|
Notice:
|
Found 13 entries in the Bibliography.
Showing entries from 1 through 13
| 2023 |
|
The Modulation of Anomalous and Galactic Cosmic-Ray Oxygen over Successive Solar Cycle Minima Both the recent 2009 and 2020 solar minima were classified as unusually quiet and characterized with unusually high galactic cosmic-ray (GCR) levels. However, unlike the trends from previous decades, in which anomalous cosmic-ray (ACR) and GCR levels strongly agreed, the ACR intensities did not reach such high, record- setting levels. This discrepancy between the behavior of GCRs and ACRs is investigated in this work by simulating the acceleration and transport of GCR and ACR oxygen under different transport conditions. Afte ... Strauss, R.~D.; Leske, R.~A.; Rankin, J.~S.; Published by: \apj Published on: feb YEAR: 2023 DOI: 10.3847/1538-4357/acb53d Parker Data Used; Galactic cosmic rays; Heliosphere; Termination shock; Interplanetary particle acceleration; 567; 711; 1690; 826; Astrophysics - Solar and Stellar Astrophysics; Astrophysics - High Energy Astrophysical Phenomena; Physics - Space Physics |
|
Parker Solar Probe Encounters the Leg of a Coronal Mass Ejection at 14 Solar Radii We use Parker Solar Probe (PSP) observations to report the first direct measurements of the particle and field environments while crossing the leg of a coronal mass ejection (CME) very close to the Sun (\raisebox-0.5ex\textasciitilde14 Rs). An analysis that combines imaging from 1 au and PSP with a CME model, predicts an encounter time and duration that correspond to an unusual, complete dropout in low-energy solar energetic ions from H-Fe, observed by the Integrated Science Investigation of the Sun (IS\ensuremath\odotIS). T ... McComas, D.~J.; Sharma, T.; Christian, E.~R.; Cohen, C.~M.~S.; Desai, M.~I.; Hill, M.~E.; Khoo, L.~Y.; Matthaeus, W.~H.; Mitchell, D.~G.; Pecora, F.; Rankin, J.~S.; Schwadron, N.~A.; Szalay, J.~R.; Shen, M.~M.; Braga, C.~R.; Mostafavi, P.~S.; Bale, S.~D.; Published by: \apj Published on: feb YEAR: 2023 DOI: 10.3847/1538-4357/acab5e Parker Data Used; Solar coronal mass ejections; interplanetary magnetic fields; Interplanetary medium; Interplanetary particle acceleration; Solar energetic particles; Solar wind; Solar coronal heating; Solar magnetic flux emergence; 310; 824; 825; 826; 1491; 1534; 1989; 2000 |
| 2022 |
|
We present observations of \ensuremath\gtrsim10-100 keV nucleon$^-1$ suprathermal (ST) H, He, O, and Fe ions associated with crossings of the heliospheric current sheet (HCS) at radial distances of <0.1 au from the Sun. Our key findings are as follows: (1) very few heavy ions are detected during the first full crossing, the heavy-ion intensities are reduced during the second partial crossing and peak just after the second crossing; (2) ion arrival times exhibit no velocity dispersion; (3) He pitch-angle distributions track t ... Desai, M.~I.; Mitchell, D.~G.; McComas, D.~J.; Drake, J.~F.; Phan, T.; Szalay, J.~R.; Roelof, E.~C.; Giacalone, J.; Hill, M.~E.; Christian, E.~R.; Schwadron, N.~A.; McNutt, R.~L.; Wiedenbeck, M.~E.; Joyce, C.; Cohen, C.~M.~S.; Davis, A.~J.; Krimigis, S.~M.; Leske, R.~A.; Matthaeus, W.~H.; Malandraki, O.; Mewaldt, R.~A.; Labrador, A.; Stone, E.~C.; Bale, S.~D.; Verniero, J.; Rahmati, A.; Whittlesey, P.; Livi, R.; Larson, D.; Pulupa, M.; MacDowall, R.~J.; Niehof, J.~T.; Kasper, J.~C.; Horbury, T.~S.; Published by: \apj Published on: mar YEAR: 2022 DOI: 10.3847/1538-4357/ac4961 Parker Data Used; The Sun; Solar magnetic reconnection; Interplanetary particle acceleration; interplanetary magnetic fields; Heliosphere; 1693; 1504; 826; 824; 711; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
|
The acceleration of charged particles by interplanetary shocks (IPs) can drain a nonnegligible fraction of the plasma pressure. In this study, we have selected 17 IPs observed in situ at 1 au by the Advanced Composition Explorer and the Wind spacecraft, and 1 shock at 0.8 au observed by Parker Solar Probe. We have calculated the time-dependent partial pressure of suprathermal and energetic particles (smaller and greater than 50 keV for protons and 30 keV for electrons, respectively) in both the upstream and downstream region ... David, Liam; Fraschetti, Federico; Giacalone, Joe; Wimmer-Schweingruber, Robert; Berger, Lars; Lario, David; Published by: \apj Published on: mar YEAR: 2022 DOI: 10.3847/1538-4357/ac54af Parker Data Used; Interplanetary shocks; Interplanetary particle acceleration; Space plasmas; 829; 826; 1544; Astrophysics - Solar and Stellar Astrophysics; Astrophysics - High Energy Astrophysical Phenomena; Physics - Plasma Physics; Physics - Space Physics |
