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arXiv 1208.0429astro-ph.HEastro-ph.CO
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短伽马射线暴的Ep-Lp和Ep-Eiso相关性可能比长伽马射线暴的暗5 ~ 100倍

Possible existence of Ep-Lp and Ep-Eiso correlations for Short Gamma-Ray Bursts with a factor 5 to 100 dimmer than those for Long Gamma-Ray Bursts

Ryo Tsutsui, Daisuke Yonetoku Takashi Nakamura, Keitaro Takahashi, Yoshiyuki Morihara

摘要:

我们分析了13个具有实测红移$z$、$T_{\rm 90}^{\rm obs}/(1+z)<2$ sec和确定的光谱参数的短伽玛暴(SGRB)候选者的静止帧光谱峰值能量$E_{\rm p}$、观测帧64 ms峰值各向同性光度$L_{\rm p}$和各向同性能量$E_{\rm iso}$之间的相关性。对于长伽玛暴(LGRB),如果一个候选SGRB位于$E_{\rm p}$- $E_{\rm iso}$关联的最佳拟合函数的3- $σ_{\rm int}$色散区,那么它被认为是一个被误导的SGRB,而其他的SGRB被认为是可能来自致密星合并的安全SGRB。使用13个SGRB候选中的8个安全SGRB,我们测试了对于SGRB是否存在$E_{\rm p}$- $E_{\rm iso}$和$E_{\rm p}$ - $L_{\rm p}$相关性。我们发现SGRB的$E_{\rm p}$相关性($E_{\rm iso} =10^{51.42 \pm 0.15}{\rm erg s^{-1}} ({E_{\rm p}}/{\rm 774.5 keV})^{1.58 \pm 0.28}$)似乎存在,相关系数$r=0.91$和机会概率$p=1.5\times10^{-3}$。我们还发现,由于$r=0.98$和$p=1.5\times10^{-5}$,SGRB($L_{\rm p} = 10^{52.29 \pm 0.066}{\rm erg s^{-1}} ({E_{\rm p}}/{\rm 774.5 keV})^{1.59 \pm 0.11}$)的$E_{\rm p}$-$L_{\rm p}$相关性比$E_{\rm p}$-$E_{\rm iso}$相关性更紧密。对于相同的$E_{\rm p}$,SGRB的两种相关性都比LGRB的相关性要暗,其因子为$\sim$ 100($E_{\rm p}$ -- $E_{\rm iso}$)和$\sim$ 5($E_{\rm p}$ -- $L_{\rm p}$)。应用更紧密的$E_{\rm p}$ - $L_{\rm p}$相关的SGRB到71个明亮的BATSE SGRB,我们发现,伪红移$z$范围从0.097到2.258,平均$<z>$为1.05。SGRB的红移明显地聚集在比LGRB($<z>\sim 2.2 $)低的红移处,这支持SGRB的合并假设.

英文摘要:

We analyzed correlations among the rest frame spectral peak energy $E_{\rm p}$, the observed frame 64ms peak isotropic luminosity $L_{\rm p}$ and the isotropic energy $E_{\rm iso}$ for 13 Short Gamma Ray Burst (SGRB) candidates having the measured redshift $z$, $T_{\rm 90}^{\rm obs}/(1+z)<2$ sec and well determined spectral parameters. A SGRB candidate is regarded as a misguided SGRB if it is located in the 3-$σ_{\rm int}$ dispersion region from the best-fit function of the $E_{\rm p}$--$E_{\rm iso}$ correlation for Long GRBs (LGRBs) while the others are regarded as secure SGRBs possibly from compact star mergers. Using 8 secure SGRBs out of 13 SGRB candidates, we tested whether $E_{\rm p}$--$E_{\rm iso}$ and $E_{\rm p}$--$L_{\rm p}$ correlations exist for SGRBs. We found that $E_{\rm p}$--$E_{\rm iso}$ correlation for SGRBs($E_{\rm iso} =10^{51.42 \pm 0.15}{\rm erg s^{-1}} ({E_{\rm p}}/{\rm 774.5 keV})^{1.58 \pm 0.28}$) seems to exist with the correlation coefficeint $r=0.91$ and chance probability $p=1.5\times10^{-3}$. We found also that the $E_{\rm p}$--$L_{\rm p}$ correlation for SGRBs($L_{\rm p} = 10^{52.29 \pm 0.066}{\rm erg s^{-1}} ({E_{\rm p}}/{\rm 774.5 keV})^{1.59 \pm 0.11}$) is tighter than $E_{\rm p}$--$E_{\rm iso}$ correlation since $r=0.98$ and $p=1.5\times10^{-5}$. Both correlations for SGRBs are dimmer than those of LGRBs for the same $E_{\rm p}$ by factors $\sim$100 ($E_{\rm p}$--$E_{\rm iso}$) and $\sim$ 5($E_{\rm p}$--$L_{\rm p}$). Applying the tighter $E_{\rm p}$--$L_{\rm p}$ correlation for SGRBs to 71 bright BATSE SGRBs, we found that pseudo redshift $z$ ranges from 0.097 to 2.258 with the mean $<z>$ of 1.05. The redshifts of SGRBs apparently cluster at lower redshift than those of LGRBs ($<z>\sim 2.2 $), which supports the merger scenario of SGRBs.

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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