Supergalactic winds driven by multiple superstar clusters

We present two dimensional hydrodynamic calculations of free expanding supergalactic winds, taking into consideration strong radiative cooling. Our main premise is that supergalactic winds are powered by collections of superstar clusters. Every individual superstar cluster is a source of a high metallicity radiative supersonic outflow (paper I, 2003, ApJ, 590, 791). The interaction of winds from neighboring knots of star formation is shown to lead to a collection of stationary oblique shocks and crossing shocks, able to structure the general outflow into a network of dense and cold, kpc long filaments that originate near the base of the outflow. The shocks also lead to extended regions of diffuse soft X-ray emission and furthermore, to channel the outflow with a high degree of collimation into the intergalactic medium.Comment: 10 pages, 5 figures, Accepted for publication in The Astrophysical Journa

Atomic physics and the polar cap

Fundamental mechanisms in polar cap phenomena related to atomic physic

Values and aspirations for coastal waters of the Kimberley: social values and participatory mapping using interviews. Technical Report. Kimberley Marine Research Program Node of the Western Australian Marine Science Institution

This is the first report from the “Values and aspirations for coastal waters of the Kimberley” research project funded by the Western Australian Government and administered by the Western Australian Marine Science Institution (Kimberley Research Node Project 2.1.2). The study area extends from the south western end of Eighty Mile Beach to the Northern Territory Border, a coastline 13,296 km in length at low water mark including the islands. The aim of this 3-year research project is to document and analyse the social values and aspirations of people associated with the existing and proposed marine parks at Eighty Mile Beach, Roebuck Bay, Lalang-garram (Camden Sound) and North Kimberley, and with other coastal waters of the Kimberley

Synthesis of Stimuli-Responsive Programmable Polymers Through Ring-Opening–Metathesis Cross-Metathesis (ROM-CM)

Stimuli-responsive polymers can change their physical and/or chemical properties in response to external stimuli. These polymers have found great success in a number of important areas including molecular gels and biomedical engineering, as well as success in applications such as targeted drug delivery and biosensors. We have been working toward the development of programmable polymers that remember the response after a stimulus is withdrawn. To this end, we set out to synthesize specific functional monomers. While different types of reactions could potentially result in the desired target monomer, we studied the ring-opening metathesis–cross-metathesis reaction (ROM-CM). Previous work of ours synthesized monomer 1a, a cis-norbornene-2,3-dicarboxylic imide precursor to functional monomer 2a. We report herein the attempts to prepare the target monomers 2a and 3 via alternative ROM-CM routes that varied in starting materials, solvent systems, reaction temperatures, and catalyst amounts. We discovered that methanol based solvent systems resulted in a higher production of oligomers and other side products. In addition, one promising route using the new maleic acid starting material in place of ethyl acrylate was found to effectively undergo the ROM-CM reaction with monomer 1b. This reaction appeared to produce the desired product 2b which is currently being converted to the diester monomer 3 for further characterization. Future efforts will involve further examination of the ROM-CM reaction of maleic acid and other olefins with the norbornene-dicarboxylic imide precursor, dilute conditions in norbornene reactions, and alternative synthetic routes

Attributes of Spirituality Described by Survivors of Sexual Violence

This study focuses on what aspects of attributes of spirituality as defined by Martsolf and Mickley (1998) are most salient for female and male survivors of sexual violence. Content analysis of secondary narrative data, provided by 50 participants in a study of women’s and men’s responses to sexual violence, was coded to the five attributes of spirituality as defined by Martsolf and Mickley. The attribute aspects of connecting with others in spiritual ways and with God/higher power were particularly significant. The attribute of transcendence was found less important, and the attributes of value, becoming, and meaning were not found important. The Martsolf and Mickley framework helped organize narrative data for a content analysis of spirituality in survivors of sexual violence

Absorption-Line Probes of Gas and Dust in Galactic Superwinds

We discuss moderate resolution spectra of the NaD absorption-line in a sample of 32 far-IR-bright starburst galaxies. In 18 cases, the line is produced primarily by interstellar gas, and in 12 of these it is blueshifted by over 100 km/s relative to the galaxy systemic velocity. The absorption-line profiles in these outflow sources span the range from near the galaxy systemic velocity to a maximum blueshift of 400 to 600 km/s. The outflows occur in galaxies systematically viewed more nearly face-on than the others. We therefore argue that the absorbing material consists of ambient interstellar gas accelerated along the minor axis of the galaxy by a hot starburst-driven superwind. The NaD lines are optically-thick, but indirect arguments imply total Hydrogen column densities of N_H = few X 10^{21} cm^{-2}. This implies that the superwind is expelling matter at a rate comparable to the star-formation rate. This outflowing material is very dusty: we find a strong correlation between the depth of the NaD profile and the line-of-sight reddening (E(B-V) = 0.3 to 1 over regions several-to-ten kpc in size). The estimated terminal velocities of superwinds inferred from these data and extant X-ray data are typically 400 to 800 km/s, are independent of the galaxy rotation speed, and are comparable to (substantially exceed) the escape velocities for $L_*$ (dwarf) galaxies. The resulting loss of metals can establish the mass-metallicity relation in spheroids, produce the observed metallicity in the ICM, and enrich a general IGM to 10$^{-1}$ solar metallicity. If the outflowing dust grains survive their journey into the IGM, their effect on observations of cosmologically-distant objects is significant.Comment: 65 pages, including 16 figures. ApJ, in pres

Evaluating the role of bacterial diversity in supporting soil ecosystem functions under anthropogenic stress

Ecosystem functions and services are under threat from anthropogenic global change at a planetary scale. Microorganisms are the dominant drivers of nearly all ecosystem functions and therefore ecosystem-scale responses are dependent on responses of resident microbial communities. However, the specific characteristics of microbial communities that contribute to ecosystem stability under anthropogenic stress are unknown. We evaluated bacterial drivers of ecosystem stability by generating wide experimental gradients of bacterial diversity in soils, applying stress to the soils, and measuring responses of several microbial-mediated ecosystem processes, including C and N cycling rates and soil enzyme activities. Some processes (e.g., C mineralization) exhibited positive correlations with bacterial diversity and losses of diversity resulted in reduced stability of nearly all processes. However, comprehensive evaluation of all potential bacterial drivers of the processes revealed that bacterial α diversity per se was never among the most important predictors of ecosystem functions. Instead, key predictors included total microbial biomass, 16S gene abundance, bacterial ASV membership, and abundances of specific prokaryotic taxa and functional groups (e.g., nitrifying taxa). These results suggest that bacterial α diversity may be a useful indicator of soil ecosystem function and stability, but that other characteristics of bacterial communities are stronger statistical predictors of ecosystem function and better reflect the biological mechanisms by which microbial communities influence ecosystems. Overall, our results provide insight into the role of microorganisms in supporting ecosystem function and stability by identifying specific characteristics of bacterial communities that are critical for understanding and predicting ecosystem responses to global change

Properties of Galactic Outflows: Measurements of the Feedback from Star Formation

Properties of starburst-driven outflows in dwarf galaxies are compared to those in more massive galaxies. Over a factor of roughly 10 in galactic rotation speed, supershells are shown to lift warm ionized gas out of the disk at rates up to several times the star formation rate. The amount of mass escaping the galactic potential, in contrast to the disk, does depend on the galactic mass. The temperature of the hottest extended \x emission shows little variation around $\sim 10^{6.7}$ K, and this gas has enough energy to escape from the galaxies with rotation speed less than approximately 130 km/s.Comment: 11 pages + 3 figues. Accepted for publication in the Astrophysical Journa