TY - JOUR A1 - Baumgärtel, Hellmut T1 - A Characteristic decay semigroup for the resonances of trace class perturbations with analyticity conditions of semibounded hamiltonians JF - International journal of theoretical physic N2 - To asymptotic complete scattering systems {M(+) + V, M(+)} on H(+) := L(2)(R(+), K, d lambda), where M(+) is the multiplication operator on H(+) and V is a trace class operator with analyticity conditions, a decay semigroup is associated such that the spectrum of the generator of this semigroup coincides with the set of all resonances (poles of the analytic continuation of the scattering matrix into the lower half plane across the positive half line), i.e. the decay semigroup yields a "time-dependent" characterization of the resonances. As a counterpart a "spectral characterization" is mentioned which is due to the "eigenvalue-like" properties of resonances. KW - Resonances KW - Scattering theory KW - Lax-Phillips theory KW - Decay semigroups Y1 - 2011 U6 - https://doi.org/10.1007/s10773-010-0533-9 SN - 0020-7748 VL - 50 IS - 7 SP - 2002 EP - 2008 PB - Springer CY - New York ER - TY - THES A1 - Barbosa Pfannes, Eva Katharina T1 - Probing the regulatory mechanisms of the actomyosin system in motile cells T1 - Erforschung von Regulationsmechanismen des Aktomyosinsystems in bewegliche Zellen N2 - Actin-based directional motility is important for embryonic development, wound healing, immune responses, and development of tissues. Actin and myosin are essential players in this process that can be subdivided into protrusion, adhesion, and traction. Protrusion is the forward movement of the membrane at the leading edge of the cell. Adhesion is required to enable movement along a substrate, and traction finally leads to the forward movement of the entire cell body, including its organelles. While actin polymerization is the main driving force in cell protrusions, myosin motors lead to the contraction of the cell body. The goal of this work was to study the regulatory mechanisms of the motile machinery by selecting a representative key player for each stage of the signaling process: the regulation of Arp2/3 activity by WASP (actin system), the role of cGMP in myosin II assembly (myosin system), and the influence of phosphoinositide signaling (upstream receptor pathway). The model organism chosen for this work was the social ameba Dictyostelium discoideum, due to the well-established knowledge of its cytoskeletal machinery, the easy handling, and the high motility of its vegetative and starvation developed cells. First, I focused on the dynamics of the actin cytoskeleton by modulating the activity of one of its key players, the Arp2/3 complex. This was achieved using the carbazole derivative Wiskostatin, an inhibitor of the Arp2/3 activator WASP. Cells treated with Wiskostatin adopted a round shape, with no of few pseudopodia. With the help of a microfluidic cell squeezer device, I could show that Wiskostatin treated cells display a reduced mechanical stability, comparable to cells treated with the actin disrupting agent Latrunculin A. Furthermore, the WASP inhibited cells adhere stronger to a surface and show a reduced motility and chemotactic performance. However, the overall F-actin content in the cells was not changed. Confocal microscopy and TIRF microscopy imaging showed that the cells maintained an intact actin cortex. Localized dynamic patches of increased actin polymerization were observed that, however, did not lead to membrane deformation. This indicated that the mechanisms of actin-driven force generation were impaired in Wiskostatin treated cells. It is concluded that in these cells, an altered architecture of the cortical network leads to a reduced overall stiffness of the