星系团和星系群中IGM标定关系的X射线研究及在低频射电观测中的应用
|
摘要
星系团和星系群的尺度达Mpc量级，是宇宙中已知的最大引力束缚体和暗物质的发现地，在星系和宇宙学研究中具有特殊重要意义。星系际介质（intergalactic medium，即IGM1）是星系团和星系群内重子物质的主导存在形式，占据了重子物质总量的约7085%。IGM的温度高达1078K，其辐射主要集中在X射线波段。因此，自上世纪70年代以来，围绕星系团和星系群开展的研究工作中有相当大一部分是借助于空间X射线观测完成的。
最近十年以来，星系团和星系群的研究呈现出两大趋势。第一，新一代X射线空间天文台Chandra等已对此类天体已进行了3000多次观测，在数据库中积累了大量优质图像和光谱数据。如何有效地深入系统挖掘其中蕴含的丰富物理信息已成为近年来美国国家航空航天局、欧洲航天局、日本宇宙科学研究所等机构的优先资助方向；第二，在与X射线相对的电磁波波谱另一端，各国纷纷设计和建造大型低频射电天文干涉阵列，并把对星系团射电晕和射电遗迹的研究列为所有这些阵列的首选科学目标之一。这两个趋势逐年升温，尤其是后者呈现已出较为活跃的局面。
我们注意到上述两个趋势事实上是高度互补且密不可分的。这是因为：（1）过去基于中、小X射线样本获得的星系团和星系群诸重要物理量之间的标定关系，虽然在总体上与自相似理论的预言非常接近，但仍存在不同程度的整体或局部偏离。这一现象涉及星系团和星系群自身、乃至更大尺度宇宙结构的形成和演化图景，已成为一个亟待解决的前沿难题。究其原因，可能与活动星系核（active galactic nucleus，即AGN）的反馈和并合等物理过程有关联。但是，受限于过去的研究样本规模较小，以及缺乏足够的AGN反馈和并合观测证据这两个事实，十多年来尚未能对标定关系的偏离现象做出合理解释。显然，为解决这个问题，除了构建更完备的X射线样本以外，还要求必须同时在迄今为止较难开展探测、但AGN反馈和并合特征更加显著的低频射电波段上积极寻找确凿证据；（2）据推算，大约三分之一的星系团拥有蕴含着星系团演化重要信息的射电晕或射电遗迹，这些特征在低频射电波段更为显著。由于这些特征可能正是起源于上面提及的AGN反馈、并合等高能过程，为了弄清其起源就必须在开展射电研究的同时密切兼顾X射线研究。此外，低频射电天文的一项要务是研究宇宙再电离时期和黑暗时期的极微弱信号。这些信号被强前景所掩盖、不宜探测，而星系团和星系群正是强前景中的主要干扰成分之一。如何正确识别并分离强度超过目标信号2-3个数量级的星系团和星系群干扰信号，是摆在全世界天文学家面前的公认难题。显然，任何可行方案都必然要以星系团的射电-X射线辐射关联性这一强观测约束为依据和出发点。基于上述两点即可判断，在X射线和低频射电波段同时开展星系团和星系群的研究，有其深刻内在物理原因，也是当前天体物理界的大趋势。
在上述背景下，我们以星系团和星系群内极高温X射线气体为对象，围绕总引力质量-气体温度关系（Mtot TX关系）、气体占总引力质量的比例（fgas）、如何在低频射电波段识别和分离星系团辐射信号等开展了相互关联的观测和模拟研究工作，取得了如下结果：（1）分析了Chandra空间X射线天文台过去13年间积累的总数1496次星系团和星系群观测，筛选出342个具有足够空间分辨率、视场覆盖、高信噪比的有效源，用这些红移分布于0-1.4的源构成了目前为止最大的Chandra星系团和星系群样本。发现高温星系团子样本严格遵循理论预言的Mtot TX关系（Mtot∝TαX，α=1.5），而低温星系团和星系群则略向高温端偏移，使整个样本呈现一个更陡的Mtot TX关系（α=1.80±0.02）。经BCES统计分析，发生偏移的是TX Tbreak的高温系统中，X射线气体占总引力质量的比例为fgas=12.9±3.3%，与ΛCDM模型预言基本一致。而在低温系统中，fgas呈现显著的随温度下降而降低的趋势。我们提出，上述两个现象的起因很可能是共同的，即IGM所受的额外加热在低温系统中更加明显；（2）在上述工作1中获得准确的Mtot TX等标定关系的重要应用意义，在于将它与其它各类观测限制和理论预言结合后，我们得以用高仿真模拟方法实现了星系团和星系群低频射电光谱和空间分布模型的构建。再辅之以银河系、河外点源（含恒星形成星系、射电噪AGN和射电宁静AGN）、宇宙再电离信号在低频射电（50200MHz）等成分的光谱和空间分布模型的高仿真构建，我们获得了目前最复杂、仿真度最高的低频射电天空模拟；（3）使用上述工作2的高仿真低频射电天空模型，我们通过引入独立成分分析和小波探测联合算法，证明了使用21CMA累积一个月的观测数据，可以成功探测到视场内大约80%的亮（中央亮温度在65MHz处>10K）星系团，并能准确提取出其表面亮度和光谱信息。此方法可以帮助我们在不久的将来使用新一代低频射电望远镜识别和分离星系团辐射信号，开展星系团并合、电子加速机制以及IGM磁场的研究；（4）使用上述工作2的高仿真低频射电天空模型，我们改进了前人提出的宇宙再电离时期中性氢21厘米信号的分离方法，提出了频谱空间中的三频带窄带二次多项式拟合法，证明了以此新方法不但可以成功恢复再电离时期中性氢21厘米信号在各个尺度上的结构特征，而且可以准确限制再电离模型参数，将能帮助我们了解再电离过程发生的时间、强度和演化速率，为检验各种宇宙学模型提供更为准确的信息。
Galaxy clusters and groups are the largest celestial sources bound by the gravity in our u-niverse, and they are also the places where the dark matter was discovered via the study of themotions of member galaxies in early1930s. In clusters and groups, the dominating baryonic mat-ter component is distributed between galaxies in the form of extremely hot (1078K) plasma, andit accounts for about7085%of the total gravitating mass, meanwhile emits thermal radiationmostly in the X-ray band. This baryonic matter component, i.e., the intergalactic medium (IGM),has played an important role in the space-borne X-ray observations performed in the past43yearsby providing us with valuable information about the structure and evolution of not only the clustersand groups themselves, but also our universe.
One of the unsolved mysteries in the X-ray study of galaxy clusters and groups is the observeddeviations of the scaling relations from the theoretical predictions. These scaling laws are expectedto be intrinsically determined by the essential physics that governs the formation and evolution ofthe Mpc-scale structures, so that there should exist tight correlations between, e.g., total gravitatingmass, gas temperature, X-ray luminosity, and some other fundamental physical quantities. In thepast decade a tremendous amount of high quality imaging and spectroscopic data have been ac-quired with the new generation X-ray satellites in more than3000pointing observations of galaxyclusters and groups. And this makes it feasible to construct cluster-group samples that are largeenough to re-examine the scaling laws with sufficiently high accuracy and precision that has notbeen achieved by the previous small-and medium-sized samples, and to explain why the scalinglaws are biased as compared with the theoretical predictions.
To help this, it is equally important to prepare for the search in the near future in the un-explored low-frequency radio band for any possible evidence for AGN feedback and/or mergerevents, which are believed to be responsible for the biases of the scaling laws and to be moreprominent in the low-frequency radio band. New techniques should be developed based on theexisting multi-band information to simulate the low-frequency radio sky with sufficiently accu-rate details, and to identify and separate the cluster/group signals correctly. Apparently, once the cluster/group signal is successfully separated, it will also greatly benefit the research of the cos-mic reionization epoch and dark age, since the radio radiations of clusters and groups stronglycontaminate the extremely weak redshifted21cm signals to be detected.
The research results of the thesis work is summarized as follows.(1) By constructing a largesample of342galaxy clusters and groups (z=01.4, TX=0.516keV), which are drawn fromthe Chandra archive database by filtering and analyzing all the corresponding data acquired in thepast decade, we calculate the total gravitating mass-X-ray gas temperature relation and gas fractionwithin r500, and find that the mass-temperature relation of the high-temperature clusters followsthe theoretical prediction (Mαtot∝TX，α=1.5), while the low-temperature clusters and groupsexhibit an apparently steeper distribution (α=1.80±0.02), with a break at Tbreak=2.58±0.17keV. We also find that the TX> Tbreakclusters show an average gas fraction of12.9±3.3%thatsatisfy the standard cosmological model, and the gas fraction decreases significantly towards thelow-temperature end. We argue that both the phenomena are caused by the fact that the effects ofextra heating is more prominent in the low-temperature systems.(2) Based on the results of work1,we simulate the50-200MHz radio sky with high accuracy by carrying out Monte Carlo simulationsto model the strong contaminating foreground of the redshifted cosmological reionization signals,including emissions from our Galaxy, galaxy clusters, and extragalactic discrete sources (i.e., star-forming galaxies, radio-quiet active galactic nuclei (AGNs), and radio-loud AGNs). We considerin detail not only random variations of morphological and spectroscopic parameters within theranges allowed by multi-band observations, but also the evolution of radio halos in galaxy clusters,assuming that relativistic electrons are re-accelerated in the IGM in merger events and lose energyvia both synchrotron emission and inverse Compton scattering with cosmic microwave backgroundphotons.(3) By adopting the complex foreground model built in work2and introducing a newapproach designed on the basis of independent component analysis and wavelet detection algo-rithm, we prove that, with a cumulative observation of one month with the21CMA array built atXinjiang, about80%of galaxy clusters with central brightness temperatures of>10K at65MHzcan be safely identified and separated from the overwhelmingly bright foreground.(4) By adoptingthe complex foreground model built in work2, we re-examine the separation approaches based onthe quadratic polynomial fitting technique in frequency space in order to investigate whether theywork satisfactorily by quantitatively evaluating the quality of restored21cm signals (both spectraand power spectra) in terms of sample statistics. We find that a significant part of the Mpc-scalecomponents of the21cm signals (75%for6h1Mpc scales and34%for1h1Mpc scales)is lost using the traditional separation algorithm, because it tends to be misidentified as part of theforeground when the single-narrow-segment separation approach is applied. The best restorationof the21cm signals and the tightest determination of the mean halo b and average ionization frac-tion xecan be obtained with the three-narrow-segment fitting technique as proposed in this paper. Similar results can be obtained at other redshifts, showing its potential use in the research of theBAO signals.
