Myungshin Im
A5030810934- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Astronomical Observations and Instrumentation
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- SAS software applications and methods
- Astrophysics and Cosmic Phenomena
- Adaptive optics and wavefront sensing
- Astrophysics and Star Formation Studies
- Radio Astronomy Observations and Technology
- Pulsars and Gravitational Waves Research
- Geophysics and Gravity Measurements
- Astro and Planetary Science
- CCD and CMOS Imaging Sensors
- Cosmology and Gravitation Theories
- Calibration and Measurement Techniques
- Scientific Research and Discoveries
- Particle Accelerators and Free-Electron Lasers
- Infrared Target Detection Methodologies
- Solar and Space Plasma Dynamics
- Remote Sensing in Agriculture
- Planetary Science and Exploration
- Particle Detector Development and Performance
- Optical Systems and Laser Technology
University of Oxford
2025
Seoul National University
2015-2024
Monash University
2018
Astronomy and Space
2017
Korea Institute for Advanced Study
2015
University of California, Los Angeles
2013
Max Planck Institute for Radio Astronomy
2013
Center for Astrophysics Harvard & Smithsonian
2013
Association of Universities For Research In Astronomy
2013
Kyung Hee University
2011
This paper describes the Seventh Data Release of Sloan Digital Sky Survey (SDSS), marking completion original goals SDSS and end phase known as SDSS-II. It includes 11,663 deg2 imaging data, with most ∼2000 increment over previous data release lying in regions low Galactic latitude. The catalog contains five-band photometry for 357 million distinct objects. survey also repeat on a 120° long, 25 wide stripe along celestial equator Southern Cap, some covered by many 90 individual runs. We...
After the All-Sky Automated Survey for SuperNovae (ASAS-SN) discovered a significant brightening of inner region NGC 2617, we began ~70 day photometric and spectroscopic monitoring campaign from X-ray through near-infrared (NIR) wavelengths. We report that 2617 went dramatic outburst, during which its flux increased by over an order magnitude followed increase optical/ultraviolet (UV) continuum almost magnitude. classified as Seyfert 1.8 galaxy in 2003, is now 1 due to appearance broad...
The DEEP2 and COMBO-17 surveys are used to study the evolution of luminosity function red blue galaxies $z \sim 1$. Schechter fits show that, since = 1$, $M^*_B$ dims by $\sim$ 1.3 mag per unit redshift for both color classes, $ϕ^*$ shows little change, while has formally nearly quadrupled. At face value, number density remained roughly constant $ z whereas that been rising. Luminosity densities support conclusions, but we note most red-galaxy occurs between our data local in highest bin,...
Selection of active galactic nuclei (AGNs) in the infrared facilitates discovery AGNs whose optical emission is extinguished by dust.In this paper, we use Spitzer Space Telescope First Look Survey (FLS) to assess fraction with mid-infrared (MIR) luminosities that are comparable quasars and missed quasar surveys because dust obscuration.We begin using Sloan Digital Sky (SDSS) database identify 54 within 4 deg 2 extragalactic FLS.These occupy a distinct region MIR color space virtue their...
The Sloan Digital Sky Survey-II (SDSS-II) has embarked on a multi-year project to identify and measure light curves for intermediate-redshift (0.05 < z 0.35) Type Ia supernovae (SNe Ia) using repeated five-band (ugriz) imaging over an area of 300 sq. deg. survey region is stripe 2.5° wide centered the celestial equator in Southern Galactic Cap that been imaged numerous times earlier years, enabling construction deep reference image discovery new objects. Supernova observations are being...
The quantitative morphological classification of distant galaxies is essential to the understanding evolution over history universe. This paper presents Hubble Space Telescope WFPC2 F606W and F814W photometric structural parameters for 7450 in "Groth Strip." These are based on a two-dimensional bulge + disk surface brightness model were obtained using an automated reduction analysis pipeline described detail here. A first set fits was performed separately each bandpass, second simultaneously...
We have gathered optical photometry data from the literature on a large sample of Swift-era gamma-ray burst (GRB) afterglows including GRBs up to September 2009, for total 76 GRBs, and present an additional three pre-Swift not included in earlier sample. Furthermore, we publish 840 new points 42 GRB afterglows, sets 050319, 050408, 050802, 050820A, 050922C, 060418, 080413A 080810. analyzed light curves all derived spectral energy distributions with best quality, allowing us estimate host...
The double explosion of SN 2009ip in 2012 raises questions about our understanding the late stages massive star evolution. Here we present a comprehensive study during its remarkable rebrightenings. High-cadence photometric and spectroscopic observations from GeV to radio band obtained variety ground-based space facilities (including Very Large Array, Swift, Fermi, Hubble Space Telescope, XMM) constrain be low energy (E ∼ 1050 erg for an ejecta mass ∼0.5 M☉) asymmetric complex medium shaped...