|
Energetic electrons of Jovian origin have been observed for decades throughout the heliosphere, as far as 11 au, and as close as 0.5 au, from the Sun. The treatment of Jupiter as a continuously emitting point source of energetic electrons has made Jovian electrons a valuable tool in the study of energetic electron transport within the heliosphere. We present observations of Jovian electrons measured by the EPI-Hi instrument in the Integrated Science Investigation of the Sun instrument suite on Parker Solar Probe at distances ... Mitchell, J.~G.; Leske, R.~A.; De Nolfo, G.~A.; Christian, E.~R.; Wiedenbeck, M.~E.; McComas, D.~J.; Cohen, C.~M.~S.; Cummings, A.~C.; Hill, M.~E.; Labrador, A.~W.; Mays, M.~L.; McNutt, R.~L.; Mewaldt, R.~A.; Mitchell, D.~G.; Odstrcil, D.; Schwadron, N.~A.; Stone, E.~C.; Szalay, J.~R.; Published by: \apj Published on: jul YEAR: 2022 DOI: 10.3847/1538-4357/ac75ce Parker Data Used; Interplanetary particle acceleration; Solar energetic particles; Corotating streams; interplanetary magnetic fields; Heliosphere; 826; 1491; 314; 824; 711 |
|
Statistical classification of the Helios solar wind observations into several populations sorted by bulk speed has revealed an outward acceleration of the wind. The faster the wind, the smaller this acceleration in the 0.3-1 au radial range. In this paper, we show that recent measurements from the Parker Solar Probe (PSP) are compatible with an extension closer to the Sun of the latter Helios classification. For instance, the well-established bulk speed/proton temperature (u, T $_p$) correlation and bulk speed/electron tempe ... Dakeyo, Jean-Baptiste; Maksimovic, Milan; emoulin, Pascal; Halekas, Jasper; Stevens, Michael; Published by: \apj Published on: dec YEAR: 2022 DOI: 10.3847/1538-4357/ac9b14 Parker Data Used; Solar wind; Interplanetary particle acceleration; Slow solar wind; Astronomy data modeling; 1534; 826; 1873; 1859 |
| 2021 |
|
The solar wind escapes from the solar corona and is accelerated, over a short distance, to its terminal velocity. The energy balance associated with this acceleration remains poorly understood. To quantify the global electrostatic contribution to the solar wind dynamics, we empirically estimate the ambipolar electric field (E$_\ensuremath\parallel$) and potential (\ensuremath\Phi$_r,\ensuremath\infty$). We analyze electron velocity distribution functions (VDFs) measured in the near-Sun solar wind between 20.3 R$_S$ and 85.3 ... Ber\vci\vc, Laura; c, Milan; Halekas, Jasper; Landi, Simone; Owen, Christopher; Verscharen, Daniel; Larson, Davin; Whittlesey, Phyllis; Badman, Samuel; Bale, Stuart.; Case, Anthony; Goetz, Keith; Harvey, Peter; Kasper, Justin; Korreck, Kelly; Livi, Roberto; MacDowall, Robert; Malaspina, David; Pulupa, Marc; Stevens, Michael; Published by: \apj Published on: nov YEAR: 2021 DOI: 10.3847/1538-4357/ac1f1c Parker Data Used; Solar wind; Space plasmas; Interplanetary particle acceleration; Collision processes; Space vehicle instruments; 1534; 1544; 826; 2065; 1548; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
|
Analysis of energetic particle inner heliospheric spacecraft data increasingly suggests the existence of anomalous diffusion phenomena that should be addressed to achieve a better understanding of energetic particle transport and acceleration in the expanding solar wind medium. Related to this is fast-growing observational evidence supporting the long-standing prediction from magnetohydrodynamic (MHD) theory and simulations of the presence of an inner heliospheric, dominant quasi-two-dimensional MHD turbulence component that ... Published by: The Astrophysical Journal Published on: 06/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abf3c6 Interplanetary particle acceleration; Solar wind; Solar magnetic reconnection; 826; 1534; 1504; Parker Data Used |
|
