A5101672069- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Solar and Space Plasma Dynamics
- Pulsars and Gravitational Waves Research
- Adaptive optics and wavefront sensing
- Ionosphere and magnetosphere dynamics
- Radio Astronomy Observations and Technology
- Galaxies: Formation, Evolution, Phenomena
- Metal and Thin Film Mechanics
- Atmospheric Ozone and Climate
- Semiconductor materials and devices
- Spectroscopy and Laser Applications
- Geophysics and Gravity Measurements
- Planetary Science and Exploration
- Diamond and Carbon-based Materials Research
- Neutrino Physics Research
- Earthquake Detection and Analysis
- Molecular Spectroscopy and Structure
- GNSS positioning and interference
Korea Astronomy and Space Science Institute
2015-2024
Rice University
2023
Seoul National University
1997-2016
Korea University of Science and Technology
2014
Pennsylvania State University
2007-2011
Space Science Institute
2011
Inha University
2009
Taiwan Semiconductor Manufacturing Company (Taiwan)
2006
Northern Netherlands Provinces alliance
2004
Electronics and Telecommunications Research Institute
1997
The Immersion Grating Infrared Spectrometer (IGRINS) is a compact high-resolution near-infrared cross-dispersed spectrograph whose primary disperser silicon immersion grating. IGRINS covers the entire portion of wavelength range between 1.45 and 2.45μm that accessible from ground does so in single exposure with resolving power 40,000. Individual volume phase holographic (VPH) gratings serve as cross-dispersing elements for separate arms covering H K bands. On 2.7m Harlan J. Smith telescope...
Abstract We present initial results from a James Webb Space Telescope (JWST) survey of the youngest Galactic core-collapse supernova remnant, Cassiopeia A (Cas A), made up NIRCam and MIRI imaging mosaics that map emission main shell, interior, surrounding circumstellar/interstellar material (CSM/ISM). also four exploratory positions Medium Resolution Spectrograph integral field unit spectroscopy sample ejecta, CSM, associated dust representative shocked unshocked regions. Surprising...
We report on the results from H{\alpha} imaging observations of eastern limb Tycho's supernova remnant (SN1572) using Wide Field Planetary Camera 2 Hubble Space Telescope. resolve detailed structure fast, collisionless shock wave into a delicate nearly edge-on filaments. find gradual increase intensity just ahead front, which we interpret as emission thin (~1") precursor. that significant amount comes precursor and this could affect temperature equilibration derived observed flux ratio broad...
We present the goals and preliminary results of an unbiased, near-infrared, narrow-band imaging survey first galactic quadrant (10° < l 65°; −13 b +13). This area includes most giant molecular clouds massive star forming regions in Northern hemisphere. The is centred on 1–0 S(1) rovibrational line H2, a proven tracer hot, dense gas star-forming regions, around evolved stars, supernova remnants. observations complement existing upcoming photometric surveys (Spitzer-GLIMPSE, UKIDSS-GPS,...
Abstract Ages and masses of young stars are often estimated by comparing their luminosities effective temperatures to pre-main-sequence stellar evolution tracks, but magnetic fields starspots complicate both the observations evolution. To understand influence, we study heavily spotted weak-lined T-Tauri star LkCa 4 searching for spectral signatures radiation originating from starspot or groups. We introduce a new methodology constraining filling factor spot temperature fitting...
Cas A is a Galactic supernova remnant whose explosion observed to be of Type IIb from spectroscopy its light echo. Having SN type known, observational constraints on the mass-loss history A's progenitor can provide crucial information final fate massive stars. In this paper, we study X-ray characteristics shocked ambient gas in using 1 Ms observation carried out with Chandra X-Ray Observatory and try constrain star. We identify thermal emission along outer boundary remnant. Comparison...
The Immersion Grating Infrared Spectrometer (IGRINS) is a revolutionary instrument that exploits broad spectral coverage at high-resolution in the near-infrared. IGRINS employs silicon immersion grating as primary disperser, and volume-phase holographic gratings cross-disperse H K bands onto Teledyne Hawaii-2RG arrays. use of an facilitates compact cryostat while providing simultaneous wavelength from 1.45 - 2.5 μm. There are no cryogenic mechanisms its high-throughput design maximizes...
