Observations of the Non-Thermal X-ray Emission from the Galactic Supernova Remnant G347.3-0.5

G347.3-0.5 (RX J1713.7-3946) is a member of the new class of shell-type Galactic supernova remnants (SNRs) that feature non-thermal components to their X-ray emission. We have analyzed the X-ray spectrum of this SNR over a broad energy range (0.5 to 30 keV) using archived data from observations made with two satellites, the Roentgenstaellit (ROSAT) and the Advanced Satellite for Cosmology and Astrophysics (ASCA), along with data from our own observations made with the Rossi X-ray Timing Explorer (RXTE). Using a combination of the models EQUIL and SRCUT to fit thermal and non-thermal emission, respectively, from this SNR, we find evidence for a modest thermal component to G347.3-0.5's diffuse emission with a corresponding energy of kT = 1.4 keV. We also obtain an estimate of 70 TeV for the maximum energy of the cosmic-ray electrons that have been accelerated by this SNR.Comment: 4 pages, 1 figure, to appear in "Neutron Stars in Supernova Remnants" (ASP Conference Proceedings), eds P. O. Slane and B. M. Gaensle

RXTE, ROSAT and ASCA Observations of G347.3-0.5 (RX J1713.7-3946): Probing Cosmic Ray Acceleration by a Galactic Shell-Type Supernova Remnant

(Abridged) We present an analysis of the X-ray spectrum of the Galactic shell-type supernova remnant (SNR) G347.3-0.5 (RX J1713.7-3946). By performing a joint spectral analysis of data from observations made of G347.3-0.5 using the ROSAT PSPC, the ASCA GIS and the RXTE PCA, we have fit the spectra of particular regions of this SNR (including the bright northwestern and southwestern rims, the northeastern rim and the interior diffuse emission) over the approximate energy range of 0.5 through 30 keV. Based on the parameters of the best fit to the spectra using the SRCUT model, we estimate the maximum energy of cosmic-ray electrons accelerated by the rims of G347.3-0.5 to be 19-25 TeV, assuming a magnetic field strength of 10 microGauss. We present a broadband (radio to gamma-ray) photon energy flux-spectrum for the northwestern rim of the SNR, using a synchrotron-inverse Compton model with a variable magnetic field strength to fit the spectrum. Our fit derived from this model yields a maximum energy of only 8.8 TeV for the accelerated cosmic-ray electrons and a magnetic field strength of 150 microGauss. However, our derived ratio of volumes for TeV emission and X-ray emission (approximately 1000) is too large to be physically acceptable. We argue that neither non-thermal bremsstrahlung nor neutral pion decay can adequately describe the TeV emission from this rim, and therefore the physical process responsible for this emission is currently uncertain. Finally, we compare the gross properties of G347.3-0.5 with other SNRs known to possess X-ray spectra dominated by non-thermal emission.Comment: 46 pages, 16 figures, accepted for publication in the Astrophysical Journal (Volume 593, 10 August 2003 Issue

Robust Weak-lensing Mass Calibration of Planck Galaxy Clusters

In light of the tension in cosmological constraints reported by the Planck team between their SZ-selected cluster counts and Cosmic Microwave Background (CMB) temperature anisotropies, we compare the Planck cluster mass estimates with robust, weak-lensing mass measurements from the Weighing the Giants (WtG) project. For the 22 clusters in common between the Planck cosmology sample and WtG, we find an overall mass ratio of \left = 0.688 \pm 0.072. Extending the sample to clusters not used in the Planck cosmology analysis yields a consistent value of $\left< M_{Planck}/M_{\rm WtG} \right> = 0.698 \pm 0.062$ from 38 clusters in common. Identifying the weak-lensing masses as proxies for the true cluster mass (on average), these ratios are $\sim 1.6\sigma$ lower than the default mass bias of 0.8 assumed in the Planck cluster analysis. Adopting the WtG weak-lensing-based mass calibration would substantially reduce the tension found between the Planck cluster count cosmology results and those from CMB temperature anisotropies, thereby dispensing of the need for "new physics" such as uncomfortably large neutrino masses (in the context of the measured Planck temperature anisotropies and other data). We also find modest evidence (at 95 per cent confidence) for a mass dependence of the calibration ratio and discuss its potential origin in light of systematic uncertainties in the temperature calibration of the X-ray measurements used to calibrate the Planck cluster masses. Our results exemplify the critical role that robust absolute mass calibration plays in cluster cosmology, and the invaluable role of accurate weak-lensing mass measurements in this regard.Comment: 5 pages, 2 figure

