Search Publications
On the slow solar wind with high Alfvénicity: from composition and microphysics to spectral properties
D'Amicis, Raffaella; Bruno, Roberto; Matteini, Lorenzo
Alfvénic fluctuations are very common features in the solar wind and are found especially within the main portion of fast-wind streams while the slow wind usually is less Alfvénic and more variable. In general, the fast and slow winds show many differences, which span from the large-scale structure to small-scale phenomena, including also a differ…
Diagnosing solar wind origins using in situ measurements in the inner heliosphere
Matteini, L.; Horbury, T. S.; Stansby, D.
Robustly identifying the solar sources of individual packets of solar wind measured in interplanetary space remains an open problem. We set out to see if this problem is easier to tackle using solar wind measurements closer to the Sun than 1 au, where the mixing and dynamical interaction of different solar wind streams is reduced. Using measuremen…
Helios Observations of Quasiperiodic Density Structures in the Slow Solar Wind at 0.3, 0.4, and 0.6 AU
Arge, C. N.; MacNeice, P.; Di Matteo, S. +3 more
Following previous investigations of quasiperiodic plasma density structures in the solar wind at 1 AU, we show using the Helios1 and Helios2 data their first identification in situ in the inner heliosphere at 0.3, 0.4, and 0.6 AU. We present five events of quasiperiodic density structures with time scales ranging from a few minutes to a couple of…
Dust observations with antenna measurements and its prospects for observations with Parker Solar Probe and Solar Orbiter
Issautier, Karine; Meyer-Vernet, Nicole; Mann, Ingrid +10 more
The electric and magnetic field instrument suite FIELDS on board the NASA Parker Solar Probe and the radio and plasma waves instrument RPW on the ESA Solar Orbiter mission that explore the inner heliosphere are sensitive to signals generated by dust impacts. Dust impacts have been observed using electric field antennas on spacecraft since the 1980…
Count-based imaging model for the Spectrometer/Telescope for Imaging X-rays (STIX) in Solar Orbiter
Massa, Paolo; Piana, Michele; Benvenuto, Federico +1 more
The Spectrometer/Telescope for Imaging X-rays (STIX) will study solar flares across the hard X-ray window provided by the Solar Orbiter cluster. Similarly to the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), STIX is a visibility-based imaging instrument that will require Fourier-based image reconstruction methods. However, in this…
The Fluid-like and Kinetic Behavior of Kinetic Alfvén Turbulence in Space Plasma
Verscharen, Daniel; Wicks, Robert T.; Chen, Christopher H. K. +3 more
Kinetic Alfvén waves (KAWs) are the short-wavelength extension of the magnetohydrodynamics Alfvén-wave branch in the case of highly oblique propagation with respect to the background magnetic field. Observations of space plasma show that small-scale turbulence is mainly KAW-like. We apply two theoretical approaches, a collisional two-fluid theory …
The Impact of Turbulent Solar Wind Fluctuations on Solar Orbiter Plasma Proton Measurements
Owen, C. J.; Nicolaou, G.; Verscharen, D. +1 more
Solar Orbiter will observe the Sun and the inner heliosphere to study the connections between solar activity, coronal structure, and the origin of the solar wind. The plasma instruments on board Solar Orbiter will determine the three-dimensional velocity distribution functions of the plasma ions and electrons with high time resolution. The analysi…
Joint hard X-ray observations with ASO-S/HXI and SO/STIX
Krucker, Säm; Su, Yang; Hurford, Gordon J. +1 more
This paper discusses the potential of future joint hard X-ray solar flare observations between the Hard X-ray Imager (HXI) onboard the Advanced Space-based Solar Observatory (ASO-S) mission and the Spectrometer/Telescope for Imaging X-rays (STIX) on Solar Orbiter. The different viewing perspectives of the two telescopes relative to the Sun will al…
Identifying Spectral Lines to Study Coronal Mass Ejection Evolution in the Lower Corona
Landi, Enrico; Rivera, Yeimy J.; Lepri, Susan T.
As prominences propagate away from the Sun via a coronal mass ejection (CME), they expand, accelerate, and are strongly heated. The heating is substantial enough to continuously ionize the prominence plasma, making it difficult to follow its dynamic evolution with a single extreme ultraviolet (EUV) narrow-band channel or a white light instrument. …
Elemental composition in quiescent prominences
Vial, J. -C.; Parenti, S.; Del Zanna, G.
Context. The first ionization potential (FIP) bias is currently used to trace the propagation of solar features ejected by the wind and solar eruptions (coronal mass ejections). The FIP bias also helps us to understand the formation of prominences, as it is a tracer for the solar origin of prominence plasma.
Aims: This work aims to provide el…