Search Publications
The Role of Clathrate Formation in Europa’s Ocean Composition
Mousis, Olivier; Bouquet, Alexis; Danger, Grégoire +2 more
We use a thermodynamic statistical model to evaluate how the composition of Europa’s internal ocean may have been affected by clathrate hydrate formation. Assuming an input of the observed O2 and CO2 from the surface into a mildly acidic ocean (pH < 6), and considering the possibility of contributions by reduced (with CH
Origin of a Massive Hyper-runaway Subgiant Star LAMOST-HVS1: Implication from Gaia and Follow-up Spectroscopy
Mahler, Guillaume; Hattori, Kohei; Castro, Norberto +3 more
We report that LAMOST-HVS1 is a massive hyper-runaway subgiant star with a mass of 8.3 {M}⊙ and super-solar metallicity, which was ejected from the inner stellar disk of the Milky Way ∼33 {Myr} ago with the intrinsic ejection velocity of {568}-17+19 {km} {{{s}}}-1 (corrected for the streaming motion of …
Evolution of the Coronal Cavity From the Quiescent to Eruptive Phase Associated with Coronal Mass Ejection
West, Matthew J.; Srivastava, Nandita; Mierla, Marilena +2 more
We present the evolution of a coronal cavity encompassing its quiescent and eruptive phases in the lower corona. Using multiple vantage-point observations from the SDO/AIA, STEREO SECCHI/EUVI, and PROBA2/Sun Watcher with the APS and Image Processing (SWAP) extreme ultraviolet (EUV) imagers, we capture a sequence of quasi-static equilibria of the q…
Automated Swirl Detection Algorithm (ASDA) and Its Application to Simulation and Observational Data
Liu, Jiajia; Erdélyi, Robertus; Nelson, Chris J.
Swirling motions in the solar atmosphere have been widely observed in recent years and suggested to play a key role in channeling energy from the photosphere into the corona. Here, we present a newly developed Automated Swirl Detection Algorithm (ASDA) and discuss its applications. ASDA is found to be very proficient at detecting swirls in a varie…
2D Isotropic Feature of Solar Wind Turbulence as Shown by Self-correlation Level Contours at Hour Timescales
He, Jiansen; Wang, Xin; Tu, Chuanyi
The slow wind anisotropy is observed by Dasso et al. as elongation along the magnetic field direction in the magnetic self-correlation contours calculated from data sets of two-day-long data and averaged for five years in 1998-2002, which is consistent with prediction by the “critical balance cascade theory.” More pronounced elongation at smaller …
Three-dimensional Density Structure of a Solar Coronal Streamer Observed by SOHO/LASCO and STEREO/COR2 in Quadrature
Van Doorsselaere, Tom; Zhukov, Andrei N.; Decraemer, Bieke
Helmet streamers are a prominent manifestation of magnetic structures with current sheets in the solar corona. These large-scale structures are regions with high plasma density, overlying active regions and filament channels. We investigate the three-dimensional (3D) structure of a coronal streamer, observed simultaneously by white-light coronagra…
{k}_{\perp }^{-8/3} Spectrum in Kinetic Alfvén Wave Turbulence: Implications for the Solar Wind
David, Vincent; Galtier, Sébastien
The nature of solar wind turbulence at large scale is rather well understood in the theoretical framework of magnetohydrodynamics. The situation is quite different at subproton scales where the magnetic energy spectrum measured by different spacecraft does not fit with the classical turbulence predictions: a power-law index close to -8/3 is genera…
Exploring the Origin of Multiwavelength Activities of High-redshift Flat-spectrum Radio Quasar PKS 1502+106 during 2014-2018
Wang, X. Y.; Gu, Q. S.; Xiong, Ding-Rong +4 more
The origin of the multiband activities (outbursts/flares) of blazars is still a heavily debated topic. Shock and magnetic reconnection have long been considered as possible triggers of the multiband activities. In this paper, we present an exploration of the origin of multiband activities for a high-redshift (z = 1.8385) flat-spectrum radio quasar…
Unresolved Binaries and Galactic Clusters’ Mass Estimates
Carraro, Giovanni; Borodina, Olga I.; Seleznev, Anton F. +1 more
Binary stars are present in all stellar systems, yet their role is far from being fully understood. We investigate the effect of unresolved binaries in the derivation of open clusters’ mass by star counts. We start from the luminosity functions of five open clusters: IC 2714, NGC 1912, NGC 2099, NGC 6834, and NGC 7142. Luminosity functions are obt…
NuSTAR Observations of the Supernova Remnant RX J1713.7-3946
Uchiyama, Yasunobu; Tanaka, Takaaki; Aharonian, Felix +4 more
The shock waves of supernova remnants (SNRs) are prominent candidates for the acceleration of the Galactic cosmic rays. SNR RX J1713.7-3946 is one well-studied particle accelerator in our Galaxy because of its strong nonthermal X-ray and gamma-ray radiation. We have performed Nuclear Spectroscopic Telescope Array (3-79 keV) observations of the nor…