A5052575283- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Molecular Spectroscopy and Structure
- Gamma-ray bursts and supernovae
- Atmospheric Ozone and Climate
- Astrophysics and Cosmic Phenomena
- biodegradable polymer synthesis and properties
- Radio Astronomy Observations and Technology
- Astronomy and Astrophysical Research
- Enzyme Catalysis and Immobilization
- Astro and Planetary Science
- Biopolymer Synthesis and Applications
- Galaxies: Formation, Evolution, Phenomena
- Geophysics and Gravity Measurements
- Amino Acid Enzymes and Metabolism
- Bone and Dental Protein Studies
- Education and Learning Interventions
- S100 Proteins and Annexins
- Carbon dioxide utilization in catalysis
- Bone Metabolism and Diseases
- GNSS positioning and interference
- Astronomical Observations and Instrumentation
- Advanced Thermodynamic Systems and Engines
- Biochemical Acid Research Studies
- TGF-β signaling in diseases
Hanyang University
2017-2025
Pusan National University Yangsan Hospital
2025
Otsuma Women's University
2020-2024
National Astronomical Observatory of Japan
2007-2020
Korea Astronomy and Space Science Institute
2014-2019
Korea Institute of Science & Technology Information
2012
Chungnam National University
2011
The University of Tokyo
2007-2010
Konkuk University
2010
Astronomical Observatory
2007-2008
We present the initial results of multi-epoch VLBI observations 22 GHz H2O masers in Orion KL region with VERA (VLBI Exploration Radio Astrometry). With dual-beam receiving system, we have carried out phase-referencing astrometry and successfully detected an annual parallax to be 2.29+/-0.10 mas, corresponding distance 437+/-19 pc from Sun. The is determined for first time method these observations. Although this value consistent that previously reported, 480+/-80 pc, which estimated...
We present analyses to determine the fundamental parameters of Galaxy based on VLBI astrometry 52 Galactic maser sources obtained with VERA, VLBA and EVN. model Galaxy's structure a set including center distance R_0, angular rotation velocity at LSR Omega_0, mean peculiar motion respect (U_src, V_src, W_src), rotation-curve shape index, V component Solar motions V_sun. Based Markov chain Monte Carlo method, we find that is constrained 5% level be R_0 = 8.05 +/- 0.45 kpc, where error bar...
Abstract We present results of phase-referencing VLBI observations SiO masers in the Orion-KL region made with VERA. Using a strong maser spot 43GHz $v =$ 2 $J=$ 1-0 emission, we derived trigonometric parallax to be 2.39$\pm$0.03mas, corresponding distance 418$\pm$6pc, highest accuracy among existing measurements source. superimposed image 1 and features based on absolute positions obtained from astrometry common reference The both transitions show similar X-shaped distributions centered at...
We present the first astrometry catalog from Japanese VLBI (very long baseline interferometer) project VERA (VLBI Exploration of Radio Astrometry). have compiled all results VERA, providing accurate trigonometric annual parallax and proper motion measurements. In total, 99 maser sources are listed in catalog. Among them, 21 newly reported while rest 78 referred to previously published or those preparation for forthcoming papers. The accuracy revisited compared with other projects such as...
We report on astrometric observations of H$_2$O masers around the red supergiant VY Canis Majoris carried out with VLBI Exploration Radio Astrometry (VERA). Based monitoring for 13 months, we successfully measured a trigonometric parallax 0.88$\pm$0.08mas, corresponding to distance 1.14$^{+0.11} _{-0.09}$kpc. This is most accurate determined CMa and first one based an annual measurement. The luminosity has been overestimated due previously accepted distance. With our result, re-estimated be...
Abstract We present results of multi-epoch VLBI observations with VERA (VLBI Exploration Radio Astrometry) the 22GHz H$_{2}$O masers associated a young stellar object (YSO) IRAS22198$+$6336 in dark cloud, L1204G. Based on phase-referencing astrometry, we derived an annual parallax to be 1.309$\pm$0.047mas, corresponding distance 764$\pm$27pc from Sun. Although most principal error source our astrometry is attributed internal structure maser spots, successfully reduced errors by employing...
We report new Atacama Large Millimeter/Submillimeter Array (ALMA) observations of a circumstellar disk around Source I in Orion KL, an archetype massive protostar candidates. detected two ortho-H2O lines at 321 GHz (102, 9–93, 6) and 336 (ν2 = 1, 52, 3–61, for the first time I. The latter one is vibrationally excited state lower energy 2939 K, suggesting evidence hot molecular gas close to integrated intensity map line elongated along bipolar outflow while unresolved with beam size 04. Both...
The rapid advancement of artificial intelligence (AI) has spurred innovation across various domains—information technology, medicine, education, and the social sciences—and is likewise creating new opportunities in architecture for understanding human–environment interactions. This study aims to develop a fine-tuned AI model that leverages electroencephalography (EEG) data analyse users’ emotional states real time apply these insights architectural spaces. Specifically, SEED dataset—an...
Regulatory roles of nicotinamide nucleotides and three key enzymes, β-ketothiolase (KT), NADPH-dependent acetoacetyl-CoA reductase (AAR), citrate synthase (CS), on poly(3-hydroxybutyrate) (PHB) synthesis in recombinant Escherichia coli harboring a plasmid containing the Alcaligenes eutrophus polyhydroxyalkanoate (PHA) biosynthesis genes were examined. Cells grown various media subsequently compared for PHB concentration, content, activities levels nucleotides. E. accumulated largest amount...
