Bumhyun Lee
A5059112124- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Spectroscopy and Laser Applications
- Gamma-ray bursts and supernovae
- Phase Equilibria and Thermodynamics
- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Gas Dynamics and Kinetic Theory
- Atomic and Subatomic Physics Research
- Scientific Research and Discoveries
- Pharmacological Effects and Assays
- Geophysics and Gravity Measurements
- Atmospheric Ozone and Climate
- Superconducting and THz Device Technology
- Plant Taxonomy and Phylogenetics
- Astro and Planetary Science
- Electrical and Thermal Properties of Materials
- Astronomical Observations and Instrumentation
- Quantum, superfluid, helium dynamics
Yonsei University
2015-2025
Korea Astronomy and Space Science Institute
2011-2023
Kavli Institute for Theoretical Sciences
2020-2023
Peking University
2020-2023
We present 12CO (2-1) data of three Virgo spirals -NGC 4330, NGC 4402 and 4522 obtained using the Submillimeter Array.These galaxies show clear evidence ram pressure stripping due to cluster medium as found in previous H I imaging studies.Using high-resolution CO data, we investigate how properties inner molecular gas disc change while a galaxy is undergoing cluster.At given sensitivity limits, do not find any signs stripping.However, both its morphology kinematics appear be quite disturbed...
This study uses HI image data from the WALLABY pilot survey with ASKAP telescope, covering Hydra cluster out to 2.5$r_{200}$. We present projected phase-space distribution of HI-detected galaxies in Hydra, and identify that nearly two thirds within $1.25r_{200}$ may be early stages ram pressure stripping. More than half these only weakly stripped, ratio strippable (i.e., where galactic restoring force is lower disk) mass fraction (over total mass) distributed uniformly below 90%....
We present the Virgo Environment Traced in CO (VERTICO) survey, a new effort to map $^{12}$CO($2-1$), $^{13}$CO($2-1$), and C$^{18}$O($2-1$) 51 Cluster galaxies with Atacama Compact Array, part of Large Millimeter/submillimeter Array (ALMA). The primary motivation VERTICO is understand physical mechanisms that perturb molecular gas disks, therefore star formation galaxy evolution, dense environments. This first paper contains an overview VERTICO's design sample selection, $^{12}$CO($2-1$)...
In this VERTICO early science paper we explore in detail how environmental mechanisms, identified HI, affect the resolved properties of molecular gas reservoirs cluster galaxies. The is probed using ALMA ACA (+TP) observations 12CO(2-1) 51 spiral galaxies Virgo (of which 49 are detected), all included VIVA HI survey. sample spans a stellar mass range 9 < log M*/Msol 11. We study radial profiles, isodensity radii, and surface densities as function galaxy deficiency morphology. There weak...
Abstract We report the detection of [C i ] 3 P 1 – 0 emission in nearby galaxy NGC 7679 using Atacama Compact Array (ACA) Large Millimeter/submillimeter (ALMA). In T. Michiyama et al., was reported as undetected based on ACA observations conducted 2019 (ALMA Cycle 6). These had ∼1 minute on-source time and used a single pointing with field view (FoV) ∼20″. 2023 (Cycle 9), we carried out mosaic seven pointings an FoV ∼27″ 4–5 minutes per pointing. The additional data have significantly...
Abstract We present a study of giant molecular cloud (GMC) properties in the Andromeda galaxy (M31) using CO(3-2) data from James Clerk Maxwell Telescope (JCMT) selected regions across disc and nuclear ring, comparing them with CO(1-0) observations IRAM 30m telescope same regions. find that GMCs centre M31 generally exhibit larger velocity dispersions (σ) sizes (R) compared to those disc, while their average surface density (Σ) turbulent pressure (Pturb) are lower. This low central region is...
Abstract We present <?CDATA $\mathrm{HCN}\ J=4\to 3$?> and ${\mathrm{HCO}}^{+}\ maps of six nearby star-forming galaxies, NGC 253, 1068, IC 342, M82, M83, 6946, obtained with the James Clerk Maxwell Telescope as part MALATANG survey. All galaxies were mapped in central 2′ × region at 14″ (FWHM) resolution (corresponding to linear scales ∼0.2–1.0 kpc). The L IR – ′ dense relation, where gas is traced by emission, measured our sample spatially resolved found follow correlation established...
