Modern Man: Popeye as an Indicator of Movement Toward an Industrialized South in William Faulkner’s Sanctuary

Traditionally, Faulkner’s Sanctuary has been classified as a sordid tale of sexual intrigue, set against a backdrop of death and decay in a post-war Deep South. The novel’s foothold in the Southern Gothic realm of literature has been further cemented by its graphic depictions of rape, prostitution and murder. Though these outrageous plot developments set the stage for much of the action in the story, they do little to explain an important role that is traditionally much overlooked – that of the character Popeye. Faulkner’s Popeye symbolizes the insertion of an unwanted Northern modernity into a world of slow Southern decline. His characterization is accompanied by attributes that earmark him as the indicator of a brazen new social order. By presenting industrial progress against that of a traditionally archaic South, implementing the “Gray Man” (an industrial, robotic character) as evidence of otherness within a machine-like social construct, and by illuminating the problems inherent within this type of abrupt cultural shift, William Faulkner sets Popeye up as the catalyst for eventual southern modernity in Sanctuary

On relative supernova rates and nucleosynthesis roles

It is shown that the Ni-56-Fe-56 observed in SN 1987A argues that core collapse supernovae may be responsible for more that 50 percent of the iron in the galaxy. Furthermore it is argued that the time averaged rate of thermonuclear driven Type I supernovae may be at least an order of magnitude lower than the average rate of core collapse supernovae. The present low rate of Type II supernovae (below their time averaged rate of approx. 1/10 yr) is either because the past rate was much higher because many core collapse supernovae are dim like SN 1987A. However, even in this latter case they are only an order of magnitude dimmer that normal Type II's due to the contribution of Ni-56 decay to the light curve

Active Carbon and Oxygen Shell Burning Hydrodynamics

We have simulated 2.5$\times10^3$ s of the late evolution of a $23 \rm M_\odot$ star with full hydrodynamic behavior. We present the first simulations of a multiple-shell burning epoch, including the concurrent evolution and interaction of an oxygen and carbon burning shell. In addition, we have evolved a 3D model of the oxygen burning shell to sufficiently long times (300 s) to begin to assess the adequacy of the 2D approximation. We summarize striking new results: (1) strong interactions occur between active carbon and oxygen burning shells, (2) hydrodynamic wave motions in nonconvective regions, generated at the convective-radiative boundaries, are energetically important in both 2D and 3D with important consequences for compositional mixing, and (3) a spectrum of mixed p- and g-modes are unambiguously identified with corresponding adiabatic waves in these computational domains. We find that 2D convective motions are exaggerated relative to 3D because of vortex instability in 3D. We discuss the implications for supernova progenitor evolution and symmetry breaking in core collapse.Comment: 5 pages, 4 figures in emulateapj format. Accepted for publication in ApJ Letters. High resolution figure version available at http://spinach.as.arizona.ed

The Impact of Hydrodynamic Mixing on Supernova Progenitors

Recent multidimensional hydrodynamic simulations have demonstrated the importance of hydrodynamic motions in the convective boundary and radiative regions of stars to transport of energy, momentum, and composition. The impact of these processes increases with stellar mass. Stellar models which approximate this physics have been tested on several classes of observational problems. In this paper we examine the implications of the improved treatment on supernova progenitors. The improved models predict substantially different interior structures. We present pre-supernova conditions and simple explosion calculations from stellar models with and without the improved mixing treatment at 23 solar masses. The results differ substantially.Comment: 12 pages, 2 figures, accepted for publication in the Astrophysical Journal Letter

Collapsars - Gamma-Ray Bursts and Explosions in "Failed Supernovae"

Using a two-dimensional hydrodynamics code (PROMETHEUS), we study the continued evolution of rotating massive helium stars whose iron core collapse does not produce a successful outgoing shock, but instead forms a black hole. We study the formation of a disk, the associated flow patterns, and the accretion rate for disk viscosity parameter, alpha ~ 0.001 and 0.1. For the standard 14 solar mass model the average accretion rate for 15 s is 0.07 solar masses per second and the total energy deposited along the rotational axes by neutrino annihilation is (1 - 14) x 10**51 erg, depending upon the evolution of the Kerr parameter and uncertain neutrino efficiencies. Simulated deposition of this energy in the polar regions results in strong relativistic outflow - jets beamed to about 1.5% of the sky. The jets remain highly focused, and are capable of penetrating the star in 5 - 10 s. After the jet breaks through the surface of the star, highly relativistic flow can commence. Because of the sensitivity of the mass ejection and jets to accretion rate, angular momentum, and disk viscosity, and the variation of observational consequences with viewing angle, a large range of outcomes is possible ranging from bright GRBs like GRB 971214 to faint GRB-supernovae like SN 1998bw. X-ray precursors are also possible as the jet first breaks out of the star. While only a small fraction of supernovae make GRBs, we predict that all GRBs longer than a few seconds will make supernovae similar to SN 1998bw. However, hard, energetic GRBs shorter than a few seconds will be difficult to make in this model.Comment: Latex, 66 pages including 27 figures (9 color), Submitted to The Astrophysical Journal, latex uses aaspp4.sty. Figures also available at http://www.ucolick.org/~andre

