| Galaxy cluster is the largest gravitational bound system in the universe, which is the cor-nerstone of the large scale structure. Galaxy group has similar structure, but is smaller. Galaxyclusters/groups are composed of stars, gas and dark matter. Stars dominate the emission in opticalband. Gas is heated by the gravitational energy released during merger and accretion to the hightemperature to emit X-ray. In merger, large amounts of relativistic electrons are produced, andsynchrotron radiation occurs when there is magnetic ?eld. Other processes, like AGN activity,supernova, will also radiate electromagnetic wave of different frequency. In order to have a com-prehensive study to clusters/gropus, multi-band observation is required. In this work, based on thestudies in X-ray and radio bands, we 1) study the 2-D temperature and abundance structures ofgalaxy clusters/groups; 2) examine the reliability of measuring the Mach number of merger shock-s with X-ray observation; 3) preview the low frequency observation to mid-redshift clusters andlarge scale structure.First, we present a Chandra study of the metal distribution in the X-ray bright compact groupHCG 62. By performing the 2-dimensional spectral analysis, we identify a remarkable high-abundance arc region at about 2′(33.6h7?01 kpc) from the X-ray peak that spans over a vast regionfrom south to northwest, a part of which roughly coinciding with the outer edge of the southwestX-ray cavity. The measured average abundance in this arc is higher than that in its neighboringregions by a factor of about 2, and the abundance ratios therein are nicely consistent with the dom-inance of the SN Ia yields. We estimate that the mass of iron contained in the arc is > 3×106h?702.5Z⊙, which accounts for > 3% of the iron synthesized in the galaxy. The high-abundance arc couldhave been formed by the AGN activities. However, it is also possible that the arc was formed in arecent merger as is supported by the recent optical kinematic study (Spavone et al. 2006), whichimplies that mergers may be as important as AGN activities in metal redistributions in early-typegalaxies and their associated groups or clusters.Second, we present a detailed Chandra study of the NGC 507 group, which exhibits a wide-angled (? 125?) sharp edge on the X-ray image, as found by Kraft et al. (2004), who ascribed theedge to the spatial variation in gas metal abundance, rather than to a cold front. However, we notethat in Kraft et al. (2004), the authors did not carry out a genuine two-dimensional spectral modelanalysis to study the possible temperature and abundance substructures, nor did they correct for the projection effect, which tends to smear out weak temperature or abundance substructures. Inthis sense the possibility of the giant edge being a cold front cannot be excluded, and should becarefully reexamined. We include the projection effects in our spectral analysis, and generate the2-D abundance and temperature maps based on a direct spectral model ?tting method. We ?nd thatalthough the metal abundance is truly high inside the edge, the correlation between the high abun-dance region and the edge is weak. On the other hand, the 2-D temperature distribution possessesa tight correlation with the edge, and the temperature inside the edge is higher than that outside at68% con?dence level, which is veri?ed by our deprojected spectral analysis. These phenomenonsimply that this sharp edge is actually a cold front. So we conclude that when determining theproperties of sharp edges in galaxy clusters/groups, projection effects should not be neglected and2-D spectral analysis can be helpful.Third, in order to perform a systematic study to the asymmetric abundance structures in galaxyclusters/groups, we compose a sample of nine poor clusters and groups. At present, we have?nished the deduction of X-ray image, 2-D temperature and abundance maps. In the next stage,we will perform deeper analysis to the data.Forth, we studied the reliability of measuring the Mach number of merger shocks with X-ray method. We ?rst perform virtual X-ray observations to a sample of simulated galaxy clusters,which contains merger shocks with known Mach number. Then we measure the Mach number withX-ray method and compare the results with the Mach number read directly from the simulationdata. We ?nd that X-ray method will probably not overestimate the Mach number.Fifth, we preview the observation to mid-redshift clusters and large scale structure with low-frequency radio observation. We plan to construct a set of radio interferometry, which works in400 ? 600 MHz band to observe the redshifted neutral hydrogen 21 cm line emission as a tracer.We perform the design of the overall system structure, the design and calibration of antennas, thecalculation of antenna noise, and the estimation of the intensity of input signal. Because the signalwe aim to detect is rather weak, whose power is only 10?5 ? 10?4 of the foreground, we needappropriate methods to exclude the foreground. We examine a currently available method, andpropose our improvement.
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