The Three-Dimensional Structure of Cassiopeia A

We used the Spitzer Space Telescope's Infrared Spectrograph to map nearly the entire extent of Cassiopeia A between 5-40 micron. Using infrared and Chandra X-ray Doppler velocity measurements, along with the locations of optical ejecta beyond the forward shock, we constructed a 3-D model of the remnant. The structure of Cas A can be characterized into a spherical component, a tilted thick disk, and multiple ejecta jets/pistons and optical fast-moving knots all populating the thick disk plane. The Bright Ring in Cas A identifies the intersection between the thick plane/pistons and a roughly spherical reverse shock. The ejecta pistons indicate a radial velocity gradient in the explosion. Some ejecta pistons are bipolar with oppositely-directed flows about the expansion center while some ejecta pistons show no such symmetry. Some ejecta pistons appear to maintain the integrity of the nuclear burning layers while others appear to have punched through the outer layers. The ejecta pistons indicate a radial velocity gradient in the explosion. In 3-D, the Fe jet in the southeast occupies a "hole" in the Si-group emission and does not represent "overturning", as previously thought. Although interaction with the circumstellar medium affects the detailed appearance of the remnant and may affect the visibility of the southeast Fe jet, the bulk of the symmetries and asymmetries in Cas A are intrinsic to the explosion.Comment: Accepted to ApJ. 54 pages, 21 figures. For high resolution figures and associated mpeg movie and 3D PDF files, see http://homepages.spa.umn.edu/~tdelaney/pape

Cosmology and Astrophysics from Relaxed Galaxy Clusters II: Cosmological Constraints

We present cosmological constraints from measurements of the gas mass fraction, $f_{gas}$, for massive, dynamically relaxed galaxy clusters. Our data set consists of Chandra observations of 40 such clusters, identified in a comprehensive search of the Chandra archive, as well as high-quality weak gravitational lensing data for a subset of these clusters. Incorporating a robust gravitational lensing calibration of the X-ray mass estimates, and restricting our measurements to the most self-similar and accurately measured regions of clusters, significantly reduces systematic uncertainties compared to previous work. Our data for the first time constrain the intrinsic scatter in $f_{gas}$, $(7.4\pm2.3)$% in a spherical shell at radii 0.8-1.2 $r_{2500}$, consistent with the expected variation in gas depletion and non-thermal pressure for relaxed clusters. From the lowest-redshift data in our sample we obtain a constraint on a combination of the Hubble parameter and cosmic baryon fraction, $h^{3/2}\Omega_b/\Omega_m=0.089\pm0.012$, that is insensitive to the nature of dark energy. Combined with standard priors on $h$ and $\Omega_b h^2$, this provides a tight constraint on the cosmic matter density, $\Omega_m=0.27\pm0.04$, which is similarly insensitive to dark energy. Using the entire cluster sample, extending to $z>1$, we obtain consistent results for $\Omega_m$ and interesting constraints on dark energy: $\Omega_\Lambda=0.65^{+0.17}_{-0.22}$ for non-flat $\Lambda$CDM models, and $w=-0.98\pm0.26$ for flat constant-$w$ models. Our results are both competitive and consistent with those from recent CMB, SNIa and BAO data. We present constraints on models of evolving dark energy from the combination of $f_{gas}$ data with these external data sets, and comment on the possibilities for improved $f_{gas}$ constraints using current and next-generation X-ray observatories and lensing data. (Abridged)Comment: 25 pages, 14 figures, 8 tables. Accepted by MNRAS. Code and data can be downloaded from http://www.slac.stanford.edu/~amantz/work/fgas14/ . v2: minor fix to table 1, updated bibliograph

Proceedings of the 17th Annual Meeting, Southern Soybean Disease Workers (March 20-22, 1990, Biloxi, Mississippi): Soybean Disease Control at a Crossroad

