Search Publications
Estimation of Nitrogen-to-Iron Abundance Ratios from Low-Resolution Spectra
Beers, Timothy C.; Lee, Young Sun; Masseron, Thomas +1 more
We present a method to determine nitrogen abundance ratios with respect to iron ([N/Fe]) from molecular CN-band features observed in low-resolution (R ∼ 2000) stellar spectra obtained by the Sloan Digital Sky Survey (SDSS) and the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST). Various tests are carried out to check the systema…
Infrared Properties of OGLE4 Mira Variables in Our Galaxy
Suh, Kyung-Won
We investigate infrared properties of OGLE4 Mira variables in our Galaxy. For each object, we cross-identify the AllWISE, 2MASS, Gaia, and IRAS counterparts. We present various IR two-color diagrams (2CDs) and period-magnitude and period-color relations for the Mira variables. Generally, the Mira variables with longer periods are brighter in the I…
Relation between Black Hole Mass and Bulge Luminosity in Hard X-Ray Selected Type 1 AGNs
Ho, Luis C.; Barth, Aaron J.; Kim, Minjin +1 more
Using I-band images of 35 nearby (z < 0.1) type 1 active galactic nuclei (AGNs) obtained with Hubble Space Telescope, selected from the 70-month Swift-BAT X-ray source catalog, we investigate the photometric properties of the host galaxies. With a careful treatment of the point-spread function (PSF) model and imaging decomposition, we robustly …
V608 Cassiopeiae: A W UMa-Type Eclipsing Binary with Two Possible Circumbinary Companions
Lee, Jae Woo; Park, Jang-Ho
We present the photometric properties of V608 Cas from detailed studies of light curves and eclipse timings. The light curve synthesis indicates that the eclipsing pair is an overcontact binary with parameters of ΔT = 155 K, q = 0.328, and f = 26%. We detected the third light ℓ_{3}, which corresponds to about 8% and 5% of the total systemic light …
Stellar Magnetic Activity Measure Based on IUE Mg II h+k Emission Lines of Main-Sequence G Stars
Choi, Hwajin; Yi, Yu; Kim, Dowoon
Stellar magnetic activity is important for formulating the evolution of the star. To represent the stellar magnetic activity, the S index is defined using the Ca II H+K flux measure from the Mount Wilson Observatory. Mg II lines are generated in a manner similar to the formation of Ca II lines, which are more sensitive to weak chromospheric activi…
Kinematic Classification of Coronal Mass Ejections in LASCO C3 Field of View
Moon, Yong-Jae; Lee, Harim; Cho, Il-Hyun +2 more
In this study, we perform a statistical investigation of the kinematic classification of 4264 coronal mass ejections (CMEs) from 1996 to 2015 observed by SOHO/LASCO C3. Using the constant acceleration model, we classify these CMEs into three groups: deceleration, constant velocity, and acceleration motion. For this, we devise three different class…