What Powered the Kilonova-like Emission after GRB 230307A in the Framework of a Neutron Star–White Dwarf Merger?
The second brightest gamma-ray burst, GRB 230307A (with a duration T _90 ∼ 40 s), exhibited characteristics indicative of a magnetar engine during the prompt emission phase. Notably, a suspected kilonova was identified in its follow-up optical and infrared observations. Here we propose that the orig...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astrophysical Journal Letters |
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| Online Access: | https://doi.org/10.3847/2041-8213/ad2df6 |
| _version_ | 1797262535351599104 |
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| author | Xiangyu Ivy Wang Yun-Wei Yu Jia Ren Jun Yang Ze-Cheng Zou Jin-Ping Zhu |
| author_facet | Xiangyu Ivy Wang Yun-Wei Yu Jia Ren Jun Yang Ze-Cheng Zou Jin-Ping Zhu |
| author_sort | Xiangyu Ivy Wang |
| collection | DOAJ |
| description | The second brightest gamma-ray burst, GRB 230307A (with a duration T _90 ∼ 40 s), exhibited characteristics indicative of a magnetar engine during the prompt emission phase. Notably, a suspected kilonova was identified in its follow-up optical and infrared observations. Here we propose that the origin of GRB 230307A is a neutron star–white dwarf (NS–WD) merger as this could naturally explain the long duration and the large physical offset from the center of its host galaxy. In the framework of such an NS–WD merger event, the late-time kilonova-like emission is very likely to be powered by the spin-down of the magnetar and the radioactive decay of ^56 Ni, rather than by the decay of r -process elements as these heavy elements may not easily be synthesized in an NS-WD merger. It is demonstrated that the above scenario can be supported by our fit to the late-time observational data, where a mass of ∼10 ^−3 M _⊙ ^56 Ni is involved in the ejecta of a mass of ∼0.1 M _⊙ . Particularly, the magnetar parameters required by the fit are consistent with those derived from the early X-ray observation. |
| first_indexed | 2024-04-24T23:58:39Z |
| format | Article |
| id | doaj.art-bf1f5e31a40b435f8c7a2711c8f57245 |
| institution | Directory Open Access Journal |
| issn | 2041-8205 |
| language | English |
| last_indexed | 2024-04-24T23:58:39Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal Letters |
| spelling | doaj.art-bf1f5e31a40b435f8c7a2711c8f572452024-03-14T10:16:45ZengIOP PublishingThe Astrophysical Journal Letters2041-82052024-01-019641L910.3847/2041-8213/ad2df6What Powered the Kilonova-like Emission after GRB 230307A in the Framework of a Neutron Star–White Dwarf Merger?Xiangyu Ivy Wang0https://orcid.org/0000-0002-9738-1238Yun-Wei Yu1https://orcid.org/0000-0002-1067-1911Jia Ren2https://orcid.org/0000-0002-9037-8642Jun Yang3https://orcid.org/0000-0002-5485-5042Ze-Cheng Zou4https://orcid.org/0000-0002-6189-8307Jin-Ping Zhu5https://orcid.org/0000-0002-9195-4904School of Astronomy and Space Science, Nanjing University , Nanjing 210093, People's Republic of ChinaInstitute of Astrophysics, Central China Normal University , Wuhan 430079, People's Republic of China ; yuyw@ccnu.edu.cn; Key Laboratory of Quark and Lepton Physics (Central China Normal University) , Ministry of Education, Wuhan 430079, People's Republic of ChinaSchool of Astronomy and Space Science, Nanjing University , Nanjing 210093, People's Republic of ChinaSchool of Astronomy and Space Science, Nanjing University , Nanjing 210093, People's Republic of ChinaSchool of Astronomy and Space Science, Nanjing University , Nanjing 210093, People's Republic of ChinaSchool of Physics and Astronomy, Monash University , Clayton Victoria 3800, Australia; OzGrav: The ARC Centre of Excellence for Gravitational Wave Discovery , Clayton Victoria 3800, AustraliaThe second brightest gamma-ray burst, GRB 230307A (with a duration T _90 ∼ 40 s), exhibited characteristics indicative of a magnetar engine during the prompt emission phase. Notably, a suspected kilonova was identified in its follow-up optical and infrared observations. Here we propose that the origin of GRB 230307A is a neutron star–white dwarf (NS–WD) merger as this could naturally explain the long duration and the large physical offset from the center of its host galaxy. In the framework of such an NS–WD merger event, the late-time kilonova-like emission is very likely to be powered by the spin-down of the magnetar and the radioactive decay of ^56 Ni, rather than by the decay of r -process elements as these heavy elements may not easily be synthesized in an NS-WD merger. It is demonstrated that the above scenario can be supported by our fit to the late-time observational data, where a mass of ∼10 ^−3 M _⊙ ^56 Ni is involved in the ejecta of a mass of ∼0.1 M _⊙ . Particularly, the magnetar parameters required by the fit are consistent with those derived from the early X-ray observation.https://doi.org/10.3847/2041-8213/ad2df6Gamma-ray bursts |
| spellingShingle | Xiangyu Ivy Wang Yun-Wei Yu Jia Ren Jun Yang Ze-Cheng Zou Jin-Ping Zhu What Powered the Kilonova-like Emission after GRB 230307A in the Framework of a Neutron Star–White Dwarf Merger? The Astrophysical Journal Letters Gamma-ray bursts |
| title | What Powered the Kilonova-like Emission after GRB 230307A in the Framework of a Neutron Star–White Dwarf Merger? |
| title_full | What Powered the Kilonova-like Emission after GRB 230307A in the Framework of a Neutron Star–White Dwarf Merger? |
| title_fullStr | What Powered the Kilonova-like Emission after GRB 230307A in the Framework of a Neutron Star–White Dwarf Merger? |
| title_full_unstemmed | What Powered the Kilonova-like Emission after GRB 230307A in the Framework of a Neutron Star–White Dwarf Merger? |
| title_short | What Powered the Kilonova-like Emission after GRB 230307A in the Framework of a Neutron Star–White Dwarf Merger? |
| title_sort | what powered the kilonova like emission after grb 230307a in the framework of a neutron star white dwarf merger |
| topic | Gamma-ray bursts |
| url | https://doi.org/10.3847/2041-8213/ad2df6 |
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