本文選題：BL + Lac天體��； 參考：《中國科學(xué)院研究生院（云南天文臺(tái)）》2014年碩士論文

【摘要】：blazars是一類特殊的活動(dòng)星系核（AGNs），它們的輻射被認(rèn)為起源于與我們視線方向夾角很小的相對(duì)論性噴流。它們通常表現(xiàn)出快速的光變、高的偏振以及強(qiáng)的非熱輻射。blazars的光譜能量分布（SEDs）通常由兩個(gè)比較寬的成分組成：一個(gè)是低能成分，從射電到X射線波段，另一個(gè)是高能成分，從X射線到伽馬射線波段。普遍認(rèn)為它們SEDs的低能成分由相對(duì)論電子的同步輻射產(chǎn)生。然而高能成分的起源目前仍然存在爭(zhēng)議。兩類模型被用于解釋blazarsSEDs的高能成分：輕子模型和強(qiáng)子模型。輕子模型認(rèn)為blazars的高能輻射由電子與背景光子的逆康普頓散射過程產(chǎn)生。強(qiáng)子模型則認(rèn)為blazars的高能輻射起源于質(zhì)子的同步輻射或者光子強(qiáng)子相互作用。我們從輕子模型和強(qiáng)子模型兩個(gè)方面研究了blazars高能伽馬輻射的起源，主要的結(jié)果是： 1.我們研究了21個(gè)具有準(zhǔn)同步SEDs的平譜射電類星體（FSRQs）伽馬射線輻射區(qū)的位置。我們提出了一種限定伽馬射線輻射區(qū)的方法。如果伽馬射線輻射區(qū)在寬線區(qū)之內(nèi)，逆康普頓（IC）散射發(fā)生在KN區(qū)域，伽馬射線譜應(yīng)該比光學(xué)近紅外譜更陡。如果伽馬射線輻射區(qū)在寬線區(qū)之外，IC散射發(fā)生在Thomson區(qū)域，伽馬射線譜的譜指數(shù)應(yīng)該與光學(xué)近紅外譜的譜指數(shù)相同。為了測(cè)試我們的理論，我們用一區(qū)的輕子模型包括同步自康普頓（SSC model）和外康普頓模型（EC model）擬合了21個(gè)FSRQs準(zhǔn)同步的SEDs，我們認(rèn)為X射線輻射由SSC過程，GeV輻射來自于EC過程，其中EC輻射可能起源于相對(duì)論電子IC散射吸積盤和BLR的輻射或者是塵埃環(huán)的輻射。我們根據(jù)譜型和SEDs的擬合結(jié)果猜測(cè)5個(gè)FSRQs的GeV輻射區(qū)在寬線區(qū)之內(nèi)，其它16個(gè)在寬線區(qū)之外。我們的SEDs擬合表明在21個(gè)FSRQs噴流中磁場(chǎng)和電場(chǎng)的能量密度接近均分。 2.我們用具有電子加速的SSC模型研究了Mrk421在2008年6月68日期間X射線和伽馬射線的爆發(fā)活動(dòng)。觀測(cè)發(fā)現(xiàn)X射線和伽馬射線明顯相關(guān)，然而光學(xué)和X射線波段并不明顯相關(guān)。我們認(rèn)為Mrk421的輻射可能起源于兩個(gè)不同的成分。一個(gè)是在外部區(qū)域的穩(wěn)定成分，它主要產(chǎn)生光學(xué)輻射，在這個(gè)區(qū)域電子被一階Fermi加速過程加速，我們用穩(wěn)態(tài)的電子譜來產(chǎn)生這一區(qū)域的SSC輻射。另一個(gè)是在內(nèi)部區(qū)域的變化成分，在這個(gè)區(qū)域電子被隨機(jī)加速過程加速，我們用一個(gè)含時(shí)的SSC模型來產(chǎn)生這一區(qū)域的輻射。我們認(rèn)為爆發(fā)是由隨機(jī)加速過程導(dǎo)致電子譜變硬引起的，電子譜的變硬將會(huì)引起X射線和伽馬射線譜的變硬。此外我們發(fā)現(xiàn)在兩個(gè)區(qū)域中磁場(chǎng)和電子的能量密度都接近均分。 3.來自于遙遠(yuǎn)blazars非常硬的伽馬射線譜挑戰(zhàn)了標(biāo)準(zhǔn)的SSC模型。硬的伽馬射線譜可能表明了存在一個(gè)高于SSC輻射的譜成分。我們研究了1ES1101232非常硬的伽馬射線譜的可能起源。H.E.S.S.的觀測(cè)表明VHE流量在任一時(shí)標(biāo)內(nèi)都不存在明顯的光變。因此我們認(rèn)為blazar1ES1101232硬的伽馬射線譜可能起源于高能質(zhì)子的輻射。我們提出了一個(gè)解釋blazar1ES1101232硬的伽馬射線譜的模型。在這個(gè)模型中，光學(xué)和X射線的輻射來自于原初電子和次級(jí)電子的同步輻射，GeV輻射由SSC過程產(chǎn)生，然而非常硬的伽馬射線起源于中性π0的衰變，其中中性π0由高能質(zhì)子與噴流內(nèi)同步輻射光子發(fā)生pγ相互作用產(chǎn)生。我們的模型能夠很好地解釋1ES1101232的多波段能譜，，尤其是1ES1101232非常硬的伽馬射線譜。為了通過pγ相互作用有效地產(chǎn)生伽馬射線，我們的模型要求相當(dāng)極端的噴流功率。
[Abstract]:Blazars is a special class of active galactic nuclei (AGNs), whose radiation is believed to originate in relativistic jets with small angles to our line of sight. They usually show fast light, high polarization, and strong non thermal radiation.Blazars spectral energy distribution (SEDs) usually composed of two wider components: one is low The energy component, from radio to X ray, is the high energy component from X to gamma ray. It is generally believed that the low energy components of their SEDs are produced by the synchrotron radiation of relativistic electrons. However, the origin of the high-energy components is still controversial. The two model is used to explain the high energy components of blazarsSEDs: lepton model and hadron. The lepton model considers that the high energy radiation of blazars is produced by the inverse Compton scattering process of the electron and background photons. The hadron model considers that the high energy radiation of blazars originates from the proton synchrotron radiation or the photon hadron interaction. We studied the blazars high-energy gamma radiation from two sides of the lepton model and the hadron model. The source, the main result is:
