Jihye Hwang
A5008364950- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Atmospheric Ozone and Climate
- Molecular Spectroscopy and Structure
- Astronomy and Astrophysical Research
- Solar and Space Plasma Dynamics
- Galaxies: Formation, Evolution, Phenomena
- Geomagnetism and Paleomagnetism Studies
- Scientific Research and Discoveries
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Magnetic and Electromagnetic Effects
- Spectroscopy and Laser Applications
- Atomic and Molecular Physics
- Fluorine in Organic Chemistry
- High-pressure geophysics and materials
- Ionosphere and magnetosphere dynamics
- Catalytic Cross-Coupling Reactions
- Advancements in Semiconductor Devices and Circuit Design
- Superconducting Materials and Applications
- Ferroelectric and Negative Capacitance Devices
- Nuclear physics research studies
- Phase Equilibria and Thermodynamics
- Radio Frequency Integrated Circuit Design
Korea Astronomy and Space Science Institute
2017-2024
Korea University of Science and Technology
2018-2024
University College London
2023
Chung-Ang University
2022
Sejong University
2017
Context. Molecular filaments and hubs have received special attention recently thanks to new studies showing their key role in star formation. While the (column) density velocity structures of both been carefully studied, magnetic field (B-field) properties yet be characterized. Consequently, B-fields formation evolution hub-filament systems is not well constrained. Aims. We aim understand B-field its interplay with turbulence gravity dynamical NGC 6334 filament network that harbours...
Interstellar molecules are excellent tools for studying the physical and chemical environments of massive star-forming regions. In particular, vibrationally excited HC_3N (HC_3N*) lines key tracers probing hot cores environments. We present Atacama Large Millimeter/submillimeter Array (ALMA) 3 mm observations HC_3N* in 60 investigate how conditions affect excitation transitions. used XCLASS line identification. Under assumption local thermodynamic equilibrium, we derived rotation temperature...
We present new observations of the active star-formation region NGC 1333 in Perseus molecular cloud complex from James Clerk Maxwell Telescope B-Fields In Star-forming Region Observations (BISTRO) survey with POL-2 instrument. The BISTRO data cover entire (~1.5 pc x 2 pc) at 0.02 resolution and spatially resolve polarized emission individual filamentary structures for first time. inferred magnetic field structure is as a whole, each filament aligned different position angles relative to...
We report 850~$\mu$m dust polarization observations of a low-mass ($\sim$12 $M_{\odot}$) starless core in the $\rho$ Ophiuchus cloud, C, made with POL-2 instrument on James Clerk Maxwell Telescope (JCMT) as part JCMT B-fields In STar-forming Region Observations (BISTRO) survey. detect an ordered magnetic field projected plane sky core. The across $\sim$0.1~pc shows predominant northeast-southwest orientation centering between $\sim$40$^\circ$ to $\sim$100$^\circ$, indicating that is well...
Abstract We present 850 μ m polarization observations of the L1689 molecular cloud, part nearby Ophiuchus cloud complex, taken with POL-2 polarimeter on James Clerk Maxwell Telescope (JCMT). observe three regions L1689: clump L1689N which houses IRAS 16293-2433 protostellar system, starless SMM-16, and core L1689B. use Davis–Chandrasekhar–Fermi method to estimate plane-of-sky field strengths 366 ± 55 G in L1689N, 284 34 72 33 L1689B, for our fiducial value dust opacity. These values indicate...
Abstract We present 850 μ m polarimetric observations toward the Serpens Main molecular cloud obtained using POL-2 polarimeter on James Clerk Maxwell Telescope as part of B-fields In STar-forming Region Observations survey. These probe magnetic field morphology about 6000 au scales, which consists cores and six filaments with different physical properties such density star formation activity. Using histogram relative orientation (HRO) technique, we find that fields are parallel to in...
