A5058097931- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Atmospheric Ozone and Climate
- Astro and Planetary Science
- Molecular Spectroscopy and Structure
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Spectroscopy and Laser Applications
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Phase Equilibria and Thermodynamics
- Advanced Chemical Physics Studies
- Adaptive optics and wavefront sensing
- Reconstructive Facial Surgery Techniques
- Quantum Chromodynamics and Particle Interactions
- Superconducting and THz Device Technology
- Body Contouring and Surgery
- Particle Detector Development and Performance
- Astrophysics and Cosmic Phenomena
- Cardiac pacing and defibrillation studies
- Calibration and Measurement Techniques
- Solar and Space Plasma Dynamics
- Reconstructive Surgery and Microvascular Techniques
- Atomic and Molecular Physics
National Tsing Hua University
2019-2024
University of Leeds
2013-2020
University of Chile
2003-2013
Hospital del Trabajador
2003-2006
Instituto Profesional Providencia
2003
Hospital Barros Luco-Trudeau
2003
Formation of stars is now believed to be tightly linked the dynamical evolution interstellar filaments in which they form. In this paper we analyze density structure and kinematics a small network infrared dark filaments, SDC13, observed both dust continuum molecular line emission with IRAM 30m telescope. These observations reveal presence 18 compact sources amongst two most massive, MM1 MM2, are located at intersection point parsec-long filaments. The dense gas velocity dispersion along...
A full understanding of high-mass star formation requires the study one most elusive components energy balance in interstellar medium: magnetic fields. We report ALMA 1.2 mm, high-resolution (700 au) dust polarization and molecular line observations rotating hot core embedded star-forming region IRAS 18089-1732. The continuum emission field morphology present spiral-like features resembling a whirlpool. velocity traced by H13CO+ (J=3-2) transition reveals complex structure with spiral...
The initial conditions found in infrared dark clouds (IRDCs) provide insights on how high-mass stars and stellar clusters form. We have conducted high-angular resolution high-sensitivity observations toward thirty-nine massive IRDC clumps, which been mosaicked using the 12m 7m arrays from Atacama Large Millimeter/submillimeter Array (ALMA). targets are 70 $\mu$m (220-4900 $M_\odot$), dense ($>$10$^4$ cm$^{-3}$), cold ($\sim$10-20K) clumps located at distances between 2 6 kpc. identify an...
Among the most central open questions regarding initial mass function (IMF) of stars is impact environment on shape core (CMF) and thus potentially IMF. The ALMA-IMF Large Program aims to investigate variations in distributions with cloud characteristics, as diagnostic observables formation process evolution clouds. present study focuses W43-MM2&MM3 mini-starburst, whose CMF has recently been found be top-heavy respect Salpeter slope. harbors a rich cluster that contains statistically...
Abstract Massive infrared dark clouds (IRDCs) are considered to host the earliest stages of high-mass star formation. In particular, 70 μ m IRDCs colder and more quiescent clouds. At a scale about 5000 au using formaldehyde (H 2 CO) emission, we investigate kinetic temperature dense cores in 12 obtained from pilot Atacama Large Millimeter/submillimeter Array Survey High-mass clumps Early Stages (ASHES). Compared 1.3 mm dust continuum other molecular lines, such as C 18 O deuterated species,...
The ALMA-IMF Large Program imaged a total noncontiguous area of 53pc2, covering 15 extreme, nearby protoclusters the Milky Way. They were selected to span relevant early protocluster evolutionary stages. Our 1.3mm and 3mm observations provide continuum images that are homogeneously sensitive point-like cores with masses 0.2 0.6Msun, respectively, matched spatial resolution 2000au. We also detect lines probe structure, kinematics, chemistry, feedback over scales from clouds filaments cores....
The ALMA-IMF Large Program observed the W43-MM2-MM3 ridge, whose 1.3mm and 3mm ALMA 12m array continuum images reach a 2500au spatial resolution. We used both best-sensitivity line-free images, reduced noise with multi-resolution segmentation technique MnGSeg, derived most complete robust core catalog possible. Using two different extraction software packages, getsf GExt2D, we identified 200 compact sources, 100 common sources have on average fluxes consistent to within 30%. filtered...
Context. The origin of the stellar initial mass function (IMF) and its relation with core (CMF) are actively debated issues important implications in astrophysics. Recent observations W43 molecular complex top-heavy CMFs, an excess high-mass cores compared to canonical distribution, raise questions about our understanding star formation processes their evolution space time. Aims. We aim compare populations protostellar prestellar three regions imaged ALMA-IMF Large Program. Methods. created...
Sites associated with high-mass star and cluster formation exhibit a so-called hot core phase, characterized by high temperatures column densities of complex organic molecules. We built comprehensive census candidates towards the ALMA-IMF protoclusters based on detection two CH3OCHO emission lines at 216.1 GHz. used source extraction algorithm GExt2D to identify peaks methyl formate (CH3OCHO) that is species commonly observed sites formation. up catalog 76 masses ranging from about 0.2 80...
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...
