Search Publications
The spatial structure and dynamical state of the open cluster NGC 2112
Gao, Xinhua; Xu, ShouKun; Xue, Lei
This paper investigates the spatial structure and dynamical state of the old open cluster NGC 2112 based on likely cluster members from Gaia Early Data Release 3. Using the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm, we find 1193 likely cluster members down to G ~ 21 mag within a radius of 1.°5 from the cluster …
Using Shell models to investigate clumping in the wind of the O7Iaf + supergiant AzV83
Hillier, D. John; Flores, Brian L.
Hot massive stars exhibit strong stellar winds that enrich the surrounding interstellar medium and affect the stars' evolution. However, the winds are inhomogeneous (clumped) and are difficult to model in radiative transfer codes. To produce more realistic spectra, many codes use a volume-filling factor (VFF) approach to incorporate the effects of…
The Nature of the Eccentric Double-lined Eclipsing Binary System KIC 2306740 with Kepler Space Photometry
Southworth, J.; Koçak, D.; Yakut, K. +4 more
We present a detailed study of KIC 2306740, an eccentric double-lined eclipsing binary system. Kepler satellite data were combined with spectroscopic data obtained with the 4.2 m William Herschel Telescope (WHT). This allowed us to determine precise orbital and physical parameters of this relatively long period (P = 10.3°) and slightly eccentric (…
Density structures in the martian lower thermosphere as inferred by Trace Gas Orbiter accelerometer measurements
Bruinsma, S.; Siddle, A. G.; Mueller-Wodarg, I. C. F. +1 more
ESA's Trace Gas Orbiter (TGO) undertook an aerobraking campaign to lower itself into the required science orbit. We present an overview of densities derived from TGO accelerometer data during aerobraking. With the addition of density data from NASA's MAVEN/NGIMS instrument, we infer that at TGO altitudes (105 km), the atmosphere is driven by dynam…
AstroSat soft X-ray observations of the symbiotic recurrent nova V3890 Sgr during its 2019 outburst
Singh, K. P.; Orio, M.; Ness, Jan-Uwe +3 more
Two long AstroSat Soft X-ray Telescope observations were taken of the third recorded outburst of the symbiotic recurrent nova V3890 Sgr. The first observing run, 8.1-9.9 d after the outburst, initially showed a stable intensity level with a hard X-ray spectrum that we attribute to shocks between the nova ejecta and the pre-existing stellar compani…
Tidally Excited Modes and δ Scuti Pulsations in the Eclipsing Triple Star IM Persei
Hong, Kyeongsoo; Lee, Jae Woo; Kim, Hye-Young
IM Per is a triple star system whose eclipsing pair masses and radii are accurate to within 1%. The Transiting Exoplanet Survey Satellite (TESS) light curve of the program target exhibits partial eclipses and multiple oscillations with millimagnitude-level amplitudes. It is found that the oscillations affect eclipse timing measurements. Binary mod…
Characterization of geomorphological features of lunar surface using Chandrayaan-1 Mini-SAR and LRO Mini-RF data
Kumar, Shashi; Vashishtha, Ankita
Signatures of UV radiation in low-mass protostars. I. Origin of HCN and CN emission in the Serpens Main region
Harsono, Daniel; Karska, Agata; Tychoniec, Łukasz +6 more
Context. Ultraviolet radiation (UV) influences the physics and chemistry of star-forming regions, but its properties and significance in the immediate surroundings of low-mass protostars are still poorly understood.
Aims: Our aim is to extend the use of the CN/HCN ratio, already established for high-mass protostars, to the low-mass regime to …
The stratified disc wind of MCG-03-58-007
Ballo, L.; Reeves, J. N.; Braito, V. +6 more
Past Suzaku, XMM-Newton, and NuSTAR observations of the nearby (z = 0.03233) bright Seyfert 2 galaxy MCG-03-58-007 revealed the presence of two deep and blue-shifted iron K-shell absorption line profiles. These could be explained with the presence of two phases of a highly ionized, high column density accretion disc wind outflowing with vout1…
Harmonization of RBSP and Arase Energetic Electron Measurements Utilizing ESA Radiation Monitor Data
Miyoshi, Yoshizumi; Shinohara, Iku; Mitani, Takefumi +11 more
Accurate measurements of trapped energetic electron fluxes are of major importance for the studies of the complex nature of radiation belts and the characterization of space radiation environment. The harmonization of measurements between different instruments increases the accuracy of scientific studies and the reliability of data-driven models t…