Arooj Faryad, Alexander G. M. Pietrow, Meetu Verma, Carsten Denker
{"title":"H \\(\\alpha \\)线中埃勒曼炸弹的自动探测","authors":"Arooj Faryad, Alexander G. M. Pietrow, Meetu Verma, Carsten Denker","doi":"10.1007/s11207-025-02534-9","DOIUrl":null,"url":null,"abstract":"<div><p>Ellerman bombs (EBs) are small and short-lived magnetic reconnection events in the lower solar atmosphere, most commonly reported in the line wings of the H<span>\\(\\alpha \\)</span> line. These events are thought to play a role in heating the solar chromosphere and corona, but their size, short lifetime, and similarity to other brightenings make them difficult to detect. We aim to automatically detect and statistically analyze EBs at different heliocentric angles to find trends in their physical properties. We developed an automated EB detection pipeline based on a star-finding algorithm. This pipeline was used on ten high-resolution H<span>\\(\\alpha \\)</span> datasets from the 1-meter Swedish Solar Telescope (SST). This pipeline identifies and tracks EBs in time, while separating them from visually similar pseudo-EBs. It returns key parameters such as size, contrast, lifetime, and occurrence rates based on a dynamic threshold and the more classical static ‘contrast threshold’ of 1.5 times the mean quiet-Sun (QS) intensity. For our dynamic threshold we found a total of 2257 EBs from 28,772 individual detections across our datasets. On average, the full detection set exhibits an area of 0.44 arcsec<sup>2</sup> (0.37 Mm<sup>2</sup>), a peak intensity contrast of 1.4 relative to the QS, and a median lifetime of 2.3 min. The stricter threshold yielded 549 EBs from 15,997 detections, with a higher median area of 0.66 arcsec<sup>2</sup> (0.57 Mm<sup>2</sup>), an intensity contrast of 1.7, and a median lifetime of 3 min. These comparisons highlight the sensitivity of EB statistics to selection thresholds and motivate further work towards consistent EB definitions. Several long-lived EBs were observed with lifetimes exceeding one hour. While the EB intensity contrast increases towards the limb, no clear trends were found between the other EB parameters and the heliocentric angle, suggesting that the local magnetic complexity and evolutionary stage dominate EB properties.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 9","pages":""},"PeriodicalIF":2.4000,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Automatic Detection of Ellerman Bombs in the H\\\\(\\\\alpha \\\\) Line\",\"authors\":\"Arooj Faryad, Alexander G. M. Pietrow, Meetu Verma, Carsten Denker\",\"doi\":\"10.1007/s11207-025-02534-9\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Ellerman bombs (EBs) are small and short-lived magnetic reconnection events in the lower solar atmosphere, most commonly reported in the line wings of the H<span>\\\\(\\\\alpha \\\\)</span> line. These events are thought to play a role in heating the solar chromosphere and corona, but their size, short lifetime, and similarity to other brightenings make them difficult to detect. We aim to automatically detect and statistically analyze EBs at different heliocentric angles to find trends in their physical properties. We developed an automated EB detection pipeline based on a star-finding algorithm. This pipeline was used on ten high-resolution H<span>\\\\(\\\\alpha \\\\)</span> datasets from the 1-meter Swedish Solar Telescope (SST). This pipeline identifies and tracks EBs in time, while separating them from visually similar pseudo-EBs. It returns key parameters such as size, contrast, lifetime, and occurrence rates based on a dynamic threshold and the more classical static ‘contrast threshold’ of 1.5 times the mean quiet-Sun (QS) intensity. For our dynamic threshold we found a total of 2257 EBs from 28,772 individual detections across our datasets. On average, the full detection set exhibits an area of 0.44 arcsec<sup>2</sup> (0.37 Mm<sup>2</sup>), a peak intensity contrast of 1.4 relative to the QS, and a median lifetime of 2.3 min. The stricter threshold yielded 549 EBs from 15,997 detections, with a higher median area of 0.66 arcsec<sup>2</sup> (0.57 Mm<sup>2</sup>), an intensity contrast of 1.7, and a median lifetime of 3 min. These comparisons highlight the sensitivity of EB statistics to selection thresholds and motivate further work towards consistent EB definitions. Several long-lived EBs were observed with lifetimes exceeding one hour. While the EB intensity contrast increases towards the limb, no clear trends were found between the other EB parameters and the heliocentric angle, suggesting that the local magnetic complexity and evolutionary stage dominate EB properties.</p></div>\",\"PeriodicalId\":777,\"journal\":{\"name\":\"Solar Physics\",\"volume\":\"300 9\",\"pages\":\"\"},\"PeriodicalIF\":2.4000,\"publicationDate\":\"2025-09-10\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Solar Physics\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s11207-025-02534-9\",\"RegionNum\":3,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ASTRONOMY & ASTROPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Solar Physics","FirstCategoryId":"101","ListUrlMain":"https://link.springer.com/article/10.1007/s11207-025-02534-9","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
Automatic Detection of Ellerman Bombs in the H\(\alpha \) Line
Ellerman bombs (EBs) are small and short-lived magnetic reconnection events in the lower solar atmosphere, most commonly reported in the line wings of the H\(\alpha \) line. These events are thought to play a role in heating the solar chromosphere and corona, but their size, short lifetime, and similarity to other brightenings make them difficult to detect. We aim to automatically detect and statistically analyze EBs at different heliocentric angles to find trends in their physical properties. We developed an automated EB detection pipeline based on a star-finding algorithm. This pipeline was used on ten high-resolution H\(\alpha \) datasets from the 1-meter Swedish Solar Telescope (SST). This pipeline identifies and tracks EBs in time, while separating them from visually similar pseudo-EBs. It returns key parameters such as size, contrast, lifetime, and occurrence rates based on a dynamic threshold and the more classical static ‘contrast threshold’ of 1.5 times the mean quiet-Sun (QS) intensity. For our dynamic threshold we found a total of 2257 EBs from 28,772 individual detections across our datasets. On average, the full detection set exhibits an area of 0.44 arcsec2 (0.37 Mm2), a peak intensity contrast of 1.4 relative to the QS, and a median lifetime of 2.3 min. The stricter threshold yielded 549 EBs from 15,997 detections, with a higher median area of 0.66 arcsec2 (0.57 Mm2), an intensity contrast of 1.7, and a median lifetime of 3 min. These comparisons highlight the sensitivity of EB statistics to selection thresholds and motivate further work towards consistent EB definitions. Several long-lived EBs were observed with lifetimes exceeding one hour. While the EB intensity contrast increases towards the limb, no clear trends were found between the other EB parameters and the heliocentric angle, suggesting that the local magnetic complexity and evolutionary stage dominate EB properties.
期刊介绍:
Solar Physics was founded in 1967 and is the principal journal for the publication of the results of fundamental research on the Sun. The journal treats all aspects of solar physics, ranging from the internal structure of the Sun and its evolution to the outer corona and solar wind in interplanetary space. Papers on solar-terrestrial physics and on stellar research are also published when their results have a direct bearing on our understanding of the Sun.