Search Publications
The MPI + CUDA Gaia AVU-GSR Parallel Solver Toward Next-generation Exascale Infrastructures
Bucciarelli, Beatrice; Vecchiato, Alberto; Cesare, Valentina +4 more
We ported to the GPU with CUDA the Astrometric Verification Unit-Global Sphere Reconstruction (AVU-GSR) Parallel Solver developed for the ESA Gaia mission, by optimizing a previous OpenACC porting of this application. The code aims to find, with a [10, 100] µarcsec precision, the astrometric parameters of ~108 stars, the attitude …
High-resolution Observations of the Low Atmospheric Response to Small Coronal Heating Events in an Active Region Core
Testa, Paola; De Pontieu, Bart; Rouppe van der Voort, Luc +1 more
High-resolution spectral observations of the lower solar atmosphere (chromosphere and transition region) during coronal heating events, in combination with predictions from models of impulsively heated loops, provide powerful diagnostics of the properties of the heating in active region cores. Here, we analyze the first coordinated observations of…
Fundamental properties of red giants from Kepler and Gaia DR3 data: diagnostic potential of the mass-metallicity diagram
Yıldız, M.
For solar-like oscillators, the asteroseismic relations connect the stellar mean density and surface gravity to observable properties of the oscillations. Since the space missions CoRoT and Kepler, the asteroseismic relations have been massively employed out of their theoretical domain of validity, that is the main-sequence solar-type stars, in pa…
Plausible association of distant late M dwarfs with low-frequency radio emission
Callingham, J. R.; Shimwell, T. W.; Hardcastle, M. J. +10 more
We present the serendipitous discovery of eight distant (> 50 pc) late M dwarfs with plausible associated radio emission at 144 MHz. The M-dwarf nature of our sources has been confirmed with optical spectroscopy performed using HET/LRS2 and Subaru/FOCAS, and their radio flux densities are within the range of 0.5−1.0 mJy at 144 MHz. Considering …
The orbital solution and dynamical masses of the binary system V* PX Virginis
Wang, Xiaoli; Fu, Yanning; Xia, Fang
V* PX Vir is a nearby single-lined spectroscopic binary with the primary being a variable of a BY Dra-type star. It has a period of ~216 d and the components of the system are two low-mass pre-main-sequence stars. By a simultaneous least-squares fit to the radial velocities, the relative positions, and the revised Hipparcos intermediate astrometri…
Characteristics of Magnetic Reconnection With a Finite X-Line Length
Lu, Quanming; Wang, Rongsheng; Lu, San +2 more
The characteristics of magnetic reconnection with a finite x-line length are studied using three-dimensional (3D) particle-in-cell (PIC) simulations. We simulate two cases: anti-parallel reconnection and guide field reconnection. In both cases, reconnection is triggered by an initial perturbation that is localized in the current direction, and the…
Kilometer-precise (UII) Umbriel physical properties from the multichord stellar occultation on 2020 September 21
Smith, N.; Sicardy, B.; Gomes-Júnior, A. R. +39 more
We report the results of the stellar occultation by (UII) Umbriel on 2020 September 21. The shadow crossed the USA and Canada, and 19 positive chords were obtained. A limb parameter accounted for putative topographic features in the limb fittings. Ellipse fittings were not robust - only upper limits were derived for the true size/shape of a putati…
A Deep Study of the Open Cluster NGC 5288 Using Photometric and Astrometric Data from GAIA DR3 and 2MASS
Bisht, D.; Sethi, R.; Rangawal, G. +1 more
This paper investigates a poorly studied open cluster, NGC 5288, using 2MASS JHKS and the recently released Gaia DR3 astrometric and photometric data. The mean proper motions in right ascension and declination are estimated as (‑3.840 ± 0.230) and (‑1.934 ± 0.162) mas yr‑1 respectively. We also derive the age and distance of …
Estimating the energy flux of transverse waves associated with Kelvin-Helmholtz instability in solar coronal loops
Guo, Mingzhe; Gao, Yuhang; Van Doorsselaere, Tom +1 more
Context. The energy flux of kink waves in coronal loops has been estimated in previous studies. Recent numerical simulations have revealed that kink oscillations can induce a Kelvin-Helmholtz Instability (KHI) in magnetic flux tubes. This non-linear process breaks the assumptions that have typically been included in previous eigenmode analyses. Th…
The Evolution of Activity and Chemical Composition in Rosetta's Comet Targets across Multiple Apparitions: Complications for CS2 as the CS Parent in Comet Nuclei
Parker, Joel Wm.; Harris, Walter M.; Bodewits, Dennis +9 more
Jupiter-family comets are ephemeral small bodies injected into the inner solar system from the Kuiper Belt, doomed to either sublimate all their volatiles and become inert or violently shatter from the activity. We investigate two target candidates of the ESA Rosetta mission, comets 46P/Wirtanen and 67P/Churyumov-Gerasimenko, which had favorable a…