cell, which is insufficient to support the force generation required for membrane deformation and pseudopod formation. Second, the role of cGMP in myosin II dynamics was investigated. Cyclic GMP is known to regulate the association of myosin II with the cytoskeleton. In Dictyostelium, intracellular cGMP levels increase when cells are exposed to chemoattractants, but also in response to osmotic stress. To study the influence of cyclic GMP on actin and myosin II dynamics, I used the laser-induced photoactivation of a DMACM-caged-Br-cGMP to locally release cGMP inside the cell. My results show that cGMP directly activates the myosin II machinery, but is also able to induce an actin response independently of cAMP receptor activation and signaling. The actin response was observed in both vegetative and developed cells. Possible explanations include cGMP-induced actin polymerization through VASP (vasodilator-stimulated phosphoprotein) or through binding of cGMP to cyclic nucleotide-dependent kinases. Finally, I investigated the role of phosphoinositide signaling using the Polyphosphoinositide-Binding Peptide (PBP10) that binds preferentially to PIP2. Phosphoinositides can recruit actin-binding proteins to defined subcellular sites and alter their activity. Neutrophils, as well as developed Dictyostelium cells produce PIP3 in the plasma membrane at their leading edge in response to an external chemotactic gradient. Although not essential for chemotaxis, phosphoinositides are proposed to act as an internal compass in the cell. When treated with the peptide PBP10, cells became round, with fewer or no pseudopods. PH-CRAC translocation to the membrane still occurs, even at low cAMP stimuli, but cell motility (random and directional) was reduced. My data revealed that the decrease in the pool of available PIP2 in the cell is sufficient to impair cell motility, but enough PIP2 remains so that PIP3 is formed in response to chemoattractant stimuli. My data thus highlights how sensitive cell motility and morphology are to changes in the phosphoinositide signaling. In summary, I have analyzed representative regulatory mechanisms that govern key parts of the motile machinery and characterized their impact on cellular properties including mechanical stability, adhesion and chemotaxis. N2 - Das Ziel der Arbeit war es, die regulatorischen Mechanismen der Zellmotilität zu untersuchen. Dazu habe ich für jedes Stadium dieses Prozesses einen repräsentativen regulatorischen Schritt ausgewählt und genauer untersucht: Die Regelung des Arp2/3 Komplexes durch WASP (Aktinsystem), die Rolle von cGMP in der Myosin II-Regulation (Myosinsystem) und der Einfluss von Phosphoinositiden im intrazellulären Signalprozess (Rezeptor-Signalweg). Die soziale Amöbe Dictyostelium discoideum wurde als Modellorganismus für diese Arbeiten gewählt. Gründe für diese Wahl waren die bereits vorliegenden detaillierten Kenntnisse über das Zytoskelett dieser Zellen, ihre einfache Handhabbarkeit im Labor, und die hohe Motilität der Zellen im vegetativen und entwickelten Zustand. Als Erstes analysierte ich die Dynamik des Aktin-Zytoskeletts durch Modulation der Aktivität des Arp2/3-Komplexes. Dafür benutzte ich das Carbazol-Derivat Wiskostatin, ein Inhibitor des Arp2/3-Aktivators WASP. Zellen, die mit Wiskostatin behandelt wurden, zeigten eine runde Form mit wenigen oder keinen Pseudopodien. Mit Hilfe des mikrofluidischen cell squeezer device konnte ich zeigen, dass Wiskostatin-behandelte Zellen eine geringere mechanische Stabilität aufweisen, vergleichbar mit Zellen unter dem Einfluss des Aktin-depolymerisierenden Wirkstoffes Latrunculin A. Darüber hinaus zeigen Wiskostatin behandelten Zellen eine erhöhte Substratadhäsion und eine verringerte Motilität und