最近十年以来，星系团和星系群的研究呈现出两大趋势。第一，新一代X射线空间天文台Chandra等已对此类天体已进行了3000多次观测，在数据库中积累了大量优质图像和光谱数据。如何有效地深入系统挖掘其中蕴含的丰富物理信息已成为近年来美国国家航空航天局、欧洲航天局、日本宇宙科学研究所等机构的优先资助方向；第二，在与X射线相对的电磁波波谱另一端，各国纷纷设计和建造大型低频射电天文干涉阵列，并把对星系团射电晕和射电遗迹的研究列为所有这些阵列的首选科学目标之一。这两个趋势逐年升温，尤其是后者呈现已出较为活跃的局面。
我们注意到上述两个趋势事实上是高度互补且密不可分的。这是因为：（1）过去基于中、小X射线样本获得的星系团和星系群诸重要物理量之间的标定关系，虽然在总体上与自相似理论的预言非常接近，但仍存在不同程度的整体或局部偏离。这一现象涉及星系团和星系群自身、乃至更大尺度宇宙结构的形成和演化图景，已成为一个亟待解决的前沿难题。究其原因，可能与活动星系核（active galactic nucleus，即AGN）的反馈和并合等物理过程有关联。但是，受限于过去的研究样本规模较小，以及缺乏足够的AGN反馈和并合观测证据这两个事实，十多年来尚未能对标定关系的偏离现象做出合理解释。显然，为解决这个问题，除了构建更完备的X射线样本以外，还要求必须同时在迄今为止较难开展探测、但AGN反馈和并合特征更加显著的低频射电波段上积极寻找确凿证据；（2）据推算，大约三分之一的星系团拥有蕴含着星系团演化重要信息的射电晕或射电遗迹，这些特征在低频射电波段更为显著。由于这些特征可能正是起源于上面提及的AGN反馈、并合等高能过程，为了弄清其起源就必须在开展射电研究的同时密切兼顾X射线研究。此外，低频射电天文的一项要务是研究宇宙再电离时期和黑暗时期的极微弱信号。这些信号被强前景所掩盖、不宜探测，而星系团和星系群正是强前景中的主要干扰成分之一。如何正确识别并分离强度超过目标信号2-3个数量级的星系团和星系群干扰信号，是摆在全世界天文学家面前的公认难题。显然，任何可行方案都必然要以星系团的射电-X射线辐射关联性这一强观测约束为依据和出发点。基于上述两点即可判断，在X射线和低频射电波段同时开展星系团和星系群的研究，有其深刻内在物理原因，也是当前天体物理界的大趋势。
在上述背景下，我们以星系团和星系群内极高温X射线气体为对象，围绕总引力质量-气体温度关系（Mtot TX关系）、气体占总引力质量的比例（fgas）、如何在低频射电波段识别和分离星系团辐射信号等开展了相互关联的观测和模拟研究工作，取得了如下结果：（1）分析了Chandra空间X射线天文台过去13年间积累的总数1496次星系团和星系群观测，筛选出342个具有足够空间分辨率、视场覆盖、高信噪比的有效源，用这些红移分布于0-1.4的源构成了目前为止最大的Chandra星系团和星系群样本。发现高温星系团子样本严格遵循理论预言的Mtot TX关系（Mtot∝TαX，α=1.5），而低温星系团和星系群则略向高温端偏移，使整个样本呈现一个更陡的Mtot TX关系（α=1.80±0.02）。经BCES统计分析，发生偏移的是TX
Galaxy clusters and groups are the largest celestial sources bound by the gravity in our u-niverse, and they are also the places where the dark matter was discovered via the study of themotions of member galaxies in early1930s. In clusters and groups, the dominating baryonic mat-ter component is distributed between galaxies in the form of extremely hot (1078K) plasma, andit accounts for about7085%of the total gravitating mass, meanwhile emits thermal radiationmostly in the X-ray band. This baryonic matter component, i.e., the intergalactic medium (IGM),has played an important role in the space-borne X-ray observations performed in the past43yearsby providing us with valuable information about the structure and evolution of not only the clustersand groups themselves, but also our universe.
One of the unsolved mysteries in the X-ray study of galaxy clusters and groups is the observeddeviations of the scaling relations from the theoretical predictions. These scaling laws are expectedto be intrinsically determined by the essential physics that governs the formation and evolution ofthe Mpc-scale structures, so that there should exist tight correlations between, e.g., total gravitatingmass, gas temperature, X-ray luminosity, and some other fundamental physical quantities. In thepast decade a tremendous amount of high quality imaging and spectroscopic data have been ac-quired with the new generation X-ray satellites in more than3000pointing observations of galaxyclusters and groups. And this makes it feasible to construct cluster-group samples that are largeenough to re-examine the scaling laws with sufficiently high accuracy and precision that has notbeen achieved by the previous small-and medium-sized samples, and to explain why the scalinglaws are biased as compared with the theoretical predictions.
To help this, it is equally important to prepare for the search in the near future in the un-explored low-frequency radio band for any possible evidence for AGN feedback and/or mergerevents, which are believed to be responsible for the biases of the scaling laws and to be moreprominent in the low-frequency radio band. New techniques should be developed based on theexisting multi-band information to simulate the low-frequency radio sky with sufficiently accu-rate details, and to identify and separate the cluster/group signals correctly. Apparently, once the cluster/group signal is successfully separated, it will also greatly benefit the research of the cos-mic reionization epoch and dark age, since the radio radiations of clusters and groups stronglycontaminate the extremely weak redshifted21cm signals to be detected.
The research results of the thesis work is summarized as follows.(1) By constructing a largesample of342galaxy clusters and groups (z=01.4, TX=0.516keV), which are drawn fromthe Chandra archive database by filtering and analyzing all the corresponding data acquired in thepast decade, we calculate the total gravitating mass-X-ray gas temperature relation and gas fractionwithin r500, and find that the mass-temperature relation of the high-temperature clusters followsthe theoretical prediction (Mαtot∝TX，α=1.5), while the low-temperature clusters and groupsexhibit an apparently steeper distribution (α=1.80±0.02), with a break at Tbreak=2.58±0.17keV. We also find that the TX> Tbreakclusters show an average gas fraction of12.9±3.3%thatsatisfy the standard cosmological model, and the gas fraction decreases significantly towards thelow-temperature end. We argue that both the phenomena are caused by the fact that the effects ofextra heating is more prominent in the low-temperature systems.(2) Based on the results of work1,we simulate the50-200MHz radio sky with high accuracy by carrying out Monte Carlo simulationsto model the strong contaminating foreground of the redshifted cosmological reionization signals,including emissions from our Galaxy, galaxy clusters, and extragalactic discrete sources (i.e., star-forming galaxies, radio-quiet active galactic nuclei (AGNs), and radio-loud AGNs). We considerin detail not only random variations of morphological and spectroscopic parameters within theranges allowed by multi-band observations, but also the evolution of radio halos in galaxy clusters,assuming that relativistic electrons are re-accelerated in the IGM in merger events and lose energyvia both synchrotron emission and inverse Compton scattering with cosmic microwave backgroundphotons.(3) By adopting the complex foreground model built in work2and introducing a newapproach designed on the basis of independent component analysis and wavelet detection algo-rithm, we prove that, with a cumulative observation of one month with the21CMA array built atXinjiang, about80%of galaxy clusters with central brightness temperatures of>10K at65MHzcan be safely identified and separated from the overwhelmingly bright foreground.(4) By adoptingthe complex foreground model built in work2, we re-examine the separation approaches based onthe quadratic polynomial fitting technique in frequency space in order to investigate whether theywork satisfactorily by quantitatively evaluating the quality of restored21cm signals (both spectraand power spectra) in terms of sample statistics. We find that a significant part of the Mpc-scalecomponents of the21cm signals (75%for6h1Mpc scales and34%for1h1Mpc scales)is lost using the traditional separation algorithm, because it tends to be misidentified as part of theforeground when the single-narrow-segment separation approach is applied. The best restorationof the21cm signals and the tightest determination of the mean halo b and average ionization frac-tion xecan be obtained with the three-narrow-segment fitting technique as proposed in this paper. Similar results can be obtained at other redshifts, showing its potential use in the research of theBAO signals.
引文
[1] MOHR J J, MATHIESEN B, EVRARD A E. Properties of the Intracluster Medium in anEnsemble of Nearby Galaxy Clusters[J]. ApJ,1999,517:627–649.
[2] PRESS W H, SCHECHTER P. Formation of Galaxies and Clusters of Galaxies by Self-Similar Gravitational Condensation[J]. ApJ,1974,187:425–438.
[3] ABAZAJIAN K, ADELMAN-MCCARTHY J K, AG U¨EROS M A, et al. The First Data Releaseof the Sloan Digital Sky Survey[J]. AJ,2003,126:2081–2086.
[4] WOLF M.U¨ber einen Nebelfleck-Haufen im Perseus[J]. Astronomische Nachrichten,1906,170:211–+.
[5] ABELL G O. The Distribution of Rich Clusters of Galaxies.[J]. ApJS,1958,3:211–+.
[6] SARAZIN C L. X-ray emission from clusters of galaxies[J]. Reviews of Modern Physics,1986,58:1–115.
[7] KELLOGG E M. UHURU Results on Extragalactic X-Ray Sources[C]//. H. BRADT&R.GIACCONI. X-and Gamma-Ray Astronomy.1973..[S.l.]:[s.n.], IAU Symposium, vol.55.
[8] KELLOGG E M. Extragalactic X-Ray Sources[C]//. R. GIACCONI&H. GURSKY. X-rayAstronomy.1974..[S.l.]:[s.n.], Astrophysics and Space Science Library, vol.43.
[9] KELLOGG E M. X-ray astronomy in the UHURU epoch and beyond/Newton Lacy PiercePrize Lecture/[J]. ApJ,1975,197:689–691.
[10] BAHCALL N A. Clusters of galaxies[J]. ARA&A,1977,15:505–540.
[11] KING I. The structure of star clusters. I. an empirical density law[J]. AJ,1962,67:471–+.
[12] PRATT G W, B O¨HRINGER H, CROSTON J H, et al. Temperature profiles of a representativesample of nearby X-ray galaxy clusters[J]. A&A,2007,461:71–80.
[13] DAVIS D S, MULCHAEY J S, MUSHOTZKY R F. The Enrichment History of Hot Gas inPoor Galaxy Groups[J]. ApJ,1999,511:34–40.
[14] FERETTI L, GIOVANNINI G, GOVONI F, et al. Clusters of galaxies: observational proper-ties of the diffuse radio emission[J]. A&A Rev.,2012,20:54.
[15] LARGE M I, MATHEWSON D S, HASLAM C G T. A High-Resolution Survey of the ComaCluster of Galaxies at408Mc./s.[J]. Nature,1959,183:1663–1664.
[16] WILLSON M A G. Radio observations of the cluster of galaxies in Coma Berenices-the5C4survey.[J]. MNRAS,1970,151:1–44.
[17] BALLARATI B, FERETTI L, FICARRA A, et al.408MHz observations of clusters of galax-ies. I-Halo sources in the Coma-A1367supercluster[J]. A&A,1981,100:323–325.
[18] GIOVANNINI G, FERETTI L, STANGHELLINI C. The Coma cluster radio source1253+275, revisited[J]. A&A,1991,252:528–537.