Contents Southern Soybean Disease Workers Officers 1989-1990 Southern Soybean Disease Workers Program Committee 1989-1990 Southern Soybean Disease Workers Committee Chairmen 1989-1990 General session Presidential address. B Gazaway Keynote address. K Smith Invited speakers Future Impacts of Biotechnology on Soybean Production and Uses. X Delannay Diseases of Soybean Associated with International Seed Trade. B Moore Impact of Regulatory Change and GLP\u27s on New Fungicide Discovery and Development. G Hammes Graduate student papers Double-Stranded RNA and Virus-Like Particles From the Soybean Stem canker Pathogen, Diaporthe phaseolorum var. caulivora. Y Lee, JP Snow, GT Berggren, and RA Valverde Development of Soybean Varieties Resistant to Phomopsis Seed Decay. MS Zimmerman and HC Minor Cloning of the vir Region of Agrobacterium tumefaciens Chry 5, a Strain Highly Virulent on Soybean. LG Kovacs, JA Wrather, and SG Pueppke Role of Overwintering Bean Leaf Beetle in the Epidemiology of Bean Pod Mottle Virus in Soybeans in Kentucky. JR dosAnjos, SA Ghabinal, DE Hershman, and DW Johnson Contributed papers SSDW soybean Disease Loss Estimates G Sciumbato Effects of Amino Acid Biosynthesis Inhibiting Herbicides on in vitro Growth and Development of Calonectria crotalariae. DK Berner, GT Berggren, and JP Snow Infection Cushion Formation by Rhizoctonia solani on Soybean Leaves. CS Kousik, JP Snow, and GT Berggren Is Stem Canker Monocyclic? KV SubbaRao, JP Snow, and GT Berggren Early-season Fungicide Sprays for Soybean Stem Canker Control. AY Chambers SSDW business session Treasurer\u27s report, 1989. G Hammes Contributed paper session Effect of Frogeye Leaf Spot on Soybeans in Florida. FM Shakes and CK Hiebsch Comparison of Application Timing of Two Foliar Fungicides for Control of Soybean Diseases. JC Rupe and MJ Cochran Performance of Soybean Lines under Stress Due to Brown Stem Rot, Soybean Cyst Nematode, and Iron Deficiency Chlorosis. LM Mansur, H Tachibana, and K Bidne Performance of Soybean Cultivars in Cyst and Peanut Root-Knot Nematode Infested Fields. CE Drye, DK Barefield, ER Shipe, and JD Mueller Yield of Aldicarb Treated Nematode Resistant and Susceptible Soybean Varieties. CE Drye, ER Garner, and JD Mueller Distribution, Races, and Effects of Soybean Cyst Nematode in Missouri. TL Niblack and GS Smith Performance of Selected Nematicides in a Field Infested with Root-Knot and Cyst Nematodes. RW Young, R Rodríguez-Kábana, and EL Carden Performance of Selected Soybean Cultivars in a Field Infested with Meloidogyne arenaria and Heterodera glycines. DG Robertson, R Rodríguez-Kábana, D Weaver, and EL Carden Sorghum-Soybean Rotation for the Management of Root-Knot and Cyst Nematodes: Long Term Effects. CF Weaver, R Rodríguez-Kábana, DB Weaver, and EL Carden Bahiagrass-Soybean Rotation for the Management of Root-Knot and Cyst Nematodes: Long Term Effects. PS King, R Rodríguez-Kábana, DB Weaver, and EL Carden Peanut-Soybean Rotations for the Management of Meloidogyne arenaria. R Rodríguez-Kábana, and DG Robertson Field Evaluation of Polyspecific Nematode Resistance in Soybean. DB Weaver, R Rodríguez-Kábana, and EL Carden Long Term Effects of Selected Rotations with Soybeans and Corn on Populations of Meloidogyne arenaria. R Rodríguez-Kábana, and D.G. Robertson Histopathology of Soybean Roots Inoculated with Fusariurn solani and Heterodera glycines. KS McLean, KW Roy and GW Lawrence. The opinions expressed by the participants at this conference are their own and do not necessarily represent the views of the southern Soybean Disease Workers (SSDW). Text, references, figures, and tables are reproduced essentially as they were supplied by the author(s) of each paper. Mention of pesticides does not constitute a recommendation for use, nor does it imply that the pesticides are registered under the Federal Insecticide, Fungicide, and Rodenticide Act as · amended. The use of trade names in this publication does not constitute a guarantee, warranty, or endorsement of the products by SSDW

Models for Nonthermal Photon Spectra

We describe models of nonthermal photon emission from a homogeneous distribution of relativistic electrons and protons. Contributions from the synchrotron, inverse Compton, nonthermal bremsstrahlung and neutral-pion decay processes are computed separately using a common parameterization of the underlying distribution of nonthermal particles. The models are intended for use in fitting spectra from multi-wavelength observations and are designed to be accurate and efficient. Although our applications have focused on Galactic supernova remnants, the software is modular, making it straightforward to customize for different applications. In particular, the shapes of the particle distribution functions and the shape of the seed photon spectrum used by the inverse Compton model are defined in separate modules and may be customized for specific applications. We assess the accuracy of these models by using a recurrence relation and by comparing them with analytic results and with previous numerical work by other authors.Comment: 14 pages, 7 figures, Accepted for publication in ApJ Supplemen