Ultrasonic Microdissection of Rat Cerebellum for Scanning Electron Microscopy

The cerebelli of rats were initially fixed with aldehydes (modified Karnovsky\u27s fixative; 503 mOsM/L) by cardiac perfusion. Blocks of tissue were razor-cut, usually longitudinal to folia, and immersed in the same fluid for 2-4 hours. Three separate methods of treatment followed: (1) immersion in 1% aqueous boric acid, or (2) in 2% phosphate buffered OsO4 followed by boric acid or (3) in an 8/2 mixture of boric acid and OsO4. After 18-48 hours immersion the blocks were dehydrated in ascending grades of acetone. They were then exposed to ultrasound in 100% acetone at frequencies of 80 kHz or 40 kHz for 10 to 20 minutes. Microdissection of cut surfaces (erosion) occurs after all three treatments. It is least extensive after boric acid, moderate after OsO4 and greatest after the combined mixture. All cerebellar cell types are recognizable as are numerous fibers according to morphology and position. Variable erosion accommodates analysis of different levels of neural organization. In general, structural situations not involving great depth of field are best revealed by H3BO3 or OsO4. Blood vascular relationships to other structures are best demonstrated in deeply eroded specimens

Massive Stars in the Range 13−25M⊙\rm 13-25 M_\odot: Evolution and Nucleosynthesis. II. the Solar Metallicity Models

We present the evolutionary properties of a set of massive stellar models (namely 13, 15, 20 and 25 $\rm M_\odot$) from the main sequence phase up to the onset of the iron core collapse. All these models have initial solar chemical composition, i.e. Y=0.285 and Z=0.02. A 179 isotope network, extending from neutron up to $\rm ^{68}Zn$ and fully coupled to the evolutionary code has been adopted from the Carbon burning onward. Our results are compared, whenever possible, to similar computations available in literature.Comment: 42 pages, 18 figures, 26 tables, accepted for publicatin in ApJ

2D Multi-Angle, Multi-Group Neutrino Radiation-Hydrodynamic Simulations of Postbounce Supernova Cores

We perform axisymmetric (2D) multi-angle, multi-group neutrino radiation-hydrodynamic calculations of the postbounce phase of core-collapse supernovae using a genuinely 2D discrete-ordinate (S_n) method. We follow the long-term postbounce evolution of the cores of one nonrotating and one rapidly-rotating 20-solar-mass stellar model for ~400 milliseconds from 160 ms to ~550 ms after bounce. We present a multi-D analysis of the multi-angle neutrino radiation fields and compare in detail with counterpart simulations carried out in the 2D multi-group flux-limited diffusion (MGFLD) approximation to neutrino transport. We find that 2D multi-angle transport is superior in capturing the global and local radiation-field variations associated with rotation-induced and SASI-induced aspherical hydrodynamic configurations. In the rotating model, multi-angle transport predicts much larger asymptotic neutrino flux asymmetries with pole to equator ratios of up to ~2.5, while MGFLD tends to sphericize the radiation fields already in the optically semi-transparent postshock regions. Along the poles, the multi-angle calculation predicts a dramatic enhancement of the neutrino heating by up to a factor of 3, which alters the postbounce evolution and results in greater polar shock radii and an earlier onset of the initially rotationally weakened SASI. In the nonrotating model, differences between multi-angle and MGFLD calculations remain small at early times when the postshock region does not depart significantly from spherical symmetry. At later times, however, the growing SASI leads to large-scale asymmetries and the multi-angle calculation predicts up to 30% higher average integral neutrino energy deposition rates than MGFLD.Comment: 20 pages, 21 figures. Minor revisions. Accepted for publication in ApJ. A version with high-resolution figures may be obtained from http://www.stellarcollapse.org/papers/Ott_et_al2008_multi_angle.pd

A dynamical model of surrogate reactions

A new dynamical model is developed to describe the whole process of surrogate reactions; transfer of several nucleons at an initial stage, thermal equilibration of residues leading to washing out of shell effects and decay of populated compound nuclei are treated in a unified framework. Multi-dimensional Langevin equations are employed to describe time-evolution of collective coordinates with a time-dependent potential energy surface corresponding to different stages of surrogate reactions. The new model is capable of calculating spin distributions of the compound nuclei, one of the most important quantity in the surrogate technique. Furthermore, various observables of surrogate reactions can be calculated, e.g., energy and angular distribution of ejectile, and mass distributions of fission fragments. These features are important to assess validity of the proposed model itself, to understand mechanisms of the surrogate reactions and to determine unknown parameters of the model. It is found that spin distributions of compound nuclei produced in $^{18}$O+$^{238}$U $\rightarrow ^{16}$O+$^{240*}$U and $^{18}$O+$^{236}$U $\rightarrow ^{16}$O+$^{238*}$U reactions are equivalent and much less than 10$\hbar$, therefore satisfy conditions proposed by Chiba and Iwamoto (PRC 81, 044604(2010)) if they are used as a pair in the surrogate ratio method.Comment: 17 pages, 5 figure

Screened thermonuclear reactions and predictive stellar evolution of detached double-lined eclipsing binaries

The low energy fusion cross sections of charged-particle nuclear reactions (and the respective reaction rates) in stellar plasmas are enhanced due to plasma screening effects. We study the impact of those effects on predictive stellar evolution simulations for detached double-lined eclipsing binaries. We follow the evolution of binary systems (pre-main sequence or main sequence stars) with precisely determined radii and masses from 1.1Mo to 23Mo (from their birth until their present state). The results indicate that all the discrepancies between the screened and unscreened models (in terms of luminosity, stellar radius, and effective temperature) are within the observational uncertainties. Moreover, no nucleosynthetic or compositional variation was found due to screening corrections. Therefore all thermonuclear screening effects on the charged-particle nuclear reactions that occur in the binary stars considered in this work (from their birth until their present state) can be totally disregarded. In other words, all relevant charged-particle nuclear reactions can be safely assumed to take place in a vacuum, thus simplifying and accelerating the simulation processes.Comment: 5 RevTex pages,no figures. Accepted for publication in Phys.Rev.