[19] MILEY G K, PEROLA G C. The Large Scale Radio Structure of NGC1275[J]. A&A,1975,45:223.
[20] NOORDAM J E, DE BRUYN A G. High dynamic range mapping of strong radio sources,with application to3C84[J]. Nature,1982,299:597.
[21] BURNS J O, SULKANEN M E, GISLER G R, et al. Where have all the cluster halos gone?[J].ApJ,1992,388:L49–L52.
[22] FERETTI L, GIOVANNINI G. Diffuse Cluster Radio Sources (Review)[C]//. EKERS RD, FANTI C, PADRIELLI L. Extragalactic Radio Sources.1996..[S.l.]:[s.n.], IAUSymposium, vol.175.
[23] FERETTI L. Observational Properties of Diffuse Halos in Clusters[C]//. A. PRAMESH RAO,G. SWARUP,&GOPAL-KRISHNA. The Universe at Low Radio Frequencies.2002..[S.l.]:
[s.n.], IAU Symposium, vol.199.
[24] GIOVANNINI G, FERETTI L. Diffuse Radio Sources and Cluster Mergers: Radio Halosand Relics[C]//. FERETTI L, GIOIA I M, GIOVANNINI G. Merging Processes in GalaxyClusters.2002..[S.l.]:[s.n.], Astrophysics and Space Science Library, vol.272.
[25] GIOVANNINI G, FERETTI L, VENTURI T, et al. The halo radio source Coma C and theorigin of halo sources[J]. ApJ,1993,406:399–406.
[26] KRONBERG P P, KOTHES R, SALTER C J, et al. Discovery of New Faint Radio Emissionon8to3’ Scales in the Coma Field, and Some Galactic and Extragalactic Implications[J].ApJ,2007,659:267–274.
[27] BROWN S, RUDNICK L. Diffuse radio emission in/around the Coma cluster: beyond simpleaccretion[J]. MNRAS,2011,412:2–12.
[28] MURGIA M, GOVONI F, FERETTI L, et al. A double radio halo in the close pair of galaxyclusters Abell399and Abell401[J]. A&A,2010,509:A86.
[29] CASSANO R, BRUNETTI G. Cluster mergers and non-thermal phenomena: a statisticalmagneto-turbulent model[J]. MNRAS,2005,357:1313–1329.
[30] CASSANO R, GITTI M, BRUNETTI G. A morphological comparison between giant radiohalos and radio mini-halos in galaxy clusters[J]. A&A,2008,486:L31–L34.
[31] BR U¨GGEN M, VAN WEEREN R J, R O¨TTGERING H J A. Magnetic fields and shock wavesin cluster outskirts[J]. Mem. Soc. Astron. Italiana,2011,82:627.
[32] SOLOVYEVA L, ANOKHIN S, FERETTI L, et al. The dynamical state of A548from XMM-Newton data: X-ray and radio connection[J]. A&A,2008,484:621–630.
[33] VAN WEEREN R J, R O¨TTGERING H J A, BR U¨GGEN M, et al. Particle Acceleration onMegaparsec Scales in a Merging Galaxy Cluster[J]. Science,2010,330:347–.
[34] VALTCHANOV I, MURPHY T, PIERRE M, et al. Abell1451and1RXS J131423.6-251521:A multi-wavelength study of two dynamically perturbed clusters of galaxies[J]. A&A,2002,392:795–805.
[35] SUBRAHMANYAN R, BEASLEY A J, GOSS W M, et al. PKS B1400-33: An Unusual RadioRelic in a Poor Cluster[J]. AJ,2003,125:1095–1106.
[36] GOVONI F, MURGIA M, MARKEVITCH M, et al. A search for diffuse radio emission inthe relaxed, cool-core galaxy clusters A1068, A1413, A1650, A1835, A2029, and Ophi-uchus[J]. A&A,2009,499:371–383.
[37] MURGIA M, ECKERT D, GOVONI F, et al. GMRT observations of the Ophiuchus galaxycluster[J]. A&A,2010,514:A76.
[38] GITTI M, BRUNETTI G, SETTI G. Modeling the interaction between ICM and relativisticplasma in cooling flows: The case of the Perseus cluster[J]. A&A,2002,386:456–463.
[39] ZUHONE J, MARKEVITCH M, BRUNETTI G. Testing the connection between radio mini-halos and core gas sloshing with MHD simulations[J]. Mem. Soc. Astron. Italiana,2011,82:632.
[40] GIOVANNINI G, TORDI M, FERETTI L. Radio halo and relic candidates from the NRAOVLA Sky Survey[J]. NewA,1999,4:141–155.
[41] CONDON J J, COTTON W D, GREISEN E W, et al. The NRAO VLA Sky Survey[J]. AJ,1998,115:1693–1716.
[42] SHAVER P A, WINDHORST R A, MADAU P, et al. Can the reionization epoch be detectedas a global signature in the cosmic background?[J]. A&A,1999,345:380–390.
[43] TOZZI P, MADAU P, MEIKSIN A, et al. Radio Signatures of H I at High Redshift: Mappingthe End of the “Dark Ages”[J]. ApJ,2000,528:597–606.
[44] ILIEV I T, MELLEMA G, PEN U L, et al. Simulating cosmic reionization at large scales-I.The geometry of reionization[J]. MNRAS,2006,369:1625–1638.
[45] FURLANETTO S R, OH S P, BRIGGS F H. Cosmology at low frequencies: The21cmtransition and the high-redshift Universe[J]. Phys. Rep.,2006,433:181–301.
[46] MORALES M F, WYITHE J S B. Reionization and Cosmology with21-cm Fluctuations[J].ARA&A,2010,48:127–171.
[47] BORGANI S, GUZZO L. X-ray clusters of galaxies as tracers of structure in the Universe[J].Nature,2001,409:39–45.
[48] XU H, JIN G, WU X. The Mass-Temperature Relation of22Nearby Clusters[J]. ApJ,2001,553:78–83.
[49] ROSATI P, BORGANI S, NORMAN C. The Evolution of X-ray Clusters of Galaxies[J].ARA&A,2002,40:539–577.
[50] SCHUECKER P, B O¨HRINGER H, COLLINS C A, et al. The REFLEX galaxy cluster survey.VII. Omegamand sigma8from cluster abundance and large-scale clustering[J]. A&A,2003,398:867–877.
[51] VOIT G M. Tracing cosmic evolution with clusters of galaxies[J]. Reviews of ModernPhysics,2005,77:207–258.
[52] ZHANG Y Y, FINOGUENOV A, B O¨HRINGER H, et al. LoCuSS: comparison of observed X-ray and lensing galaxy cluster scaling relations with simulations[J]. A&A,2008,482:451–472.
[53] SUN M, VOIT G M, DONAHUE M, et al. Chandra Studies of the X-Ray Gas Properties ofGalaxy Groups[J]. ApJ,2009,693:1142–1172.
[54] VIKHLININ A, KRAVTSOV A V, BURENIN R A, et al. Chandra Cluster Cosmology ProjectIII: Cosmological Parameter Constraints[J]. ApJ,2009,692:1060–1074.
[55] ALLEN S W, EVRARD A E, MANTZ A B. Cosmological Parameters from Observations ofGalaxy Clusters[J]. ARA&A,2011,49:409–470.
[56] KAISER N. Evolution and clustering of rich clusters[J]. MNRAS,1986,222:323–345.
[57] VIKHLININ A, KRAVTSOV A, FORMAN W, et al. Chandra Sample of Nearby RelaxedGalaxy Clusters: Mass, Gas Fraction, and Mass-Temperature Relation[J]. ApJ,2006,640:691–709.
[58] ETTORI S, GASTALDELLO F, LECCARDI A, et al. Mass profiles and c-MDMrelation inX-ray luminous galaxy clusters[J]. A&A,2010,524:A68.
[59] PRATT G W, ARNAUD M, PIFFARETTI R, et al. Gas entropy in a representative sample ofnearby X-ray galaxy clusters (REXCESS): relationship to gas mass fraction[J]. A&A,2010,511:A85.
[60] JUETT A M, DAVIS D S, MUSHOTZKY R. Testing the Reliability of Cluster Mass Indica-tors with a Systematics Limited Data Set[J]. ApJ,2010,709:L103–L107.
[61] B O¨HRINGER H, DOLAG K, CHON G. Modelling self-similar appearance of galaxy clustersin X-rays[J]. A&A,2012,539:A120.
[62] SANDERSON A J R, PONMAN T J, O’SULLIVAN E. A statistically selected Chandra sam-ple of20galaxy clusters-I. Temperature and cooling time profiles[J]. MNRAS,2006,372:1496–1508.
[63] BURNS J O, HALLMAN E J, GANTNER B, et al. Why Do Only Some Galaxy ClustersHave Cool Cores?[J]. ApJ,2008,675:1125–1140.
[64] BAUER F E, FABIAN A C, SANDERS J S, et al. The prevalence of cooling cores in clustersof galaxies at z0.15-0.4[J]. MNRAS,2005,359:1481–1490.
[65] O’HARA T B, MOHR J J, BIALEK J J, et al. Effects of Mergers and Core Structure on theBulk Properties of Nearby Galaxy Clusters[J]. ApJ,2006,639:64–80.
[66] DONAHUE M. Cold Gas in Cluster Cores[C]//. B O¨HRINGER H, PRATT G W, FINOGUENOVA, et al. Heating versus Cooling in Galaxies and Clusters of Galaxies..[S.l.]:[s.n.],2007:20.
[67] HUDSON D S, MITTAL R, REIPRICH T H, et al. What is a cool-core cluster? a detailedanalysis of the cores of the X-ray flux-limited HIFLUGCS cluster sample[J]. A&A,2010,513:A37.
[68] POOLE G B, FARDAL M A, BABUL A, et al. The impact of mergers on relaxed X-ray clus-ters-I. Dynamical evolution and emergent transient structures[J]. MNRAS,2006,373:881–905.
[69] MAUGHAN B J, JONES C, FORMAN W, et al. Images, Structural Properties, and MetalAbundances of Galaxy Clusters Observed with Chandra ACIS-I at0.1 [70] HARTLEY W G, GAZZOLA L, PEARCE F R, et al. Nature versus nurture: the curved spineof the galaxy cluster X-ray luminosity-temperature relation[J]. MNRAS,2008,386:2015–2021.
[71] B O¨HRINGER H, PRATT G W, ARNAUD M, et al. Substructure of the galaxy clusters in theREXCESS sample: observed statistics and comparison to numerical simulations[J]. A&A,2010,514:A32.
[72] ECKMILLER H J, HUDSON D S, REIPRICH T H. Testing the low-mass end of X-ray scalingrelations with a sample of Chandra galaxy groups[J]. A&A,2011,535:A105.
[73] SNOWDEN S L, EGGER R, FINKBEINER D P, et al. Progress on Establishing the SpatialDistribution of Material Responsible for the14keV Soft X-Ray Diffuse Background Localand Halo Components[J]. ApJ,1998,493:715.
