Discovery of the Fastest Early Optical Emission from Overluminous SN Ia 2020hvf: A Thermonuclear Explosion within a Dense Circumstellar Environment
Discovery of the Fastest Early Optical Emission from Overluminous SN Ia 2020hvf: A Thermonuclear Explosion within a Dense Circumstellar Environment
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DOI：
10.3847/2041-8213/ac375f
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发表时间：
2021-11
期刊：
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通讯作者：
Jiachen Jiang;K. Maeda;M. Kawabata;M. Doi;T. Shigeyama;Masaomi Tanaka;N. Tominaga;K. Nomoto;Y. Niino;S. Sako;R. Ohsawa;M. Schramm;M. Yamanaka;N. Kobayashi;H. Takahashi;T. Nakaoka;K. Kawabata;K. Isogai;T. Aoki;S. Kondo;Y. Mori;K. Arimatsu;T. Kasuga;S. Okumura;S. Urakawa;D. Reichart;K. Taguchi;Noriaki Arima;J. Beniyama;K. Uno;Taisei Hamada
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作者：
Jiachen Jiang;K. Maeda;M. Kawabata;M. Doi;T. Shigeyama;Masaomi Tanaka;N. Tominaga;K. Nomoto;Y. Niino;S. Sako;R. Ohsawa;M. Schramm;M. Yamanaka;N. Kobayashi;H. Takahashi;T. Nakaoka;K. Kawabata;K. Isogai;T. Aoki;S. Kondo;Y. Mori;K. Arimatsu;T. Kasuga;S. Okumura;S. Urakawa;D. Reichart;K. Taguchi;Noriaki Arima;J. Beniyama;K. Uno;Taisei Hamada
在这封信中，我们报告了第一个宽视场镶嵌CMOS传感器成像仪Tomo-e Gozen相机在超新星爆炸约5小时内发现了一颗特殊的过亮Ia型超新星SN 2020 hvf的突出闪光。早期闪光的快速演变是通过Tomo-e Gozen高节奏巡天的密集夜间观测捕获的。数值模拟结果表明，这种显著而快速的早期辐射很可能是由0.01 M ~ 1013 cm距离处的星周物质（CSM）与超新星爆发后不久的喷出物相互作用产生的，表明SN 2020 hvf的前身在演化的最后阶段形成了一个封闭的致密CSM。基于CSM-喷出物相互作用引起的早期闪光，过亮的光变曲线，以及SN 2020 hvf的高喷出物速度，我们认为SN 2020 hvf可能起源于一个超M Ch WD的热核爆炸。为了进一步验证所提出的假设并了解这颗奇特超新星的起源，需要对超新星M Ch WD爆炸的机制和流体动力学模拟进行系统的研究。
In this Letter we report a discovery of a prominent flash of a peculiar overluminous Type Ia supernova, SN 2020hvf, in about 5 hr of the supernova explosion by the first wide-field mosaic CMOS sensor imager, the Tomo-e Gozen Camera. The fast evolution of the early flash was captured by intensive intranight observations via the Tomo-e Gozen high-cadence survey. Numerical simulations show that such a prominent and fast early emission is most likely generated from an interaction between 0.01 M ⊙ circumstellar material (CSM) extending to a distance of ∼1013 cm and supernova ejecta soon after the explosion, indicating a confined dense CSM formation at the final evolution stage of the progenitor of SN 2020hvf. Based on the CSM–ejecta interaction-induced early flash, the overluminous light curve, and the high ejecta velocity of SN 2020hvf, we suggest that the SN 2020hvf may originate from a thermonuclear explosion of a super-Chandrasekhar-mass white dwarf (“super-M Ch WD”). Systematical investigations on explosion mechanisms and hydrodynamic simulations of the super-M Ch WD explosion are required to further test the suggested scenario and understand the progenitor of this peculiar supernova.