Modeling Hadronic Gamma-Ray Emissions from Solar Flares and Prospects for Detecting Nonthermal Signatures from Protostars
We investigate gamma-ray emission in the impulsive phase of solar flares and the detectability of nonthermal signatures from protostellar flares. Energetic solar flares emit high-energy gamma rays of GeV energies, but their production mechanism and emission site are still unknown. Young stellar obje...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/acb649 |
| _version_ | 1797702003950878720 |
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| author | Shigeo S. Kimura Shinsuke Takasao Kengo Tomida |
| author_facet | Shigeo S. Kimura Shinsuke Takasao Kengo Tomida |
| author_sort | Shigeo S. Kimura |
| collection | DOAJ |
| description | We investigate gamma-ray emission in the impulsive phase of solar flares and the detectability of nonthermal signatures from protostellar flares. Energetic solar flares emit high-energy gamma rays of GeV energies, but their production mechanism and emission site are still unknown. Young stellar objects, including protostars, also exhibit luminous X-ray flares, but the triggering mechanism of the flaring activity is still unclear owing to the strong obscuration. Nonthermal signatures in millimeter/submillimeter and gamma-ray bands are useful to probe protostellar flares owing to their strong penetration power. We develop a nonthermal emission model of the impulsive phase of solar flares, where cosmic-ray protons accelerated at the termination shock produce high-energy gamma rays via hadronuclear interaction with the evaporation plasma. This model can reproduce gamma-ray data in the impulsive phase of a solar flare. We apply our model to protostellar flares and show that the Cherenkov Telescope Array will be able to detect gamma rays of TeV energies if particle acceleration in protostellar flares is efficient. Nonthermal electrons accelerated together with protons can emit strong millimeter and submillimeter signals via synchrotron radiation, whose power is consistent with the energetic millimeter/submillimeter transients observed from young stars. Future gamma-ray and millimeter/submillimeter observations from protostars, coordinated with a hard X-ray observation, will unravel the nonthermal particle production and triggering mechanism of protostellar flares. |
| first_indexed | 2024-03-12T04:44:54Z |
| format | Article |
| id | doaj.art-54c412a4b0184c8d977cba84318ecfc5 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T04:44:54Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-54c412a4b0184c8d977cba84318ecfc52023-09-03T09:29:45ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-01944219210.3847/1538-4357/acb649Modeling Hadronic Gamma-Ray Emissions from Solar Flares and Prospects for Detecting Nonthermal Signatures from ProtostarsShigeo S. Kimura0https://orcid.org/0000-0003-2579-7266Shinsuke Takasao1https://orcid.org/0000-0003-3882-3945Kengo Tomida2https://orcid.org/0000-0001-8105-8113Frontier Research Institute for Interdisciplinary Sciences, Tohoku University , Sendai 980-8578, Japan ; shigeo@astr.tohoku.ac.jp; Astronomical Institute, Graduate School of Science, Tohoku University , Sendai 980-8578, JapanDepartment of Earth and Space Science, Osaka University , Toyonaka, Osaka, 560-0043, JapanAstronomical Institute, Graduate School of Science, Tohoku University , Sendai 980-8578, JapanWe investigate gamma-ray emission in the impulsive phase of solar flares and the detectability of nonthermal signatures from protostellar flares. Energetic solar flares emit high-energy gamma rays of GeV energies, but their production mechanism and emission site are still unknown. Young stellar objects, including protostars, also exhibit luminous X-ray flares, but the triggering mechanism of the flaring activity is still unclear owing to the strong obscuration. Nonthermal signatures in millimeter/submillimeter and gamma-ray bands are useful to probe protostellar flares owing to their strong penetration power. We develop a nonthermal emission model of the impulsive phase of solar flares, where cosmic-ray protons accelerated at the termination shock produce high-energy gamma rays via hadronuclear interaction with the evaporation plasma. This model can reproduce gamma-ray data in the impulsive phase of a solar flare. We apply our model to protostellar flares and show that the Cherenkov Telescope Array will be able to detect gamma rays of TeV energies if particle acceleration in protostellar flares is efficient. Nonthermal electrons accelerated together with protons can emit strong millimeter and submillimeter signals via synchrotron radiation, whose power is consistent with the energetic millimeter/submillimeter transients observed from young stars. Future gamma-ray and millimeter/submillimeter observations from protostars, coordinated with a hard X-ray observation, will unravel the nonthermal particle production and triggering mechanism of protostellar flares.https://doi.org/10.3847/1538-4357/acb649Solar flaresStellar flaresProtostarsGamma-ray transient sourcesNon-thermal radiation sourcesRadio transient sources |
| spellingShingle | Shigeo S. Kimura Shinsuke Takasao Kengo Tomida Modeling Hadronic Gamma-Ray Emissions from Solar Flares and Prospects for Detecting Nonthermal Signatures from Protostars The Astrophysical Journal Solar flares Stellar flares Protostars Gamma-ray transient sources Non-thermal radiation sources Radio transient sources |
| title | Modeling Hadronic Gamma-Ray Emissions from Solar Flares and Prospects for Detecting Nonthermal Signatures from Protostars |
| title_full | Modeling Hadronic Gamma-Ray Emissions from Solar Flares and Prospects for Detecting Nonthermal Signatures from Protostars |
| title_fullStr | Modeling Hadronic Gamma-Ray Emissions from Solar Flares and Prospects for Detecting Nonthermal Signatures from Protostars |
| title_full_unstemmed | Modeling Hadronic Gamma-Ray Emissions from Solar Flares and Prospects for Detecting Nonthermal Signatures from Protostars |
| title_short | Modeling Hadronic Gamma-Ray Emissions from Solar Flares and Prospects for Detecting Nonthermal Signatures from Protostars |
| title_sort | modeling hadronic gamma ray emissions from solar flares and prospects for detecting nonthermal signatures from protostars |
| topic | Solar flares Stellar flares Protostars Gamma-ray transient sources Non-thermal radiation sources Radio transient sources |
| url | https://doi.org/10.3847/1538-4357/acb649 |
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