204 citations · 529 across the 15 of their papers we have counts for
15 papers
Similar image retrieval using Autoencoder. I. Automatic morphology classification of galaxies
Eunsuk Seo, Suk Kim, Youngdae Lee +4
We present the construction of an image similarity retrieval engine for the morphological classification of galaxies using the Convolutional AutoEncoder (CAE). The CAE is trained o…
Nonlinear Color-Metallicity Relations of Globular Clusters. XI. Nonlinearity Effect Revealed by NGC 5128 (Centaurus A) and NGC 4594 (Sombrero) Galaxies
Hak-Sub Kim, Suk-Jin Yoon, Sang-Yoon Lee +1
Metallicity distributions (MDs) of globular clusters (GCs) provide crucial clues for the assembly and star formation history of their host galaxies. GC colors, when GCs are old, ha…
New sub-grouping of multiple stellar populations in NGC 2808 based on low-resolution spectroscopy
Seungsoo Hong, Dongwook Lim, Chul Chung +3
We performed low-resolution spectroscopy for the red giant branch stars in an intriguing globular cluster (GC) NGC 2808, which hosts subpopulations with extreme helium and light-el…
Narrowband Ca Photometry for Dwarf Spheroidal Galaxies. I. Chemostructural Study on Draco, Sextans, and Canes Venatici I
Sang-Il Han, Hak-Sub Kim, Suk-Jin Yoon +4
A few dozen dwarf satellite galaxies of the Milky Way have been discovered, which are often viewed as the remaining building blocks of our Galaxy. The follow-up spectroscopy showed…
RR Lyrae Stars in the Field of Sagittarius II
Seok-Joo Joo, Jaemann Kyeong, Soung-Chul Yang +10
We present the detection of RR Lyrae variable stars in the field of the Sagittarius II (Sgr II) ultra-faint dwarf (UFD) galaxy. Using B, V time-series photometry obtained with the…
A Possible Relic Star Cluster in the Sextans Dwarf Galaxy
Hak-Sub Kim, Sang-Il Han, Seok-Joo Joo +2
We report a possible discovery of a relic star cluster in the Sextans dwarf spheroidal galaxy. Using the \textit{hk} index (()()) as a photometric metallicity…
RR Lyrae Variable Stars in the Crater II Dwarf Galaxy
Seok-Joo Joo, Jaemann Kyeong, Soung-Chul Yang +10
We report the detection of RR Lyrae variable stars in Crater II, a recently discovered large and diffuse satellite dwarf galaxy of the Milky Way (MW). Based on B, V time-series pho…
Reversed radial distribution trend of subpopulations in the globular clusters NGC 362 and NGC 6723
Dongwook Lim, Young-Wook Lee, Mario Pasquato +2
Most globular clusters (GCs) are now known to host multiple stellar populations with different light element abundances. Here we use narrow-band photometry and low-resolution spect…
Evidence for Enrichment by Supernovae in the Globular Cluster NGC 6273
Sang-Il Han, Dongwook Lim, Hyunju Seo +1
In our recent investigation (Lim et al. 2015), we have shown that narrow-band photometry can be combined with low-resolution spectroscopy to effectively search for globular cluster…
Low-resolution Spectroscopy for the Globular Clusters with Signs of Supernova Enrichment: M22, NGC 1851 and NGC 288
Dongwook Lim, Sang-Il Han, Young-Wook Lee +5
There is increasing evidence for the presence of multiple red giant branches (RGBs) in the color-magnitude diagrams of massive globular clusters (GCs). In order to investigate the…
Two distinct red giant branch populations in the globular cluster NGC 2419 as tracers of a merger event in the Milky Way
Young-Wook Lee, Sang-Il Han, Seok-Joo Joo +7
Recent spectroscopic observations of the outer halo globular cluster (GC) NGC 2419 show that it is unique among GCs, in terms of chemical abundance patterns, and some suggest that…
Two Distinct Red Giant Branches in the Globular Cluster NGC 288
Dong-Goo Roh, Young-Wook Lee, Seok-Joo Joo +3
We report the presence of two distinct red giant branches (RGBs) in the globular cluster NGC 288 from the narrow-band calcium and Strömgren b & y photometry obtained at the CTIO 4m…
The Presence of Two Distinct Red Giant Branches in the Globular Cluster NGC 1851
Sang-Il Han, Young-Wook Lee, Seok-Joo Joo +4
There is a growing body of evidence for the presence of multiple stellar populations in some globular clusters, including NGC 1851. For most of these peculiar globular clusters, ho…
On the Origin of Bimodal Horizontal-Branches in Massive Globular Clusters: The Case of NGC 6388 and NGC 6441
Suk-Jin Yoon, Seok-Joo Joo, Chang H. Ree +3
Despite the efforts of the past decade, the origin of the bimodal horizontal-branch (HB) found in some globular clusters (GCs) remains a conundrum. Inspired by the discovery of mul…
Super Helium-Rich Population and the Origin of Extreme Horizontal-Branch Stars in Globular Clusters
Young-Wook Lee, Seok-Joo Joo, Sang-Il Han +7
Recent observations for the color-magnitude diagrams (CMDs) of the massive globular cluster Omega Centauri have shown that it has a striking double main sequence (MS), with a minor…