To begin understanding how the architecture of hot Jupiter planetary systems can be so radically different from that of our own solar system, requires the dynamical evolution of planets to be known. By measuring the sky-projected obliquity � of a system it is possible to determine the dominant process in the dynamical evolution. If a transiting exoplanet that crosses the disc of its host star passes over a starspot, then the amount of received intensity from the star will change. By modelling the position of the anomaly in the lightcurve it is possible to precisely determine the position of the starspot on the stellar disc. If the position of the starspot can be found at two distinct times using two closely spaced transits, then it is possible to measure. Before now there was no definitive model capable of accurately modelling both a planetary transit and a starspot. This research focuses on the development of prism which is capable of accurately modelling a transit containing a starspot anomaly. Due to the nature of the parameter space a new optimisation algorithm was developed, gemc, which is a hybrid between a genetic algorithm and MCMC.

This thesis is in three parts: 1) a kinematical study of exoplanet host stars, 2) a study of the detached eclipsing binary V1094 Tau and 3) and observations of other eclipsing binaries. Part I investigates kinematical biases between two methods of detecting exoplanets; the ground based transit and radial velocity methods. Distances of the host stars from each method lie in almost non-overlapping groups. Samples of host stars from each group are selected. They are compared by means of matching comparison samples of stars not known to have exoplanets. The detection methods are found to introduce a negligible bias into the metallicities of the host stars but the ground based transit method introduces a median age bias of about -2 Gyr. Part II describes a detailed analysis of V1094 Tau. Spectra were analysed by the cross-correlation software TODCOR to obtain radial velocities, and uvby photometric light curves were analysed by the JKTEBOP software. Part III describes an observing run at SAAO Sutherland, aimed to survey detached eclipsing binaries. Light curves and two spectra each from two binaries were analysed, to determine masses and radii to the 10 to 30% level. This is a proof in principle that runs on 2-metre class telescopes can identify targets for detailed follow-up observations.

Simple single parameter models describing the evolution of globular cluster mass functions (GCMFs) are applied to early type Virgo galaxies. These models assume the dominant form of mass-loss in globular clusters (GCs) is two-body relaxation driven evaporation, and that the cluster initial mass function (CIMF) is described by a Schechter (1976) function. It is concluded that evaporation is primarily responsible for turning a Schechter (1976) CIMF into an evolved GCMF as observed in the Milky Way and other extant galaxies, and an estimate for the corresponding mass-loss rate is made. However, these models do not address the problem of why the GCMF is observed to be the same at all radii, and do not fully recover the shape of the GCMF in the most massive galaxies.

This thesis explores the growth of galaxies during the first few billion years of galaxy formation and their potential role as the sources which powered the process of reionization. The data used throughout the thesis is taken from the Cosmic Assembly Near-infrared Extragalactic Legacy Survey (CANDELS). First, we measure new estimates for the galaxy stellar mass function and star formation rates for samples of galaxies at z ~ 4, 5, 6 &7 using data in the CANDELS GOODS South field. The deep near-infrared observations allow us to construct the stellar mass function at z > 6 directly for the first time. We estimate stellar masses for our sample by fitting the observed spectral energy distributions with synthetic stellar populations, including the contributions from nebular line and continuum emission. The observed UV luminosity functions for the samples are consistent with previous observations, however we find that the observed M(UV) - stellar mass relation has a shallow slope more consistent with a constant mass to light ratio and a normalisation which evolves with redshift. We observe stellar mass functions which have steep low-mass slopes (alpha ~ -1.9), steeper than previously observed at these redshifts and closer to that of the UV luminosity function. Integrating our new mass functions, we find the observed stellar mass density evolves from log10(rho) = 6.64 +0.58/-0.89 at z ~ 7 to 7.36 +/- 0.06 solar masses per Mpc^-3 at z ~ 4. Combining the measured UV continuum slopes (beta) with their rest-frame UV luminosities, we calculate dust corrected star-formation rates (SFR) for our sample. We find the specific star-formation rate for a fixed stellar mass increases with redshift whilst the global SFR density falls rapidly over this period. Our new SFR density estimates are higher than previously observed at this redshift. Next, we utilise the same dataset to test a new method for estimating the merger fraction of galaxies in photometric surveys. Using a probabilistic method for estimating close galaxy pairs using photometric redshift probability distributions, we estimate the merger fraction of galaxies at z > 2. For projected separations of 5 <= r <= 20 kpc and 5 <= r <= 30 kpc we measure the merger fraction for mass selected samples of log(M) > 9.5 and log(M)> 10 and merger ratios of 1:4 or less (major mergers). For assumed merger timescales based on hydrodynamical simulations, we estimate the average time between mergers per galaxy (Gamma, Gyr) and the comoving merger rate (R, /Gyr/Mpc^-3). Over the redshift range 2 < z < 4 we find that the average time between mergers per galaxy is approximately constant. Compared to the star-formation rates measured for galaxies at these masses, we conclude that star-formation is the dominant form of growth (by a factor ~10 times) during this epoch. Although we find that the methodology performs well at z ~ 4, more data is required to make robust estimations of the merger fraction at z ~5 or z ~ 6. Similarly, tighter constraints on the observed stellar mass functions are required before we can draw meaningful conclusions from the observed comoving merger rates. Finally, we present a new analysis of the ionizing emissivity (N_ion, /s/Mpc^-3 for galaxies during the epoch of reionization and their potential for completing and maintaining reionization. We use extensive SED modelling -- incorporating two plausible mechanisms for the escape of Lyman continuum photon -- to explore the range and evolution of ionizing efficiencies consistent with new results on galaxy colours (beta) during this epoch. We estimate N_ion for the latest observations of the luminosity and star-formation rate density at z < 10, outlining the range of emissivity histories consistent with our new model. Given the growing observational evidence for a UV colour-magnitude relation in high-redshift galaxies, we find that for any plausible evolution in galaxy properties, red (brighter) galaxies are less efficient at producing ionizing photons than their blue (fainter) counterparts. The assumption of a redshift and luminosity evolution in beta leads to two important conclusions. Firstly, the ionizing efficiency of galaxies naturally increases with redshift. Secondly, for a luminosity dependent ionizing efficiency, we find that galaxies down to a rest-frame magnitude of M_uv ~ -15 alone can potentially produce sufficient numbers of ionizing photons to maintain reionization as early as z ~ 8 for a clumping factor of C = 3.

