Solar Neutron Events of 2003 October–November

Watanabe, Kyoko; Gros, M.; Stoker, P. H.; Kudela, K.; Lopate, C.; Galicia, J. F. Valdés; Hurtado, A.; Musalém, O.; Ogasawara, Ryusuke; Mizumoto, Y.; Nakagiri, M.; Miyashita, Akihiko; Matsubara, Y.; Sako, T.; Muraki, Y.; Sakai, Takehiro; Shibata, S.

doi:10.1086/498086

Cited by 40 publications

(10 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is because the light curves of the 4-7 MeV nuclear gamma-ray emission, which obviously reflect ion acceleration at the Sun, are approximately described by a Gaussian function (e.g., Chupp et al 1990;Watanabe et al 2003). Furthermore, according to various solar X-ray and gamma-ray observations (e.g., Forrest & Chupp 1983;Watanabe et al 2006), the rise and peak times of the 4-7 MeV nuclear gamma-ray light curve are roughly similar to those of the HXR emission. In this work we treat three neutron emission profiles, since it is natural that ions are accelerated in solar flares at the same time as electrons.…”

Section: Nm Light Curvesmentioning

confidence: 99%

“…We assume the function N(E n ) to have a form of α(E n /100 MeV) −β (sr −1 MeV −1 ), which is theoretically expected from the shock acceleration process of ions in solar flares (see Hua et al 2002, and references therein). Here, the powerlaw index β is assumed to take values of 3, 4, and 5 as conservative ones (Chupp et al 1987;Muraki et al 1992;Struminsky et al 1994;Watanabe et al 2003Watanabe et al , 2006. Since θ varies from flare to flare (Table 1), A(θ, E n ) is interpolated from effective areas calculated for a set of incident angles of 6.6…”

Section: Calculation Of An Upper Limit Of the Solar-neutron Fluxmentioning

confidence: 99%

“…Except for 800621 (gray filled circle; Ramaty et al 1983) and 840824 flares (black filled circle; Evenson et al 1990), observed by satellites, the station altitude is displayed. The references are; Chupp et al (1987) for the 820603 flare (open triangle), Debrunner et al (1993Debrunner et al ( , 1997 for the 900524 flare (filled triangle), Watanabe et al (2003) for the 001124 (open circle), and Bieber et al (2005) and Watanabe et al (2006) for the 031028 (open square). Neutrons from the 910604 flare were detected by two different detectors installed at Mt.…”

Section: Calculation Of An Upper Limit Of the Solar-neutron Fluxmentioning

confidence: 99%

“…(4), for the two (X3.7 and X3.3) of our final sample flares. For comparison, the previous positive detections (Ramaty et al 1983;Chupp et al 1987;Evenson et al 1990;Muraki et al 1992;Debrunner et al 1993; Struminsky et al 1994;Debrunner et al 1997;Watanabe et al 2003;Bieber et al 2005;Watanabe et al 2006) are also plotted. Here, the horizontal axis in Fig.…”

Section: Calculation Of An Upper Limit Of the Solar-neutron Fluxmentioning

confidence: 99%

See 3 more Smart Citations

Upper limits on the solar-neutron flux at the Yangbajing neutron monitor from BATSE-detected solar flares

Tsuchiya

Miyasaka

Takahashi

et al. 2007

A&A

View full text Add to dashboard Cite

Aims. The purpose of this work is to search the data from Yangbajing neutron monitor obtained between 1998 October and 2000 June for the solar neutrons associated with solar flares. Methods. Using the onset times of 166 BATSE-detected flares with the GOES peak flux (1-8 Å) higher than 1.0 × 10 −5 Wm −2 , we prepared a light curve of the Yangbajing neutron monitor for each flare, spanning ±1.5 h from the BATSE onset time. Based on the light curves, a systematic search for solar neutrons in energies above 100 MeV from the 166 flares was performed. No statistically significant signals due to solar neutrons were found. Therefore, we put upper limits on the ≥100 MeV solar-neutron flux for 18 events consisting of 2 X and 16 M class flares. The calculation assumed a power-law shaped neutron energy spectrum and three types of neutron emission profiles at the Sun. Results. Compared with the other positive neutron detections associated with X-class flares, typical 95% confidence level upper limits for the two X-class flares are found to be comparable to the lowest and second lowest neutron fluxes at the top of the atmosphere. In addition, the upper limits for M-class flares scatter in the range of 10 −2 to 1 neutrons cm −2 s −1 . This provides the first upper limits on the solar-neutron flux from M-class solar flares, using space observatories, as well as ground-based neutron monitors.