chemotaktische Effizienz. Der F-Aktingehalt der Zelle insgesamt blieb jedoch unverändert. Konfokal- und TIRF-mikroskopische Aufnahmen zeigten, dass die Zellen einen intakten Aktinkortex aufweisen. Es konnten lokalisierte dynamische Regionen erhöhter Aktinpolymerisation beobachtet werden, die jedoch nicht zur Ausbildung von Membrandeformationen führten. Daraus kann man rückschließen, dass die Mechanismen der Krafterzeugung im Aktin-Zytoskelett in WASP-inhibierten Zellen beeinträchtigt sind. Vermutlich liegt in diesen Zellen eine veränderte Mikroarchitektur des kortikalen Netzwerks vor, die zu einer verminderten Steifigkeit der Zelle führt, so dass die zur Bildung von Pseudopodien erforderlichen Kräfte nicht entfaltet werden können. Als Zweites wurde die Rolle von cGMP in der Myosin II-Dynamik untersucht. Es ist bekannt, dass cGMP die Assoziation von Myosin II mit dem Zytoskelett reguliert. In Dictyostelium steigt die intrazelluläre Konzentration von cGMP in Gegenwart von chemoattraktiven Lockstoffen sowie in Antwort auf osmotischen Stress. Um den Einfluss von cGMP auf die Aktin und Myosin II -Dynamik zu untersuchen, benutzte ich laserinduzierte Photoaktivierung von DMACM-caged-Br-cGMP, um cGMP lokal innerhalb der Zelle freizusetzen. Meine Ergebnisse zeigten, dass intrazelluläres cGMP direkt zur Aktivierung von Myosin II führt, jedoch auch Aktinantworten unabhängig vom cAMP-Rezeptorsignalweg induzieren kann. Die Aktinreaktion wurde sowohl in vegetativen als auch in entwickelten Zellen beobachtet. Eine mögliche Erklärung könnte die cGMP-induzierte Aktinpolymerisation über VASP (vasodilator-stimulated phosphoprotein) sein oder über die Bindung von cGMP an Nukleotid-abhängige Proteinkinasen. Als dritten Punkt meiner Arbeit untersuchte ich die Rolle der Phosphoinositide mit Hilfe des Phosphoinositide-bindenden Proteins PBP10, das bevorzugt an PIP2 bindet. Phosphoinositiden können Aktin-bindende Proteine zu definierten subzellulären Orten rekrutieren und ihre Aktivität verändern. Sowohl Neutrophile als auch entwickelte Dictyostelium Zellen produzieren PIP3 in der Plasmamembran an ihrer leading edge in Antwort auf externe Gradienten chemischer Lockstoffe. Obwohl Zellen auch ohne PIP3 chemotaktisches Verhalten zeigen, werden Phosphoinositide im Allgemeinen mit dem inneren chemotaktischen Kompass der Zelle in Verbindung gebracht. Mit dem Peptid PBP10 behandelte Zellen nahmen eine runde Form an, mit wenigen oder keinen Pseudopodien. PH-CRAC -Translokation zur Membran konnte in PBP10-behandelten Zellen selbst bei geringen cAMP-Stimuli weiterhin beobachtet werden. Ungerichtete wie auch gerichtete Zellmotiliät waren jedoch beeinträchtigt. Meine Daten zeigen, dass die Abnahme des PIP2-Pools in der Zelle durch PBP10 ausreicht, um die Zellmotilität zu beeinträchtigen, dass jedoch genug PIP2 erhalten bleibt um in Folge einer Rezeptorstimulation PIP3 zu produzieren. Die Ergebnisse demonstrieren daher, wie empfindlich Zellmotilität und -morphologie gegenüber Modifikationen im Phosphoinositid-Signalweg sind. Zusammenfassend habe ich mehrere repräsentative Beispiele für regulatorische Mechanismen der Zellmotilität untersucht und deren Auswirkung auf Eigenschaften der Zelle wie mechanische Stabilität, Zelladhäsion und Chemotaxis charakterisiert. KW - Dictyostelium KW - Aktomyosin KW - Wiskostatin KW - cGMP KW - PBP10 KW - Dictyostelium KW - actomyosin KW - Wiskostatin KW - cGMP KW - PBP10 Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57812 ER - TY - JOUR A1 - Bagnich, Sergey A. A1 - Unger, Th. A1 - Jaiser, Frank A1 - Neher, Dieter A1 - Thesen, M. W. A1 - Krüger, H. T1 - Efficient green electrophosphorescence based on ambipolar nonconjugated polymers evaluation of transport and emission properties JF - Journal of applied physics N2 - New materials for polymer organic light-emitting diodes based on a polymer matrix doped with phosphorescent dyes are presented. The matrix system is based on a polystyrene backbone bearing either electron or hole transporting units at the 4-position of each repeat unit. Random copolymers and polymer blend systems of the homopolymers are prepared, both with 62 wt.