This thesis investigates the evolution of massive galaxies throughout the last 11 billion years using measured stellar masses and star formation rates. Firstly, we present a study of the resolved star-forming properties of a sample of distant massive (M > 10{11}) galaxies in the GOODS NICMOS Survey (GNS) within the redshift range 1.5 < z < 3 in order to measure the spatial location of ongoing star formation (SF). We find that the SFRs present in different regions of a galaxy reflect the already existent stellar mass density, i.e. high density regions have higher SFRs than lower density regions, on average. We find that these massive galaxies fall into three broad classifications of SF distributions. These different SF distributions increase the effective radii to z=0, by ~16 plus-minus 5 % , with little change in the Sersic index (n), with an average delta n = -0.9 plus-minus 0.9, after evolution. These results are not in agreement with the observed change in the effective radius and n between z ~2.5 and z ~0. We conclude that SF and stellar migration alone cannot account for the observed change in structural parameters for this galaxy population, implying that other mechanisms must additionally be at work to produce the evolution, such as merging. In Chapter 2, we present a study of the stellar mass growth of the progenitors of local massive galaxies at number densities of n < or = 1x10{-4} Mpc{-3} in the redshift range 0.3<z<3.0. We select the progenitors of massive galaxies using two number density selection techniques: a constant number density selection, and one which is adjusted to account for major mergers. We find that the direct progenitors of massive galaxies grow by a factor of four in total stellar mass over this redshift range. On average the stellar mass added via the processes of star formation, major, and minor mergers account for 23 plus-minus 8 %, 17 plus-minus 15 % and 35 plus-minus 14 %, respectively, of the total galaxy stellar mass at z=0.3. Therefore, 52 plus-minus 20% of the total stellar mass in massive galaxies at z=0.3 is created externally to local massive galaxies. We examine the dominance of these processes across this redshift range and find that at z>1.5 SF is the dominant form of stellar mass growth, while at z<1.5 mergers become the dominant form with minor mergers the dominant form of growth at z<1.0. We also explore the implication of these results on other galaxy formation processes such as the cold gas accretion rate of the progenitors of most massive galaxies over the same redshift range. We find that the gas accretion rate decreases with redshift with an average gas accretion rate of ~65 M yr{-1} over the redshift range of 1.5<z<3.0. Finally, we investigate the evolution of the properties of local massive galaxies over the redshift range 0.3<z<3.0. We again select the progenitors of local massive galaxies using a constant number density selection. We find that the average progenitor galaxy appears passive in $UVJ$ colours since at least z=3.0. We examine the UVJ colours and find that the average progenitor of a local massive galaxy has not lived on the blue cloud since z=3.0. The passive fraction of the progenitor population has increased from 56 plus-minus 7% at z=3.0 to 94 plus-minus 8% at z=0.3. This result implies that the majority of the progenitors of local massive galaxies have stopped actively star forming by z=3.0. Examining the structural properties of the progenitor galaxies we show that the size evolution of a galaxy sample selected this way is on average lower than the findings of other investigations into the size evolution of massive galaxies which have found that they must grow in size by a factor of 2-4 from redshift 3.0 to the present day. The average n of the progenitor population evolves significantly over the redshift range studied, with the population being dominated by low n objects (n<2.5) at z>1.7 and transitioning to high n objects at z<1.7. Splitting the high and low $n$ objects into SFing and passive samples. We find that 41 plus-minus 4 % of the sample at z>2.5 are passive low n systems, possibly implying that local massive galaxies were passive disk-like systems at early cosmic times.

