Search Publications
Effect of Target Layering in Gravity-Dominated Cratering in Nature, Experiments, and Numerical Simulations
Rossi, A. P.; Raducan, S. D.; Collins, G. S. +4 more
Impacts into layered targets may generate "concentric craters" where a wider outer crater in the top layer surrounds a smaller, nested crater in the basement, which itself may be complex or simple. The influence of target on cratering depends on the ratio of target strength to lithostatic stress, which, in turn, is affected by gravity, target dens…
Three-dimensional Venusian ionosphere model
Chaufray, Jean-Yves; Lefèvre, Franck; Lebonnois, Sébastien +3 more
To study the Venusian ionosphere, a 3D ionospheric model is included in the Venus Planetary Climate Model (Venus PCM), which we present here with a number of recent extensions and improvements. Our ionospheric model of Venus consists of 15 charged species (electron and 14 ions), 13 photo-ionization for 8 species, an ion-neutral chemistry (61 react…
Revealing the Impact of Critical Stellar Central Density on Galaxy Quenching through Cosmic Time
Xu, Bingxiao; Peng, Yingjie
In a previous work, we investigated the structural and environmental dependence on quenching in the nearby universe. In this work, we extend our investigations to higher redshifts by combining galaxies from the Sloan Digital Sky Survey and The FourStar Galaxy Evolution surveys. In low density, we find a characteristic Σ1 kpc above which…
Stratospheric aerosols and C6H6 in Jupiter's south polar region from JWST/MIRI observations
de Pater, Imke; Fletcher, Leigh N.; Vinatier, Sandrine +14 more
Context. The polar atmosphere of Jupiter is significantly affected by auroral activity, which can induce both thermal and chemical differences compared to the rest of the atmosphere. In particular, auroral activity enhances the production of various hydrocarbons, including benzene. Benzene could be a potential precursor to the formation of the str…
Modeling the Enceladus dust plume based on in situ measurements performed with the Cassini Cosmic Dust Analyzer
Kempf, S.; Postberg, F.; Srama, R. +5 more
We analyzed data recorded by the Cosmic Dust Analyzer on board the Cassini spacecraft during Enceladus dust plume traversals. Our focus was on profiles of relative abundances of grains of different compositional types derived from mass spectra recorded with the Dust Analyzer subsystem during the Cassini flybys E5 and E17. The E5 profile, correspon…
Star Formation Characteristics of Galaxies Hosting AGN
Nandi, Payel; Subramonian Stalin, Chelliah
We present an analysis of the ultra-violet (UV) observations of two Seyfert type active galactic nuclei (AGN), namely NGC 4051 and NGC 4151. These observations aimed at studying the star formation in the hosts of these AGN were carried out with the ultra-violet imaging telescope on board AstroSat in far-UV. A total of 193 and 328 star-forming regi…
First Solar Orbiter observation of a dark halo in the solar atmosphere
Parenti, S.; Long, D. M.; Andretta, V. +5 more
Context. Solar active regions (ARs) are often surrounded by dark large areas of reduced emission compared to the quiet Sun, observed at various wavelengths corresponding to the chromosphere, transition region (TR), and corona, known as dark halos (DHs). The mechanisms behind the darker emission of DHs remain unclear and merit a wider scope of stud…
Dampening long-period doppler shift oscillations using deep machine learning techniques in the solar network and internetwork
Tavabi, Ehsan; Sadeghi, Rayhaneh
This study aimed to explore the Doppler shift at different wavelengths in the IRIS solar spectrum and analyze the evolution and statistical properties of longitudinal oscillations with damping in chromosphere and transition region bright points (BPs). Understanding the damping mechanism and statistical properties of oscillations in BPs is crucial …
How Does the Structure of Rarefaction Regions Develop?
Němeček, Zdeněk; Ďurovcová, Tereza; Šafránková, Jana
A rarefaction region (RR) occurs at the trailing edge of the fast solar wind stream. It comes from an area of small longitudinal extent on the solar surface and exhibits a fine and complex structure. In our study, we did a superposed epoch analysis of the proton and α parameters across the RR and observed their gradual evolution. We did not find a…
Comparison of Solar Multifrequency Microwave Data with Other Solar Indices for Understanding Solar and Stellar Microwave Data
Namekata, Kosuke; Shimojo, Masumi; Watanabe, Kyoko +2 more
Thermal microwave emissions detected from stellar atmospheres contain information on stellar activity. However, even for the Sun, the relationship between multifrequency microwave data and other activity indices remains unclear. We investigated the relationships among the thermal microwave fluxes with 1, 2, 3.75, and 9.4 GHz, their circular polari…