A5083656064- 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
- Astrophysical Phenomena and Observations
- Solar and Space Plasma Dynamics
- Astronomical Observations and Instrumentation
- Galaxies: Formation, Evolution, Phenomena
- Adaptive optics and wavefront sensing
- Tribology and Lubrication Engineering
- Gamma-ray bursts and supernovae
- Superconducting and THz Device Technology
- Atomic and Molecular Physics
- Venomous Animal Envenomation and Studies
- Biochemical and Structural Characterization
- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Inertial Sensor and Navigation
- Magnetic and Electromagnetic Effects
- Superconducting Materials and Applications
- Nuclear physics research studies
- High-pressure geophysics and materials
- Quantum Chromodynamics and Particle Interactions
Korea Astronomy and Space Science Institute
2015-2024
Korea University of Science and Technology
2019
Space Science Institute
2011
Institute of Astronomy and Astrophysics, Academia Sinica
2004-2010
Australian Defence Force Academy
2003-2004
UNSW Sydney
2003-2004
We present the first results from B-fields In STar-forming Region Observations (BISTRO) survey, using Sub-millimetre Common-User Bolometer Array 2 (SCUBA-2) camera, with its associated polarimeter (POL-2), on James Clerk Maxwell Telescope (JCMT) in Hawaii. discuss survey's aims and objectives. describe rationale behind questions which survey will aim to answer. The most important of these is role magnetic fields star formation process scale individual filaments cores dense regions. data...
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...
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...
We present new continuum and line observations, along with modelling, of the faint (6-8) Myr old T Tauri star ET Cha belonging to eta Chamaeleontis cluster. have acquired HERSCHEL/PACS photometric fluxes at 70 mic 160 mic, as well a detection [OI] 63 fine-structure in emission, derived upper limits for some other far-IR OI, CII, CO o-H2O lines. The HERSCHEL data is complemented by ANDICAM B-K photometry, HST/COS HST/STIS UV-observations, non-detection J=3-2 APEX, re-analysis UCLES...
Abstract Most protostars have luminosities that are fainter than expected from steady accretion over the protostellar lifetime. The solution to this problem may lie in episodic mass accretion—prolonged periods of very low punctuated by short bursts rapid accretion. However, timescale and amplitude for variability at phase is almost entirely unconstrained. In A James Clerk Maxwell Telescope/SCUBA-2 Transient Survey Protostars Nearby Star-forming Regions, we monitoring monthly with SCUBA-2...
We present the results of dust emission polarization measurements Ophiuchus-B (Oph-B) carried out using Submillimetre Common-User Bolometer Array 2 (SCUBA-2) camera with its associated polarimeter (POL-2) on James Clerk Maxwell Telescope (JCMT) in Hawaii. This work is part B-fields In Star-forming Region Observations (BISTRO) survey initiated to understand role magnetic fields star formation for nearby star-forming molecular clouds. a first look at geometry and strength Oph-B. The field...
Abstract We present 850 μ m imaging polarimetry data of the ρ Oph-A core taken with Submillimeter Common-User Bolometer Array-2 (SCUBA-2) and its polarimeter (POL-2) as part our ongoing survey project, <?CDATA ${\boldsymbol{B}}$?> -fields In STar forming RegiOns (BISTRO). The polarization vectors are used to identify orientation magnetic field projected on plane sky at a resolution 0.01 pc. 10 subregions distinct fractions angles in 0.2 pc core; some them can be coherent structure Oph...
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 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...
We present \sim1" resolution 1.3 millimeter dust continuum and spectral line (12CO 13CO J=2-1) observations of the transitional disk system HD 135344B obtained with Submillimeter Array. The shows a Keplerian rotation pattern an inclination \sim11{\deg}, based on spatially spectrally resolved 12CO emission. data show clear evidence for both gas surface density reductions in inner region (radius \lesssim 50 AU) from J=2-1 data, respectively. presence this cavity is more consistent clearing by...
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 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...
High-resolution spectroscopic study of late-type members the ≈9-L39-old η Chamaeleontis star cluster shows that four stars, RECX 5, 9, 11 and ECHA J0843.3–7905, have broad Hα profiles indicative ballistic accretion material from circumstellar discs first identified by virtue their infrared (IR) excess emission. Quantitative analysis finds in Cha stars at rates comparable to derived Muzerolle et al. for similarly aged TW Hydrae Association (TWA); 1–3 orders magnitude lower than younger...
We have analyzed JHKL observations of the stellar population ~9 Myr-old eta Chamaeleontis cluster. Using infrared (IR) colour-colour and colour-excess diagrams, we find fraction systems with near-IR excess emission is 0.60 pm 0.13 (2_sigma). This results implies considerably longer disc lifetimes than found in some recent studies other young clusters. For classical T Tauri (CTT) weak-lined (WTT) star population, also a strong correlation between IR H_alpha emission. The excesses these stars...
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>...
We present a study of calibrated low-resolution spectra the 18 known primaries ≈9-Myr-old η Chamaeleontis (η Cha) pre-main-sequence (PMS) star cluster. Using synthetic broad-band colours and narrow-band continuum-sensitive, temperature-sensitive gravity-sensitive indices derived from spectra, we compare Cha stars to standard dwarfs. find that VRI PMS are indistinguishable those main-sequence stars, but B-band excess attaining ≈0.2 mag for late-M cluster is present, which might be an...
We report the outcome of deep optical/infrared photometric survey central region (33 × 33 arcmin2 or 0.9 pc2) η Chamaeleontis (η Cha) pre-main sequence star cluster. The completeness limits photometry are I= 19.1, J= 18.2 and H= 17.6, faint enough to reveal low-mass members down brown dwarf planet boundary ≈13 MJup. found no such in this region. Our result combined with a previous shallower (I= 17) but larger area indicates that objects (0.013 < M/M⊙ 0.075) were either not created Cha...
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 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 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...