Abstract Fragmentation during the early stages of high-mass star formation is crucial for understanding clusters. We investigated fragmentation within 39 star-forming clumps as part Atacama Large Millimeter/submillimeter Array Survey 70 μ m Dark High-mass Clumps in Early Stages (ASHES) survey. Considering projection effects, we have estimated core separations 839 cores identified from continuum emission and found mean values between 0.08 0.32 pc each clump. find compatibility observed masses...
Context . A crucial aspect in addressing the challenge of measuring core mass function (CMF), that is pivotal for comprehending origin initial (IMF), lies constraining temperatures cores. Aims We aim to measure luminosity, mass, column density and dust temperature star-forming regions imaged by ALMA-IMF large program. These fields were chosen encompass early evolutionary stages massive protoclusters. High angular resolution mapping required capture properties protostellar pre-stellar cores...
We present early results from the JCMT Plane Survey (JPS), which has surveyed northern inner Galactic plane between longitudes l=7 and l=63 degrees in 850-{\mu}m continuum with SCUBA-2, as part of James Clerk Maxwell Telescope Legacy programme. Data l=30 degree survey region, contains massive star-forming regions W43 G29.96, are analysed after approximately 40% observations had been completed. The pixel-to-pixel noise is found to be 19 mJy/beam, a smooth over beam area, projected equivalent...
We present the first data release of James Clerk Maxwell Telescope Plane Survey (JPS), JPS Public Release 1. is an 850-μm continuum survey six fields in northern inner Galactic plane a longitude range ℓ = 7°–63°, made with Submillimetre Common-User Bolometer Array 2. This consists emission maps regions average pixel-to-pixel noise 7.19 mJy beam−1, when smoothed over beam, and compact source catalogue containing 7813 sources. The 95 per cent completeness limits are estimated at 0.04 Jy beam−1...
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 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...
Quantifying the accretion flow from large cloud scales down to individual protostars is a central ingredient understanding of (high-mass) star formation. We characterize and quantify this multi-scale for prototypical high-mass star-forming region. In analysis parsec ∼50,au scales, we combined multiple single-dish interferometric observations study gas large-scale sizes several (Mopra) via intermediate-scale filamentary flows (ALMA-IMF) cores (ALMA DIHCA configuration 10 data). The...
Aims: We characterize and quantify this multi-scale flow for a prototypical high-mass star-forming region. Methods: In analysis from parsec to ~50au scales, we combined multiple single-dish interferometric observations study the gas large-scale sizes of several (Mopra) via intermediate-scale filamentary flows (ALMA-IMF) central cores (ALMA DIHCA configuration 10 data). The highest-resolution multi-configuration ALMA dataset achieved spatial resolution 0.027''x0.022'' or 50au. Results: This...
Abstract With a mass of ∼1000 M ⊙ and surface density ∼0.5 g cm −2 , G023.477+0.114, also known as IRDC 18310-4, is an infrared dark cloud (IRDC) that has the potential to form high-mass stars been recognized promising prestellar clump candidate. To characterize early stages star formation, we have observed G023.477+0.114 part Atacama Large Millimeter/submillimeter Array (ALMA) Survey 70 μ m Dark High-mass Clumps in Early Stages. We conducted ∼1.″2 resolution observations with ALMA at 1.3 mm...
ALMA-IMF is an Atacama Large Millimeter/submillimeter Array (ALMA) Program designed to measure the core mass function (CMF) of 15 protoclusters chosen span their early evolutionary stages. It further aims understand kinematics, chemistry, and impact gas inflow, accretion, dynamics on CMF. We present here first release line data cubes (DR1), produced from combination two ALMA 12m-array configurations. The include 12 spectral windows, with eight at 1.3mm four 3mm. broad coverage (~6.7 GHz...
Abstract Filaments are ubiquitous structures in molecular clouds and play an important role the mass assembly of stars. We present results dynamical stability analyses for filaments infrared dark cloud G14.225−0.506, where a delayed onset massive star formation was reported two hubs at convergence multiple parsec length. Full-synthesis imaging is performed with Atacama Large Millimeter/submillimeter Array to map <?CDATA ${{\rm{N}}}_{2}{{\rm{H}}}^{+}\,(1\mbox{--}0)$?> emission hub-filament...
We present the first data release of ALMA-IMF Large Program, which covers 12m-array continuum calibration and imaging. The Program is a survey fifteen dense molecular cloud regions spanning range evolutionary stages that aims to measure core mass function (CMF). describe acquisition done by Atacama Millimeter/submillimeter Array (ALMA) observatory subsequent imaging we performed. image products are combinations multiple 12m array configurations created from selection observed bandwidth using...
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...
We observed the high-mass protostellar core G335.579-0.272 ALMA1 at ${\sim}200$ au (0.05") resolution with Atacama Large Millimeter/submillimeter Array (ALMA) 226 GHz (with a mass sensitivity of $5\sigma=0.2$ M$_\odot$ 10 K). discovered that least binary system is forming inside this region, an additional nearby bow-like structure (${\lesssim}1000$ au) could add member to stellar system. These three sources are located center gravitational potential well region and larger MM1 cluster. The...