Abstract We report 850 μ m continuum polarization observations toward the filamentary high-mass star-forming region NGC 2264, taken as part of B -fields In STar forming Regions Observations large program on James Clerk Maxwell Telescope. These data reveal a well-structured nonuniform magnetic field in 2264C and 2264D regions with prevailing orientation around 30° from north to east. Field strength estimates virial analysis major clumps indicate that is globally dominated by gravity, while...
Abstract We report on Atacama Large Millimeter/submillimeter Array observations of polarized dust emission at 1.2 mm from NGC6334I, a source known for its significant flux outbursts. Between five months, our data show no substantial change in total intensity and modest 8% variation linear polarization, suggesting phase stability or the conclusion outburst. The magnetic field, inferred this emission, displays predominantly radial pattern northwest to southeast with intricate disturbances...
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...
We present the magnetic field in dense material of Central Molecular Zone (CMZ) Milky Way, traced 850 $\mu$m polarized dust emission as part James Clerk Maxwell Telescope (JCMT) B-fields In STar-forming Region Observations (BISTRO) Survey. observe a highly ordered across CMZ between Sgr B2 and C, which is strongly preferentially aligned with orbital gas flows within clouds CMZ. find that observed relative orientations are non-random at $>$99% confidence level consistent models vectors...
Abstract We present the magnetic field in dense material of Central Molecular Zone (CMZ) Milky Way, traced 850 μ m polarized dust emission as part James Clerk Maxwell Telescope B -fields STar-forming Region Observations survey. observe a highly ordered across CMZ between Sgr B2 and C that is strongly preferentially aligned with orbital gas flows within clouds CMZ. find observed relative orientations are nonrandom at >99% confidence level consistent models which vectors 30° to 3D. The...
Abstract We have obtained sensitive dust continuum polarization observations at 850 μ m in the B213 region of Taurus using POL-2 on SCUBA-2 James Clerk Maxwell Telescope as part B -fields STar-forming Region Observations (BISTRO) survey. These allow us to probe magnetic field ( -field) high spatial resolution (∼2000 au or ∼0.01 pc 140 pc) two protostellar cores (K04166 and K04169) one prestellar core (Miz-8b) that lie within filament. Using Davis–Chandrasekhar–Fermi method, we estimate...
Abstract Measurement of magnetic field strengths in a molecular cloud is essential for determining the criticality support against gravitational collapse. In this paper, as part JCMT BISTRO survey, we suggest new application Davis–Chandrasekhar–Fermi (DCF) method to estimate distribution OMC-1 region. We use observations dust polarization emission at 450 and 850 μ m, C 18 O (3–2) spectral line data obtained with JCMT. volume density, velocity dispersion, angle dispersion box, 40″ × (5×5...
Abstract We report the first high spatial resolution measurement of magnetic fields surrounding LkH α 101, part Auriga–California molecular cloud. The observations were taken with POL-2 polarimeter on James Clerk Maxwell Telescope within framework B-fields In Star-forming Region Observations (BISTRO) survey. Observed polarization thermal dust emission at 850 μ m is found to be mostly associated redshifted gas component field displays a relatively complex morphology. Two variants...
We study the HII regions associated with NGC 6334 molecular cloud observed in sub-millimeter and taken as part of B-fields In STar-forming Region Observations (BISTRO) Survey. particular, we investigate polarization patterns magnetic field morphologies these regions. Through pattern pressure calculation analyses, several bubbles indicate that gas lines have been pushed away from bubble, toward an almost tangential (to bubble) morphology. densest 6334, where morphology is similar to...
We present ALMA Band 7 polarisation observations of the OMC-1 region Orion molecular cloud. find that pattern observed in is likely to have been significantly altered by radiation field $>10^{4}$ L$_{\odot}$ high-mass protostar Source I. In protostar's optically thick disc, arise from dust self-scattering. material south I - previously identified as a 'anomalous' emission we observe geometry concentric around demonstrate I's extreme luminosity may be sufficient make radiative precession...
We present 850 $\mu$m dust polarization observations of the massive DR21 filament from B-fields In STar-forming Region Observations (BISTRO) survey, using POL-2 polarimeter and SCUBA-2 camera on James Clerk Maxwell Telescope. detect ordered magnetic fields perpendicular to parsec-scale ridge main filament. sub-filaments, are mainly parallel filamentary structures smoothly connect compare Planck study field 0.1--10 pc scales. The revealed in data well aligned with those data, indicating a...
