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arXiv 2402.10587astro-ph.HE
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奇特GRB 230307A的前身星与中心引擎

The progenitor and central engine of a peculiar GRB 230307A

ZhaoWei Du, HouJun Lü, Yong Yuan, Xing Yang, EnWei Liang

AI总结:

本文研究了低红移且缺乏超新星关联的GRB 230307A,通过其重元素核合成与软X射线辐射特征推断中心引擎为双致密星并合形成的磁星,并利用磁星中心引擎模型拟合观测数据约束了参数范围,但前身星的具体并合类型仍未知。

摘要:

最近,在如此低的红移 $z=0.065$ 处缺乏超新星关联的长持续时间伽马射线暴(GRB 230307A),但却与可能的千新星辐射相关联,引起了极大关注。其重元素核合成与软X射线辐射特征表明,GRB 230307A的中心引擎是源于双致密星并合的磁星。计算得出的较低值 $\varepsilon \sim 0.05$ 表明,GRB 230307A的前身星似乎不明确。较低的 $f_{\rm eff}=1.23$ 值意味着GRB 230307A不太可能源于“冰山一角”效应。我们采用磁星中心引擎模型,以变化的效率拟合观测到的软X射线辐射,发现磁星的参数约束落入合理范围,即对于 $\Gamma_{\rm sat} = 10^3$,$B<9.4\times10^{15}$ G 且 $P<2.5$ ms;对于 $\Gamma_{\rm sat} = 10^4$,$B<3.6\times10^{15}$ G 且 $P<1.05$ ms。GRB 230307A的前身星是源于中子星-白矮星(NS - WD)还是中子星-中子星(NS - NS)的并合,目前仍未知。

英文摘要:

Recently, a lack of supernova-associated long-duration gamma-ray burst (GRB 230307A) at such a low redshift $z=0.065$, but associated with a possible kilonova emission, has attracted great attention. Its heavy element nucleosynthesis and the characteristic of soft X-ray emission suggests that the central engine of GRB 230307A is magnetar which is originated from a binary compact star merger. The calculated lower value of $\varepsilon \sim 0.05$ suggests that the GRB 230307A seems to be with ambiguous progenitor. The lower value of $f_{\rm eff}=1.23$ implies that the GRB 230307A is not likely to be from the effect of "tip of iceberg". We adopt the magnetar central engine model to fit the observed soft X-ray emission with a varying efficiency and find that the parameters constraints of magnetar fall into a reasonable range, i.e., $B<9.4\times10^{15}$ G and $P<2.5$ ms for $Γ_{\rm sat} = 10^3$, and $B<3.6\times10^{15}$ G and $P<1.05$ ms for $Γ_{\rm sat} = 10^4$. Whether the progenitor of GBR 230307A is from the mergers of neutron star - white dwarf (NS - WD) or neutron star - neutron star (NS - NS) remains unknown.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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