The Immersion GRating INfrared Spectrometer (IGRINS) was designed for high-throughput with the expectation of being a visitor instrument at progressively larger observing facilities. IGRINS achieves R∼45000 and > 20,000 resolution elements spanning H K bands (1.45-2.5μm) by employing silicon immersion grating as primary disperser volume-phase holographic gratings cross-dispersers. After commissioning on 2.7 meter Harlan J. Smith Telescope McDonald Observatory, had more than 350 scheduled...
We report 21 cm spectral-line and continuum observations of the Galactic supernova remnant IC 443 using Very Large Array (VLA) Arecibo telescope. By combining VLA data, both covering full extent 443, we have achieved an unprecedented combination sensitivity angular resolution, over continuous range scales from ∼40'' to ∼1°. Our new radio not only reveal previously unknown features but also show details more clearly. The morphology consists two nearly concentric shells. data that shells...
We present an Hα spectral observation of a Balmer-dominated shock on the eastern side Tycho's supernova remnant using Subaru Telescope. Utilizing High Dispersion Spectrograph (HDS), we measure spatial variation line profile between preshock and postshock gas. Our clearly shows broadening centroid shift narrow-component relative to emission from The supports existence thin precursor where gas is heated accelerated ahead shock. Furthermore, Balmer filament gradual gradient in intensity width...
Westerlund 1 is the most important starburst cluster in Galaxy due to its massive star content. We have performed BVIC and JKS photometry investigate initial mass function (IMF). By comparing observed color with spectral-type–intrinsic-color relation, we obtain mean interstellar reddening of 〈E(B − V)〉 = 4.19 ± 0.23 〈E(J KS)〉 1.70 0.21. Due heavy extinction toward cluster, zero-age main sequence fitting method based on optical proved be inappropriate for distance determination, while...
We present $BVI$ surface photometry of 31 dwarf galaxy candidates discovered in a deep image stack from the KMTNet Supernova Program $\sim$ 30 square degrees centered on nearby NGC 2784 group. Our final images have 3$\sigma$ brightness detection limit $\mu_V\approx 28.5$ mag arcsec$^{-2}$. The faintest central that we measure is $\mu_{0,V} = 26.1$ If these are at distance 2784, then they absolute magnitudes greater than $M_V -9.5$ and effective radii larger 170 pc. Their radial number...
Abstract We present fundamental parameters for 110 canonical K - and M -type (1.3−0.13 ⊙ ) Taurus-Auriga young stellar objects (YSOs). The analysis produces a simultaneous determination of effective temperature ( T eff ), surface gravity (log g magnetic-field strength (B), projected rotational velocity <?CDATA $v\sin i$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>v</mml:mi> <mml:mi>sin</mml:mi> <mml:mi>i</mml:mi> </mml:math> ). Our method employed...
We present initial results from a JWST survey of the youngest Galactic core-collapse supernova remnant Cassiopeia A (Cas A), made up NIRCam and MIRI imaging mosaics that map emission main shell, interior, surrounding circumstellar/interstellar material (CSM/ISM). also four exploratory positions MIRI/MRS IFU spectroscopy sample ejecta, CSM, associated dust representative shocked unshocked regions. Surprising discoveries include: 1) web-like network ejecta filaments resolved to 0.01 pc scales...
The consortium for Galactic studies with the Arecibo L-band Feed Array (ALFA) is conducting a neutral hydrogen (H I) survey of whole sky (declination range from -1° to 38°), high angular (35) and velocity resolution (0.2 km s-1). precursor observations ALFA region in anticenter reveal numerous isolated, small (a few parsecs size), cold (Tk < 400 K) H I clouds at low negative velocities, distinctly separated disk emission ("low-velocity clouds" [LVCs]). These are most likely located...
The broad components of the Hα lines in most non-radiative shocks can be fit with single-Gaussian components. We have obtained a high-quality spectrum position Tycho's supernova remnant MMT and Blue Channel Spectrograph which shows, for first time, that single Gaussian does not provide an acceptable fit. This implies temperature Maxwellian particle velocity distribution cannot produce emission. Possible alternative explanations are explored, including multiple along line sight, pickup ion...
