The First Ten Years of Swift Supernovae

The Swift Gamma Ray Burst Explorer has proven to be an incredible platform for studying the multiwavelength properties of supernova explosions. In its first ten years, Swift has observed over three hundred supernovae. The ultraviolet observations reveal a complex diversity of behavior across supernova types and classes. Even amongst the standard candle type Ia supernovae, ultraviolet observations reveal distinct groups. When the UVOT data is combined with higher redshift optical data, the relative populations of these groups appear to change with redshift. Among core-collapse supernovae, Swift discovered the shock breakout of two supernovae and the Swift data show a diversity in the cooling phase of the shock breakout of supernovae discovered from the ground and promptly followed up with Swift. Swift observations have resulted in an incredible dataset of UV and X-ray data for comparison with high-redshift supernova observations and theoretical models. Swift's supernova program has the potential to dramatically improve our understanding of stellar life and death as well as the history of our universe.Comment: Invited review paper accepted into the Journal of High Energy Astrophysics for the dedicated issue: "Swift: Ten Years of Discovery" 8 pages, 4 figure

Grouping Normal Type Ia Supernovae by UV to Optical Color Differences

Observations of many SNe Ia with the UVOT instrument on the Swift satellite has revealed that there exists order to the differences in the UV-OPT colors of normal SNe. We examine UV-OPT color curves for 25 SNe Ia, dividing them into 4 groups, finding that ~1/3 of these SNe Ia have bluer UV-OPT colors than the larger group, with these "NUV-blue" SNe Ia 0.4 mag bluer than the "NUV-red" SNe Ia in u-v. Another group of events feature colors similar to NUV-red SNe Ia in the u-v to uvw1-v colors, but similar to the NUV-blue SNe Ia in the uvm2-v color. We name these events "MUV-blue". The last group initially has colors similar to NUV-red SNe Ia, but with color curves that feature more modest changes than the larger NUV-red group. These "irregular" events are comprised of all the NUV-red events with the broadest optical peaks, which leads us to consider this minor group a subset of the NUV-red group. When so separated and the accounting is made for the rapid time evolution of the UV-OPT colors, we find that the scatter in two NUV-OPT colors, u-v & uvw1-v, is at the level of the scatter in b-v. This finding is promising for extending the cosmological utilization of SNe Ia into the NUV. We generate spectrophotometry of SNe Ia that have been observed with HST and argue that there is a fundamental spectral difference in the 2900-3500A wavelength range, a range suggested to be dominated by absorption from iron-peak elements. The NUV-blue SNe Ia feature less NUV absorption than the NUV-red SNe Ia. We show that all the NUV-blue SNe Ia in this sample have also featured evidence of unburned carbon in optical spectra, whereas only one NUV-red SN Ia features that absorption line. Every NUV-blue event also exhibits a low gradient of the SiII 6355A absorption feature, but many NUV-red events also exhibit a low gradient, perhaps suggestive that NUV-blue events are a subset of the larger LVG group.Comment: Accepted to the Astrophysical Journal Updated version: Sept 16, 201

Woodbury, Town of and Woodbury Police Benevolent Association (Dispatchers)

In the Matter of TOWN OF WOODBURY, Orange County and WOODBURY POLICE BENEVOLENT ASSOCIATION (Dispatchers). FINDINGS OF FACT and RECOMMENDATIONS FOR RESOLUTION. Peter A. Korn, Fact Finder

Heterodon simus

Number of Pages: 2Integrative BiologyGeological Science

Exact solution for the Green's function describing time-dependent thermal Comptonization

We obtain an exact, closed-form expression for the time-dependent Green's function solution to the Kompaneets equation. The result, which is expressed as the integral of a product of two Whittaker functions, describes the evolution in energy space of a photon distribution that is initially monoenergetic. Effects of spatial transport within a homogeneous scattering cloud are also included within the formalism. The Kompaneets equation that we solve includes both the recoil and energy diffusion terms, and therefore our solution for the Green's function approaches the Wien spectrum at large times. We show that the Green's function can be used to generate all of the previously known steady-state and time-dependent solutions to the Kompaneets equation. The new solution allows the direct determination of the spectrum, without the need to numerically solve the partial differential equation. Based upon the Green's function, we obtain a new time-dependent solution for the photon distribution resulting from the reprocessing of an optically thin bremsstrahlung initial spectrum with a low-energy cutoff. The new bremsstrahlung solution possesses a finite photon number density, and therefore it displays proper equilibration to a Wien spectrum at large times. The relevance of our results for the interpretation of emission from variable X-ray sources is discussed, with particular attention to the production of hard X-ray time lags, and the Compton broadening of narrow features such as iron lines.Comment: text plus 9 figures, MNRAS 2003, in pres

A rationality criterion for unbounded operators

Let G be a group, let U(G) denote the set of unbounded operators on L^2(G) which are affiliated to the group von Neumann algebra W(G) of G, and let D(G) denote the division closure of CG in U(G). Thus D(G) is the smallest subring of U(G) containing CG which is closed under taking inverses. If G is a free group then D(G) is a division ring, and in this case we shall give a criterion for an element of U(G) to be in D(G). This extends a result of Duchamp and Reutenauer, which was concerned with proving a conjecture of Connes.Comment: 7 pages, to appear in the Comptes Rendu

Systematics of Charged Particle Production in Heavy-Ion Collisions with the PHOBOS Detector at RHIC

The multiplicity of charged particles produced in Au+Au collisions as a function of energy, centrality, rapidity and azimuthal angle has been measured with the PHOBOS detector at RHIC. These results contribute to our understanding of the initial state of heavy ion collisions and provide a means to compare basic features of particle production in nuclear collisions with more elementary systems.Comment: 4 pages, 4 figures (in eps) talk given at XXXI International Symposium on Multiparticle Dynamics, Sep. 1-7, 2001, Datong China URL http://ismd31.ccnu.edu.cn