{"title":"重温短高原SN 2018gj","authors":"V. P. Utrobin, N. N. Chugai","doi":"10.1007/s10509-024-04311-9","DOIUrl":null,"url":null,"abstract":"<div><p>We present an alternative model of unusual type-IIP SN 2018gj. Despite the short plateau and early gamma-ray escape seeming to favor low-mass ejecta, our hydrodynamic model requires a large ejected mass (≈23 <span>\\(M_{\\odot }\\)</span>). The high ejecta velocity, we find from hydrogen lines in early spectra, is among the crucial constraints on the hydrodynamic model. We recover the wind density that rules out a notable contribution of the circumstellar interaction to the bolometric luminosity. The early radioactive gamma-ray escape is found to be due to the high velocity of <sup>56</sup>Ni, whereas the asymmetry of the H<span>\\(\\alpha \\)</span> emission is attributed to the asymmetry of the <sup>56</sup>Ni ejecta. The available sample of type-IIP supernovae studied hydrodynamically in a uniform way indicates that the asymmetry of the <sup>56</sup>Ni ejecta is probably their intrinsic property. Hydrogen lines in the early spectra of SN 2018gi and SN 2020jfo are found to imply a clumpy structure of the outer ejecta. With two already known similar cases of SN 2008in and SN 2012A we speculate that the clumpiness of the outer ejecta is inherent to type-IIP supernovae related to the red supergiant explosion.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":null,"pages":null},"PeriodicalIF":1.8000,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Revisiting short-plateau SN 2018gj\",\"authors\":\"V. P. Utrobin, N. N. Chugai\",\"doi\":\"10.1007/s10509-024-04311-9\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>We present an alternative model of unusual type-IIP SN 2018gj. Despite the short plateau and early gamma-ray escape seeming to favor low-mass ejecta, our hydrodynamic model requires a large ejected mass (≈23 <span>\\\\(M_{\\\\odot }\\\\)</span>). The high ejecta velocity, we find from hydrogen lines in early spectra, is among the crucial constraints on the hydrodynamic model. We recover the wind density that rules out a notable contribution of the circumstellar interaction to the bolometric luminosity. The early radioactive gamma-ray escape is found to be due to the high velocity of <sup>56</sup>Ni, whereas the asymmetry of the H<span>\\\\(\\\\alpha \\\\)</span> emission is attributed to the asymmetry of the <sup>56</sup>Ni ejecta. The available sample of type-IIP supernovae studied hydrodynamically in a uniform way indicates that the asymmetry of the <sup>56</sup>Ni ejecta is probably their intrinsic property. Hydrogen lines in the early spectra of SN 2018gi and SN 2020jfo are found to imply a clumpy structure of the outer ejecta. With two already known similar cases of SN 2008in and SN 2012A we speculate that the clumpiness of the outer ejecta is inherent to type-IIP supernovae related to the red supergiant explosion.</p></div>\",\"PeriodicalId\":8644,\"journal\":{\"name\":\"Astrophysics and Space Science\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.8000,\"publicationDate\":\"2024-05-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Astrophysics and Space Science\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s10509-024-04311-9\",\"RegionNum\":4,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"ASTRONOMY & ASTROPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Astrophysics and Space Science","FirstCategoryId":"101","ListUrlMain":"https://link.springer.com/article/10.1007/s10509-024-04311-9","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
We present an alternative model of unusual type-IIP SN 2018gj. Despite the short plateau and early gamma-ray escape seeming to favor low-mass ejecta, our hydrodynamic model requires a large ejected mass (≈23 \(M_{\odot }\)). The high ejecta velocity, we find from hydrogen lines in early spectra, is among the crucial constraints on the hydrodynamic model. We recover the wind density that rules out a notable contribution of the circumstellar interaction to the bolometric luminosity. The early radioactive gamma-ray escape is found to be due to the high velocity of 56Ni, whereas the asymmetry of the H\(\alpha \) emission is attributed to the asymmetry of the 56Ni ejecta. The available sample of type-IIP supernovae studied hydrodynamically in a uniform way indicates that the asymmetry of the 56Ni ejecta is probably their intrinsic property. Hydrogen lines in the early spectra of SN 2018gi and SN 2020jfo are found to imply a clumpy structure of the outer ejecta. With two already known similar cases of SN 2008in and SN 2012A we speculate that the clumpiness of the outer ejecta is inherent to type-IIP supernovae related to the red supergiant explosion.
期刊介绍:
Astrophysics and Space Science publishes original contributions and invited reviews covering the entire range of astronomy, astrophysics, astrophysical cosmology, planetary and space science and the astrophysical aspects of astrobiology. This includes both observational and theoretical research, the techniques of astronomical instrumentation and data analysis and astronomical space instrumentation. We particularly welcome papers in the general fields of high-energy astrophysics, astrophysical and astrochemical studies of the interstellar medium including star formation, planetary astrophysics, the formation and evolution of galaxies and the evolution of large scale structure in the Universe. Papers in mathematical physics or in general relativity which do not establish clear astrophysical applications will no longer be considered.
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