We give an overview and describe the rationale, methods, first results from NIRCam images of JWST "Prime Extragalactic Areas for Reionization Lensing Science" ("PEARLS") project. PEARLS uses up to eight filters survey several prime extragalactic areas: two fields at North Ecliptic Pole (NEP); seven gravitationally lensing clusters; high redshift proto-clusters; iconic backlit VV 191 galaxy system map its dust attenuation. also includes NIRISS spectra one NEP NIRSpec high-redshift quasars....
Using the Spitzer Space Telescope and Very Large Array (VLA), we present first direct evidence that well-known far-infrared/radio correlation is valid to cosmologically significant redshift. We also confirm, with improved statistics compared previous surveys, a similar result for mid-IR/radio correlation. explore dependence of monochromatic q24 q70 on z. The results were obtained by matching sources at 24 70 μm VLA 1.4 GHz microjansky radio First Look Survey (FLS). Spectroscopic redshifts...
The Sloan Digital Sky Survey-II Supernova Survey has identified a large number of new transient sources in 300 deg2 region along the celestial equator during its first two seasons three-season campaign. Multi-band (ugriz) light curves were measured for most sources, which include solar system objects, galactic variable stars, active nuclei, supernovae (SNe), and other astronomical transients. imaging survey is augmented by an extensive spectroscopic follow-up program to identify SNe, measure...
We present an analysis of the host galaxy dependences Type Ia Supernovae (SNe Ia) from full three year sample SDSS-II Supernova Survey. re-discover, to high significance, strong correlation between type and width observed SN light curve, i.e., fainter, quickly declining SNe favor passive galaxies, while brighter, slowly Ia's star-forming galaxies. also find evidence (at 2σ 3σ) that are ≃0.1 ± 0.04 mag brighter in galaxies than hosts, after curves have been standardized using light-curve...
Abstract We present Hubble Space Telescope ( HST ) and Chandra imaging, combined with Very Large MUSE integral field spectroscopy of the counterpart host galaxy first binary neutron star merger detected via gravitational-wave emission by LIGO Virgo, GW170817. The galaxy, NGC 4993, is an S0 at z = 0.009783. There evidence for large, face-on spiral shells in continuum edge-on features visible nebular lines. This suggests that 4993 has undergone a relatively recent <mml:math...
ABSTRACT We present ground-based optical photometric monitoring data for NGC 5548, part of an extended multiwavelength reverberation mapping campaign. The light curves have nearly daily cadence from 2014 January to July in nine filters ( BVRI and ugriz ). Combined with ultraviolet the Hubble Space Telescope Swift , we confirm significant time delays between continuum bands as a function wavelength, extending wavelength coverage 1158 Å z band (~9160 Å). find that lags at wavelengths longer...
We present the discovery of one or two extremely faint z~6 quasars in 6.5 deg^2 utilizing a unique capability wide-field imaging Subaru/Suprime-Cam. The quasar selection was made (i'-z_B) and (z_B-z_R) colors, where z_B z_R are bandpasses with central wavelengths 8842A 9841A, respectively. color can effectively isolate at from M/L/T dwarfs without J-band photometry down to z_R<24.0, which is 3.5 mag. deeper than SDSS. have selected 17 promising candidates. follow-up spectroscopy for seven...
The recent discovery of a faint gamma-ray burst (GRB) coincident with the gravitational wave (GW) event GW 170817 revealed existence population low-luminosity short duration transients produced by neutron star mergers in nearby Universe. These events could be routinely detected existing monitors, yet previous observations failed to identify them without aid triggers. Here we show that GRB150101B was an analogue GRB170817A located at cosmological distance. GRB 150101B characterized bright...
We have obtained three-dimensional maps of the universe in $\sim200\times200\times80$ comoving Mpc$^3$ (cMpc$^3$) volumes each at $z=5.7$ and $6.6$ based on a spectroscopic sample 179 galaxies that achieves $\gtrsim80$\% completeness down to Ly$\alpha$ luminosity $\log(L_{\rm Ly\alpha}/[\mathrm{erg\ s^{-1}}])=43.0$, our Keck Gemini observations literature. The reveal filamentary large-scale structures two remarkable overdensities made out least 44 12 $z=5.692$ (z57OD) $z=6.585$ (z66OD),...
We present the luminosity function and color-redshift relation of a magnitude-limited sample 145 mostly red field E/S0 galaxies at z < 1 from DEEP Groth Strip Survey (GSS). Most E/S0s (86%) form envelope in redshift-color diagram, consistent with predictions spectral synthesis models which dominant stellar population is formed redshifts > 1.5. Constructing full E/S0s, we find that there about 1.1--1.9 magnitude brightening rest-frame B band back to = 0.8 z=0, other studies. Together colors,...
The Deep Extragalactic Evolutionary Probe (DEEP) is a series of spectroscopic surveys faint galaxies, targeted at understanding the properties and clustering galaxies redshifts z ~ 1. We present redshift catalog DEEP1 Groth Strip pilot phase this project, Keck LRIS survey in Survey imaged with HST WFPC2. data, including reduced spectra, are made publicly available through Web-accessible database. contains 658 secure galaxy median = 0.65. distribution these shows large-scale structure walls...