Ranches with Wolves: How straight talk is the salvation of open range in the Northern Rockies

Since U.S. Fish and Wildlife Service reintroduced gray wolves into Yellowstone National Park and central Idaho in 1995 and 1996, conflicts between wolves and livestock have increased as the wolf population has grown and expanded. Ranchers in wolf country face a changing ecology that now includes wolves as a keystone predator, and failing to adapt to the change has meant hard losses for some ranchers. In other cases, ranchers have found ways to compensate for the reintroduced predator. These ranching situations, both the unchanged and the changed, offer lessons to livestock producers who can anticipate wolves becoming part of the landscape. And the values most likely to make the transition from ranching without a viable wolf population to ranching with a viable population as painless as possible, the ranchers say, are communication and cooperation between themselves, their neighbors, wildlife managers and government trappers

Gamma-Ray Bursts via Pair Plasma Fireballs from Heated Neutron Stars

In this paper we model the emission from a relativistically expanding electron-positron pair plasma fireball originating near the surface of a heated neutron star. This pair fireball is deposited via the annihilation of neutrino pairs emanating from the surface of the hot neutron star. The heating of neutron stars may occur in close neutron star binary systems near their last stable orbit. We model the relativistic expansion and subsequent emission of the plasma and find 10^51 to 10^52 ergs in gamma-rays are produced with spectral and temporal properties consistent with observed gamma-ray bursts.Comment: 5 pages, 3 figures. Submitted to the Conference Proceedings of the 5th Huntsville Gamma-Ray Burst Symposiu

Granary Building environmental impact assessment

The Port of Bellingham proposes to partially demolish the Granary Building on the Bellingham New Whatcom redevelopment site located on the downtown waterfront. Partial demolition of the building--removing the northern portion of the building, increasing the distance between the building and the shoreline--is preferable to either complete preservation or total demolition for a number of reasons. Preserving at least some of the original structure would retain historic value within the proposed historic district of the New Whatcom waterfront space. Removing part of the structure would create more of a shoreline buffer to enhance habitat restoration of the adjacent Whatcom Waterway. Partial removal would also increase waterfront access to the former Georgia Pacific site in accordance with the Port\u27s new proposed straight street grid plan. Moreover, this new street grid creates Bloedel Avenue, a road that connects Central Avenue--where the Granary Building sits--to the innards of the New Whatcom site. In terms of sustainable development, strengthening the structural integrity of the building would require a certain degree of seismic upgrades and implementation of new sustainable technologies depending on the proposed future use of the building. However, renovating and reusing the current building would be more environmentally sustainable in the long term than the demolition or no action alternatives

Bulk Viscosity, Decaying Dark Matter, and the Cosmic Acceleration

We discuss a cosmology in which cold dark-matter particles decay into relativistic particles. We argue that such decays could lead naturally to a bulk viscosity in the cosmic fluid. For decay lifetimes comparable to the present hubble age, this bulk viscosity enters the cosmic energy equation as an effective negative pressure. We investigate whether this negative pressure is of sufficient magnitude to account fo the observed cosmic acceleration. We show that a single decaying species in a flat, dark-matter dominated cosmology without a cosmological constant cannot reproduce the observed magnitude-redshift relation from Type Ia supernovae. However, a delayed bulk viscosity, possibly due to a cascade of decaying particles may be able to account for a significant fraction of the apparent cosmic acceleration. Possible candidate nonrelativistic particles for this scenario include sterile neutrinos or gauge-mediated decaying supersymmetric particles.Comment: 7 pages, 4 figure

Early science with the Large Millimetre Telescope:New mm-wave detections of circumstellar discs in IC 348 from LMT/AzTEC

We present the most complete sample of mm measurements of protoplanetary discs in the star-forming region IC 348 to date. New observations from the Large Millimetre Telescope and the 1.1 mm camera AzTEC are combined with literature results in order to characterize the disc population as relating to both stellar properties within the IC 348 region and across other star-forming regions. In addition to detecting 28 of 116 observed known infrared-excess sources, we detected emission from two previously unknown candidate transition discs in the region. When combined with literature results, we find evidence for a steeper-than-expected slope, on average, in disc spectral energy distributions at millimetre wavelengths in the IC 348 region. We show that the presence or absence of high mass discs is a sensitive indicator of regional evolution, both among star-forming regions and within IC 348. In contrast, low mass discs exhibit almost no apparent evolution within the first ∼5 Myr when compared among regions

Gamma-Ray Bursts via the Neutrino Emission from Heated Neutron Stars

A model is proposed for gamma-ray bursts based upon a neutrino burst of about 10^52 ergs lasting a few seconds above a heated collapsing neutron star. This type of thermal neutrino burst is suggested by relativistic hydrodynamic studies of the compression, heating, and collapse of close binary neutron stars as they approach their last stable orbit, but may arise from other sources as well. We present a hydrodynamic simulation of the formation and evolution of the pair plasma associated with such a neutrino burst. This pair plasma leads to the production of ~10^51 - 10^52 ergs in gamma-rays with spectral and temporal properties consistent with observed gamma-ray bursts.Comment: Final version. 30 pages, 10 figures, 6 tables, accepted for publication in The Astrophysical Journa

Very compact millimeter sizes for composite star-forming/AGN submillimeter galaxies

We report the study of far-IR sizes of submillimeter galaxies (SMGs) in relation to their dust-obscured star formation rate (SFR) and active galactic nuclei (AGN) presence, determined using mid-IR photometry. We determined the millimeter-wave ($\lambda_{\rm obs}=1100 \mu$m) sizes of 69 ALMA-identified SMGs, selected with $\geq10$$\sigma$ confidence on ALMA images ($F_{\rm 1100 \mu m}=1.7$--7.4 mJy). We found that all the SMGs are located above an avoidance region in the millimeter size-flux plane, as expected by the Eddington limit for star formation. In order to understand what drives the different millimeter-wave sizes in SMGs, we investigated the relation between millimeter-wave size and AGN fraction for 25 of our SMGs at $z=1$--3. We found that the SMGs for which the mid-IR emission is dominated by star formation or AGN have extended millimeter-sizes, with respective median $R_{\rm c,e} = 1.6^{+0.34}_{-0.21}$ and 1.5$^{+0.93}_{-0.24}$ kpc. Instead, the SMGs for which the mid-IR emission corresponds to star-forming/AGN composites have more compact millimeter-wave sizes, with median $R_{\rm c,e}=1.0^{+0.20}_{-0.20}$ kpc. The relation between millimeter-wave size and AGN fraction suggests that this size may be related to the evolutionary stage of the SMG. The very compact sizes for composite star-forming/AGN systems could be explained by supermassive black holes growing rapidly during the SMG coalescing, star-formation phase.Comment: 9 pages, 4 figures, 1 table. Accepted for publication in ApJ Lette