1. we studied the location of 21 gamma ray radiant regions with quasi synchronous SEDs. We proposed a method to limit gamma ray radiation. If the gamma ray radiation area is within the wide line area, the inverse Compton (IC) scattering occurs in the KN region, and the gamma ray spectrum should be steeper than the optical near infrared spectrum. The Kogama ray radiation area is outside the wide line area, IC scattering occurs in the Thomson region, the spectral exponent of the gamma ray spectrum should be the same as the spectral exponent of the optical near infrared spectrum. In order to test our theory, we use a region of lepton model including synchronous self Compton (SSC model) and the outer Compton model (EC model) to fit 21 FSRQs quasi synchronization. SEDs, we think that the X ray radiation is from the SSC process, the GeV radiation comes from the EC process, in which the EC radiation may originate from the radiation of the relativistic electronic IC scattering accretion disk and BLR or the radiation of the dust ring. We conjecture that the GeV radiation area of the 5 FSRQs is within the wide line area according to the fitting results of spectral and SEDs, and the other 16 are outside the wide line area. The SEDs fit shows that the energy density of magnetic field and electric field is nearly equal in 21 FSRQs jets.
2. we studied the X ray and gamma ray eruptions of Mrk421 during the June 68, 2008 with an electron accelerated SSC model. The observation found that X rays were obviously related to gamma rays, but the optical and X ray bands were not obviously related. We think that the radiation of Mrk421 may originate from two different components. One is in the external region. The stable component of the domain, which mainly produces optical radiation, is accelerated by the first order Fermi acceleration process in this region. We use the steady-state electron spectrum to produce the SSC radiation in this region. The other is the variation in the internal region, in which the electrons are accelerated by the random acceleration process, and we use a time-dependent SSC model to produce this Radiation in a region. We think that the eruption is caused by the hardening of the electron spectrum by the random acceleration process. The hardening of the electron spectrum will cause the hardening of the X ray and the gamma ray spectrum. In addition, we find that the energy density of the magnetic field and the electron in the two regions are nearly equal.
3. a very hard gamma ray spectrum from remote blazars challenges the standard SSC model. The hard gamma ray spectrum may indicate a spectral composition higher than SSC radiation. We studied the possible origin of the very hard gamma ray spectrum of 1ES1101232. The observation of the possible origin of the.H.E.S.S. showed that there was no obvious light in VHE flow at any time. So we think that the blazar1ES1101232 hard gamma ray spectrum may originate from the radiation of high energy protons. We have proposed a model to explain the blazar1ES1101232 hard gamma ray spectrum. In this model, the radiation of optical and X rays comes from the synchrotron radiation of the original and secondary electrons, and the GeV radiation is produced by the SSC process. The very hard gamma ray originates from the decay of neutral PI 0, in which the neutral PI 0 is produced by the interaction of high energy protons and synchrotron photon P gamma interaction in the jet. Our model can well explain the multiband energy spectrum of 1ES1101232, especially the very hard gamma ray spectrum of 1ES1101232. In order to produce the P gamma interaction effectively Gamma ray, our model requires quite extreme jet power.

【學(xué)位授予單位】：中國科學(xué)院研究生院（云南天文臺(tái)）
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：P157.6;P172.3

【參考文獻(xiàn)】

相關(guān)期刊論文 前2條

1 童曉鳴;;低壓電動(dòng)機(jī)的容量、保護(hù)及保護(hù)配置的選擇[J];安徽建筑;2011年01期

2 ;The estimations of four basic parameters for gamma-ray loud blazars[J];Research in Astronomy and Astrophysics;2009年05期

本文編號(hào)：1846921