Letter from Thomas Bolton to James B. Finley

Bolton writes concerning a petition for the pardon of a convict, William Ray. Bolton asks Finley to present the petition. In the event Ray is discharged, a small sum will be sent to Finley to pay for his trip home. Abstract Number - 1089https://digitalcommons.owu.edu/finley-letters/2073/thumbnail.jp

Thomas E. Long in a Senior Voice Recital

This is the program for the senior voice recital of baritone Thomas E. Long, accompanied by Thomas W. Bolton on piano. The recital was held on April 30, 1968, in Mitchell Hall Auditorium

Central dark matter trends in early-type galaxies from strong lensing, dynamics and stellar populations

We analyze the correlations between central dark matter (DM) content of early-type galaxies and their sizes and ages, using a sample of intermediate-redshift (z ~ 0.2) gravitational lenses from the SLACS survey, and by comparing them to a larger sample of z ~ 0 galaxies. We decompose the deprojected galaxy masses into DM and stellar components using combinations of strong lensing, stellar dynamics, and stellar populations modeling. For a given stellar mass, we find that for galaxies with larger sizes, the DM fraction increases and the mean DM density decreases, consistently with the cuspy halos expected in cosmological formation scenarios. The DM fraction also decreases with stellar age, which can be partially explained by the inverse correlation between size and age. The residual trend may point to systematic dependencies on formation epoch of halo contraction or stellar initial mass functions. These results are in agreement with recent findings based on local galaxies by Napolitano, Romanowsky & Tortora (2010) and suggest negligible evidence of galaxy evolution over the last ~ 2.5 Gyr other than passive stellar aging.Comment: 5 pages, 3 figures, accepted for publication on ApJL. Version including further updates and a complementary note added in proo

Frances Scott and Thomas Bolton in a Faculty Recital

This is the program for the faculty recital featuring soprano Frances Scott and tenor Thomas Bolton. Ms. Scott and Mr. Bolton were assisted by pianists Dora Ann Purdy and William Bill Trantham. This recital took place on March 22, 1976, in the Mabee Fine Arts Center Recital Hall

Can dry merging explain the size evolution of early-type galaxies?

The characteristic size of early-type galaxies (ETGs) of given stellar mass is observed to increase significantly with cosmic time, from redshift z>2 to the present. A popular explanation for this size evolution is that ETGs grow through dissipationless ("dry") mergers, thus becoming less compact. Combining N-body simulations with up-to-date scaling relations of local ETGs, we show that such an explanation is problematic, because dry mergers do not decrease the galaxy stellar-mass surface-density enough to explain the observed size evolution, and also introduce substantial scatter in the scaling relations. Based on our set of simulations, we estimate that major and minor dry mergers increase half-light radius and projected velocity dispersion with stellar mass (M) as M^(1.09+/-0.29) and M^(0.07+/-0.11), respectively. This implies that: 1) if the high-z ETGs are indeed as dense as estimated, they cannot evolve into present-day ETGs via dry mergers; 2) present-day ETGs cannot have assembled more than ~45% of their stellar mass via dry mergers. Alternatively, dry mergers could be reconciled with the observations if there was extreme fine tuning between merger history and galaxy properties, at variance with our assumptions. Full cosmological simulations will be needed to evaluate whether this fine-tuned solution is acceptable.Comment: 5 pages, 2 figures. Accepted for publication in ApJ Letter

Thermal constraints on the reionisation of hydrogen by population-II stellar sources

Measurements of the intergalactic medium (IGM) temperature provide a potentially powerful constraint on the reionisation history due to the thermal imprint left by the photo-ionisation of neutral hydrogen. However, until recently IGM temperature measurements were limited to redshifts 2 < z < 4.8, restricting the ability of these data to probe the reionisation history at z > 6. In this work, we use recent measurements of the IGM temperature in the near-zones of seven quasars at z ~ 5.8 - 6.4, combined with a semi-numerical model for inhomogeneous reionisation, to establish new constraints on the redshift at which hydrogen reionisation completed. We calibrate the model to reproduce observational constraints on the electron scattering optical depth and the HI photo-ionisation rate, and compute the resulting spatially inhomogeneous temperature distribution at z ~ 6 for a variety of reionisation scenarios. Under standard assumptions for the ionising spectra of population-II sources, the near-zone temperature measurements constrain the redshift by which hydrogen reionisation was complete to be z > 7.9 (6.5) at 68 (95) per cent confidence. We conclude that future temperature measurements around other high redshift quasars will significantly increase the power of this technique, enabling these results to be tightened and generalised.Comment: 15 pages, 8 figures, accepted for publication in MNRA

Effect of Thermal Losses and Fluid-Structure Interaction on the Transfer Impedance of Microperforated Films

It has been shown previously that incompressible computational fluid dynamics (CFD) models can be solved in the time domain to calculate the transfer impedances of microperforated panels. However, these models require relatively lengthy run times, do not allow for thermal losses due to irreversible heat transfer to the panels, and rely on the assumption that the solid parts of the panels are rigid. In the present work, compressible, thermo-acoustic models, solved in the frequency domain, have been used to compute thermal losses in addition to viscous losses; these calculations enable the visualization and spatial localization of both loss mechanisms. Thermal losses prove to be relatively small compared to viscous losses in typical geometries, but they become progressively more important as the frequency increases. Additionally, the fully-coupled fluid-structure interaction (FSI) problem has been solved to determine the range of parameters within which the transfer impedance of a rigid microperforated panel can be added in parallel to the impedance of a limp panel ( ) to account for panel flexibility. In particular it will be shown under what conditions the relative motion between the fluid velocity through the perforations and the velocity of the panel, including its phase, must be explicitly considered

Thomas Wayne Bolton in a Junior Voice Recital

This is the program for the voice recital of tenor Thomas Wayne Bolton, accompanied by Glenda Plummer on piano. The recital was held on April 21, 1967, at Calvary Baptist Church

Guided Graph Spectral Embedding: Application to the C. elegans Connectome

Graph spectral analysis can yield meaningful embeddings of graphs by providing insight into distributed features not directly accessible in nodal domain. Recent efforts in graph signal processing have proposed new decompositions-e.g., based on wavelets and Slepians-that can be applied to filter signals defined on the graph. In this work, we take inspiration from these constructions to define a new guided spectral embedding that combines maximizing energy concentration with minimizing modified embedded distance for a given importance weighting of the nodes. We show these optimization goals are intrinsically opposite, leading to a well-defined and stable spectral decomposition. The importance weighting allows to put the focus on particular nodes and tune the trade-off between global and local effects. Following the derivation of our new optimization criterion and its linear approximation, we exemplify the methodology on the C. elegans structural connectome. The results of our analyses confirm known observations on the nematode's neural network in terms of functionality and importance of cells. Compared to Laplacian embedding, the guided approach, focused on a certain class of cells (sensory, inter- and motoneurons), provides more biological insights, such as the distinction between somatic positions of cells, and their involvement in low or high order processing functions.Comment: 43 pages, 7 figures, submitted to Network Neuroscienc