% electron transporting and 38 wt.% hole transporting moieties. Adding a green electrophosphorescent dye to the polymer matrix leads to efficient electroluminescence with a maximum current efficiency of 35 cd/A and a maximum external quantum efficiency of up to 10%. The mobilities of electrons and holes in the dye-doped copolymer, as measured by transient electroluminescence, are around 5 x 10(-5) and 5 x 10(-6) cm(2)/Vs, respectively, while the blend of the two homopolymers exhibits slightly lower mobilities of both types of carriers. Despite the pronounced imbalance of charge transport, the device performance is almost entirely limited by the phosphorescence efficiency of the dye, implying balanced flow of holes and electrons into the active region. Also, devices made with either the copolymer or the blend yielded very similar device efficiencies, despite the noticeable difference in electron and hole mobility. It is proposed that electrons are efficiently blocked at the interlayer and that the so-formed space charge assists the balanced injection of holes. Y1 - 2011 U6 - https://doi.org/10.1063/1.3618681 SN - 0021-8979 SN - 1089-7550 VL - 110 IS - 3 PB - American Institute of Physics CY - Melville ER - TY - THES A1 - Avila, Gastón T1 - Asymptotic staticity and tensor decompositions with fast decay conditions T1 - Asymptotisch statische Anfangsdaten und Tensor-Zerlegungen mit starken Abfallbedingungen N2 - Corvino, Corvino and Schoen, Chruściel and Delay have shown the existence of a large class of asymptotically flat vacuum initial data for Einstein's field equations which are static or stationary in a neighborhood of space-like infinity, yet quite general in the interior. The proof relies on some abstract, non-constructive arguments which makes it difficult to calculate such data numerically by using similar arguments. A quasilinear elliptic system of equations is presented of which we expect that it can be used to construct vacuum initial data which are asymptotically flat, time-reflection symmetric, and asymptotic to static data up to a prescribed order at space-like infinity. A perturbation argument is used to show the existence of solutions. It is valid when the order at which the solutions approach staticity is restricted to a certain range. Difficulties appear when trying to improve this result to show the existence of solutions that are asymptotically static at higher order. The problems arise from the lack of surjectivity of a certain operator. Some tensor decompositions in asymptotically flat manifolds exhibit some of the difficulties encountered above. The Helmholtz decomposition, which plays a role in the preparation of initial data for the Maxwell equations, is discussed as a model problem. A method to circumvent the difficulties that arise when fast decay rates are required is discussed. This is done in a way that opens the possibility to perform numerical computations. The insights from the analysis of the Helmholtz decomposition are applied to the York decomposition, which is related to that part of the quasilinear system which gives rise to the difficulties. For this decomposition analogous results are obtained. It turns out, however, that in this case the presence of symmetries of the underlying metric leads to certain complications. The question, whether the results obtained so far can be used again to show by