[74] ETTORI S, BALESTRA I. The outer regions of galaxy clusters: Chandra constraints on theX-ray surface brightness[J]. A&A,2009,496:343–349.
[75] BALDI A, ETTORI S, MOLENDI S, et al. Self-similarity of temperature profiles in distantgalaxy clusters: the quest for a universal law[J]. A&A,2012,545:A41.
[76] ZHANG Y Y, ANDERNACH H, CARETTA C A, et al. HIFLUGCS: Galaxy cluster scalingrelations between X-ray luminosity, gas mass, cluster radius, and velocity dispersion[J].A&A,2011,526:A105.
[77] JONES A W, HOBSON M P, MUKHERJEE P, et al. The effect of a spatially varying Galacticspectral index on the maximum entropy reconstruction of Planck Surveyor satellite data[J].ArXiv Astrophysics e-prints,1998.
[78] PLATANIA P, BURIGANA C, MAINO D, et al. Full sky study of diffuse Galactic emissionat decimeter wavelengths[J]. A&A,2003,410:847–863.
[79] GLESER L, NUSSER A, BENSON A J. Decontamination of cosmological21-cm maps[J].MNRAS,2008,391:383–398.
[80] GAENSLER B M, DICKEY J M, MCCLURE-GRIFFITHS N M, et al. Radio Polarizationfrom the Inner Galaxy at Arcminute Resolution[J]. ApJ,2001,549:959–978.
[81] WIERINGA M H, DE BRUYN A G, JANSEN D, et al. Small scale polarization structure inthe diffuse galactic emission at325MHz[J]. A&A,1993,268:215–229.
[82] GRAY A D, LANDECKER T L, DEWDNEY P E, et al. Radio Polarimetric Imagingof the Interstellar Medium: Magnetic Field and Diffuse Ionized Gas Structure near theW3/W4/W5/HB3Complex[J]. ApJ,1999,514:221–231.
[83] HAVERKORN M, KATGERT P, DE BRUYN A G. Structure in the local Galactic ISM onscales down to1pc, from multi-band radio polarization observations[J]. A&A,2000,356:L13–L16.
[84] TUCCI M, CARRETTI E, CECCHINI S, et al. Polarization Angular Spectra of GalacticSynchrotron Emission on Arcminute Scales[J]. ApJ,2002,579:607–615.
[85] BERNARDI G, DE BRUYN A G, BRENTJENS M A, et al. Foregrounds for observations ofthe cosmological21cm line. I. First Westerbork measurements of Galactic emission at150MHz in a low latitude field[J]. A&A,2009,500:965–979.
[86] GIARDINO G, BANDAY A J, G O′RSKI K M, et al. Towards a model of full-sky Galacticsynchrotron intensity and linear polarisation: A re-analysis of the Parkes data[J]. A&A,2002,387:82–97.
[87] HASLAM C G T, SALTER C J, STOFFEL H, et al. A408MHz all-sky continuum survey. II-The atlas of contour maps[J]. A&AS,1982,47:1.
[88] SMOOT G F. Galactic Free-free and H-alpha Emission[J]. ArXiv Astrophysics e-prints,1998.
[89] REYNOLDS R J, HAFFNER L M. Mapping the Galactic Free-Free Foreground via Interstel-lar H-Alpha Emission[J]. ArXiv Astrophysics e-prints,2000.
[90] FINKBEINER D P. A Full-Sky Hα Template for Microwave Foreground Prediction[J].ApJS,2003,146:407–415.
[91] CAPPELLARI M, COPIN Y. Adaptive Spatial Binning of2D Spectra and Images UsingVoronoi Tessellations[C]//. ROSADA M, BINETTE L, ARIAS L. Galaxies: the Third Di-mension.2002..[S.l.]:[s.n.], Astronomical Society of the Pacific Conference Series, vol.282.
[92] BENNETT C L, HILL R S, HINSHAW G, et al. First-Year Wilkinson Microwave AnisotropyProbe (WMAP) Observations: Foreground Emission[J]. ApJS,2003,148:97–117.
[93] JELI C′V, ZAROUBI S, LABROPOULOS P, et al. Foreground simulations for the LOFAR-epoch of reionization experiment[J]. MNRAS,2008,389:1319–1335.
[94] ZHANG Y Y, WU X P. The Effect of Radiative Cooling on the Sunyaev-Zeldovich ClusterCounts and Angular Power Spectra: Analytic Treatment[J]. ApJ,2003,583:529–534.
[95] ZENTNER A R, BERLIND A A, BULLOCK J S, et al. The Physics of Galaxy Clustering. I.A Model for Subhalo Populations[J]. ApJ,2005,624:505–525.
[96] FEDELI C, MENEGHETTI M, BARTELMANN M, et al. A fast method for computing strong-lensing cross sections: application to merging clusters[J]. A&A,2006,447:419–430.
[97] DREXLER J. A Relativistic-Proton Dark Matter Would Be Evidence The Big Bang ProbablySatisfied The Second Law Of Thermodynamics[J]. ArXiv Physics e-prints,2007.
[98] HOLDER G, HAIMAN Z, MOHR J J. Constraints on m,, and σ8from Galaxy ClusterRedshift Distributions[J]. ApJ,2001,560:L111–L114.
[99] ENSSLIN T A, R O¨TTGERING H. The radio luminosity function of cluster radio halos[J].A&A,2002,396:83–89.
[100] CASSANO R. Large-scale Diffuse Radio Emission from Clusters of Galaxies and the Im-portance of Low Frequency Radio Observations[C]//. SAIKIA D J, GREEN D A, GUPTAY, et al. The Low-Frequency Radio Universe.2009..[S.l.]:[s.n.], Astronomical Societyof the Pacific Conference Series, vol.407.
[101] FERRARI C, GOVONI F, SCHINDLER S, et al. Observations of Extended Radio Emissionin Clusters[J]. Space Sci. Rev.,2008,134:93–118.
[102] PARMA P, MURGIA M, MORGANTI R, et al. Radiative ages in a representative sample oflow luminosity radio galaxies[J]. A&A,1999,344:7–16.
[103] REPHAELI Y, GRUBER D. RXTE Observations of A2256[J]. ArXiv Astrophysics e-prints,2003.
[104] REPHAELI Y, GRUBER D, ARIELI Y. Long RXTE Observations of A2163[J]. ApJ,2006,649:673–677.
[105] MATHIESEN B F, EVRARD A E. Four Measures of the Intracluster Medium Temperatureand Their Relation to a Cluster’s Dynamical State[J]. ApJ,2001,546:100–116.
[106] GIOVANNINI G, BONAFEDE A, FERETTI L, et al. Radio halos in nearby (z <0.4) clustersof galaxies[J]. A&A,2009,507:1257–1270.
[107] CASSANO R, BRUNETTI G, SETTI G. Statistics of giant radio haloes from electron reac-celeration models[J]. MNRAS,2006,369:1577–1595.
[108] GOVONI F, ENSSLIN T A, FERETTI L, et al. A comparison of radio and X-ray morphologiesof four clusters of galaxies containing radio halos[J]. A&A,2001,369:441–449.
[109] CAVALIERE A, FUSCO-FEMIANO R. X-rays from hot plasma in clusters of galaxies[J].A&A,1976,49:137–144.
[110] JONES L R, SCHARF C, EBELING H, et al. The WARPS Survey. II. The log N–log SRelation and the X-Ray Evolution of Low-Luminosity Clusters of Galaxies[J]. ApJ,1998,495:100.
[111] ETTORI S. Brief history of metal accumulation in the intracluster medium[J]. MNRAS,2005,362:110–116.
[112] LUMB D H, BARTLETT J G, ROMER A K, et al. The XMM-NEWTON project. I. TheX-ray luminosity-temperature relation at z>0.4[J]. A&A,2004,420:853–872.
[113] EVRARD A E, METZLER C A, NAVARRO J F. Mass Estimates of X-Ray Clusters[J]. ApJ,1996,469:494.
[114] BRUNETTI G, CASSANO R, DOLAG K, et al. On the evolution of giant radio halos andtheir connection with cluster mergers[J]. A&A,2009,507:661–669.
[115] BRUNETTI G, BLASI P, CASSANO R, et al. Alfve′nic reacceleration of relativistic particlesin galaxy clusters: MHD waves, leptons and hadrons[J]. MNRAS,2004,350:1174–1194.
[116] WANG X, TEGMARK M, SANTOS M G, et al.21cm Tomography with Foregrounds[J].ApJ,2006,650:529–537.
[117] SANTOS M G, COORAY A, KNOX L. Multifrequency Analysis of21Centimeter Fluctua-tions from the Era of Reionization[J]. ApJ,2005,625:575–587.
[118] WILMAN R J, MILLER L, JARVIS M J, et al. A semi-empirical simulation of the ex-tragalactic radio continuum sky for next generation radio telescopes[J]. MNRAS,2008,388:1335–1348.
[119] SNELLEN I A G, SCHILIZZI R T, MILEY G K, et al. On the evolution of young radio-loudAGN[J]. MNRAS,2000,319:445–456.
[120] DE VRIES W H, BARTHEL P D, O’DEA C P. Radio spectra of Gigahertz Peaked Spectrumradio sources.[J]. A&A,1997,321:105–110.
[121] FANTI C, POZZI F, DALLACASA D, et al. Multi-frequency VLA observations of a newsample of CSS/GPS radio sources[J]. A&A,2001,369:380–420.
[122] O’DEA C P. The Compact Steep-Spectrum and Gigahertz Peaked-Spectrum RadioSources[J]. PASP,1998,110:493–532.
[123] STAWARZ, OSTORERO L, BEGELMAN M C, et al. Evolution of and High-Energy Emis-sion from GHz-Peaked Spectrum Sources[J]. ApJ,2008,680:911–925.
[124] THOMPSON A R, MORAN J M, SWENSON G W, JR. Interferometry and Synthesis inRadio Astronomy,2nd Edition[M].[S.l.]:[s.n.],2001.
[125] SARAZIN C L, KEMPNER J C. Nonthermal Bremsstrahlung and Hard X-Ray Emissionfrom Clusters of Galaxies[J]. ApJ,2000,533:73–83.
[126] POPESSO P, B O¨HRINGER H, BRINKMANN J, et al. RASS-SDSS Galaxy clusters survey. I.The catalog and the correlation of X-ray and optical properties[J]. A&A,2004,423:449–467.
[127] SCHEKOCHIHIN A A, COWLEY S C, KULSRUD R M, et al. Plasma Instabilities and Mag-netic Field Growth in Clusters of Galaxies[J]. ApJ,2005,629:139–142.
[128] LAZARIAN A. Enhancement and Suppression of Heat Transfer by MHD Turbulence[J].ApJ,2006,645:L25–L28.
