLBI (very long baseline interferometer) project VERA (VLBI Exploration of Radio Astrometry). We have compiled all the ast…
Extremely high excitation SiO lines in disk-outflow system in Orion Source I
Mi Kyoung Kim, Tomoya Hirota, Masahiro N. Machida +4
We present high-resolution images of the submillimeter SiO line emissions of a massive young stellar object Orion Source I using the Atacama Large Millimeter/ Submillimeter Array (…
Disk-Driven Rotating Bipolar Outflow in Orion Source I
Tomoya Hirota, Masahiro N. Machida, Yuko Matsushita +5
One of the outstanding problems in star-formation theory concerns the transfer of angular momentum such that mass can accrete onto a newly born young stellar object (YSO). From a t…
ALMA band 8 continuum emission from Orion Source I
Tomoya Hirota, Masahiro N. Machida, Yuko Matsushita +5
We have measured continuum flux densities of a high-mass protostar candidate, a radio source I in the Orion KL region (Orion Source I) using the Atacama Large Millimeter/Submillime…
ALMA Observation of the 658 GHz Vibrationally Excited HO Maser in Orion KL Source I
Tomoya Hirota, Mi Kyoung Kim, Mareki Honma
We present an observational study of the vibrationally excited HO line at 658 GHz (=1, 1-1) toward Orion KL using the Atacama Large Millimeter/Submil…
ALMA Imaging of Millimeter/Submillimeter Continuum Emission in Orion KL
Tomoya Hirota, Mi Kyoung Kim, Yasutaka Kurono +1
We have carried out high resolution observations with Atacama Large Millimeter/Submillimeter Array (ALMA) of continuum emission from Orion KL region. We identify 11 compact sources…
VERA and ALMA Observations of the H2O Supermaser Burst in Orion KL
Tomoya Hirota, Masato Tsuboi, Yasutaka Kurono +5
The 22 GHz H2O maser in Orion KL has shown extraordinary burst events in 1979-1985 and 1998-1999, sometimes called supermaser. We have conducted monitoring observations of the supe…
Hot Molecular Circumstellar Disk around Massive Protostar Orion Source I
Tomoya Hirota, Mi Kyoung Kim, Yasutaka Kurono +1
We report new Atacama Large Millimeter/Submillimeter Array (ALMA) observations of a circumstellar disk around Source I in Orion KL, an archetype of massive protostar candidate. We…
Accurate Parallax Measurement toward the Symbiotic Star R Aquarii
Cheulhong Min, Naoko Matsumoto, Mi Kyoung Kim +5
Multi-epoch phase-referencing VLBI (Very Long Baseline Interferometry) observations with VERA (VLBI Exploration of Radio Astrometry) were performed for the symbiotic star R Aquarii…
Fundamental Parameters of the Milky Way Galaxy Based on VLBI astrometry
Mareki Honma, Takumi Nagayama, Kazuma Ando +31
We present analyses to determine the fundamental parameters of the Galaxy based on VLBI astrometry of 52 Galactic maser sources obtained with VERA, VLBA and EVN. We model the Galax…
The first detection of the 232 GHz vibrationally excited H2O maser in Orion KL with ALMA
Tomoya Hirota, Mi Kyoung Kim, Mareki Honma
We investigated the ALMA science verification data of Orion KL and found a spectral signature of the vibrationally excited H2O maser line at 232.68670 GHz (nu2=1, 5,5,0-6,4,3). Thi…
Identification of Bursting Water Maser Features in Orion KL
Tomoya Hirota, Masato Tsuboi, Kenta Fujisawa +10
In February 2011, a burst event of the HO maser in Orion KL (Kleinmann-Low object) has started after 13-year silence. This is the third time to detect such phenomena in Orion…
VLBI Astrometry of AGB Variables with VERA -- A Semiregular Variable S Crateris --
Akiharu Nakagawa, Miyuki Tsushima, Kazuma Ando +40
We present a distance measurement for the semiregular variable S Crateris (S Crt) based on its annual parallax. With the unique dual beam system of the VLBI Exploration for Radio A…
Distance to VY Canis Majoris with VERA
Yoon Kyung Choi, Tomoya Hirota, Mareki Honma +33
We report astrometric observations of H2O masers around the red supergiant VY Canis Majoris (VY CMa) carried out with VLBI Exploration of Radio Astrometry (VERA). Based on astromet…
Astrometry of HO Masers in Nearby Star-Forming Regions with VERA. III. IRAS 22198+6336 in L1204G
Tomoya Hirota, Kazuma Ando, Takeshi Bushimata +35
We present results of multi-epoch VLBI observations with VERA (VLBI Exploration of Radio Astrometry) of the 22 GHz HO masers associated with a young stellar object (YSO) IRAS…
Distance to NGC 281 in a Galactic Fragmenting Superbubble: Parallax Measurements with VERA
Mayumi Sato, Tomoya Hirota, Mareki Honma +30
We have used the Japanese VLBI array VERA to perform high-precision astrometry of an H2O maser source in the Galactic star-forming region NGC 281 West, which has been considered to…
Distance to Orion KL Measured with VERA
Tomoya Hirota, Takeshi Bushimata, Yoon Kyung Choi +34
We present the initial results of multi-epoch VLBI observations of the 22 GHz H2O masers in the Orion KL region with VERA (VLBI Exploration of Radio Astrometry). With the VERA dual…
Absolute Proper Motions of H2O Masers Away from the Galactic Plane Measured with VERA in the "Superbubble" Region NGC 281
Mayumi Sato, Tomoya Hirota, Mareki Honma +34
We report on absolute proper-motion measurements of an H2O maser source in the NGC 281 West molecular cloud, which is located ~320 pc above the Galactic plane and is associated wit…