Neutrino Event Rates from Gamma Ray Bursts

We recalculate the diffuse flux of high energy neutrinos produced by Gamma Ray Bursts (GRB) in the relativistic fireball model. Although we confirm that the average single burst produces only ~10^{-2} high energy neutrino events in a detector with 1 km^2 effective area, i.e. about 10 events per year, we show that the observed rate is dominated by burst-to-burst fluctuations which are very large. We find event rates that are expected to be larger by one order of magnitude, likely more, which are dominated by a few very bright bursts. This greatly simplifies their detection.Comment: 14 pages, Latex2.09, uses aastex4.0 and epsf.sty, 3 postscript files. Minor revisions. To be published in ApJ Letter

Low-frequency component electric microfield distributions in plasmas

Low frequency component electric microfield distributions in plasma

Off-duty activity equipment and facilities for advanced spacecraft /preliminary design/

Off-duty activity equipment and facilities preliminary design for advanced spacecraf

Elusive Destiny: The Internationalist Movement in Modern Hawaii

Humanities Open Book Program, a joint initiative of the National Endowment for the Humanities and the Andrew W. Mellon FoundationFor nearly two centuries, Hawaii's leaders have endeavored to forge a unique international role for the Islands in Pacific and even in world affairs. Colorful figures such as Kalakaua, Walter Murray Gibson, and a host of others labored mightily to transform the Islands into an oceanic political power. Although their campaigns eventually failed, Hawaii was put forever on the diplomatic map with such ventures as the attempted annexation of a distant South Pacific islands group, the provocation of a quarrel with Germany that led to the brink of war, and the persistent defense of the interests of Pacific islanders in the capitals of Europe and America. A very different but nonetheless ambitious surge of activism followed Hawaii's annexation by the United States at the turn of the present century. Shortly after World War I, local internationalists formed the Pan-Pacific Union and the Institute of Pacific Relations as the foci of a concerted effort to foster greater political and cultural understanding throughout the Pacific and the world. While both groups frequently created headlines with various programs and proposals, the latter organization became widely known when it came under the attack of the anticommunist movement during the late 1940's and 1950's. Related endeavors in more recent years have produced numerous activities in educational, political, scientific, and commercial circles that presently involve a fair proportion of the Island establishment as well as numerous prominent figures from abroad. Elusive Destiny brings the details of this little-known but always present impulse in Hawaiian history together for the first time and goes on to speculate about the likely causes of successes or failures. Carefully researched and documented, richly illustrated, and concisely written, the book should interest all persons concerned with the modern Hawaiian experience

Extracting the Gamma Ray Signal from Dark Matter Annihilation in the Galactic Center Region

The GLAST satellite mission will study the gamma ray sky with considerably greater exposure than its predecessor EGRET. In addition, it will be capable of measuring the arrival directions of gamma rays with much greater precision. These features each significantly enhance GLAST's potential for identifying gamma rays produced in the annihilations of dark matter particles. The combined use of spectral and angular information, however, is essential if the full sensitivity of GLAST to dark matter is to be exploited. In this paper, we discuss the separation of dark matter annihilation products from astrophysical backgrounds, focusing on the Galactic Center region, and perform a forecast for such an analysis. We consider both point-like and diffuse astrophysical backgrounds and model them using a point-spread-function for GLAST. While the results of our study depend on the specific characteristics of the dark matter signal and astrophysical backgrounds, we find that in many scenarios it is possible to successfully identify dark matter annihilation radiation, even in the presence of significant astrophysical backgrounds.Comment: 8 pages, 5 figures. Minor changes, note added. Matches published versio

The Milky Way as a Kiloparsec-Scale Axionscope

Very high energy gamma-rays are expected to be absorbed by the extragalactic background light over cosmological distances via the process of electron-positron pair production. Recent observations of cosmologically distant gamma-ray emitters by ground based gamma-ray telescopes have, however, revealed a surprising degree of transparency of the universe to very high energy photons. One possible mechanism to explain this observation is the oscillation between photons and axion-like-particles (ALPs). Here we explore this possibility further, focusing on photon-ALP conversion in the magnetic fields in and around gamma-ray sources and in the magnetic field of the Milky Way, where some fraction of the ALP flux is converted back into photons. We show that this mechanism can be efficient in allowed regions of the ALP parameter space, as well as in typical configurations of the Galactic Magnetic Field. As case examples, we consider the spectrum observed from two HESS sources: 1ES1101-232 at redshift z=0.186 and H 2356-309 at z=0.165. We also discuss features of this scenario which could be used to distinguish it from standard or other exotic models.Comment: 7 pages, 4 figures. Matches published versio