[129] BRUNETTI G, GIACINTUCCI S, CASSANO R, et al. A low-frequency radio halo associatedwith a cluster of galaxies[J]. Nature,2008,455:944–947.
[130] ENSSLIN T A, GOPAL-KRISHNA. Reviving fossil radio plasma in clusters of galaxies byadiabatic compression in environmental shock waves[J]. A&A,2001,366:26–34.
[131] BRUNETTI G, SETTI G, FERETTI L, et al. Particle reacceleration in the Coma cluster: radioproperties and hard X-ray emission[J]. MNRAS,2001,320:365–378.
[132] PETERSON J B, PEN U, WU X. Searching for Early Ionization with the Primeval StructureTelescope[C]//. KASSIM N, PEREZ M, JUNOR W, et al. From Clark Lake to the LongWavelength Array: Bill Erickson’s Radio Science.2005..[S.l.]:[s.n.], AstronomicalSociety of the Pacific Conference Series, vol.345.
[133] R O¨TTGERING H, DE BRUYN A G, FENDER R P, et al. Lofar: a New Radio Telescopefor Low Frequency Radio Observations:. Science and Project Status[C]//. BANDIERA R,MAIOLINO R, MANNUCCI F. Texas in Tuscany. XXI Symposium on Relativistic Astro-physics..[S.l.]:[s.n.],2003:69–76.
[134] MORALES M F, HEWITT J. Toward Epoch of Reionization Measurements with Wide-FieldRadio Observations[J]. ApJ,2004,615:7–18.
[135] CASSANO R, BRUNETTI G, R O¨TTGERING H J A, et al. Unveiling radio halos in galaxyclusters in the LOFAR era[J]. A&A,2010,509:A68.
[136] VENTURI T, GIACINTUCCI S, BRUNETTI G, et al. GMRT radio halo survey in galaxyclusters at z=0.2-0.4. I. The REFLEX sub-sample[J]. A&A,2007,463:937–947.
[137] VENTURI T, GIACINTUCCI S, DALLACASA D, et al. GMRT radio halo survey in galaxyclusters at z=0.2-0.4. II. The eBCS clusters and analysis of the complete sample[J]. A&A,2008,484:327–340.
[138] COMON P. Independent component analysis, A new concept?[J]. Signal Processing,1994,36(3):287–314.
[139] SHENSA M J. The discrete wavelet transform: wedding the a trous and Mallat algorithms[J].IEEE Transactions on Signal Processing,1992,40:2464–2482.
[140] LEACH S M, CARDOSO J F, BACCIGALUPI C, et al. Component separation methods forthe PLANCK mission[J]. A&A,2008,491:597–615.
[141] HYVARINEN A. Gaussian moments for noisy independent component analysis[J]. IEEESignal Processing Letters,1999,6:145–147.
[142] DE BERNARDIS P, BUCHER M, BURIGANA C, et al. B-Pol: detecting primordial gravita-tional waves generated during inflation[J]. Experimental Astronomy,2009,23:5–16.
[143] BACCIGALUPI C, BEDINI L, BURIGANA C, et al. Neural networks and the separation ofcosmic microwave background and astrophysical signals in sky maps[J]. MNRAS,2000,318:769–780.
[144] MAINO D, DONZELLI S, BANDAY A J, et al. Cosmic microwave background signal inWilkinson Microwave Anisotropy Probe three-year data with FASTICA[J]. MNRAS,2007,374:1207–1215.
[145] BOTTINO M, BANDAY A J, MAINO D. Foreground analysis of the Wilkinson MicrowaveAnisotropy Probe3-yr data with FASTICA[J]. MNRAS,2008,389:1190–1208.
[146] ZITO T, WILBERT N, WISKOTT L, et al. Modular toolkit for Data Processing (MDP): aPython data processing framework[J]. Frontiers in Neuroinformatics,2009,2(8).
[147] SLEZAK E, BIJAOUI A, MARS G. Identification of structures from galaxy counts-Use ofthe wavelet transform[J]. A&A,1990,227:301–316.
[148] VIKHLININ A, FORMAN W, JONES C. Another Collision for the Coma Cluster[J]. ApJ,1997,474:L7.
[149] GU L, XU H, GU J, et al. A Chandra Study of Temperature Substructures in Intermediate-Redshift Galaxy Clusters[J]. ApJ,2009,700:1161–1172.
[150] DI MATTEO T, PERNA R, ABEL T, et al. Radio Foregrounds for the21Centimeter Tomog-raphy of the Neutral Intergalactic Medium at High Redshifts[J]. ApJ,2002,564:576–580.
[151] DI MATTEO T, CIARDI B, MINIATI F. The21-cm emission from the reionization epoch:extended and point source foregrounds[J]. MNRAS,2004,355:1053–1065.
[152] BOWMAN J D, MORALES M F, HEWITT J N. Foreground Contamination in InterferometricMeasurements of the Redshifted21cm Power Spectrum[J]. ApJ,2009,695:183–199.
[153] LIU A, TEGMARK M, ZALDARRIAGA M. Will point sources spoil21-cm tomography?[J].MNRAS,2009,394:1575–1587.
[154] HARKER G, ZAROUBI S, BERNARDI G, et al. Non-parametric foreground subtraction for21-cm epoch of reionization experiments[J]. MNRAS,2009,397:1138–1152.
[155] CHAPMAN E, ABDALLA F B, HARKER G, et al. Foreground removal using FASTICA: ashowcase of LOFAR-EoR[J]. MNRAS,2012,423:2518–2532.
[156] FURLANETTO S R, ZALDARRIAGA M, HERNQUIST L. The Growth of H II Regions DuringReionization[J]. ApJ,2004,613:1–15.
[157] WYITHE J S B, LOEB A. A characteristic size of10Mpc for the ionized bubbles at the endof cosmic reionization[J]. Nature,2004,432:194–196.
[158] FURLANETTO S R, OH S P. Taxing the rich: recombinations and bubble growth duringreionization[J]. MNRAS,2005,363:1031–1048.
[159] PETROVIC N, OH S P. Systematic effects of foreground removal in21-cm surveys ofreionization[J]. MNRAS,2011,413:2103–2120.
[160] MESINGER A, FURLANETTO S. Efficient Simulations of Early Structure Formation andReionization[J]. ApJ,2007,669:663–675.
[161] SANTOS M G, COORAY A, HAIMAN Z, et al. Small-Scale Cosmic Microwave Back-ground Temperature and Polarization Anisotropies Due to Patchy Reionization[J]. ApJ,2003,598:756–766.
[162] PEACOCK J A. Cosmological Physics[M].[S.l.]:[s.n.],1999.
[163] PINDOR B, WYITHE J S B, MITCHELL D A, et al. Subtraction of Bright Point Sourcesfrom Synthesis Images of the Epoch of Reionization[J]. PASA,2011,28:46–57.
[164] MCQUINN M, ZAHN O, ZALDARRIAGA M, et al. Cosmological Parameter EstimationUsing21cm Radiation from the Epoch of Reionization[J]. ApJ,2006,653:815–834.
[165] ZAROUBI S, DE BRUYN A G, HARKER G, et al. Imaging neutral hydrogen on large scalesduring the Epoch of Reionization with LOFAR[J]. MNRAS,2012,425:2964–2973.
[166] HARKER G, ZAROUBI S, BERNARDI G, et al. Power spectrum extraction for redshifted21-cm Epoch of Reionization experiments: the LOFAR case[J]. MNRAS,2010,405:2492–2504.
[167] SANTOS M G, AMBLARD A, PRITCHARD J, et al. Cosmic Reionization and the21cmSignal: Comparison between an Analytical Model and a Simulation[J]. ApJ,2008,689:1–16.
[168] ANSARI R, CAMPAGNE J E, COLOM P, et al.21cm observation of large-scale structuresat z1. Instrument sensitivity and foreground subtraction[J]. A&A,2012,540:A129.
[169] BHARADWAJ S, SETHI S K, SAINI T D. Estimation of cosmological parameters fromneutral hydrogen observations of the post-reionization epoch[J]. Phys. Rev. D,2009,79(8):083538.
[170] VISBAL E, LOEB A, WYITHE S. Cosmological constraints from21cm surveys after reion-ization[J]. JCAP,2009,10:30.
[171] BAGLA J S, KHANDAI N, DATTA K K. HI as a probe of the large-scale structure in thepost-reionization universe[J]. MNRAS,2010,407:567–580.
[172] SEO H J, DODELSON S, MARRINER J, et al. A Ground-based21cm Baryon AcousticOscillation Survey[J]. ApJ,2010,721:164–173.
[173] BARKANA R, LOEB A. The physics and early history of the intergalactic medium[J]. Re-ports on Progress in Physics,2007,70:627–657.
[174] PRITCHARD J R, LOEB A. Evolution of the21cm signal throughout cosmic history[J].Phys. Rev. D,2008,78(10):103511.
[175] CHANG T C, PEN U L, PETERSON J B, et al. Baryon Acoustic Oscillation Intensity Map-ping of Dark Energy[J]. Physical Review Letters,2008,100(9):091303.
[176] ZWAAN M A, MEYER M J, STAVELEY-SMITH L, et al. The HIPASS catalogue: HIandenvironmental effects on the HI mass function of galaxies[J]. MNRAS,2005,359:L30–L34.
[177] PROCHASKA J X, HERBERT-FORT S, WOLFE A M. The SDSS Damped Lyα Survey: DataRelease3[J]. ApJ,2005,635:123–142.
[178] RAO S M, TURNSHEK D A, NESTOR D B. Damped Lyα Systems at z<1.65: The Expand-ed Sloan Digital Sky Survey Hubble Space Telescope Sample[J]. ApJ,2006,636:610–630.
[2] PRESS W H, SCHECHTER P. Formation of Galaxies and Clusters of Galaxies by Self-Similar Gravitational Condensation[J]. ApJ,1974,187:425–438.
[3] ABAZAJIAN K, ADELMAN-MCCARTHY J K, AG U¨EROS M A, et al. The First Data Releaseof the Sloan Digital Sky Survey[J]. AJ,2003,126:2081–2086.
[4] WOLF M.U¨ber einen Nebelfleck-Haufen im Perseus[J]. Astronomische Nachrichten,1906,170:211–+.
[5] ABELL G O. The Distribution of Rich Clusters of Galaxies.[J]. ApJS,1958,3:211–+.
[6] SARAZIN C L. X-ray emission from clusters of galaxies[J]. Reviews of Modern Physics,1986,58:1–115.
[7] KELLOGG E M. UHURU Results on Extragalactic X-Ray Sources[C]//. H. BRADT&R.GIACCONI. X-and Gamma-Ray Astronomy.1973..[S.l.]:[s.n.], IAU Symposium, vol.55.
[8] KELLOGG E M. Extragalactic X-Ray Sources[C]//. R. GIACCONI&H. GURSKY. X-rayAstronomy.1974..[S.l.]:[s.n.], Astrophysics and Space Science Library, vol.43.