We present and analyze observations of polarized dust emission at 850 $\mu$m towards the central 1 pc $\times$ hub-filament structure Monoceros R2 (Mon R2). The data are obtained with SCUBA-2/POL-2 on James Clerk Maxwell Telescope (JCMT) as part BISTRO (B-fields in Star-forming Region Observations) survey. orientations magnetic field follow spiral Mon R2, which well-described by an axisymmetric model. estimate turbulent component using angle difference between our best-fit model underlying...
Abstract We present observations of polarized dust emission at 850 μ m from the L43 molecular cloud, which sits in Ophiuchus cloud complex. The data were taken using SCUBA-2/POL-2 on James Clerk Maxwell Telescope as a part BISTRO large program. is dense ( <?CDATA ${N}_{{{\rm{H}}}_{2}}\sim {10}^{22}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>N</mml:mi> </mml:mrow> <mml:mi mathvariant="normal">H</mml:mi> <mml:mn>2</mml:mn>...
Abstract We present the 850 μ m polarization observations toward IC 5146 filamentary cloud taken using Submillimetre Common-User Bolometer Array 2 (SCUBA-2) and its associated polarimeter (POL-2), mounted on James Clerk Maxwell Telescope, as part of B -fields In STar forming Regions Observations. This work is aimed at revealing magnetic field morphology within a core-scale (≲1.0 pc) hub-filament structure (HFS) located end parsec-scale filament. To investigate whether observed traces in HFS,...
We present the results of simultaneous 450 $\mu$m and 850 polarization observations toward massive star forming region NGC 2071IR, a target BISTRO (B-fields in Star-Forming Region Observations) Survey, using POL-2 polarimeter SCUBA-2 camera mounted on James Clerk Maxwell Telescope. find pinched magnetic field morphology central dense core region, which could be due to rotating toroidal disk-like structure bipolar outflow originating from young stellar object, IRS 3. Using modified...
Abstract We present the first polarized dust emission measurements of Horsehead Nebula, obtained using POL-2 polarimeter on Submillimetre Common-User Bolometer Array 2 (SCUBA-2) camera James Clerk Maxwell Telescope. The Nebula contains two submillimeter sources: a photodissociation region (PDR; SMM1) and starless core (SMM2). see well-ordered magnetic fields in both sources. estimated plane-of-sky field strengths 56 ± 9 129 21 μ G SMM1 SMM2, respectively, mass-to-flux ratios Alfvén Mach...
Abstract The contribution of the magnetic field to formation high-mass stars is poorly understood. We report high angular resolution (∼0.″3, 870 au) map projected on plane sky ( B POS ) toward star-forming region G333.46−0.16 (G333), obtained with Atacama Large Millimeter/submillimeter Array at 1.2 mm as part Magnetic fields in Massive Regions survey. morphology found this consistent a canonical “hourglass” an embedded flattened envelope perpendicular direction, which suggests dynamically...
Abstract We investigate the internal 3D magnetic structure of dense interstellar filaments within NGC 1333 using polarization data at 850 μ m from B -fields In STar-forming Region Observations survey James Clerk Maxwell Telescope. Theoretical models predict that field lines in a filament will tend to be dragged radially inward (i.e., pinched) toward central axis due filament’s self-gravity. study cross-sectional profiles total intensity ( I ) and polarized (PI) dust emission four segments...
ABSTRACT Polarized dust emission is a key tracer in the study of interstellar medium and star formation. The observed polarization, however, product magnetic field structure, grain properties, alignment efficiency, as well their variations line sight, making it difficult to interpret polarization unambiguously. comparison polarimetry at multiple wavelengths possible way mitigating this problem. We use data from HAWC+ /SOFIA SCUBA-2/POL-2 (from BISTRO survey) analyse NGC 2071 molecular cloud...