In this thesis, we present the optical to X-ray scaling relations from the XMM Cluster Survey (XCS) and the red-sequence Matched-filter Probabilistic Percolation cluster finding algorithm (redMaPPer) cluster catalogs. XCS finds galaxy clusters in the XMM-Newton public archive and redMaPPer uses optical data from the Sloan Digital Sky Survey eighth data release (SDSS-DR8) and the Dark Energy Survey first year data release (DES Y1). redMaPPer catalogs provide reliable photometric redshift estimations that have been calibrated with spectroscopic redshifts. The XCS temperature and luminosity pipelines need redshift information to calculate the X-ray observables. We introduced third generation of the XCS Post Processing Pipeline (XCS3P). A description of the previous versions is given, highlighting the modifications made for XCS3P-v3. This methodology was validated by comparing the LX - TX relation obtained from XCS3Pv1, XCS3P-v2 and the current version, the results are similar to XCS3P-v2 finding a self similar evolution. Samples of clusters are defined after several control filters, each cluster has optical and X-ray follow up, the sample has 327 unique clusters that span a redshift range of 0:08 < z < 0:8. Optical to X-ray scaling relations are obtained for the samples XCS-RM (SDSS DR8), XCS-RM (DES Y1) and XCS-RM (SDSS+DES Y1). Obtaining as a result, the most comprehensive examination of the TX - λ and LX - λ relations up to date, showing a clear correlation between the observables. This work confirms that it is possible to relate optical properties with the underlying mass. Cluster observables like the X-ray temperature, X-ray luminosity and the optical richness are well known mass tracers. The XCS3P-v3 methodology and the process followed to obtain the scaling relations are validated using four non-redMaPPer cluster catalogs, two from the optical (CAMIRA and GMBCG) and two from the millimiter (SPT and Planck). The results show a clear correlation between X-ray and optical and millimeter observables. This analysis is not a robust as for redMaPPer, thus further work is needed to present this results to the scientific community.

by Feng Xue. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 76-84). / ACKNOWLEDGMENTS --- p.I / ABSTRACT --- p.II / TABLE OF CONTENTS --- p.III / LIST OF TABLES --- p.V / LIST OF FIGURES --- p.VI / Chapter CHAPTER 1: --- INTRODUCTION --- p.1 / Chapter 1. --- supramolecular chemistry --- p.1 / Chapter 2. --- Infinite multi-dimensional architecture --- p.10 / Chapter 3. --- Chemistry of pseudohalides --- p.15 / Chapter 4. --- Chemistry of hexamethylenetetramine --- p.20 / Chapter 5. --- Objectives of the present research --- p.24 / Chapter CHAPTER 2: --- EXPERIMENTAL --- p.25 / Chapter 1. --- Preparation --- p.25 / Chapter 1.1 --- Materials --- p.25 / Chapter 1.2 --- Preparation of the compounds --- p.25 / Chapter 2. --- X-ray crystallography --- p.26 / Chapter CHAPTER 3: --- DESCRIPTION OF CRYSTAL STRUCTURES --- p.28 / Chapter 1. --- isostructural compounds K2[FEII(CN)6] ´Ø 2[(CH2)6n4H] ´Ø 4H2 O(1) and K2[FEIII(CN)6] ´Ø [(CH2)6N4H] ´Ø [(CH2)6N4] ´Ø 4H2O (2) --- p.28 / Chapter 2. --- Crystal structure of NA2[FEIII(CN)6] ´Ø [(CH2)6N4H] ´Ø [(CH2)6N4] ´Ø 5H2O (3) --- p.33 / Chapter 3. --- Crystal structure of K3[FEIII(CN)6] ´Ø 2[(CH2)6N4] ´Ø 4H2O (4) --- p.37 / Chapter 4. --- Crystal Structure of ferricyanic acid-HMT adduct H3[FEIII(CN)6] ´Ø 2[(CH2)6N4] ´Ø 2H2O (5) --- p.43 / Chapter 5. --- "Crystal structure of cadmium chloride-HMT adduct, Cd2[C6H12N4H2]Cl6´Ø 3H2O (6)" --- p.48 / Chapter 6. --- "Crystal structure of cadmium bromide-HMT adduct, CdBr2 ´Ø 2[(CH2)6N4] ´Ø 2H2O (7)" --- p.53 / Chapter 7. --- "Crystal structure of cadmium iodide-HMT adduct, 3CdI2 ´Ø 2[(CH2)6N4] ´Ø 4H2O (8)" --- p.57 / Chapter 8. --- Crystal structure of cadmium thiocyanate-HMT adduct Cd(SCN)2 ´Ø 1(CH2)6N4] ´Ø MeOH (9) --- p.61 / Chapter 9. --- Crystal structure of cobalt cyanate-HMT adduct Co(NCO)2 ´Ø [(CH2)6N4] ´Ø 2H2O (10) --- p.67 / Chapter CHAPTER 4: --- SUMMARY AND DISCUSSIONS --- p.72 / REFERENCES --- p.76 / TABLE A1 Crystallographic data for compounds 1 ~5 --- p.85 / TABLE A2 Crystallographic data for compounds 6~10 --- p.86 / APPENDIX 1 Atomic Coordinates (Ax 104) and Equivalent Isotropic Thermal Parameters (A 2x103) --- p.87 / APPENDIX 2 Anisotropic thermal parameters (A2x 103) --- p.92 / APPENDIX 3 H-atom coordinates (x 104) and isotropic thermal parameters (A2x 103) --- p.96