[9] KELLOGG E M. X-ray astronomy in the UHURU epoch and beyond/Newton Lacy PiercePrize Lecture/[J]. ApJ,1975,197:689–691.
[10] BAHCALL N A. Clusters of galaxies[J]. ARA&A,1977,15:505–540.
[11] KING I. The structure of star clusters. I. an empirical density law[J]. AJ,1962,67:471–+.
[12] PRATT G W, B O¨HRINGER H, CROSTON J H, et al. Temperature profiles of a representativesample of nearby X-ray galaxy clusters[J]. A&A,2007,461:71–80.
[13] DAVIS D S, MULCHAEY J S, MUSHOTZKY R F. The Enrichment History of Hot Gas inPoor Galaxy Groups[J]. ApJ,1999,511:34–40.
[14] FERETTI L, GIOVANNINI G, GOVONI F, et al. Clusters of galaxies: observational proper-ties of the diffuse radio emission[J]. A&A Rev.,2012,20:54.
[15] LARGE M I, MATHEWSON D S, HASLAM C G T. A High-Resolution Survey of the ComaCluster of Galaxies at408Mc./s.[J]. Nature,1959,183:1663–1664.
[16] WILLSON M A G. Radio observations of the cluster of galaxies in Coma Berenices-the5C4survey.[J]. MNRAS,1970,151:1–44.
[17] BALLARATI B, FERETTI L, FICARRA A, et al.408MHz observations of clusters of galax-ies. I-Halo sources in the Coma-A1367supercluster[J]. A&A,1981,100:323–325.
[18] GIOVANNINI G, FERETTI L, STANGHELLINI C. The Coma cluster radio source1253+275, revisited[J]. A&A,1991,252:528–537.
[19] MILEY G K, PEROLA G C. The Large Scale Radio Structure of NGC1275[J]. A&A,1975,45:223.
[20] NOORDAM J E, DE BRUYN A G. High dynamic range mapping of strong radio sources,with application to3C84[J]. Nature,1982,299:597.
[21] BURNS J O, SULKANEN M E, GISLER G R, et al. Where have all the cluster halos gone?[J].ApJ,1992,388:L49–L52.
[22] FERETTI L, GIOVANNINI G. Diffuse Cluster Radio Sources (Review)[C]//. EKERS RD, FANTI C, PADRIELLI L. Extragalactic Radio Sources.1996..[S.l.]:[s.n.], IAUSymposium, vol.175.
[23] FERETTI L. Observational Properties of Diffuse Halos in Clusters[C]//. A. PRAMESH RAO,G. SWARUP,&GOPAL-KRISHNA. The Universe at Low Radio Frequencies.2002..[S.l.]:
[s.n.], IAU Symposium, vol.199.
[24] GIOVANNINI G, FERETTI L. Diffuse Radio Sources and Cluster Mergers: Radio Halosand Relics[C]//. FERETTI L, GIOIA I M, GIOVANNINI G. Merging Processes in GalaxyClusters.2002..[S.l.]:[s.n.], Astrophysics and Space Science Library, vol.272.
[25] GIOVANNINI G, FERETTI L, VENTURI T, et al. The halo radio source Coma C and theorigin of halo sources[J]. ApJ,1993,406:399–406.
[26] KRONBERG P P, KOTHES R, SALTER C J, et al. Discovery of New Faint Radio Emissionon8to3’ Scales in the Coma Field, and Some Galactic and Extragalactic Implications[J].ApJ,2007,659:267–274.
[27] BROWN S, RUDNICK L. Diffuse radio emission in/around the Coma cluster: beyond simpleaccretion[J]. MNRAS,2011,412:2–12.
[28] MURGIA M, GOVONI F, FERETTI L, et al. A double radio halo in the close pair of galaxyclusters Abell399and Abell401[J]. A&A,2010,509:A86.
[29] CASSANO R, BRUNETTI G. Cluster mergers and non-thermal phenomena: a statisticalmagneto-turbulent model[J]. MNRAS,2005,357:1313–1329.
[30] CASSANO R, GITTI M, BRUNETTI G. A morphological comparison between giant radiohalos and radio mini-halos in galaxy clusters[J]. A&A,2008,486:L31–L34.
[31] BR U¨GGEN M, VAN WEEREN R J, R O¨TTGERING H J A. Magnetic fields and shock wavesin cluster outskirts[J]. Mem. Soc. Astron. Italiana,2011,82:627.
[32] SOLOVYEVA L, ANOKHIN S, FERETTI L, et al. The dynamical state of A548from XMM-Newton data: X-ray and radio connection[J]. A&A,2008,484:621–630.
[33] VAN WEEREN R J, R O¨TTGERING H J A, BR U¨GGEN M, et al. Particle Acceleration onMegaparsec Scales in a Merging Galaxy Cluster[J]. Science,2010,330:347–.
[34] VALTCHANOV I, MURPHY T, PIERRE M, et al. Abell1451and1RXS J131423.6-251521:A multi-wavelength study of two dynamically perturbed clusters of galaxies[J]. A&A,2002,392:795–805.
[35] SUBRAHMANYAN R, BEASLEY A J, GOSS W M, et al. PKS B1400-33: An Unusual RadioRelic in a Poor Cluster[J]. AJ,2003,125:1095–1106.
[36] GOVONI F, MURGIA M, MARKEVITCH M, et al. A search for diffuse radio emission inthe relaxed, cool-core galaxy clusters A1068, A1413, A1650, A1835, A2029, and Ophi-uchus[J]. A&A,2009,499:371–383.
[37] MURGIA M, ECKERT D, GOVONI F, et al. GMRT observations of the Ophiuchus galaxycluster[J]. A&A,2010,514:A76.
[38] GITTI M, BRUNETTI G, SETTI G. Modeling the interaction between ICM and relativisticplasma in cooling flows: The case of the Perseus cluster[J]. A&A,2002,386:456–463.
[39] ZUHONE J, MARKEVITCH M, BRUNETTI G. Testing the connection between radio mini-halos and core gas sloshing with MHD simulations[J]. Mem. Soc. Astron. Italiana,2011,82:632.
[40] GIOVANNINI G, TORDI M, FERETTI L. Radio halo and relic candidates from the NRAOVLA Sky Survey[J]. NewA,1999,4:141–155.
[41] CONDON J J, COTTON W D, GREISEN E W, et al. The NRAO VLA Sky Survey[J]. AJ,1998,115:1693–1716.
[42] SHAVER P A, WINDHORST R A, MADAU P, et al. Can the reionization epoch be detectedas a global signature in the cosmic background?[J]. A&A,1999,345:380–390.
[43] TOZZI P, MADAU P, MEIKSIN A, et al. Radio Signatures of H I at High Redshift: Mappingthe End of the “Dark Ages”[J]. ApJ,2000,528:597–606.
[44] ILIEV I T, MELLEMA G, PEN U L, et al. Simulating cosmic reionization at large scales-I.The geometry of reionization[J]. MNRAS,2006,369:1625–1638.
[45] FURLANETTO S R, OH S P, BRIGGS F H. Cosmology at low frequencies: The21cmtransition and the high-redshift Universe[J]. Phys. Rep.,2006,433:181–301.
[46] MORALES M F, WYITHE J S B. Reionization and Cosmology with21-cm Fluctuations[J].ARA&A,2010,48:127–171.
[47] BORGANI S, GUZZO L. X-ray clusters of galaxies as tracers of structure in the Universe[J].Nature,2001,409:39–45.
[48] XU H, JIN G, WU X. The Mass-Temperature Relation of22Nearby Clusters[J]. ApJ,2001,553:78–83.
[49] ROSATI P, BORGANI S, NORMAN C. The Evolution of X-ray Clusters of Galaxies[J].ARA&A,2002,40:539–577.
[50] SCHUECKER P, B O¨HRINGER H, COLLINS C A, et al. The REFLEX galaxy cluster survey.VII. Omegamand sigma8from cluster abundance and large-scale clustering[J]. A&A,2003,398:867–877.
[51] VOIT G M. Tracing cosmic evolution with clusters of galaxies[J]. Reviews of ModernPhysics,2005,77:207–258.
[52] ZHANG Y Y, FINOGUENOV A, B O¨HRINGER H, et al. LoCuSS: comparison of observed X-ray and lensing galaxy cluster scaling relations with simulations[J]. A&A,2008,482:451–472.
[53] SUN M, VOIT G M, DONAHUE M, et al. Chandra Studies of the X-Ray Gas Properties ofGalaxy Groups[J]. ApJ,2009,693:1142–1172.
[54] VIKHLININ A, KRAVTSOV A V, BURENIN R A, et al. Chandra Cluster Cosmology ProjectIII: Cosmological Parameter Constraints[J]. ApJ,2009,692:1060–1074.
[55] ALLEN S W, EVRARD A E, MANTZ A B. Cosmological Parameters from Observations ofGalaxy Clusters[J]. ARA&A,2011,49:409–470.
[56] KAISER N. Evolution and clustering of rich clusters[J]. MNRAS,1986,222:323–345.
[57] VIKHLININ A, KRAVTSOV A, FORMAN W, et al. Chandra Sample of Nearby RelaxedGalaxy Clusters: Mass, Gas Fraction, and Mass-Temperature Relation[J]. ApJ,2006,640:691–709.
[58] ETTORI S, GASTALDELLO F, LECCARDI A, et al. Mass profiles and c-MDMrelation inX-ray luminous galaxy clusters[J]. A&A,2010,524:A68.
[59] PRATT G W, ARNAUD M, PIFFARETTI R, et al. Gas entropy in a representative sample ofnearby X-ray galaxy clusters (REXCESS): relationship to gas mass fraction[J]. A&A,2010,511:A85.
[60] JUETT A M, DAVIS D S, MUSHOTZKY R. Testing the Reliability of Cluster Mass Indica-tors with a Systematics Limited Data Set[J]. ApJ,2010,709:L103–L107.
[61] B O¨HRINGER H, DOLAG K, CHON G. Modelling self-similar appearance of galaxy clustersin X-rays[J]. A&A,2012,539:A120.
[62] SANDERSON A J R, PONMAN T J, O’SULLIVAN E. A statistically selected Chandra sam-ple of20galaxy clusters-I. Temperature and cooling time profiles[J]. MNRAS,2006,372:1496–1508.
[63] BURNS J O, HALLMAN E J, GANTNER B, et al. Why Do Only Some Galaxy ClustersHave Cool Cores?[J]. ApJ,2008,675:1125–1140.
[64] BAUER F E, FABIAN A C, SANDERS J S, et al. The prevalence of cooling cores in clustersof galaxies at z0.15-0.4[J]. MNRAS,2005,359:1481–1490.
[65] O’HARA T B, MOHR J J, BIALEK J J, et al. Effects of Mergers and Core Structure on theBulk Properties of Nearby Galaxy Clusters[J]. ApJ,2006,639:64–80.
