Search Publications
A novel "spectral‑ratio model fitting" to resolve complicated X‑ray spectral variations in active galactic nuclei
Ebisawa, Ken; Mizumoto, Misaki; Midooka, Takuya
Radiation‑magnetohydrodynamic simulation of the active galactic nuclei predicts the presence of the strong accretion disk wind, which gets unstable far from the central region and turns into gas clumps. These inner wind and outer clumps may be actually observed as the ultrafast outflows (UFOs) and the clumpy absorbers, respectively. We call this p…
Revealing the Binarity of HD 36030—One of the Hottest Flare Stars
Karpov, Sergey; Németh, Péter; Maryeva, Olga
The Kepler and TESS space missions significantly expanded our knowledge of what types of stars display flaring activity by recording a vast amount of super-flares from solar-like stars, as well as detecting flares from hotter stars of A-F spectral types. Currently, we know that flaring occurs in the stars as hot as B-type ones. However, the struct…
Asteroid landing analysis for multi-node probe based on spring damping device
Wang, Bang; Xu, Rui; Li, Zhaoyu +3 more
Soft landing on the surface of an asteroid is a prerequisite for performing surface exploration. Due to the weakness of gravitational field, complex surface, and unknown soil properties of asteroids, a single probe may rebound from the surface with uncontrollable long-range tumbling during landing, leading to a deviation from its original landing …
Firefly: A Browser-based Interactive 3D Data Visualization Tool for Millions of Data Points
Geller, Aaron M.; Gurvich, Alexander B.
We present Firefly, a new browser-based interactive tool for visualizing 3D particle data sets. On a typical personal computer, Firefly can simultaneously render and enable real-time interactions with ≳10 million particles, and can interactively explore data sets with billions of particles using the included custom-built octree render engine. Once…
A high-resolution spectroscopic search for multiple populations in the 2 Gyr old cluster NGC 1846
Da Costa, G. S.; Mackey, A. D.; Nordlander, T. +1 more
We present detailed C, O, Na, Mg, Si, Ca, Ti, V, Fe, Zr, Ba, and Eu abundance measurements for 20 red giant branch (RGB) stars in the Large Magellanic Cloud (LMC) star cluster NGC 1846 ([Fe/H] = -0.59). This cluster is 1.95 Gyr old and lies just below the supposed lower age limit (2 Gyr) for the presence of multiple populations in massive star clu…
A Search for Exoplanets around Northern Circumpolar Stars VII. Detection of Planetary Companion Orbiting the Largest Host Star HD 18438
Lee, Byeong-Cheol; Park, Myeong-Gu; Choi, Yeon-Ho +3 more
We have been conducting a exoplanet search survey using Bohyunsen Observatory Echelle Spectrograph (BOES) for the last 18 years. We present the detection of exoplanet candidate in orbit around HD 18438 from high-precision radial velocity (RV) mesurements. The target was already reported in 2018 (Bang et al. 2018). They conclude that the RV variati…
Combination of MRO SHARAD and deep-learning-based DTM to search for subsurface features in Oxia Planum, Mars
Tao, Yu; Muller, Jan-Peter; Xiong, Siting +3 more
Context. Oxia Planum is a mid-latitude region on Mars that attracts a great amount of interest worldwide. An orbiting radar provides an effective way to probe the Martian subsurface and detect buried layers or geomorphological features. The Shallow radar orbital radar system on board the NASA Mars reconnaissance orbiter transmits pulsed signals to…
Mass Ratio Distribution of Hierarchical Triple Systems from the LAMOST-MRS Survey
Han, Zhanwen; Chen, Xuefei; Li, Jiangdan +3 more
Hierarchical triple-star systems consists of three components organized into an inner binary (M 1, M 2) and a more distant outer tertiary (M 3) star. The LAMOST Medium-Resolution Spectroscopic Survey has offered a great sample for the study of triple-system populations. We used the peak amplitude ratio method to ob…
Investigation into the reflection properties of the neutron star low-mass X-ray binary 4U 1636-53
Wang, H. G.; García, F.; Zhang, G. B. +1 more
We present the spectroscopy of the neutron star low-mass X-ray binary 4U 1636-53 using six simultaneous XMM-Newton and Rossi X-ray Timing Explorer observations. We applied different self-consistent reflection models to explore the features when the disk is illuminated by either the corona or the neutron star surface. We found that the spectra coul…
RZ Piscium Hosts a Compact and Highly Perturbed Debris Disk
Hughes, A. Meredith; Liu, Hauyu Baobab; Rieke, G. H. +6 more
RZ Piscium (RZ Psc) is well known in the variable star field because of its numerous irregular optical dips in the past 5 decades, but the nature of the system is heavily debated in the literature. We present multiyear infrared monitoring data from Spitzer and WISE to track the activities of the inner debris production, revealing stochastic infrar…