show abstract

Section: Nm Light Curvesmentioning

confidence: 99%

Section: Calculation Of An Upper Limit Of the Solar-neutron Fluxmentioning

confidence: 99%

Section: Calculation Of An Upper Limit Of the Solar-neutron Fluxmentioning

confidence: 99%

Section: Calculation Of An Upper Limit Of the Solar-neutron Fluxmentioning

confidence: 99%

See 2 more Smart Citations

Upper limits on the solar-neutron flux at the Yangbajing neutron monitor from BATSE-detected solar flares

Tsuchiya

Miyasaka

Takahashi

et al. 2007

A&A

View full text Add to dashboard Cite

show abstract

“…They can travel to the Earth [18], but it is not easy to observe them. Usually, solar neutrons are observed by neutron monitors and solar neutron telescopes located on the Earth [19,20,21]. However, the neutron detectors have to be located on the sunlit side of the Earth, and they have to be able to penetrate through the attenuation caused by the Earth's atmosphere to be detected.…”

Section: Introductionmentioning

confidence: 99%

Capability of the accelerated protons as the origin of white-light emission of solar flare

Watanabe¹,

Masuda²,

Ohno³

2017

Proceedings of 35th International Cosmic Ray Conference — PoS(ICRC2017)

View full text Add to dashboard Cite

In association with strong solar flares, we sometimes observe enhancements of visible continuum radiation, which is known as a "white-light flare". As most white-light (WL) events show close correlations in time and location with hard X-rays and/or radio emission, there is some consensus that WL emission originates from accelerated particles, especially non-thermal electrons. One model proposes that WL is emitted near the photosphere; however, non-thermal electrons are thermalized in the chromosphere and cannot reach the photosphere. Thus, there is a problem: how can the energy of non-thermal electrons − and/or other accelerated particles such as high-energy protons − propagate to the photosphere and produce WL emission? In the present study, we investigate the possibility that accelerated protons may produce the WL emission of solar flares. We found 51 WL events observed by Hinode/SOT. Among them, gamma-rays with energies greater than 1 MeV were observed only in the X1.8-class flare on October 23, 2012 and in the M7.9-class flare on June 25, 2015. Focusing on these flare events, we compare the energetics of WL emission and of accelerated ion fluxes. We find that it is difficult for accelerated ions to provide sufficient energy to account for WL emission.

show abstract

Properties of Energetic Ions in the Solar Atmosphere from γ-Ray and Neutron Observations

Vilmer¹,

MacKinnon²,

Hurford³

2011

High-Energy Aspects of Solar Flares

View full text Add to dashboard Cite

Gamma-rays and neutrons are the only sources of information on energetic ions present during solar flares and on properties of these ions when they interact in the solar atmosphere. The production of γ-rays and neutrons results from convolution of the nuclear cross-sections with the ion distribution functions in the atmosphere. The observed γ-ray and neutron fluxes thus provide useful diagnostics for the properties of energetic ions, yielding strong constraints on acceleration mechanisms as well as properties of the interaction sites. The problem of ion transport between the accelerating and interaction sites must also be addressed to infer as much information as possible on the properties of the primary ion accelerator. In the last couple of decades, both theoretical and observational developments have led to substantial progress in understanding the origin of solar γ-rays and neutrons. This chapter reviews recent developments in the study of solar γ-rays and of solar neutrons at the time of the RHESSI era. The unprecedented quality of the RHESSI data reveals γray line shapes for the first time and provides γ-ray images. Our previous understanding of the properties of energetic ions based on measurements from the former solar cycles is also summarized. The new results -obtained owing both to the gain in spectral resolution (both with RHESSI and with the non solar-dedicated INTEGRAL/SPI instrument) and to the pioneering imaging technique in the γ-ray domain -are presented in the context of this previous knowledge. Still open questions are emphasized in the last section of the chapter and future perspectives on this field are briefly discussed.

show abstract

Solar Neutron Events of 2003 October–November

Cited by 40 publications

References 21 publications

Upper limits on the solar-neutron flux at the Yangbajing neutron monitor from BATSE-detected solar flares

Upper limits on the solar-neutron flux at the Yangbajing neutron monitor from BATSE-detected solar flares

Capability of the accelerated protons as the origin of white-light emission of solar flare

Properties of Energetic Ions in the Solar Atmosphere from γ-Ray and Neutron Observations

Contact Info

Product

Resources

About