[reaction: see text] A novel trifluoroacetophenone-based binding motif has been developed that recognizes anions such as carboxylates through reversible formation of anion-ionophore adducts are stabilized by intramolecular H-bonding. The H-bonding resulted in more than 10-fold enhancement the affinity and an enthalpy gain (DeltaH degrees ) 3.0 kcal/mol for acetate ion when compared to case without
Poly-β-hydroxybutyrate biosynthesis was studied in Alcaligenes eutrophus under various nutrient-limiting conditions. When the cells were cultivated nitrogen-limited media, both levels of NAD(P)H and ratios NAD(P)H/NAD(P) higher than those nitrogen-sufficient The specific poly-β-hydroxybutyrate production rate found to increase with values NADH/NAD NADPH/NADP, indicating that synthesis is directly regulated by nicotinamide nucleotides. effects nucleotides on investigated regard enzyme...
We have used the Japanese VLBI array VERA to perform high-precision astrometry of an H2O maser source in Galactic star-forming region NGC 281 West, which has been considered be part a 300-pc superbubble. successfully detected trigonometric parallax 0.355+/-0.030 mas, corresponding distance 2.82+/-0.24 kpc. Our direct determination resolved large discrepancy between previous photometric and kinematic studies; likely is far side Perseus spiral arm. The as well absolute proper motions were...
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 (R Aqr) from September 2005 to Oct 2006. Tracing one $v=2$, $J=1-0$ SiO maser spots, we measured an annual parallax $\pi = 4.59\pm0.24$ mas, corresponding a distance $218_{-11}^{+12}$ pc. Our result is consistent earlier measurements, but yields highest accuracy about $5\%$ level. Applying our distance, derived...
Abstract We present a distance measurement for the semiregular variable S Crateris (S Crt) based on its annual parallax. With unique dual beam system of VLBI Exploration Radio Astrometry (VERA) telescopes, we measured absolute proper motion water maser spot associated with Crt, referred to quasar J1147$-$0724 located at an angular separation 1.23D. In observations spanning nearly two years, detected LSR velocity 34.7kms$^{-1}$, which parallax 2.33$\pm$0.13mas, corresponding...
We investigated the ALMA science verification data of Orion KL and found a spectral signature vibrationally excited H2O maser line at 232.68670 GHz (ν2 = 1, 55, 0–64, 3). This has been detected previously in circumstellar envelopes late-type stars but not young stellar objects such as KL. Thus, this is first detection 232 star-forming regions. The distribution concentrated position radio Source I, which remarkably different from other molecular lines. spectrum shows double-peak structure...
We have carried out high resolution observations with Atacama Large Millimeter/Submillimeter Array (ALMA) of continuum emission from Orion KL region. identify 11 compact sources at ALMA band 6 (245 GHz) and 7 (339 GHz), including Hot Core, Compact Ridge, SMA1, IRc4, IRc7, a radio source I (Source I). Spectral energy distribution (SED) each is determined by using previous 3 mm data. Physical properties such as size, mass, hydrogen number density column are discussed based on the dust graybody...
Abstract In 2019 September, a sudden flare of the 6.7 GHz methanol maser was observed toward high-mass young stellar object (HMYSO) G24.33+0.14. This may represent fourth detection transient mass accretion event in an HMYSO after S255IR NIRS3, NGC 6334I-MM1, and G358.93−0.03-MM1. G24.33+0.14 is unique among these sources as it clearly shows repeating with 8 yr interval. Using Atacama Large Millimeter/submillimeter Array (ALMA), we millimeter continuum molecular lines pre-flare phase 2016...
We investigated the expression of formyl peptide receptor (FPR) and its functional role in human bone marrow‐derived mesenchymal stem cells (MSCs). analyzed FPR by using ligand‐binding assay with radio‐labeled N ‐formyl‐met‐leu‐phe (fMLF), found that MSCs express FPR. FMLF stimulated intracellular calcium increase, mitogen‐activated protein kinases activation, Akt which were mediated G i proteins. chemotactically migrated to fMLF. FMLF‐induced MSC chemotaxis was also completely inhibited...
Abstract Recent astrochemical models and experiments have explained that complex organic molecules (COMs; composed of six or more atoms) are produced on the dust grain mantles in cold dense gas prestellar cores. However, detailed chemical processes roles physical conditions chemistry still far from understood. To address these questions, we investigated 12 high-mass star-forming regions using Atacama Large Millimeter/submillimeter Array (ALMA) Band 6 observations. They associated with 44/95...
In 2011 February, a burst event of the H2O maser in Orion KL (Kleinmann–Low object) has started after 13 year silence. This is third time such phenomena been detected KL, followed by events 1979–1985 and 1998. We have carried out astrometric observations bursting features with VLBI Exploration Radio Astrometry (VERA), Japanese very long baseline interferometry network dedicated for astrometry. The total flux feature at local standard rest (LSR) velocity 7.58 km s−1 reaches 4.4 × 104 Jy...
The 22 GHz H2O maser in Orion KL has shown extraordinary burst events 1979-1985 and 1998-1999, sometimes called supermaser. We have conducted monitoring observations of the supermaser using VERA, VLBI Exploration Radio Astrometry, current third since 2011 March. Three flux maxima are detected 2012 with rising falling timescales 2-7 months. Time variations seem symmetric for all active phases. maximum total density 135000 Jy is observed June while it still one order magnitude lower than those...