Galaxy formation is still a current topic in astronomy. An important tool to understanding it is through simulation, which allows galaxies to be studied from all angles and across time. It allows us to explore the gap between observation and theory, but only if the results are sufficiently accurate. In this thesis I look at the majority of the simulation pipeline from running through the various stages of analysis, and some of the limits of their accuracy, and the fidelity of the subsequent analysis tools. It starts by looking at running simulations from initial conditions, and what influence changing parameters and simulation engines has on the outcome. Then I look in detail at how successful subhalo detection is by comparing a number of substructure finders, and examining their strengths and weaknesses. Following this I focus on a single parameter recovered for such haloes, the spin, and how well it was recovered, and what it tells us about the spin of substructures. Following this I investigated the building of merger trees, by writing my own merger tree program, and comparing it with some of the established ones. Then I look at using these processes as input to semi-analytic models, and how mass changes could affect the outcome. Finally I used a number of these tools to investigate the fate of some of the larger haloes formed at early times in an attempt to show where ultra-compact dwarf galaxies are formed and their fate.

This thesis is a study of the magnetic and thermal structuring and dynamics of the solar corona. The work presented here is primarily split into two sections: Initially a study of sausage oscillations of coronal structures in two geometries. Then the development of a static model of a coronal active region. Initially the basic concepts involved in studying the solar corona, in particular those relevant to this thesis, are introduced and explained. In the second chapter sausage mode oscillations in a cylindrical geometry are studied in more detail. In particular a model of these oscillations is developed and used to study the behaviour of these oscillations over a wide range of wavelengths. The use of a wide range of wavelengths allows the resolution of a long-standing disagreement between results found in the long and short wavelength regions. The results of the model developed in chapter 2 are then compared with a novel analytical expansion of the dispersion relation. In chapter 3 the study is extended to the slab geometry, and this is compared to the results found in the cylindrical geometry. The second section of work begins in chapter 4, we develop amodel of a static active region, from magnetogram data taken by the Helioseismic and Magnetic Imager onboard the Solar Dynamics Observatory (SDO/HMI). This was done using a NLFF magnetic field extrapolation, and a 1-D hydrostatic model. The initial results of this modelling are also compared to EUV observations of these active regions. In chapter 5 the results and behaviour of this model is explored in more detail. In particular the behaviour of the hydrostatic model with a varying heating rate. Several individual loops are considered from the magnetic field model and studied in more depth. Various potential diagnostics for the coronal heating function are also considered.

Measuring black hole spin has become a key topic in astrophysics, and recent focus on the spin powering of jets in X-ray binaries has heightened the need for accurate measurements of spin. However, the effects of spin are subtle, and are only imprinted on emission from very close to the black hole. This is revealed since the black hole spin defines the radius of the last stable orbit of the accretion disc, which is smaller for larger spin. Recent advances in X-ray observatories and spectroscopic techniques have enabled spin estimates for a number of black holes in X-ray binaries,but the accuracy of these methods, and the link between spin and jet power,have become very controversial subjects. In this thesis I address the former of these problems through X-ray reflection, which is one of two leading X-ray spectroscopic methods to measure black hole spin (the other being the ‘continuum’ method). Firstly, I investigate the systematic uncertainties associated with the X-ray reflection technique, and display how model degeneracies can severely affect the determination of spin. After establishing these potential flaws I then performed a systematic study of X-ray reflection during four hard state observations of the black hole GX 339−4, and show that the relativistic effects vary significantly over two orders of magnitude in luminosity. I show that this requires the accretion disc to be substantially truncated from the last stable orbit that is used to measure spin, thus rendering spin estimates impossible in the hard state. Following this I analyse over 500 archival observations of the same source with the Rossi Timing X-ray Explorer. Whilst these data cannot directly measure the inner disc radius, they allow a quantitative investigation of how X-ray reflection and the power-law co-evolve. Since the latter gives rise to the former, this allows changes in the accretion geometry to be revealed, which I show to be consistent with a truncated accretion disc in the hard state, and a gradual collapse of the corona in the soft state. Finally, I present three recent observations of GX 339−4 in the hard state with XMM-Newton, which allow an unprecedented simultaneous constraint on the inner accretion disc radius via the reflection and continuum methods. The two techniques agree, and present further compelling evidence for accretion disc truncation in the hard state.

