Conveners
Day 3 / Session 2: Poster A
- There are no conveners in this block
Day 3 / Session 2: Talk
- Mitsuo Oka (UC Berkeley)
The solar phenomenon are of varied synthesis process whereas the actual process of sunspot and inside the sunspot with neutrino oscillation give a new glimpses of understanding the present research.
Various effects of primordial magnetic fields (PMFs) on nuclear abundances are reported. It has been known that a strong PMF enhances the cosmic expansion rate and distribution functions of electrons and positrons in the early universe. Therefore, primordial nuclear abundances are a probe of the PMF during the big bang nucleosynthesis (BBN). A fast expansion due to the magnetic field energy...
Solar flare and magnetotail observations show simultaneous acceleration of ions and electrons into power-law energy distributions extending to high energy. This suggests a common reconnection acceleration process but the underlying physics is not well understood. During magnetic reconnection, energetic particles undergo a universal Fermi acceleration process involving the curvature drift of...
We have been developing X-ray optics for a fourth FOXSI (Focusing Optics X-ray Solar Imager) sounding rocket experiment, FOXSI-4, which will be launched in 2024 and part of a flare campaign to elucidate of the acceleration / heating mechanism of solar flares. Because much brighter X-ray emissions are expected, high imaging performance rather than effective area is essential. To achieve the...
Electrons are accelerated to non-thermal energies during explosive energy-release in solar flares and Earth's magnetotail. To understand the origin of energetic electrons, magnetic reconnection and associated kinetic structures have been studied extensively. However, it still remains unclear how the electron energy spectrum evolve during magnetotail reconnection and how energies are...
Solar nanoflares are small eruptive events releasing magnetic energy in the quiet corona. If nanoflares follow the same physics as their larger counterparts, they should emit hard X-rays (HXRs) but with a rather faint intensity. A copious and continuous presence of nanoflares would result in a sustained and persistent emission in HXRs, which in turn would deliver enormous amounts of energy...
The Spectrometer/Telescope for Imaging X-rays (STIX) onboard the Solar Orbiter is dedicated to the study of solar flares. STIX measures HXR spectra in the range 4 to 150 keV with up to 1 keV resolution, binned on board into 30 scientifically useful energy bins over 32 pixellated detectors. These spectra are also binned in time between 20 seconds, at standard background level, down to 0.5...
We present the imaging spectroscopy of C-class flare SOL2017-04-04 observed by Expanded Owens Valley Solar Array (EOVSA) to investigate the source morphology of the low-frequency microwave emission. At the low frequencies, the microwave flare source showed an extended emission almost ten times as large as the usually observed high-frequency and hard X-ray flare emission. The source area seems...
Particle-in-cell (PIC) simulation has long been used in theoretical plasma physics. In PIC simulation, the Boris solver is the de-facto standard for solving particle motion, and it has been used over a half century. Meanwhile, there is a continuous demand for better particle solvers. In this contribution, we introduce a family of Boris-type schemes for integrating the motion of charged...
The physical links between CMEs and solar storms were well understood, but the CMEs were not still confirmed for particle acceleration at the Sun. It was observed that CME associated shocks accelerate particles in the interplanetary (IP) space, but it was not understood at what distance from the Sun such acceleration becomes important. Although m-type II bursts, indicative of MHD shocks low in...
Search for neutrinos produced during solar flares has been discussed for the last 60 years while clear signals of neutrinos associated with solar flares (solar flare neutrinos) have not been identified yet. Since neutrinos are not affected by the interplanetary magnetic field, solar flare neutrinos may give a hint of particle acceleration mechanism in solar flares. According to some...
Solar flares are the most powerful energy release phenomena and important sites for particle acceleration in the solar system. Although many particle acceleration mechanisms have been proposed, it remains controversial which process plays a dominant role and can explain various observational signatures of particle energization. In solar flares, HXR and radio observations provide primary...
Geomagnetic storms are crucial phenomena during severe space weather conditions, which directly or indirectly affects us. Temporal evolution of the storm is investigated using Dst or SYM-H index. Usually, CIR generated storms are weaker but have quite a longer recovery phase than ICME generated stronger storm recovery phase. In the investigation of specific storm events, we noticed that ICME...
The large-scale magnetic configuration and plasma beta in solar flares are similar to those in the magnetotail during reconnection. Studies of suprathermal electrons in the magnetotail may thus shed light on suprathermal electron production during flares. We will discuss statistical and case studies of MMS magnetotail measurements. In particular, we will assess: (1) whether primary electron...