[66] DONAHUE M. Cold Gas in Cluster Cores[C]//. B O¨HRINGER H, PRATT G W, FINOGUENOVA, et al. Heating versus Cooling in Galaxies and Clusters of Galaxies..[S.l.]:[s.n.],2007:20.
[67] HUDSON D S, MITTAL R, REIPRICH T H, et al. What is a cool-core cluster? a detailedanalysis of the cores of the X-ray flux-limited HIFLUGCS cluster sample[J]. A&A,2010,513:A37.
[68] POOLE G B, FARDAL M A, BABUL A, et al. The impact of mergers on relaxed X-ray clus-ters-I. Dynamical evolution and emergent transient structures[J]. MNRAS,2006,373:881–905.
[69] MAUGHAN B J, JONES C, FORMAN W, et al. Images, Structural Properties, and MetalAbundances of Galaxy Clusters Observed with Chandra ACIS-I at0.1
[71] B O¨HRINGER H, PRATT G W, ARNAUD M, et al. Substructure of the galaxy clusters in theREXCESS sample: observed statistics and comparison to numerical simulations[J]. A&A,2010,514:A32.
[72] ECKMILLER H J, HUDSON D S, REIPRICH T H. Testing the low-mass end of X-ray scalingrelations with a sample of Chandra galaxy groups[J]. A&A,2011,535:A105.
[73] SNOWDEN S L, EGGER R, FINKBEINER D P, et al. Progress on Establishing the SpatialDistribution of Material Responsible for the14keV Soft X-Ray Diffuse Background Localand Halo Components[J]. ApJ,1998,493:715.
[74] ETTORI S, BALESTRA I. The outer regions of galaxy clusters: Chandra constraints on theX-ray surface brightness[J]. A&A,2009,496:343–349.
[75] BALDI A, ETTORI S, MOLENDI S, et al. Self-similarity of temperature profiles in distantgalaxy clusters: the quest for a universal law[J]. A&A,2012,545:A41.
[76] ZHANG Y Y, ANDERNACH H, CARETTA C A, et al. HIFLUGCS: Galaxy cluster scalingrelations between X-ray luminosity, gas mass, cluster radius, and velocity dispersion[J].A&A,2011,526:A105.
[77] JONES A W, HOBSON M P, MUKHERJEE P, et al. The effect of a spatially varying Galacticspectral index on the maximum entropy reconstruction of Planck Surveyor satellite data[J].ArXiv Astrophysics e-prints,1998.
[78] PLATANIA P, BURIGANA C, MAINO D, et al. Full sky study of diffuse Galactic emissionat decimeter wavelengths[J]. A&A,2003,410:847–863.
[79] GLESER L, NUSSER A, BENSON A J. Decontamination of cosmological21-cm maps[J].MNRAS,2008,391:383–398.
[80] GAENSLER B M, DICKEY J M, MCCLURE-GRIFFITHS N M, et al. Radio Polarizationfrom the Inner Galaxy at Arcminute Resolution[J]. ApJ,2001,549:959–978.
[81] WIERINGA M H, DE BRUYN A G, JANSEN D, et al. Small scale polarization structure inthe diffuse galactic emission at325MHz[J]. A&A,1993,268:215–229.
[82] GRAY A D, LANDECKER T L, DEWDNEY P E, et al. Radio Polarimetric Imagingof the Interstellar Medium: Magnetic Field and Diffuse Ionized Gas Structure near theW3/W4/W5/HB3Complex[J]. ApJ,1999,514:221–231.
[83] HAVERKORN M, KATGERT P, DE BRUYN A G. Structure in the local Galactic ISM onscales down to1pc, from multi-band radio polarization observations[J]. A&A,2000,356:L13–L16.
[84] TUCCI M, CARRETTI E, CECCHINI S, et al. Polarization Angular Spectra of GalacticSynchrotron Emission on Arcminute Scales[J]. ApJ,2002,579:607–615.
[85] BERNARDI G, DE BRUYN A G, BRENTJENS M A, et al. Foregrounds for observations ofthe cosmological21cm line. I. First Westerbork measurements of Galactic emission at150MHz in a low latitude field[J]. A&A,2009,500:965–979.
[86] GIARDINO G, BANDAY A J, G O′RSKI K M, et al. Towards a model of full-sky Galacticsynchrotron intensity and linear polarisation: A re-analysis of the Parkes data[J]. A&A,2002,387:82–97.
[87] HASLAM C G T, SALTER C J, STOFFEL H, et al. A408MHz all-sky continuum survey. II-The atlas of contour maps[J]. A&AS,1982,47:1.
[88] SMOOT G F. Galactic Free-free and H-alpha Emission[J]. ArXiv Astrophysics e-prints,1998.
[89] REYNOLDS R J, HAFFNER L M. Mapping the Galactic Free-Free Foreground via Interstel-lar H-Alpha Emission[J]. ArXiv Astrophysics e-prints,2000.
[90] FINKBEINER D P. A Full-Sky Hα Template for Microwave Foreground Prediction[J].ApJS,2003,146:407–415.
[91] CAPPELLARI M, COPIN Y. Adaptive Spatial Binning of2D Spectra and Images UsingVoronoi Tessellations[C]//. ROSADA M, BINETTE L, ARIAS L. Galaxies: the Third Di-mension.2002..[S.l.]:[s.n.], Astronomical Society of the Pacific Conference Series, vol.282.
[92] BENNETT C L, HILL R S, HINSHAW G, et al. First-Year Wilkinson Microwave AnisotropyProbe (WMAP) Observations: Foreground Emission[J]. ApJS,2003,148:97–117.
[93] JELI C′V, ZAROUBI S, LABROPOULOS P, et al. Foreground simulations for the LOFAR-epoch of reionization experiment[J]. MNRAS,2008,389:1319–1335.
[94] ZHANG Y Y, WU X P. The Effect of Radiative Cooling on the Sunyaev-Zeldovich ClusterCounts and Angular Power Spectra: Analytic Treatment[J]. ApJ,2003,583:529–534.
[95] ZENTNER A R, BERLIND A A, BULLOCK J S, et al. The Physics of Galaxy Clustering. I.A Model for Subhalo Populations[J]. ApJ,2005,624:505–525.
[96] FEDELI C, MENEGHETTI M, BARTELMANN M, et al. A fast method for computing strong-lensing cross sections: application to merging clusters[J]. A&A,2006,447:419–430.
[97] DREXLER J. A Relativistic-Proton Dark Matter Would Be Evidence The Big Bang ProbablySatisfied The Second Law Of Thermodynamics[J]. ArXiv Physics e-prints,2007.
[98] HOLDER G, HAIMAN Z, MOHR J J. Constraints on m,, and σ8from Galaxy ClusterRedshift Distributions[J]. ApJ,2001,560:L111–L114.
[99] ENSSLIN T A, R O¨TTGERING H. The radio luminosity function of cluster radio halos[J].A&A,2002,396:83–89.
[100] CASSANO R. Large-scale Diffuse Radio Emission from Clusters of Galaxies and the Im-portance of Low Frequency Radio Observations[C]//. SAIKIA D J, GREEN D A, GUPTAY, et al. The Low-Frequency Radio Universe.2009..[S.l.]:[s.n.], Astronomical Societyof the Pacific Conference Series, vol.407.
[101] FERRARI C, GOVONI F, SCHINDLER S, et al. Observations of Extended Radio Emissionin Clusters[J]. Space Sci. Rev.,2008,134:93–118.
[102] PARMA P, MURGIA M, MORGANTI R, et al. Radiative ages in a representative sample oflow luminosity radio galaxies[J]. A&A,1999,344:7–16.
[103] REPHAELI Y, GRUBER D. RXTE Observations of A2256[J]. ArXiv Astrophysics e-prints,2003.
[104] REPHAELI Y, GRUBER D, ARIELI Y. Long RXTE Observations of A2163[J]. ApJ,2006,649:673–677.
[105] MATHIESEN B F, EVRARD A E. Four Measures of the Intracluster Medium Temperatureand Their Relation to a Cluster’s Dynamical State[J]. ApJ,2001,546:100–116.
[106] GIOVANNINI G, BONAFEDE A, FERETTI L, et al. Radio halos in nearby (z <0.4) clustersof galaxies[J]. A&A,2009,507:1257–1270.
[107] CASSANO R, BRUNETTI G, SETTI G. Statistics of giant radio haloes from electron reac-celeration models[J]. MNRAS,2006,369:1577–1595.
[108] GOVONI F, ENSSLIN T A, FERETTI L, et al. A comparison of radio and X-ray morphologiesof four clusters of galaxies containing radio halos[J]. A&A,2001,369:441–449.
[109] CAVALIERE A, FUSCO-FEMIANO R. X-rays from hot plasma in clusters of galaxies[J].A&A,1976,49:137–144.
[110] JONES L R, SCHARF C, EBELING H, et al. The WARPS Survey. II. The log N–log SRelation and the X-Ray Evolution of Low-Luminosity Clusters of Galaxies[J]. ApJ,1998,495:100.
[111] ETTORI S. Brief history of metal accumulation in the intracluster medium[J]. MNRAS,2005,362:110–116.
[112] LUMB D H, BARTLETT J G, ROMER A K, et al. The XMM-NEWTON project. I. TheX-ray luminosity-temperature relation at z>0.4[J]. A&A,2004,420:853–872.
[113] EVRARD A E, METZLER C A, NAVARRO J F. Mass Estimates of X-Ray Clusters[J]. ApJ,1996,469:494.
[114] BRUNETTI G, CASSANO R, DOLAG K, et al. On the evolution of giant radio halos andtheir connection with cluster mergers[J]. A&A,2009,507:661–669.
[115] BRUNETTI G, BLASI P, CASSANO R, et al. Alfve′nic reacceleration of relativistic particlesin galaxy clusters: MHD waves, leptons and hadrons[J]. MNRAS,2004,350:1174–1194.
[116] WANG X, TEGMARK M, SANTOS M G, et al.21cm Tomography with Foregrounds[J].ApJ,2006,650:529–537.
[117] SANTOS M G, COORAY A, KNOX L. Multifrequency Analysis of21Centimeter Fluctua-tions from the Era of Reionization[J]. ApJ,2005,625:575–587.
[118] WILMAN R J, MILLER L, JARVIS M J, et al. A semi-empirical simulation of the ex-tragalactic radio continuum sky for next generation radio telescopes[J]. MNRAS,2008,388:1335–1348.
[119] SNELLEN I A G, SCHILIZZI R T, MILEY G K, et al. On the evolution of young radio-loudAGN[J]. MNRAS,2000,319:445–456.
[120] DE VRIES W H, BARTHEL P D, O’DEA C P. Radio spectra of Gigahertz Peaked Spectrumradio sources.[J]. A&A,1997,321:105–110.
[121] FANTI C, POZZI F, DALLACASA D, et al. Multi-frequency VLA observations of a newsample of CSS/GPS radio sources[J]. A&A,2001,369:380–420.
[122] O’DEA C P. The Compact Steep-Spectrum and Gigahertz Peaked-Spectrum RadioSources[J]. PASP,1998,110:493–532.
