【摘要】：γ射線暴是一種在短時間內(nèi)能量劇烈爆發(fā)的天文學(xué)現(xiàn)象,是人們研究宇宙線起源的重要手段。到2015年12月31日為止,衛(wèi)星實驗在keV～MeV能段已經(jīng)探測到了 5000多個γ射線暴,但對能量大于10 GeV的高能γ射線暴,目前還沒有觀測到確定的結(jié)果。高能γ射線暴不僅能夠提供γ射線暴產(chǎn)生機制的直接證據(jù),而且能檢驗當(dāng)前存在爭議的γ射線暴的模型,因而其研究具有重要意義。為了得到γ射線暴從低能到高能的完整信息,必須聯(lián)合衛(wèi)星實驗和地面實驗。位于羊八井觀測站的ARGO和ASγ實驗憑借其高海拔、寬視場、大面積等特點在探測高能γ射線暴方面占據(jù)著一席之地,值得注意的是,其中ARGO實驗中的"雙前峰面"事例具有降低閾能值、提高靈敏度的獨特優(yōu)勢,為高能γ射線暴的探測提供了一種全新的方式。首先,本文對"雙前峰面"事例探測高能γ射線暴的靈敏度進行模擬。結(jié)果表明:在持續(xù)時間為1s、天頂角為10°且紅移為0時,"雙前峰面"事例探測E10GeV γ射線暴的流強為10-4～10-3erg/cm2。與此同時,"雙前峰面"事例的靈敏度在Emax30GeV時高于"觸發(fā)"事例的,因此利用"雙前峰面"事例尋找高能γ射線暴存在巨大潛能。其次,分析Fermi衛(wèi)星從2008年到2015年期間觀測到的1756個γ射線暴,利用Band模型將這些γ射線暴的能譜延伸到羊八井地面實驗的能區(qū)范圍內(nèi),計算其到達羊八井地面實驗中的流強。結(jié)果表明:對于在羊八井視場范圍內(nèi)且光子能量在GeV能區(qū)的Fermi γ暴,若不考慮河外背景光子的吸收效應(yīng),ARGO實驗運行期間內(nèi),在其靈敏度范圍內(nèi)的有3個;新升級的ASy實驗運行期間內(nèi),在其靈敏度范圍內(nèi)的有4個。這些結(jié)果為羊八井地面實驗(包括"雙前峰面"事例)與衛(wèi)星γ暴的符合尋找提供重要信息。最后,結(jié)合ARGO實驗中GRB100225703的"雙前峰面"事例數(shù)據(jù)與Fermi衛(wèi)星的數(shù)據(jù)來符合尋找高能γ射線暴。結(jié)果表明:顯著性最高的事例團作為本底漲落的概率(Pb)為1.72×10-6,相當(dāng)于高斯分布的4.643σ,但考慮到實驗次數(shù)后,其超出不足以認(rèn)定為γ射線暴。
[Abstract]:緯-ray burst is an astronomical phenomenon which erupts violently in a short period of time and is an important means to study the origin of cosmic rays. Up to December 31, 2015, more than 5000 緯-ray bursts have been detected in the keV~MeV energy range in satellite experiments, but no definite results have been observed for high energy 緯-ray bursts with energy greater than 10 GeV. High energy 緯-ray bursts can not only provide direct evidence of the mechanism of 緯-ray bursts, but also test the models of 緯-ray bursts which are currently controversial, so their research is of great significance. In order to obtain the complete information of 緯-ray bursts from low energy to high energy, it is necessary to combine satellite experiments and ground experiments. The ARGO and AS 緯 experiments at Yangbajing observation Station occupy a place in detecting high energy 緯 -ray bursts due to their characteristics of high altitude, wide field of view and large area. The "double front peak" in ARGO experiment has the unique advantage of reducing threshold energy and improving sensitivity, which provides a new way for detecting high energy 緯 -ray bursts. First, the sensitivity of "double front peak" cases for detecting high energy 緯-ray bursts is simulated. The results show that when the duration is 1 s, the zenith angle is 10 擄and the red shift is 0, the current intensity of the "double front peak" event for detecting E10GeV 緯 -ray bursts is 10 ~ (-4) ~ 10 ~ (-3) erg / cm ~ (2). At the same time, the sensitivity of "double front peak" event is higher than that of "trigger" event at Emax30GeV, so there is great potential to use "double front peak" event to find high energy 緯 -ray burst. Secondly, 1756 緯-ray bursts observed by Fermi satellite from 2008 to 2015 are analyzed. The energy spectrum of these 緯-ray bursts is extended to the energy range of the surface experiment of Yangbajing by using the Band model, and the current intensity in the surface experiment of Yangbajing is calculated. The results show that for the Fermi 緯 bursts in the range of view field of Yangbajing and the photon energy in the GeV region, if the photon absorption effect of the background outside the river is not taken into account, there are three Fermi 緯 bursts in the range of sensitivity during the operation of the ARGO experiment. During the running of the newly upgraded ASy experiment, there are four in the range of sensitivity. These results provide important information for the coincidence search between the surface experiments of Yangbajing (including the case of "double front peak") and satellite 緯-ray bursts. Finally, combining the "double front peak" case data of GRB100225703 in ARGO experiment with the data of Fermi satellite, we can find the high energy 緯 -ray bursts. The results show that the probability of the most significant event cluster as the background fluctuation is 1.72 脳 10 ~ (-6), which is equivalent to 4.643 蟽 of Gao Si's distribution, but considering the number of experiments, its excess is not enough to be considered as 緯 -ray burst.
【學(xué)位授予單位】：西南交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：O571.323

【相似文獻】

相關(guān)期刊論文 前10條

1 Tsvi Piran ,謝懿;為γ射線暴降能[J];世界科學(xué);2002年04期

2 Robert Irion ,謝懿;追蹤γ射線暴[J];世界科學(xué);2003年05期

3 韋光;;γ射線暴的“炮彈模型”[J];科學(xué);2008年05期

4 戴聞;;短γ射線暴[J];物理;2009年11期

5 樹華;;γ射線暴可能會殺死海洋生物[J];物理;2011年11期

6 李惕碚;γ射線暴相關(guān)性質(zhì)的長期變化[J];天體物理學(xué)報;1997年03期

7 廣泉;關(guān)于γ射線暴起源的新解釋[J];科學(xué)中國人;1998年08期

8 黃文耿,楊丕博,陸燁;γ射線暴火球的演化與余輝[J];天文學(xué)報;2001年01期

9 陸W，

本文編號：2405974