A5082872121- Astrophysics and Star Formation Studies
- Molecular Spectroscopy and Structure
- Atmospheric Ozone and Climate
- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Advanced Chemical Physics Studies
- Spectroscopy and Laser Applications
- Galaxies: Formation, Evolution, Phenomena
- Superconducting and THz Device Technology
- Astronomy and Astrophysical Research
- Phase Equilibria and Thermodynamics
- Calibration and Measurement Techniques
- Microwave Engineering and Waveguides
- Astrophysical Phenomena and Observations
- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Chemical Synthesis and Characterization
- Ionosphere and magnetosphere dynamics
- HIV/AIDS Impact and Responses
- Antenna Design and Optimization
- Particle accelerators and beam dynamics
- Gas Dynamics and Kinetic Theory
- Spacecraft and Cryogenic Technologies
- Solar and Space Plasma Dynamics
- Radioactive element chemistry and processing
National Astronomical Observatory of Japan
2017-2024
National Institutes of Natural Sciences
2018-2024
Institute of Astronomy and Astrophysics, Academia Sinica
2022
Gakushuin University
2019-2021
University of Virginia
2018-2020
The Graduate University for Advanced Studies, SOKENDAI
2015-2019
Rakuno Gakuen University
2018
Toho University
2014-2016
Okayama Prefecture
2016
Shimane University
2005-2008
Abstract A complete understanding of the initial conditions high-mass star formation and what processes determine multiplicity requires study magnetic field in young massive cores. Using Atacama Large Millimeter/submillimeter Array (ALMA) 250 GHz polarization observations (0 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mrow> <mml:mi>.</mml:mi> </mml:mrow> <mml:mi>″</mml:mi> </mml:mover> </mml:math> 3 = 1000 au) ALMA 220...
Bovine mastitis is an inflammation of the mammary gland caused by bacterial infection in dairy cattle. It most costly disease industry because high use antibiotics. Staphylococcus aureus one major causative agents bovine and antimicrobial resistance. Therefore, new strategies to control are required industry. One potential strategy bacteriophage (phage) therapy. In present study, we examined host range previously isolated S. phages ΦSA012 ΦSA039 against strains from mastitic cows. These...
Abstract The dominant mechanism forming multiple stellar systems in the high-mass regime ( M * ≳ 8 ⊙ ) remained unknown because direct imaging of protostellar at early phases star formation is very challenging. High-mass stars are expected to form clustered environments containing binaries and higher-order multiplicity systems. So far only a few protobinary systems, no definitive multiples, have been detected. Here we report discovery one quintuple, quadruple, triple four binary...
We have analyzed the NH$_{2}$CHO, HNCO, H$_{2}$CO, and CH$_{3}$CN ($^{13}$CH$_{3}$CN) molecular lines at an angular resolution of $\sim 0.3''$ obtained by Atacama Large Millimeter/submillimeter Array (ALMA) Band 6 toward 30 high-mass star-forming regions. The NH$_{2}$CHO emission has been detected in 23 regions, while other species 29 A total 44 hot cores (HMCs) identified using moment 0 maps line. fractional abundances four derived each HMC. In order to investigate pure chemical...
Abstract We observed the high-mass star-forming core G336.01–0.82 at 1.3 mm and 0.″05 (∼150 au) angular resolution with Atacama Large Millimeter/submillimeter Array (ALMA) as part of Digging into Interior Hot Cores ALMA survey. These high-resolution observations reveal two spiral streamers feeding a circumstellar disk opposite sides in great detail. Molecular line emission from CH 3 OH shows velocity gradients along consistent infall. Similarly, flattened envelope model rotation infall...
Abstract Streamers bring gas from outer regions to protostellar systems and could change the chemical composition around protostars protoplanetary disks. We have carried out mapping observations of carbon-chain species (HC 3 N, HC 5 CCH, CCS) in mm 7 bands toward streamer flowing Class 0 young stellar object (YSO) Per-emb-2 with Nobeyama 45 m radio telescope. A region a diameter ∼0.04 pc is located north at distance ∼20,500 au YSO. The connects this northern region, which its origin....
We present a wide-field $(60\arcmin \times 30\arcmin)$ study of dense region within the Polaris Flare, hereafter referred to as `Polaris molecular cloud', using $^{12}$CO, $^{13}$CO, and C$^{18}$O ($J=1-0$) observations at $20\arcsec$ resolution, obtained with Nobeyama 45 m Radio Telescope. The analysis reveals gas formation occurring column densities up $\sim10^{21}$ cm$^{-2}$, evidenced by an anti-correlation between $\textsc{Hi}$ CO distributions, indicating active atomic-to-molecular...