JINGLE is a new JCMT legacy survey designed to systematically study the cold interstellar medium of galaxies in local Universe. As part we perform 850 µm continuum measurements with SCUBA-2 for representative sample 193 Herschel-selected M* > 109 M⊙, as well integrated CO(2–1) line fluxes RxA3m subset 90 these galaxies. The selected from fields covered by Herschel-ATLAS that are also targeted MaNGA optical integral-field spectroscopic survey. observations combined multiwavelength ancillary...
We conduct a $^{12}$C$^{16}$O($J$=1-0) (hereafter CO) mapping survey of 64 galaxies in the Fornax cluster using ALMA Morita array cycle 5. CO emission is detected from 23 out galaxies. Our sample includes dwarf, spiral and elliptical with stellar masses $M_{\rm star}\sim10^{6.3-11.6}$~M$_\odot$. The achieved beam size sensitivity are $15''\times8''$ $\sim12$~mJy~beam$^{-1}$ at velocity resolution $\sim10$~km~s$^{-1}$, respectively. study cold-gas (molecular- atomic-gas) properties 38...
Abstract The quenching of cluster satellite galaxies is inextricably linked to the suppression their cold interstellar medium (ISM) by environmental mechanisms. While removal neutral atomic hydrogen (H i ) at large radii well studied, how environment impacts remaining gas in centres galaxies, which are dominated molecular gas, less clear. Using new observations from Virgo Environment traced CO survey (VERTICO) and archival H data, we study within optical discs on 1.2-kpc scales with...
Abstract NGC 4522 is a Virgo spiral that currently undergoing active ram pressure stripping. In previous single-dish observations, 12 CO emission was detected outside of the stellar disk, some which coincides with extraplanar H i gas and α patches. The identified in multi-wavelength data makes this galaxy an ideal case to study impact due cluster medium on interstellar various phases. Letter, we present high-resolution CO(1–0) 13 obtained using Atacama Large Millimeter/submillimeter Array...
Abstract We study the tidal interaction of galaxies in Eridanus supergroup, using H i data from pre-pilot survey Widefield ASKAP L -band Legacy All-sky Blind surveY. obtain optical photometric measurements and quantify strength perturbation a parameter S sum . For low-mass M * ≲ 10 9 ⊙ , we find dependence decreasing to disk size ratio with increasing but no spectral line asymmetry This is consistent behavior expected under stripping. confirm that color profile shape gradient depend on...
We measure the molecular-to-atomic gas ratio, $R_{\rm mol}$, and star formation rate (SFR) per unit molecular mass, SFE$_{\rm in 38 nearby galaxies selected from Virgo Environment Traced CO (VERTICO) survey. determine their scale-lengths for stellar components find a roughly 3:5 ratio between them compared to $\sim$1:1 field galaxies, indicating that emission is more centrally concentrated than stars. compute mol}$ as function of different physical quantities. While spatially-resolved on...
In this VERTICO science paper we aim to study how the star formation process depends on galactic environment and gravitational interactions in context of galaxy evolution. We explore scaling relation between rate (SFR) surface density molecular gas density, also known as Kennicutt-Schmidt (KS) relation, a subsample Virgo cluster spiral galaxies. use new ACA TP observations from VERTICO-ALMA Large Program at 720pc resolution resolve content, traced by 12CO(2-1) transition, across disks 37...
We present new results of a 12CO(J=1-0) imaging survey using the Atacama Compact Array (ACA) for 31 HI detected galaxies in IC 1459 and NGC 4636 groups. This is first CO loose galaxy obtained well-resolved data (~0.7-1.5 kpc) total 16 two environments. By comparing our ACA with UV data, we probe impacts group environment on cold gas components (CO gas) star formation activity. find that and/or morphologies are disturbed members, some which show highly asymmetric distributions (e.g., 5264,...
We estimate the strength of ram pressure stripping (RPS) for HI-rich galaxies in X-ray detected clusters. find that under stronger RPS tend to show more significantly reduced total HI mass and enhanced central SFR, compared control field which have similar stellar mass, surface density integral star formation rate. Galaxies strong or weak account around 40% population at R200, even beyond R200 most massive Our results imply important role as a channel environmental processing far before...