Gravitational waves are an important prediction of Einstein's General theory of Relativity. Derived as a solution to the Einstein field equations, they are predicted to be produced in systems where there is an asymmetric acceleration of matter, and exist as a time varying quadrupolar distortion in spacetime. Due to the rich variety of scientifically interesting astrophysical sources predicted to be producing gravitational radiation, there is significant international effort directed towards their detection. A large network of ground based interferometric detectors is in operation, with upgrades to increase sensitivity already in progress. They operate on the principle of measuring the time varying displacement in the interferometer path length an incident gravitational wave will induce. However, the predicted amplitude of gravitational waves requires the measurement to be made over several kilometres with a displacement sensitivity of less than 10^-18m/sqrt(Hz). Ground based detectors operate in the ~10-10000 Hz region, and are fundamentally limited at the low frequency end by the noisy gravitational environment of the Earth. To enable detection of low frequency sources, LISA - the Laser Interferometer Space Antenna - is a planned mission to place an interferometric gravitational wave detector in space, sensitive to gravitational waves in the 0.1-1000 mHz region. Consisting of a triangular constellation of three spacecraft, LISA will aim to detect gravitational waves by monitoring the fluctuation in the separation between free-falling test masses over a baseline of 5 million kilometres with an accuracy of around 10pm/sqrt(Hz). To demonstrate that LISA technology, such as the ability to place test masses into a suitably quiet gravitational free-fall, is viable, a precursor mission - LISA Pathfinder - will launch in the next few years. LISA Pathfinder will monitor the relative displacement between two free-falling inertial test masses using an interferometer, with the goal of verifying that the required quality of free-fall is achievable in LISA. This work presented in this thesis relates to the development of interferometry for LISA Pathfinder and LISA, the construction of the LISA Pathfinder flight model interferometer, and initial work on developing the interferometer for LISA. The interferometers required for LISA and LISA Pathfinder must be constructed to be durable enough to survive launch and stable enough to measure displacements of a few picometres at frequencies down to a few mHz. Further, to help minimise noise from sources such as residual jitter of the test masses, the beams which probe the test masses must be aligned to within ±25 micrometers of the nominal reflection point. Using ultra low expansion substrates like Zerodur, and attaching optical components with hydroxide catalysis bonding offers one solution which can provide the durability and stability required. To achieve the accuracy of beam positioning, a system which allows measurement of absolute propagation direction of a laser beam was developed. Combined with a coordinate measuring machine, this allows the absolute position of a mm-scale laser beam to be measured with an accuracy of around ±5 micrometers and ±20 microradians. This system can operate in two modes: first as a measurement system allowing measurement of an existing beam; and secondly as a target, where it can be positioned to a desired theoretical (such as the nominal reflection point of a test mass) and a beam can be aligned onto it. Combined with a method of precision adjusting optical components at the sub-micron and microradian level prior to hydroxide catalysis bonding, it enables absolute alignment of ultra-stable interferometers to micron level. Using these techniques, the flight model interferometer for LISA Pathfinder was successfully constructed to meet the alignment and performance requirements. The control system that will maintain the test masses in near free-fall requires a very accurate measure of the attitude of the test masses. This measurement will be provided by the interferometer using differential wavefront sensing (DWS). The flight model interferometer was calibrated to establish the coupling factors between the DWS read-out and the attitude of the test mass to ensure maximum performance of the control system. Building upon the experience gained in developing and building the LISA Pathfinder interferometer, a prototype of the LISA optical bench is in development. The LISA interferometer is significantly more complicated than that of LISA Pathfinder. Some of its features include: imaging systems to minimise coupling of beam tilt to displacement noise; a precision beam expander to generate a beam appropriate for the telescope; a redundant fibre injector system, creating two beams collinear to within a few microns and 10-20 microradians; and polarisation optics for beam steering. The development and current state of the design for the prototype optical bench is presented, along with an overview of its features.