[123] STAWARZ, OSTORERO L, BEGELMAN M C, et al. Evolution of and High-Energy Emis-sion from GHz-Peaked Spectrum Sources[J]. ApJ,2008,680:911–925.
[124] THOMPSON A R, MORAN J M, SWENSON G W, JR. Interferometry and Synthesis inRadio Astronomy,2nd Edition[M].[S.l.]:[s.n.],2001.
[125] SARAZIN C L, KEMPNER J C. Nonthermal Bremsstrahlung and Hard X-Ray Emissionfrom Clusters of Galaxies[J]. ApJ,2000,533:73–83.
[126] POPESSO P, B O¨HRINGER H, BRINKMANN J, et al. RASS-SDSS Galaxy clusters survey. I.The catalog and the correlation of X-ray and optical properties[J]. A&A,2004,423:449–467.
[127] SCHEKOCHIHIN A A, COWLEY S C, KULSRUD R M, et al. Plasma Instabilities and Mag-netic Field Growth in Clusters of Galaxies[J]. ApJ,2005,629:139–142.
[128] LAZARIAN A. Enhancement and Suppression of Heat Transfer by MHD Turbulence[J].ApJ,2006,645:L25–L28.
[129] BRUNETTI G, GIACINTUCCI S, CASSANO R, et al. A low-frequency radio halo associatedwith a cluster of galaxies[J]. Nature,2008,455:944–947.
[130] ENSSLIN T A, GOPAL-KRISHNA. Reviving fossil radio plasma in clusters of galaxies byadiabatic compression in environmental shock waves[J]. A&A,2001,366:26–34.
[131] BRUNETTI G, SETTI G, FERETTI L, et al. Particle reacceleration in the Coma cluster: radioproperties and hard X-ray emission[J]. MNRAS,2001,320:365–378.
[132] PETERSON J B, PEN U, WU X. Searching for Early Ionization with the Primeval StructureTelescope[C]//. KASSIM N, PEREZ M, JUNOR W, et al. From Clark Lake to the LongWavelength Array: Bill Erickson’s Radio Science.2005..[S.l.]:[s.n.], AstronomicalSociety of the Pacific Conference Series, vol.345.
[133] R O¨TTGERING H, DE BRUYN A G, FENDER R P, et al. Lofar: a New Radio Telescopefor Low Frequency Radio Observations:. Science and Project Status[C]//. BANDIERA R,MAIOLINO R, MANNUCCI F. Texas in Tuscany. XXI Symposium on Relativistic Astro-physics..[S.l.]:[s.n.],2003:69–76.
[134] MORALES M F, HEWITT J. Toward Epoch of Reionization Measurements with Wide-FieldRadio Observations[J]. ApJ,2004,615:7–18.
[135] CASSANO R, BRUNETTI G, R O¨TTGERING H J A, et al. Unveiling radio halos in galaxyclusters in the LOFAR era[J]. A&A,2010,509:A68.
[136] VENTURI T, GIACINTUCCI S, BRUNETTI G, et al. GMRT radio halo survey in galaxyclusters at z=0.2-0.4. I. The REFLEX sub-sample[J]. A&A,2007,463:937–947.
[137] VENTURI T, GIACINTUCCI S, DALLACASA D, et al. GMRT radio halo survey in galaxyclusters at z=0.2-0.4. II. The eBCS clusters and analysis of the complete sample[J]. A&A,2008,484:327–340.
[138] COMON P. Independent component analysis, A new concept?[J]. Signal Processing,1994,36(3):287–314.
[139] SHENSA M J. The discrete wavelet transform: wedding the a trous and Mallat algorithms[J].IEEE Transactions on Signal Processing,1992,40:2464–2482.
[140] LEACH S M, CARDOSO J F, BACCIGALUPI C, et al. Component separation methods forthe PLANCK mission[J]. A&A,2008,491:597–615.
[141] HYVARINEN A. Gaussian moments for noisy independent component analysis[J]. IEEESignal Processing Letters,1999,6:145–147.
[142] DE BERNARDIS P, BUCHER M, BURIGANA C, et al. B-Pol: detecting primordial gravita-tional waves generated during inflation[J]. Experimental Astronomy,2009,23:5–16.
[143] BACCIGALUPI C, BEDINI L, BURIGANA C, et al. Neural networks and the separation ofcosmic microwave background and astrophysical signals in sky maps[J]. MNRAS,2000,318:769–780.
[144] MAINO D, DONZELLI S, BANDAY A J, et al. Cosmic microwave background signal inWilkinson Microwave Anisotropy Probe three-year data with FASTICA[J]. MNRAS,2007,374:1207–1215.
[145] BOTTINO M, BANDAY A J, MAINO D. Foreground analysis of the Wilkinson MicrowaveAnisotropy Probe3-yr data with FASTICA[J]. MNRAS,2008,389:1190–1208.
[146] ZITO T, WILBERT N, WISKOTT L, et al. Modular toolkit for Data Processing (MDP): aPython data processing framework[J]. Frontiers in Neuroinformatics,2009,2(8).
[147] SLEZAK E, BIJAOUI A, MARS G. Identification of structures from galaxy counts-Use ofthe wavelet transform[J]. A&A,1990,227:301–316.
[148] VIKHLININ A, FORMAN W, JONES C. Another Collision for the Coma Cluster[J]. ApJ,1997,474:L7.
[149] GU L, XU H, GU J, et al. A Chandra Study of Temperature Substructures in Intermediate-Redshift Galaxy Clusters[J]. ApJ,2009,700:1161–1172.
[150] DI MATTEO T, PERNA R, ABEL T, et al. Radio Foregrounds for the21Centimeter Tomog-raphy of the Neutral Intergalactic Medium at High Redshifts[J]. ApJ,2002,564:576–580.
[151] DI MATTEO T, CIARDI B, MINIATI F. The21-cm emission from the reionization epoch:extended and point source foregrounds[J]. MNRAS,2004,355:1053–1065.
[152] BOWMAN J D, MORALES M F, HEWITT J N. Foreground Contamination in InterferometricMeasurements of the Redshifted21cm Power Spectrum[J]. ApJ,2009,695:183–199.
[153] LIU A, TEGMARK M, ZALDARRIAGA M. Will point sources spoil21-cm tomography?[J].MNRAS,2009,394:1575–1587.
[154] HARKER G, ZAROUBI S, BERNARDI G, et al. Non-parametric foreground subtraction for21-cm epoch of reionization experiments[J]. MNRAS,2009,397:1138–1152.
[155] CHAPMAN E, ABDALLA F B, HARKER G, et al. Foreground removal using FASTICA: ashowcase of LOFAR-EoR[J]. MNRAS,2012,423:2518–2532.
[156] FURLANETTO S R, ZALDARRIAGA M, HERNQUIST L. The Growth of H II Regions DuringReionization[J]. ApJ,2004,613:1–15.
[157] WYITHE J S B, LOEB A. A characteristic size of10Mpc for the ionized bubbles at the endof cosmic reionization[J]. Nature,2004,432:194–196.
[158] FURLANETTO S R, OH S P. Taxing the rich: recombinations and bubble growth duringreionization[J]. MNRAS,2005,363:1031–1048.
[159] PETROVIC N, OH S P. Systematic effects of foreground removal in21-cm surveys ofreionization[J]. MNRAS,2011,413:2103–2120.
[160] MESINGER A, FURLANETTO S. Efficient Simulations of Early Structure Formation andReionization[J]. ApJ,2007,669:663–675.
[161] SANTOS M G, COORAY A, HAIMAN Z, et al. Small-Scale Cosmic Microwave Back-ground Temperature and Polarization Anisotropies Due to Patchy Reionization[J]. ApJ,2003,598:756–766.
[162] PEACOCK J A. Cosmological Physics[M].[S.l.]:[s.n.],1999.
[163] PINDOR B, WYITHE J S B, MITCHELL D A, et al. Subtraction of Bright Point Sourcesfrom Synthesis Images of the Epoch of Reionization[J]. PASA,2011,28:46–57.
[164] MCQUINN M, ZAHN O, ZALDARRIAGA M, et al. Cosmological Parameter EstimationUsing21cm Radiation from the Epoch of Reionization[J]. ApJ,2006,653:815–834.
[165] ZAROUBI S, DE BRUYN A G, HARKER G, et al. Imaging neutral hydrogen on large scalesduring the Epoch of Reionization with LOFAR[J]. MNRAS,2012,425:2964–2973.
[166] HARKER G, ZAROUBI S, BERNARDI G, et al. Power spectrum extraction for redshifted21-cm Epoch of Reionization experiments: the LOFAR case[J]. MNRAS,2010,405:2492–2504.
[167] SANTOS M G, AMBLARD A, PRITCHARD J, et al. Cosmic Reionization and the21cmSignal: Comparison between an Analytical Model and a Simulation[J]. ApJ,2008,689:1–16.
[168] ANSARI R, CAMPAGNE J E, COLOM P, et al.21cm observation of large-scale structuresat z1. Instrument sensitivity and foreground subtraction[J]. A&A,2012,540:A129.
[169] BHARADWAJ S, SETHI S K, SAINI T D. Estimation of cosmological parameters fromneutral hydrogen observations of the post-reionization epoch[J]. Phys. Rev. D,2009,79(8):083538.
[170] VISBAL E, LOEB A, WYITHE S. Cosmological constraints from21cm surveys after reion-ization[J]. JCAP,2009,10:30.
[171] BAGLA J S, KHANDAI N, DATTA K K. HI as a probe of the large-scale structure in thepost-reionization universe[J]. MNRAS,2010,407:567–580.
[172] SEO H J, DODELSON S, MARRINER J, et al. A Ground-based21cm Baryon AcousticOscillation Survey[J]. ApJ,2010,721:164–173.
[173] BARKANA R, LOEB A. The physics and early history of the intergalactic medium[J]. Re-ports on Progress in Physics,2007,70:627–657.
[174] PRITCHARD J R, LOEB A. Evolution of the21cm signal throughout cosmic history[J].Phys. Rev. D,2008,78(10):103511.
[175] CHANG T C, PEN U L, PETERSON J B, et al. Baryon Acoustic Oscillation Intensity Map-ping of Dark Energy[J]. Physical Review Letters,2008,100(9):091303.
[176] ZWAAN M A, MEYER M J, STAVELEY-SMITH L, et al. The HIPASS catalogue: HIandenvironmental effects on the HI mass function of galaxies[J]. MNRAS,2005,359:L30–L34.
[177] PROCHASKA J X, HERBERT-FORT S, WOLFE A M. The SDSS Damped Lyα Survey: DataRelease3[J]. ApJ,2005,635:123–142.
[178] RAO S M, TURNSHEK D A, NESTOR D B. Damped Lyα Systems at z<1.65: The Expand-ed Sloan Digital Sky Survey Hubble Space Telescope Sample[J]. ApJ,2006,636:610–630.