Abstract We study how environment regulates the star formation cycle of 33 Virgo Cluster satellite galaxies on 720 pc scales. present resolved star-forming main sequence for cluster galaxies, dividing sample based their global H i properties and comparing to a control field galaxies. –poor have reduced rate (SFR) surface densities with respect both –normal (∼0.5 dex), suggesting that mechanisms regulating content are responsible quenching local formation. demonstrate observed in is caused by...
We analyze cold-gas distributions in Virgo cluster galaxies using resolved CO(2-1) (tracing molecular hydrogen, H2) and HI observations from the Environment Traced In CO (VERTICO) VLA Imaging of Atomic Gas (VIVA) surveys. From a theoretical perspective, it is expected that environmental processes clusters will have stronger influence on diffuse atomic gas compared to relatively dense component, these perturbations can compress cold interstellar medium leading elevated star formation. this...
To study the high-transition dense-gas tracers and their relationships to star formation of inner $\sim$ 2 kpc circumnuclear region NGC253, we present HCN $J=4-3$ HCO$^+ J=4-3$ maps obtained with James Clerk Maxwell Telescope (JCMT). With spatially resolved data, compute concentration indices $r_{90}/r_{50}$ for different tracers. HCO$^+$ 4-3 emission features tend be centrally concentrated, which is in contrast shallower distribution CO 1-0 stellar component. The fraction ($f_\text{dense}$,...
Abstract We present the results of surveying [C i ] 3 P 1 – 0 , 12 CO J = 4 − 3, and 630 μ m dust continuum emission for 36 nearby ultra/luminous infrared galaxies (U/LIRGs) using Band 8 receiver mounted on Atacama Compact Array Large Millimeter/submillimeter Array. describe survey, observations, data reduction, results; main are as follows. (i) confirmed that has a linear relationship with both continuum. (ii) In NGC 6052 7679, was detected but not / ratio ≲0.08. Two possible scenarios weak...
Abstract Combining new H i data from a synergetic survey of Australian Square Kilometre Array Pathfinder (ASKAP) Widefield ASKAP L -band Legacy All-sky Blind surveY and Five-hundred-meter Aperture Spherical radio Telescope with the Arecibo Fast ALFA data, we study effect ram pressure tidal interactions in NGC 4636 group. We develop two parameters to quantify disentangle these effects on gas stripping -bearing galaxies: strength external forces at optical-disk edge, outside-in extents -disk...
We present the result of Infrared Medium-deep Survey (IMS) $z\sim6$ quasar survey, using combination IMS near-infrared images and Canada-France-Hawaii Telescope Legacy (CFHTLS) optical images. The traditional color-selection method results in 25 candidates over $86$ deg$^{2}$. introduce corrected Akaike Information Criterion (AICc) with high-redshift late-type star models to prioritize efficiently. Among color-selected candidates, seven plausible finally passed AICc selection which three are...
Abstract This paper presents data from a 21 cm H i emission drift scan observation of field partially covering the NGC 4636 galaxy group with Five-hundred meter Aperture Radio Telescope (FAST). We construct pipeline to reduce data, and use SoFiA for source finding. When not contaminated by Frequency Interference (RFI), FAST observations are capable detecting all galaxies previously detected Arecibo Legacy Fast ALFA (ALFALFA) survey in same region. Comparing ALFALFA detections common, show...
Observing nearby galaxies with submillimeter telescopes on the ground has two major challenges. First, brightness is significantly reduced at long wavelengths compared to peak of dust emission. Second, it necessary use a high-pass spatial filter remove atmospheric noise large angular scales, which unwelcome by-product also removing galaxy's large-scale structure. We have developed technique for producing high-resolution images size by using telescope determine small-scale structure (the...
The quenching of cluster satellite galaxies is inextricably linked to the suppression their cold interstellar medium (ISM) by environmental mechanisms. While removal neutral atomic hydrogen (HI) at large radii well studied, how environment impacts remaining gas in centres galaxies, which are dominated molecular gas, less clear. Using new observations from Virgo Environment traced CO survey (VERTICO) and archival HI data, we study within optical discs on 1.2-kpc scales with spatially resolved...