We observed the J = 9-8 and 16-15 rotational transitions of normal species five 13C isotopologues HC5N to study its formation mechanisms toward cyanopolyyne peak in Taurus Molecular Cloud-1, with 45-m radio telescope Nobeyama Radio Observatory. detected high signal-to-noise ratios between 12 20, as well species. The abundance are found be 1.00:0.97:1.03:1.05:1.16 (0.19) for [H13CCCCCN]:[HC13CCCCN]:[HCC13CCCN]:[HCCC13CCN]:[HCCCC13CN]. do not find any significant differences among...
We observed the J=9-8 and 10-9 rotational lines of three13C isotopologues HC3N in L1527 G28.28-0.36 with 45-m radio telescope Nobeyama Radio Observatory order to constrain main formation mechanisms each source. The abundance ratios three 13C are found be 0.9 (0.2) : 1.00 1.29 (0.19) (1sigma) 1.0 1.47 (0.17) for [H13CCCN]: [HC13CCN]: [HCC13CN] G28.28-0.36, respectively. recognize a similar isotopic fractionation pattern that abundances H13CCCN HC13CCN comparable, HCC13CN is more abundant than...
Abstract We present the results of mapping observations toward a nearby starless filamentary cloud, Taurus Molecular Cloud 1 (TMC-1), in CCS ( <?CDATA ${J}_{N}={4}_{3}-{3}_{2}$?> , 45.379033 GHz) emission line, using Nobeyama 45 m telescope. The map shows that TMC-1 filament has diameter ∼0.1 pc and length ∼0.5 at distance 140 pc. position–velocity diagrams clearly indicate existence velocity-coherent substructures filament. identify 21 are coherent position–position–velocity space by eye....
Abstract We present emission maps ( <?CDATA $1\buildrel{\,\prime}\over{.} 5\,\times \,1\buildrel{\,\prime}\over{.} 5$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>1</mml:mn> <mml:mrow> <mml:mo>.′</mml:mo> </mml:mrow> <mml:mn>5</mml:mn> <mml:mspace width="0.25em" /> <mml:mo>×</mml:mo> </mml:math> scale, corresponding to 0.18 pc) of the DCN J = 2 − 1) and DCO + lines in mm band toward Orion KL region obtained with receiver system named B4R installed on...
Abstract We present a wide-field <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo stretchy="false">(</mml:mo> <mml:mn>60</mml:mn> <mml:mi>′</mml:mi> <mml:mo>×</mml:mo> <mml:mn>30</mml:mn> stretchy="false">)</mml:mo> </mml:math> study of dense region within the Polaris Flare using 12 CO, 13 and C 18 O ( J = 1–0) observations at 15″ resolution, obtained with Nobeyama 45 m Radio Telescope. The analysis reveals molecular gas formation occurring column densities...
Abstract We have observed the 13 CH 3 OH 5 1 −4 A + , 14 −13 2 − and DOH 8 2,6 −8 1,7 e 0 lines toward 24 high-mass star-forming regions by using Atacama Large Millimeter/submillimeter Array with an angular resolution of about <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover> <mml:mrow> <mml:mo>.</mml:mo> </mml:mrow> <mml:mtext>″</mml:mtext> </mml:mover> </mml:math> 3. This corresponds to a linear scale 400–1600 au, allowing us resolve individual cores...
Abstract Fragmentation contributes to the formation and evolution of stars. Observationally, high-mass stars are known form multiple-star systems, preferentially in cluster environments. Theoretically, Jeans instability has been suggested determine characteristic fragmentation scales, thermal or turbulent motion parental gas clump mainly instability. To search for such a scale, we have analyzed Atacama Large Millimeter/submillimeter Array (ALMA) 1.33 mm continuum observations toward 30...
Abstract We observed the <?CDATA $J=5-4$?> rotational lines of normal species and three 13 C isotopologues HC 3 N at 45 GHz band toward two low-mass starless cores, L1521B L134N (L183), using Nobeyama m radio telescope in order to study main formation pathways each core. The abundance ratios are derived be [H CCCN]:[HC CCN]:[HCC CN] = 0.98 (±0.14):1.00:1.52 (±0.16) ( $1\sigma $?> ). fractionation pattern is consistent with that cyanopolyyne peak Taurus Molecular Cloud-1. This suggests...
We report the first detection of HC$_{5}$$^{15}$N with $J=9-8$ rotational line from cyanopolyyne peak in Taurus Molecular Cloud-1 (TMC-1 CP) using 45-m radio telescope Nobeyama Radio Observatory. The column density is derived to be (1.9 +- 0.5)*$10^{11}$ cm$^{-2}$ (1 sigma). apply double isotope method derive $^{14}$N/$^{15}$N ratios HC$_{5}$N and HC$_{3}$N TMC-1 CP. are calculated 344 53 257 54 for HC$_{3}$N, respectively. ratio lower than elemental local interstellar medium (~440) slightly...
