ON THE MEASUREMENT OF A COSMOLOGICAL DIPOLE IN THE PHOTON NUMBER COUNTS OF GAMMA-RAY BURSTS

If gamma-ray bursts are cosmological or in a halo distribution their properties are expected to be isotropic (at least to 1st order). However, our motion with respect to the burst parent population (whose proper frame is expected to be that of the Cosmic Microwave Background (CMB), or that of a static halo) will cause a dipole effect in the distribution of bursts and in their photon number counts (together termed a Compton-Getting effect). We argue that the photon number count information is necessary to distinguish a genuine Compton-Getting effect from some other anisotropy and to fully test the proper frame isotropy of the bursts. Using the 2B burst catalogue and the dipole determined from the CMB, we find the surprising result that although the number weighted distribution is consistent with isotropy, the fluence weighted dipole has a correlation with the CMB dipole that has a probability of occuring only 10% of the time for an isotropic photon distribution. Furthermore, the photon and number dipoles are inconsistent under the hypothesis of isotropy, at the 2-sigma level. This could be an indication that a non-negligible fraction of gamma-ray bursts originate in the local, anisotropic universe. (shortened Abstract)Comment: Accepted by ApJ. Self-unpacking (use csh), uuencoded, compressed Postscript, 16 pages + 4 Figures (5 files

The Chandra Fornax Survey - I: The Cluster Environment

We present the first results of a deep Chandra survey of the inner 1 degree of the Fornax cluster of galaxies. Ten 50 ksec pointings were obtained in a mosaic centered on the giant elliptical galaxy NGC 1399 at the nominal cluster center. Emission and temperature maps of Fornax are presented, and an initial study of 771 detected X-ray point sources is made. Regions as small as 100pc are resolved. The intra-cluster gas in Fornax exhibits a highly asymmetric morphology and temperature structure, dominated by a 180 kpc extended ``plume'' of low surface brightness, cool, ~1 keV) gas to the North-East of NGC 1399 with a sharper edge to the South West. The elliptical galaxy NGC 1404 also exhibits a cool halo of X-ray gas within the cluster, with a highly sharpened leading edge as it presumably falls into the cluster, and a cometary-like tail. We estimate that some ~200-400 point sources are physically associated with Fornax. Confirming earlier works, we find that the globular cluster population in NGC 1399 is highly X-ray active, extending to globulars which may in fact be intra-cluster systems. We have also found a remarkable correlation between the location of giant and dwarf cluster galaxies and the presence of X-ray counterparts, such that systems inhabiting regions of low gas density are more likely to show X-ray activity. Not only does this correlate with the asymmetry of the intra-cluster gas but also with the axis joining the center of Fornax to an infalling group 1 Mpc to the South-West. We suggest that Fornax may be experiencing an intergalactic ``headwind'' due to motion relative to the surrounding large-scale structure.Comment: 35 pages, 15 figures, submitted to ApJ. Most figures not included owing to severe compression degradation - we strongly recommend downloading the full resolution paper from http://www.astro.columbia.edu/~caleb/ms_highres.pdf (1.9Mb

Siphonaptera Records and Host Associations From the Central and Eastern Upper Peninsula of Michigan

Fleas were collected from birds and mammals over a five year period in four upper peninsula counties. Identified specimens were compared to published records of distribution for the parasite species and its host species, and only those records which are new county distributions for host or parasite are listed. Four new host records for Michigan, four new flea distribution records for the upper peninsula, and 26 new county records are listed

Ixodes brunneus (Acari: Ixodidae) from Two Bird Hosts: A New Michigan Tick

The tick Ixodes brunneus Koch (Acari: Ixodidae) is reported for the first time in Michigan from two bird hosts at two locations in the lower peninsula. All stages of this tick exclusively feed on birds, and are primarily known from the southern U.S., although abundant records occur from northern states. The role of this species as a vector of pathogens is discussed

Quantum Gravitational Bremsstrahlung, Massless versus Massive Gravity

The massive spin-2 quantum gauge theory previously developed is applied to calculate gravitational bremsstrahlung. It is shown that this theory is unique and free from defects. In particular, there is no strong coupling if the graviton mass becomes small. The cross sections go over smoothly into the ones of the massless theory in the limit of vanishing graviton mass. The massless cross sections are calculated for the full tensor theory.Comment: 13 pages, 1 figur

The Galaxy Cluster Luminosity-Temperature Relationship and Iron Abundances - A Measure of Formation History ?

Both the X-ray luminosity-temperature (L-T) relationship and the iron abundance distribution of galaxy clusters show intrinsic dispersion. Using a large set of galaxy clusters with measured iron abundances we find a correlation between abundance and the relative deviation of a cluster from the mean L-T relationship. We argue that these observations can be explained by taking into account the range of cluster formation epochs expected within a hierarchical universe. The known relationship of cooling flow mass deposition rate to luminosity and temperature is also consistent with this explanation. From the observed cluster population we estimate that the oldest clusters formed at z>~2. We propose that the iron abundance of a galaxy cluster can provide a parameterization of its age and dynamical history.Comment: 13 pages Latex, 2 figures, postscript. Accepted for publication in ApJ Letter

Contextual variety, Internet-of-things and the choice of tailoring over platform : mass customisation strategy in supply chain management

This paper considers the implications for Supply Chain Management from the development of the Internet of Things (IoT) or Internet Connected Objects (ICO). We focus on the opportunities and challenges arising from consumption data as a result of ICO and how this can be translated into a provider’s strategy of offering different varieties of products. In our model, we consider two possible strategies: tailoring strategy and platform strategy. Tailoring strategy implies that a provider produces multiple varieties of a product that meet consumers’ needs. Platform strategy depicts the provider’s actions in offering a flexible and standardised platform which enables consumers’ needs to be met by incorporating personal ICO data onto various customisable applications independently produced by other providers that could be called on in context and on demand. We derive conditions under which each of the strategies may be profitable for the provider through maximising consumers’ value. We conclude by considering the implications for SCM research and practice including an extension of postponement taxonomies to include the customer as the completer of the product