A5069657599- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- History and Developments in Astronomy
- Material Science and Thermodynamics
- Molecular spectroscopy and chirality
- Ionosphere and magnetosphere dynamics
- Spacecraft and Cryogenic Technologies
- Superconducting and THz Device Technology
- X-ray Diffraction in Crystallography
- Nonlinear Waves and Solitons
- Protein Interaction Studies and Fluorescence Analysis
- Geomagnetism and Paleomagnetism Studies
- Calibration and Measurement Techniques
- Educator Training and Historical Pedagogy
- Hemoglobin structure and function
- Crystal Structures and Properties
- Atmospheric Ozone and Climate
- Advanced Chemical Physics Studies
- Geophysics and Gravity Measurements
- Solar and Space Plasma Dynamics
Korea Astronomy and Space Science Institute
2020-2023
Peking University
2018-2022
Kavli Institute for Theoretical Sciences
2018-2022
Seoul National University
2013-2020
We present the results from a wide-field spectroscopic survey of globular clusters (GCs) in Virgo Cluster. obtain spectra for 201 GCs and 55 ultracompact dwarfs (UCDs) using Hectospec on Multiple Mirror Telescope, derive their radial velocities. identify 46 genuine intracluster (IGCs), not associated with any galaxies, 3D GMM test spatial velocity distribution.They are located at projected distance 200 kpc $\lesssim$ R 500 center M87. The distribution these IGCs shows two peaks, one $v_{\rm...
We present a study of ultra compact dwarf (UCD) galaxies in the Virgo cluster based mainly on imaging from Next Generation Cluster Survey (NGVS). Using $\sim$100 deg$^{2}$ $u^*giz$ imaging, we have identified more than 600 candidate UCDs, core out to its virial radius. Candidates been selected through combination magnitudes, ellipticities, colors, surface brightnesses, half-light radii and, when available, radial velocities. were also visually validated deep NGVS images. Subsamples varying...
We study the mass distribution and kinematics of giant elliptical galaxy M87 (NGC 4486) using discrete chemo-dynamical, axisymmetric Jeans equation modelling. Our catalogue comprises 894 globular clusters (GCs) extending to a projected radius $\sim 430$ kpc with line-of-sight velocities colours, Multi Unit Spectroscopic Explorer (MUSE) integral field unit data within central $2.4$ main galaxy. The gravitational potential for our models is combination luminous matter varying mass-to-light...
We present spectroscopy of 28 supernova remnant (SNR) candidates as well one H ii region in M81 and two SNR M82. Twenty-six the turn out to be genuine SNRs, M82 may shocked condensations galactic outflow or SNRs. The distribution [N ii]/Hα ratios SNRs is bimodal. are divided into groups spectral line ratio diagrams: an [O iii]-strong group iii]-weak group. latter larger have faster shock velocities. show a strong correlation with [S ratios. They clear radial gradient their ratios: dLog ([N...
Abstract M85 is a peculiar S0 galaxy in Virgo and well-known merger remnant. We present the first spectroscopic study of globular clusters (GCs) M85. obtain spectra for 21 GC candidates nucleus using Gemini Multi-Object Spectrograph on North 8.1 m telescope. From their radial velocities, 20 GCs are found to be members find strong rotation signal system with amplitude 235 km s −1 . The axis has position angle about 161°, which 51.°5 larger than that stellar light. rotation-corrected velocity...
Abstract We present a study of the stellar populations globular clusters (GCs) in Virgo Cluster core with homogeneous spectroscopic catalog 692 GCs within major-axis distance R maj = 840 kpc from M87. investigate radial and azimuthal variations mean age, total metallicity, [Fe/H], α -element abundance blue (metal-poor) red (metal-rich) using their co-added spectra. find that have steep gradient [Z/H] 165 kpc, roughly equal contributions [Fe/H] [ /Fe], flat gradients beyond. By contrast, show...
We survey globular clusters (GCs) in M85 using $ugi$-band images of a $1^{\circ} \times 1^{\circ}$ field obtained with the MegaCam at 3.6 m Canada-France-Hawaii Telescope. identify 1318 GC candidates 20.0 mag $< g_0
We present the science case for a broadband X-ray imager with high-resolution spectroscopy, including simulations of spectral diagnostics both active regions and solar flares. This is part trilogy white papers discussing science, instrument (Bandler et al. 2010), missions (Bookbinder 2010) to exploit major advances recently made in transition-edge sensor (TES) detector technology that enable resolution better than 2 eV an array can handle high count rates. Combined modest mirror, this would...
Abstract We present a study on the stellar population and kinematics of globular clusters (GCs) in peculiar galaxy M85. obtain optical spectra 89 GCs at 8 kpc < R 160 using MMT/Hectospec. divide them into three groups, blue/green/red (B/G/RGCs), with their ( g − i ) 0 colors. All GC subpopulations have mean ages about 10 Gyr, but showing differences metallicities. The BGCs RGCs are most metal-poor ([Z/H] ∼ −1.49) metal-rich −0.45), respectively, GGCs between. find that inner system...
The occurrence of planetary nebulae (PNe) in globular clusters (GCs) provides an excellent chance to study low-mass stellar evolution a special (low-metallicity, high density) environment. We report systematic spectroscopic survey for the [O{\sc iii}] 5007 emission line PNe 1469 Virgo GCs and 121 ultra-compact dwarfs (UCDs), mainly hosted giant elliptical galaxies M87, M49, M86, M84. detected zero our UCD sample discovered one PN ($M_{5007} = -4.1$ mag) associated with M87 GC. used detection...
Abstract Combining data from the ACS Virgo Cluster Survey and Next Generation cluster Survey, we extend previous studies of color gradients globular (GC) systems two most massive galaxies in cluster, M87 M49, to radii ∼15 R e (∼200 kpc for ∼250 where is effective radius). We find significant negative gradients, i.e., becoming bluer with increasing distance, out these large radii. The are driven mainly by outward decrease ratio red blue GC numbers. also detected subpopulations GCs taken...
Abstract We present the first results of an MMT/Hectospec campaign to measure kinematics globular clusters (GCs) around M49—the brightest galaxy in Virgo cluster, which dominates B subcluster. The data include kinematic tracers beyond 95 kpc (∼5.2 effective radii) for M49 time, enabling us achieve three key insights reported here. First, ∼20′–30′ (∼100–150 kpc), GC sampled along minor photometric axis become increasingly hotter, indicating a transition from GCs related those representing...
We present a study of Ks band luminosity evolution the asymptotic giant branch (AGB) population in simple stellar systems using star clusters Large Magellanic Cloud (LMC). determine physical parameters LMC including center coordinates, radii, and foreground reddenings. Ages 83 are derived from isochrone fitting with Padova models, those 19 taken literature. The AGB stars 102 log(age) = 7.3 - 9.5 selected near-infrared color magnitude diagrams based on 2MASS photometry. Then we obtain...
M104 (NGC 4594, the Sombrero galaxy) is a mysterious massive early-type galaxy that shows dominant bulge and prominent disk. However, presence of halo in has been elusive, it not yet known how acquired such peculiar structure. Using wide ($\sim2$ deg$^2$) deep $ugi$ images obtained with CFHT/MegaCam, we detect large number globular clusters (GCs) found out to $R\approx35'$ ($\sim100$ kpc). The color distribution these GCs two subpopulations: blue (metal-poor) system red (metal-rich) system....