In 1916 Einstein published his General Theory of Relativity, from which the existence of gravitational waves was predicted. Gravitational waves are considered to be ripples or fluctuations in the curvature of space-time, propagating isotropically from their source at the speed of light. However, due to the weak nature of gravity, observing this phenomenon presents a great challenge to the scientific community. Small deviations in the apparent positions of stellar objects were measured by Eddington during a solar eclipse in 1919, which confirmed the curvature of space-time and its effect on light, and there have since been many astronomical observations of gravitational lenses. In 1993 Hulse and Taylor were awarded the Nobel Prize in Physics for their observations of a pulsar in a binary system, providing strong evidence for energy loss by emission of gravitational waves. However, the quest for a direct detection of gravitational waves is ongoing through the development of ever more sensitive technology. The development of laser interferometry, based on Michelson topologies, pro- vides the most encouraging route to observing gravitational radiation. There is currently a global network of first generation interferometric gravitational wave detectors in operation, including GEO600 (UK/Germany), Virgo (Italy/France) and TAMA (Japan) as well as several second generation detectors under construction such as Advanced LIGO (USA) and LIGO-Australia (Australia). In the coming years GEO600 will also undergo a series of small sequential upgrades to GEO-HF, while Virgo aims to become an order of magnitude more sensitive across the entire frequency band, as Advanced Virgo. The Institute for Gravitational Research (IGR) at the University of Glasgow has for many years been in strong collaboration with the Albert Einstein Institute in Hanover and Golm, the University of Hanover, the University of Cardiff and the University of Birmingham. The Glasgow group have been involved with developments on GEO600 since its initial construction in 1995, from which a lot of technology has been subsequently adopted for use in other large baseline detectors. There is a 10m prototype interferometer housed in the JIF laboratory at Glasgow, which is utilised for testing new technology and optical configurations of interest to this and the wider collaboration. The research contained in this thesis has been carried out on the Glasgow prototype to investigate novel technology of potential importance to future generations of gravitational wave detectors. In Chapter 1 the history of gravitational radiation is discussed, along with a summary of Einstein’s General Theory of Relativity to reveal the nature of gravitational radiation production. From this analysis several potential sources of astronomical origin are detailed for which the design of ground based detectors are optimised. Various interferometric solutions for detecting gravitational waves are described in Chapter 2, beginning with the most fundamental Michelson topology and thereupon key enhancements, such as Fabry-Perot cavities, power recycling and signal recycling are outlined. The Pound-Drever-Hall scheme used to sense and control the relative distances between each optical component is detailed, including modifications to this technique for controlling significantly more complex systems with many optical elements. The most important attribute in the overall design of an interferometric gravitational wave detector is the total noise limit to the sensitivity, which is comprised of both technical noise and fundamental noise. A summary is provided of the seismic, thermal, and laser noise contributing to technical noise as well as the fundamental quantum noise, consisting of photon shot noise and radiation pressure noise. From this discussion, the author introduces the current global network, and proposed future generations of ground-based detectors intended to open a new field of gravitational wave astronomy. In all proposed upgrades and future detectors the input power must be increased to improve detector sensitivity. Two experiments were designed, con- structed and completed at the Glasgow prototype interferometer related to separate issues of concern for high power regimes. In the first experiment, one of the arms of the Glasgow prototype was commissioned as an all-reflective optical cavity, whereby the partially transmissive input mirror was replaced with a three-port diffraction grating mounted on the bottom stage of a triple pendulum. This investigation was designed to characterise the performance of the grating compared to the conventional input mirror of a Fabry-Perot cavity, whilst revealing issues related to the dynamics of suspended grating input couplers on the control signals. The realisation of grating devices for use in interferometric systems would open a pathway to mitigating the otherwise limiting thermal noise associated to the mirror coatings. The other arm of the Glasgow prototype was chosen to investigate the modified dynamic behaviour of suspended cavity mirrors when signifiant radiation pressure forces are incident. The experiment involved replacing one of the suspended cavity mirrors with a light-weight counterpart designed specifically to increase the overall sensitivity to radiation pressure. By probing the system response for different cavity detunings, it was possible to observe and char- acterise the opto-mechanical resonance, commonly termed an optical spring, which induces optical rigidity at lower frequencies and enhanced sensitivity around the resonant feature. Although optical rigidity suppresses the system response, which is otherwise undesired within gravitational wave detectors, it does however enable systems, which under the right conditions can be self-locking, i.e. the mirror control turned off. Furthermore, the enhanced detector sensitivity at the optical spring frequency can be optimised for different frequencies of interest, and could potentially be used to beat the limit imposed by the Heisenberg Uncertainty Principle for independent cavity mirrors. Together, these experiments may provide information useful to the design of future interferometric gravitational wave detectors.