a perturbation argument the existence of vacuum initial data which approach static solutions at infinity at any given order, thus remains open. The answer requires further analysis and perhaps new methods. N2 - Corvino, Corvino und Schoen als auch Chruściel und Delay haben die Existenz einer grossen Klasse asymptotisch flacher Anfangsdaten für Einsteins Vakuumfeldgleichungen gezeigt, die in einer Umgebung des raumartig Unendlichen statisch oder stationär aber im Inneren der Anfangshyperfläche sehr allgemein sind. Der Beweis beruht zum Teil auf abstrakten, nicht konstruktiven Argumenten, die Schwierigkeiten bereiten, wenn derartige Daten numerisch berechnet werden sollen. In der Arbeit wird ein quasilineares elliptisches Gleichungssystem vorgestellt, von dem wir annehmen, dass es geeignet ist, asymptotisch flache Vakuumanfangsdaten zu berechnen, die zeitreflektionssymmetrisch sind und im raumartig Unendlichen in einer vorgeschriebenen Ordnung asymptotisch zu statischen Daten sind. Mit einem Störungsargument wird ein Existenzsatz bewiesen, der gilt, solange die Ordnung, in welcher die Lösungen asymptotisch statische Lösungen approximieren, in einem gewissen eingeschränkten Bereich liegt. Versucht man, den Gültigkeitsbereich des Satzes zu erweitern, treten Schwierigkeiten auf. Diese hängen damit zusammen, dass ein gewisser Operator nicht mehr surjektiv ist. In einigen Tensorzerlegungen auf asymptotisch flachen Räumen treten ähnliche Probleme auf, wie die oben erwähnten. Die Helmholtzzerlegung, die bei der Bereitstellung von Anfangsdaten für die Maxwellgleichungen eine Rolle spielt, wird als ein Modellfall diskutiert. Es wird eine Methode angegeben, die es erlaubt, die Schwierigkeiten zu umgehen, die auftreten, wenn ein schnelles Abfallverhalten des gesuchten Vektorfeldes im raumartig Unendlichen gefordert wird. Diese Methode gestattet es, solche Felder auch numerisch zu berechnen. Die Einsichten aus der Analyse der Helmholtzzerlegung werden dann auf die Yorkzerlegung angewandt, die in den Teil des quasilinearen Systems eingeht, der Anlass zu den genannten Schwierigkeiten gibt. Für diese Zerlegung ergeben sich analoge Resultate. Es treten allerdings Schwierigkeiten auf, wenn die zu Grunde liegende Metrik Symmetrien aufweist. Die Frage, ob die Ergebnisse, die soweit erhalten wurden, in einem Störungsargument verwendet werden können um die Existenz von Vakuumdaten zu zeigen, die im räumlich Unendlichen in jeder Ordnung statische Daten approximieren, bleibt daher offen. Die Antwort erfordert eine weitergehende Untersuchung und möglicherweise auch neue Methoden. KW - Einsteins Feldgleichungen KW - Zwangsgleichungen KW - Tensor-Zerlegungen KW - raumartige Unendliche KW - elliptisches Gleichungssystem KW - Einstein's field equations KW - constraint equations KW - tensor decompositions KW - space-like infinity KW - elliptic systems Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-54046 ER - TY - JOUR A1 - Arhammar, C. A1 - Pietzsch, Annette A1 - Bock, Nicolas A1 - Holmstroem, Erik A1 - Araujo, C. Moyses A1 - Grasjo, Johan A1 - Zhao, Shuxi A1 - Green, Sara A1 - Peery, T. A1 - Hennies, Franz A1 - Amerioun, Shahrad A1 - Föhlisch, Alexander A1 - Schlappa, Justine A1 - Schmitt, Thorsten A1 - Strocov, Vladimir N. A1 - Niklasson, Gunnar A. A1 - Wallace, Duane C. A1 - Rubensson, Jan-Erik A1 - Johansson, Borje A1 - Ahuja, Rajeev C. T1 - Unveiling the complex electronic structure of amorphous metal oxides JF - Proceedings of the National Academy of Sciences of the United States of America N2 - Amorphous materials represent a large and important emerging area of material's science. Amorphous oxides are key technological oxides in applications such as a gate dielectric in Complementary metal-oxide semiconductor devices and