The Galactic supernova remnant (SNR) IC 443 is one of the most studied core-collapse SNRs for its interaction with molecular clouds. However, ambient clouds which interacting have not been thoroughly and remain poorly understood. Using Five College Radio Astronomy Observatory 14 m telescope, we obtained fully sampled maps ∼1° × 1° region toward in 12CO J = 1–0 HCO+ lines. In addition to previously known velocity range vLSR −6 −1 km s−1 (−3 clouds), our observations reveal two new cloud...
We report on the results from our deep Chandra observation (120 ks) of supernova remnant (SNR) N49 and soft Gamma-ray repeater (SGR) 0526-66 in Large Magellanic Cloud. firmly establish detection an ejecta "bullet" beyond southwestern boundary N49. The X-ray spectrum bullet is distinguished that main SNR shell, showing significantly enhanced Si S abundances. also detect feature eastern which shows metal overabundances similar to those bullet. If was produced by a core-collapse explosion...
We present a library of high-resolution (R $\equiv$ $\lambda$/$\Delta$$\lambda$ $\sim$ 45,000) and high signal-to-noise ratio (S/N $\geq$ 200) near-infrared spectra for stars wide range spectral types luminosity classes. The were obtained with the Immersion GRating INfrared Spectrograph (IGRINS) covering full H (1.496-1.780 $\mu$m) K (2.080-2.460 atmospheric windows. targets primarily selected being MK standard effective temperatures surface gravities metallicities close to Solar value....
Abstract The cosmic origin of fluorine is still not well constrained. Several nucleosynthetic channels at different phases stellar evolution have been suggested, but these must be constrained by observations. For this, the abundance trend with metallicity spanning a wide range required. Our aim to determine abundances for <?CDATA $-1.1\lt [\mathrm{Fe}/{\rm{H}}]\lt +0.4$?> . We from HF lines in infrared K -band spectra ( $\sim 2.3\,\mu {\rm{m}}$?> ) cool giants, observed IGRINS and Phoenix...
Abstract The Immersion GRating INfrared Spectrometer (IGRINS) is a compact, high-resolution ( R ∼ 45,000) near-infrared spectrograph spanning 1.45–2.45 μ m in single exposure. We introduce the Raw and Reduced IGRINS Spectral Archive (RRISA), which provides public data access for all non-proprietary taken at McDonald Observatory's Harlan J. Smith Telescope, Lowell Discovery Telescope (formerly Channel Telescope), Gemini South. RRISA to raw files, reduced products, cross-matched targets with...
We present the extended source catalogue for UKIRT Wide Field Infrared Survey H2 (UWISH2). The survey is unbiased along inner Galactic Plane from |$l \approx 357\deg$| to 65\deg$| and |b| ≤ 1| $_{.}^{\circ}$|5 covers 209 deg2. A further 42.0 35.5 deg2 of high dust column density regions have been targeted in Cygnus Auriga. identified 33 200 individual features. They classified be associated with about 700 groups jets outflows, 284 (candidate) planetary nebulae, 30 supernova remnants 1300...
We have performed deep X-ray observations of the remnant Kepler's supernova (SN 1604) as a Key Project Suzaku Observatory. Our main goal is to detect secondary Fe-peak elements in (SN) ejecta gain insights into Type Ia SN explosion mechanism and nature progenitor. Here, we report our initial results. made conclusive detection emission lines from highly ionized Mn, Cr, Ni well Fe. The observed Mn-to-Cr line flux ratio ∼0.60, ∼30% larger than that measured Tycho's remnant. estimate an mass...
ABSTRACT Recent high-resolution infrared space missions have revealed supernova remnants (SNRs) of diverse morphology in (IR) dust emission that are often very different from their X-ray appearance. The observed range infrared-to-X-ray (IRX) flux ratios SNRs is also wide. For a sample 20 Galactic SNRs, we obtain IR and properties investigate the physical causes for such large differences. We find IRX ( <?CDATA ${R}_{{\rm{IRX,obs}}}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"...