First Observations of Anomalous Cosmic Rays in to 36 Solar Radii NASA s Parker Solar Probe mission continues to travel closer to the Sun than any prior human-made object, with an expected closest approach of <10 solar radii (<0.046 au) by 2024. On board, the Integrated Science Investigation of the Sun instrument suite makes unprecedented in situ measurements of energetic particles in the near-Sun environment. The current low level of solar activity offers a prime opportunity to measure cosmic rays closer to the Sun than ever before. We present the first observations of anomalous cosmic ra ... Rankin, J.; McComas, D.; Leske, R.; Christian, E.; Cohen, C.; Cummings, A.; Joyce, C.; Labrador, A.; Mewaldt, R.; Posner, A.; Schwadron, N.; Strauss, R.; Stone, E.; Wiedenbeck, M.; Published by: The Astrophysical Journal Published on: 05/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abec7e cosmic rays; Solar wind; Heliosphere; Solar energetic particles; Solar Physics; solar cycle; Quiet Sun; Particle astrophysics; interplanetary magnetic fields; Plasma astrophysics; Interplanetary particle acceleration; Pickup ions; 329; 1534; 711; 1491; 1476; 1487; 1322; 96; 824; 1261; 826; 1239; Parker Data Used |
|
Observations of plasma waves by the Fields Suite and of electrons by the Solar Wind Electrons Alphas and Protons Investigation on the Parker Solar Probe provide strong evidence for pitch angle scattering of strahl-energy electrons by narrowband whistler-mode waves at radial distances less than ∼0.3 au. We present two example intervals of a few hours each that include eight waveform captures with whistler-mode waves and 26 representative electron distributions that are examined in detail. Two were narrow, seventeen were cle ... Cattell, C.; Breneman, A.; Dombeck, J.; Short, B.; Wygant, J.; Halekas, J.; Case, Tony; Kasper, J.; Larson, D.; Stevens, Mike; Whittesley, P.; Bale, S.; de Wit, Dudok; Goodrich, K.; MacDowall, R.; Moncuquet, M.; Malaspina, D.; Pulupa, M.; Published by: The Astrophysical Journal Published on: 04/2021 YEAR: 2021 DOI: 10.3847/2041-8213/abefdd Parker Data Used; Solar wind; Space plasmas; Plasma astrophysics; Interplanetary physics; Interplanetary particle acceleration; 1534; 1544; 1261; 827; 826; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
|
Wijsen, Nicolas; Samara, Evangelia; Aran, Angels; Lario, David; Pomoell, Jens; Poedts, Stefaan; Published by: \apjl Published on: 02/2021 YEAR: 2021 DOI: 10.3847/2041-8213/abe1cb Solar wind; Corotating streams; Interplanetary particle acceleration; 1534; 314; 826; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics |
| 2019 |
|
Electron Energy Partition across Interplanetary Shocks. II. Statistics A statistical analysis of 15,210 electron velocity distribution function (VDF) fits, observed within \textpm2 hr of 52 interplanetary (IP) shocks by the Wind spacecraft near 1 au, is presented. This is the second in a three-part series on electron VDFs near IP shocks. The electron velocity moment statistics for the dense, low-energy core, tenuous, hot halo, and field-aligned beam/strahl are a statistically significant list of values illustrated with both histograms and tabular lists for reference and baselines in future w ... Wilson, Lynn; Chen, Li-Jen; Wang, Shan; Schwartz, Steven; Turner, Drew; Stevens, Michael; Kasper, Justin; Osmane, Adnane; Caprioli, Damiano; Bale, Stuart; Pulupa, Marc; Salem, Chadi; Goodrich, Katherine; Published by: The Astrophysical Journal Supplement Series Published on: 12/2019 YEAR: 2019 DOI: 10.3847/1538-4365/ab5445 Astrophysics - Solar and Stellar Astrophysics; Interplanetary particle acceleration; Interplanetary shocks; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Plasma astrophysics; Plasma physics; Solar coronal mass ejection shocks; Solar coronal mass ejections; Solar Probe Plus; Solar wind; Space plasmas |
|
Velocity distributions of particles are key elements in the study of solar wind. The physical mechanisms that regulate their many features are a matter of debate. The present work addresses the subject with a fully analytical method in order to establish the shape of particle velocity distributions in solar wind. The method consists of solving the steady-state kinetic equation for particles and the related fluid equations, with spatial profiles for density and temperature that match general observational data. The model i ... Published by: The Astrophysical Journal Published on: 09/2019 YEAR: 2019 DOI: 10.3847/1538-4357/ab2fcd Interplanetary particle acceleration; Kappa mechanism; Parallel field; parker solar probe; Solar coronal transients; Solar Probe Plus; Solar wind |
1
