星系團中央?yún)^(qū)域熱氣體二維溫度結(jié)構(gòu)探測和熱力學成分研究
發(fā)布時間：2018-08-18 12:34
【摘要】： 在本論文中,利用新一代X射線天文衛(wèi)星的高空間和高能量分辨能力,我們分析了星系團中央?yún)^(qū)域氣體的二維溫度結(jié)構(gòu)特征和熱力學成分,從而為解決星系團氣體加熱機制等重要前沿課題提供了觀測約束。同時,進一步定量評估了探測到的二維溫度結(jié)構(gòu)以及其對應的氣體加熱對測量星系團總引力質(zhì)量輪廓所造成的影響。 (一)使用高質(zhì)量Chandra觀測數(shù)據(jù),我們分析了紅移為0.1左右的九個星系團中央400h7?11 kpc區(qū)域的二維氣體溫度分布。應用小波變換和傅里葉功率譜方法,我們探測到了尺度為100h?711 kpc左右的顯著二維溫度結(jié)構(gòu)。這些二維溫度結(jié)構(gòu)的氣體溫度比周圍氣體溫度高約2 ? 3 keV,所對應的能量超出為1058?60 erg�？紤]到星系團氣體中典型的湍流速度為200 ? 400 km s?1,這些二維溫度結(jié)構(gòu)的有效熱傳導時標約為108 ?109年,比氣體冷卻時間小一個量級。因此,可以排除非均勻輻射冷卻造成這些溫度結(jié)構(gòu)的可能性。通過計算由中央AGN爆發(fā)所導致的氣泡狀結(jié)構(gòu)上升時標,我們推測中央AGN反饋加熱[1]有可能是形成這些二維溫度結(jié)構(gòu)的主要機制。 為了進一步定量估計星系團中央?yún)^(qū)域的二維溫度結(jié)構(gòu)對總引力質(zhì)量分布的X射線測量造成的偏離,我們分析了一個包含65個X射線亮星系團樣本的二維溫度分布和總引力質(zhì)量輪廓。在流體靜力學假定下,利用傳統(tǒng)角向平均方法得到的星系團中央?yún)^(qū)域總引力質(zhì)量輪廓顯著偏離于扣除探測到的二維溫度結(jié)構(gòu)后的總引力質(zhì)量輪廓,最大偏離為10?75%。這反映了目前利用X射線方法測量星系團中央?yún)^(qū)域暗物質(zhì)分布的精度上限。同時這一工作也為將來精確計算星系團質(zhì)量輪廓提供了條件。 (二)為了更全面地研究星系團中央?yún)^(qū)域氣體的熱力學狀態(tài)及其成分,我們分析了一個鄰近的典型cD星系團A1795的高質(zhì)量Chandra、XMM-Newton和Suzaku觀測數(shù)據(jù)。我們發(fā)現(xiàn)在中央80h?711 kpc區(qū)域內(nèi)主要存在兩相星系團氣體成分,其低溫成分和高溫成分的特征溫度分別為2.0 ? 2.4 keV和5.0 ? 5.7 keV。同時,我們探測到了一個較弱的0.8 keV成分,對應中央cD星系內(nèi)氣體。通過對比二維輻射量度(emission measure)比值和金屬豐度分布,我們發(fā)現(xiàn)在半徑為50 ? 100h7?11kpc區(qū)域內(nèi)低溫成分含有較高的金屬豐度。采用cD corona模型[2],我們解釋了觀測得到的兩相氣體溫度、密度和輻射量度分布。在此模型中,因受到星系團磁場的約束氣體低溫成分分布于星系團中央?yún)^(qū)域,且與周圍高溫成分保持基本絕熱。另外,由于此模型預言的加熱源尺度和星系團中央射電瓣尺度一致(≈10h7?11kpc),我們推測中央星系A(chǔ)GN反饋能防止低溫高密度成分過快冷卻,使其保持熱力學穩(wěn)定態(tài).