published_or_final_version / Physiology / Master / Master of Philosophy

Supersoft and quasisoft X-ray sources are collectively known as Very Soft X-ray Sources (VSSs) characterized by their considerably lower effective temperatures than normal X-ray emitting objects and the lack of significant emission above 1 keV, with measured temperatures ranging from about tens to less than about 300 eV, respectively. They are defined observationally and believed to be associated with a wide variety of astrophysical systems such as white dwarfs, neutron stars, and black holes. VSSs have been identified in our own Galaxy, the Magellanic Clouds, and other external galaxies. Due to the vicinity of the Magellanic Clouds and the low associated absorption of soft X-ray photons, they are unique in the studies of VSSs. However, no attempt has been made to search for VSSs and investigate the source population in the Magellanic Clouds using all the available archival data. A systematic survey of VSSs in the Magellanic Clouds was therefore performed using data from both XMM-Newton and Chandra. VSSs were identified by selection algorithim based on X-ray hardness ratio after the background galaxies and foreground stars were filtered. A total of 47 new supersoft and 75 new quasisoft candidates were identified. Six of them were strong enough for spectral analysis with derived temperatures of 15 – 250 eV and luminosities of of 3.5 ×?10?^34– 5.4 ×?10?^36 erg s^(-1). The softest and brightest candidate represents a promising supersoft candidate with a possible UV counterpart identified with XMM-Newton Optical Monitor having an estimated UV luminosity of ~2.7 ×?10?^35 erg s^(-1). The large dataset also allows the long-term studies of some of the previously identified supersoft X-ray sources. Through the comprehensive survey with multi-epoch data, an X-ray/UV stellar flare was discovered and its analysis is also reported. / published_or_final_version / Physics / Master / Master of Philosophy

This thesis presents work on theoretical tools used to study transient and quantum-fluctuating impurity potentials that arise in resonant x-ray scattering and ultracold atomic gases. These tools fall under two main classes, functional determinants for exact evaluation of many-fermion matrix elements, and the variational polaron transformation. The following work carefully introduces both approaches and compares theoretical predictions to known experimental and computational results. In several cases this thesis presents arguments that experiments on high-temperature superconducting cup rates must be reinterpreted in terms of a quasiparticle picture. Where no experimental data exist, predictions are made and suggestions given for new uses for simple experimental techniques. For example, indirect resonant inelastic x-ray scattering turns out to be a versatile pseudo gap probe, and radio frequency absorption of a fermi gas with an impurity can detect a repulsively-bound state. / Physics

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Cellulosomes are the most efficient plant cell wall degradation machines discovered to date. All cellulosomal components contain protein modules connected by linkers of varying lengths, which are predicted to be flexible. Consequently, structural studies of the cellulosome have employed a “dissect and build” strategy, whereby individual modules are studied in isolation with the hope to later model the intact complex. However, representative individual structures are now available for all of the cellulosome modules and many questions still remain. The studies described in this thesis depart from the ‘dissection’ stage and enter the ‘build’ stage of cellulosome structural studies of the cellulosome from Clostridium thermocellum. We first describe the crystal structure of a heterodimeric complex comprising the type-II cohesin (CohII) from cell surface anchoring protein SdbA and a trimodular C-terminal truncation of the CipA scaffoldin protein containing the ninth type-I cohesin module (CohI9), a linker, the X-module (X), and the type-II dockerin module (DocII). This structure revealed novel intertwining of scaffoldin molecules and extensive reciprocal contacts between the CohI9 and the X-module of another scaffoldin molecule. Sedimentation velocity experiments indicate dimerization also occurs in solution. We have carried out the crystallization and structural analysis of a heterotrimeric complex containing the CohI9—X-DocII:CohII complex bound to the type-I dockerin module (DocI) from the Cel9D enzyme, which represents the largest cellulosome fragment ever determined. Identical inter-scaffoldin interactions were observed in the heterotrimeric complex structure as were seen in the heterodimeric complex. However, small angle X-ray scattering (SAXS) studies indicate that this dimerization does not occur in solution. The crystal structures and additional SAXS studies reveal flexibility in the CohI9—X linker that is surprisingly restricted to two dimensions. In addition, this structure provides the first evidence of an orientation bias in DocI binding. Finally, SAXS was used to investigate modular orientations and linker flexibility in several cellulosome fragments. These studies indicate that cellulosomal linkers exhibit restricted and in some cases highly restrained flexibility. Specifically, scaffoldin linkers display two dimensional motions, enzymes maintain close contact with their cognate DocI modules, and enzyme positions rotate about 90° relative to neighbouring enzymes on the scaffoldin. / Thesis (Ph.D, Biochemistry) -- Queen's University, 2010-09-02 02:50:11.12

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