We have carried out observations in the 42$-$46 and 82$-$103 GHz bands with Nobeyama 45-m radio telescope, 338.2$-$339.2 348.45$-$349.45 ASTE 10-m telescope toward three high-mass star-forming regions containing massive young stellar objects (MYSOs), G12.89+0.49, G16.86$-$2.16, G28.28$-$0.36. detected HC$_{3}$N including its $^{13}$C D isotopologues, CH$_{3}$OH, CH$_{3}$CCH, several complex organic molecules (COMs). Combining our previous results of HC$_{5}$N these sources, we compare...
Abstract We report on the development and commissioning of a new Q-band receiver for Nobeyama 45 m telescope, covering 30–50 GHz with noise temperature about 15 K. name it eQ (extended Q-band) receiver. The system temperatures observations are measured to be ∼30 K at 33 ∼75 GHz. half-power beam-width (HPBW) is around 38${^{\prime \prime }}$ 43 To enhance observation capability, we tested smoothed bandpass calibration technique demonstrated that time can significantly reduced compared...
Unveiling the emergence and prevalence of massive/bright galaxies during epoch reionization beyond, within first 600 million years Universe, stands as a pivotal pursuit in astronomy. Remarkable progress has been made by <i>JWST</i> identifying an immense population bright galaxies, which hints at exceptionally efficient galaxy assembly processes. However, underlying physical mechanisms propelling their rapid growth remain unclear. With this mind, millimeter submillimeter-wave spectroscopic...
We have analyzed the Atacama Large Millimeter/submillimeter Array (ALMA) cycle 2 data of band 6 toward G345.4938+01.4677 massive young protostellar object (G345.5+1.47 MYSO) in IRAS 16562--3959 high-mass star-forming region with an angular resolution $\sim 0.3"$, corresponding to 760$ au. spatially resolve central which consists three prominent molecular emission cores. A hypercompact (HC) H$_{\rm {II}}$ (Core A) and two molecule-rich cores B Core C) are identified using moment zero images...
We have carried out survey observations of molecular emission lines from HC$_{3}$N, N$_{2}$H$^{+}$, CCS, and cyclic-C$_{3}$H$_{2}$ in the 81$-$94 GHz band toward 17 high-mass starless cores (HMSCs) 28 protostellar objects (HMPOs) with Nobeyama 45-m radio telescope. detected N$_{2}$H$^{+}$ all target sources except one HC$_{3}$N 14 HMSCs 26 HMPOs. investigate $N$(N$_{2}$H$^{+}$)/$N$(HC$_{3}$N) column density ratio as a chemical evolutionary indicator massive cores. Using Kolmogorov-Smirnov...
Abstract We carried out survey observations of HC 3 N and 5 in the 42−45 GHz band toward 17 high-mass starless cores (HMSCs) 35 protostellar objects (HMPOs) with Nobeyama 45 m radio telescope. have detected from 15 HMSCs 28 HMPOs, 14 respectively. The average values column density are found to be <?CDATA $(5.7\pm 0.7)\,\times \,{10}^{12}$?> $(1.03\pm 0.12)\times{10}^{13}$?> cm −2 fractional abundance derived $(6.6\pm 0.8)\times {10}^{-11}$?> $(3.6\pm 0.5)\times find that decreases HMPOs...
We have carried out observations of CCH and its two $^{13}$C isotopologues, $^{13}$CCH C$^{13}$CH, in the 84 - 88 GHz band toward starless cores, L1521B L134N (L183), using Nobeyama 45 m radio telescope. detected C$^{13}$CH with a signal-to-noise (S/N) ratio 4, whereas no line was either dark clouds. The column densities normal species were derived to be ($1.66 \pm 0.18$)$\times 10^{14}$ cm$^{-2}$ ($7.3 0.9$)$\times 10^{13}$ ($1 \sigma$) L134N, respectively. density ratios...
Abstract We report the statistical physical properties of C 18 O( J = 1–0) clumps present in a prominent cluster-forming region, Cygnus X, using data set obtained by Nobeyama 45 m radio telescope. This survey covers 9 deg 2 northern and southern regions and, total, 174 O are identified dendrogram method. Assuming distance 1.4 kpc, these have radii 0.2–1 pc, velocity dispersions <2.2 km s −1 , gas masses 30–3000 M ⊙ H densities (0.2–5.5) × 10 4 cm −3 . confirm that region higher density...