[Abstract]:In this paper, using the high spatial and high energy resolution of the new generation of X-ray astronomical satellites, we analyze the two-dimensional temperature structure and thermodynamic composition of the gas in the central region of the cluster. Thus, the observation constraints are provided for solving the important frontier problems such as the gas heating mechanism of the cluster of galaxies. At the same time, the effect of the detected two-dimensional temperature structure and the corresponding gas heating on the measurement of the total gravitational mass profile of the cluster is further quantitatively evaluated. (1) using the high quality Chandra data, we analyze the two-dimensional gas temperature distribution in the central 400h7?11 kpc region of nine galaxies with a redshift of about 0.1. Using wavelet transform and Fourier power spectrum method, we have detected a significant two-dimensional temperature structure with a scale of about 100h?711 kpc. The gas temperature of these two dimensional temperature structures is about 2? 3 Kev higher than that of the surrounding gas, and the corresponding energy exceeds 1058 ~ 60 erg. Considering the typical turbulent velocity of 200 ~ 400 km / s ~ (-1) in a cluster gas, the effective heat conduction time scale of these two-dimensional temperature structures is about 108 ~ 109 years, which is an order of magnitude less than the cooling time of the gas. Thus, the possibility of inhomogeneous radiation cooling resulting in these temperature structures can be excluded. By calculating the rising time scales of bubble structures caused by central AGN bursts, we speculate that central AGN feedback heating [1] may be the main mechanism for the formation of these two-dimensional temperature structures. In order to further quantitatively estimate the deviation caused by the two-dimensional temperature structure in the central region of the cluster from the X-ray measurements of the total gravitational mass distribution, We analyze a two-dimensional temperature distribution and total gravitational mass profile for a sample of 65 X-ray bright clusters. On the assumption of hydrostatics, the total gravity mass profile of the central region of the galaxy cluster obtained by the traditional angular averaging method deviates significantly from the total gravity mass profile after subtracting the detected two-dimensional temperature structure, the maximum deviation being 1075. This reflects the present upper limit of the accuracy of X-ray measurement of dark matter distribution in the central region of the cluster. At the same time, this work also provides the condition for the accurate calculation of the mass profile of the cluster in the future. (2) in order to study more fully the thermodynamic state and composition of gases in the central region of the cluster, we have analysed the high quality Chandra-XMM-Newton and Suzaku observations of a nearby typical CD cluster A1795. It is found that there are mainly two-phase cluster gases in the central 80h?711 kpc region. The characteristic temperatures of the low temperature composition and high temperature composition are 2.0? 2.4 keV and 5.0? 5.7 Kev, respectively. At the same time, we have detected a weak 0. 8 keV component corresponding to the gas in the central CD galaxy. By comparing the (emission measure) ratio and the distribution of metal abundance, we find that the low temperature composition in the region with a radius of 50? 100h7?11kpc contains higher metal abundance. Using the CD corona model [2], we explain the observed distributions of temperature, density and radiance of two-phase gas. In this model, the low temperature composition of the gas confined by the magnetic field of the cluster is distributed in the central region of the cluster, and it remains basically adiabatic with the surrounding high temperature composition. In addition, because the scale of heating source predicted by this model is consistent with the scale of central radio lobe of cluster (鈮，
本文編號：2189489
[Abstract]:In this paper, using the high spatial and high energy resolution of the new generation of X-ray astronomical satellites, we analyze the two-dimensional temperature structure and thermodynamic composition of the gas in the central region of the cluster. Thus, the observation constraints are provided for solving the important frontier problems such as the gas heating mechanism of the cluster of galaxies. At the same time, the effect of the detected two-dimensional temperature structure and the corresponding gas heating on the measurement of the total gravitational mass profile of the cluster is further quantitatively evaluated. (1) using the high quality Chandra data, we analyze the two-dimensional gas temperature distribution in the central 400h7?11 kpc region of nine galaxies with a redshift of about 0.1. Using wavelet transform and Fourier power spectrum method, we have detected a significant two-dimensional temperature structure with a scale of about 100h?711 kpc. The gas temperature of these two dimensional temperature structures is about 2? 3 Kev higher than that of the surrounding gas, and the corresponding energy exceeds 1058 ~ 60 erg. Considering the typical turbulent velocity of 200 ~ 400 km / s ~ (-1) in a cluster gas, the effective heat conduction time scale of these two-dimensional temperature structures is about 108 ~ 109 years, which is an order of magnitude less than the cooling time of the gas. Thus, the possibility of inhomogeneous radiation cooling resulting in these temperature structures can be excluded. By calculating the rising time scales of bubble structures caused by central AGN bursts, we speculate that central AGN feedback heating [1] may be the main mechanism for the formation of these two-dimensional temperature structures. In order to further quantitatively estimate the deviation caused by the two-dimensional temperature structure in the central region of the cluster from the X-ray measurements of the total gravitational mass distribution, We analyze a two-dimensional temperature distribution and total gravitational mass profile for a sample of 65 X-ray bright clusters. On the assumption of hydrostatics, the total gravity mass profile of the central region of the galaxy cluster obtained by the traditional angular averaging method deviates significantly from the total gravity mass profile after subtracting the detected two-dimensional temperature structure, the maximum deviation being 1075. This reflects the present upper limit of the accuracy of X-ray measurement of dark matter distribution in the central region of the cluster. At the same time, this work also provides the condition for the accurate calculation of the mass profile of the cluster in the future. (2) in order to study more fully the thermodynamic state and composition of gases in the central region of the cluster, we have analysed the high quality Chandra-XMM-Newton and Suzaku observations of a nearby typical CD cluster A1795. It is found that there are mainly two-phase cluster gases in the central 80h?711 kpc region. The characteristic temperatures of the low temperature composition and high temperature composition are 2.0? 2.4 keV and 5.0? 5.7 Kev, respectively. At the same time, we have detected a weak 0. 8 keV component corresponding to the gas in the central CD galaxy. By comparing the (emission measure) ratio and the distribution of metal abundance, we find that the low temperature composition in the region with a radius of 50? 100h7?11kpc contains higher metal abundance. Using the CD corona model [2], we explain the observed distributions of temperature, density and radiance of two-phase gas. In this model, the low temperature composition of the gas confined by the magnetic field of the cluster is distributed in the central region of the cluster, and it remains basically adiabatic with the surrounding high temperature composition. In addition, because the scale of heating source predicted by this model is consistent with the scale of central radio lobe of cluster (鈮，
本文編號：2189489
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