Search Publications
Description of turbulent dynamics in the interstellar medium: Multifractal microcanonical analysis. II. Sparse filtering of Herschel observation maps and visualization of filamentary structures at different length scales
Schneider, N.; Bontemps, S.; Simon, R. +15 more
We present significant improvements to our previous work on noise reduction in Herschel observation maps by defining sparse filtering tools capable of handling, in a unified formalism, a significantly improved noise reduction as well as a deconvolution in order to reduce effects introduced by the limited instrumental response (beam). We implement …
Crustal origin for olivine in the lunar Shioli crater ejecta boulders: Insights from the geological setting of Theophilus crater and Nectaris basin
Bhattacharya, Satadru; Pathak, Sumit; Kumar, P. Senthil +6 more
On the Moon, impact craters and basins expose a wide range of crustal and mantle rocks that provide excellent opportunity for sampling them, understanding their origins and reconstructing spatial and temporal evolution of lunar interior. The previous studies detected olivine-bearing mantle rocks in and around large impact craters and basins. The J…
XMM-Newton Perspective of the Unique Magnetic Binary-ϵ Lupi
Wade, Gregg A.; Biswas, Ayan; Chandra, Poonam +3 more
The ϵ Lupi A (HD 136504) system stands out among magnetic massive binaries as the only short-period binary system in which both components have detectable magnetic fields. The proximity of the magnetospheres of the components leads to magnetospheric interactions, which are revealed as periodic pulses in the radio light curve of this system. In thi…
Transition Region Brightening in a Moss Region and Their Relation with Lower Atmospheric Dynamics
Joshi, Jayant; Chen, Yajie; Yurchyshyn, Vasyl +5 more
Small-scale brightenings (SBs) are commonly observed in the transition region (TR) that separates the solar chromosphere from the corona. These brightenings, omnipresent in active region patches known as "moss" regions, could potentially contribute to the heating of active region plasma. In this study, we investigate the properties of SB events in…
KIC 8840638: A Newly Discovered Eclipsing Binary with δ Scuti–Type Oscillations
Yang, Tao-Zhi; Zuo, Zhao-Yu; Liu, Jun-Hui +4 more
In this paper, we analyze the light variation of KIC 8840638 using high-precision time-series data from the Kepler mission. The analysis reveals that this target is a new detached eclipsing binary system with a δ Scuti component, rather than a single δ Scuti star as previously known. The frequency analysis of short-cadence data reveals 95 signific…
The Dynamic Venusian Bow Shock Model With the Nonlinear Effect of Magnetosonic Mach Number Based on Venus Express Observations
Xu, Qi; Zhang, Tielong; Zuo, Pingbing +8 more
Utilizing the 8.5-year Venus Express observations, we investigate the effects of solar wind magnetosonic Mach number MMS $\left({M}_{MS}\right)$, solar extreme ultraviolet (EUV) radiation, solar wind dynamic pressure Pd $\left({P}_{d}\right)$ and interplanetary magnetic field (IMF) on the shape of the Venusian bow shock. Our statistical analysis y…
TESS Observations of Outbursts on Polars—Superflares
Qian, Shengbang; Wang, Qishan; Fang, Xiaohui
Flare events are magnetic activities on the stellar surface, which can provide us with information about the accretion behavior and evolution of polars. In this paper, we search for flare events on polars from all the available 2 minute cadence TESS data through visual inspection, and identify six flare events on five flaring stars from 185 polars…
Curlometer and gradient techniques: past and future applications
Escoubet, C. P.; Dunlop, M. W.; Shen, C. +5 more
We review the range of applications and use of multi spacecraft techniques, applicable to close formation arrays of spacecraft, focusing on spatial gradient based methods, and the curlometer in particular. The curlometer was originally applied to Cluster multi-spacecraft magnetic field data, but later was updated for different environments and mea…
Semi-supervised spectral classification of DESI white dwarfs by dimensionality reduction
Bonsor, Amy; Manser, Christopher J.; Rogers, Laura K. +1 more
As a new generation of large-sky spectroscopic surveys comes online, the enormous data volume poses unprecedented challenges in classifying spectra. Modern unsupervised techniques have the power to group spectra based on their dominant features, circumventing the complete reliance on training data suffered by supervised methods. We outline the use…
The ap Prediction Tool Implemented by the A.Ne.Mo.S./NKUA Group
Mavromichalaki, Helen; Livada, Maria; Stassinakis, Argyris +4 more
A novel tool utilizing machine learning techniques was designed to forecast ap index values for the next three consecutive days (24 values). The tool employs time series data from the 3 h ap index of solar cycles 23 and 24 to train the Long Short-Term Memory (LSTM) model, predicting ap index values for the next 72 h at three-hour intervals. During…