in Silicon-Oxide-Nitride-Oxide-Silicon and TANOS (TaN-Al2O3-Si3N4-SiO2-Silicon) flash memories. These technologies are required for the high packing density of today's integrated circuits. Therefore the investigation of defect states in these structures is crucial. In this work we present X-ray synchrotron measurements, with an energy resolution which is about 5-10 times higher than is attainable with standard spectrometers, of amorphous alumina. We demonstrate that our experimental results are in agreement with calculated spectra of amorphous alumina which we have generated by stochastic quenching. This first principles method, which we have recently developed, is found to be superior to molecular dynamics in simulating the rapid gas to solid transition that takes place as this material is deposited for thin film applications. We detect and analyze in detail states in the band gap that originate from oxygen pairs. Similar states were previously found in amorphous alumina by other spectroscopic methods and were assigned to oxygen vacancies claimed to act mutually as electron and hole traps. The oxygen pairs which we probe in this work act as hole traps only and will influence the information retention in electronic devices. In amorphous silica oxygen pairs have already been found, thus they may be a feature which is characteristic also of other amorphous metal oxides. KW - stochastic quench KW - X-ray absorption spectroscopy KW - ab initio KW - coating Y1 - 2011 U6 - https://doi.org/10.1073/pnas.1019698108 SN - 0027-8424 VL - 108 IS - 16 SP - 6355 EP - 6360 PB - National Acad. of Sciences CY - Washington ER - TY - JOUR A1 - Aliu, E. A1 - Aune, T. A1 - Beilicke, M. A1 - Benbow, W. A1 - Boettcher, Markus A1 - Bouvier, A. A1 - Bradbury, S. M. A1 - Buckley, J. H. A1 - Bugaev, V. A1 - Cannon, A. A1 - Cesarini, A. A1 - Ciupik, L. A1 - Connolly, M. P. A1 - Cui, W. A1 - Decerprit, G. A1 - Dickherber, R. A1 - Duke, C. A1 - Errando, M. A1 - Falcone, A. A1 - Feng, Q. A1 - Finnegan, G. A1 - Fortson, L. A1 - Furniss, A. A1 - Galante, N. A1 - Gall, D. A1 - Gillanders, G. H. A1 - Godambe, S. A1 - Griffin, S. A1 - Grube, J. A1 - Gyuk, G. A1 - Hanna, D. A1 - Hivick, B. A1 - Holder, J. A1 - Huan, H. A1 - Hughes, G. A1 - Hui, C. M. A1 - Humensky, T. B. A1 - Kaaret, P. A1 - Karlsson, N. A1 - Kertzman, M. A1 - Kieda, D. A1 - Krawczynski, H. A1 - Krennrich, F. A1 - Maier, G. A1 - Majumdar, P. A1 - McArthur, S. A1 - McCann, A. A1 - Moriarty, P. A1 - Mukherjee, R. A1 - Nelson, T. A1 - Ong, R. A. A1 - Orr, M. A1 - Otte, A. N. A1 - Park, N. A1 - Perkins, J. S. A1 - Pichel, A. A1 - Pohl, Martin A1 - Prokoph, H. A1 - Quinn, J. A1 - Ragan, K. A1 - Reyes, L. C. A1 - Reynolds, P. T. A1 - Roache, E. A1 - Rose, H. J. A1 - Ruppel, J. A1 - Saxon, D. B. A1 - Sembroski, G. H. A1 - Skole, C. A1 - Smith, A. W. A1 - Staszak, D. A1 - Tesic, G. A1 - Theiling, M. A1 - Thibadeau, S. A1 - Tsurusaki, K. A1 - Tyler, J. A1 - Varlotta, A. A1 - Vassiliev, V. V. A1 - Wakely, S. P. A1 - Weekes, T. C. A1 - Weinstein, A. A1 - Williams, D. A. A1 - Zitzer, B. A1 - Ciprini, S. A1 - Fumagalli, M. A1 - Kaplan, K. A1 - Paneque, D. A1 - Prochaska, J. X. T1 - Multiwavelenght observations of the previously unidentified blzar RX J0648.7+1516 JF - The astrophysical journal : an international review of spectroscopy and astronomical physics N2 - We report on the VERITAS discovery of very high energy (VHE) gamma-ray emission above 200 GeV from the high-frequency-peaked BL Lac (HBL) object RX J0648.7+1516 (GB J0648+1516), associated with 1FGL J0648.8+1516. The photon spectrum above 200 GeV is fitted by a power law dN/dE = F-0(E/E-0)(-Gamma) with a photon index Gamma of 4.4 +/- 0.8(stat) +/- 0.3(syst) and a flux normalization F-0 of (2.3 +/- 0.5(stat) +/- 1.2(sys)) x 10(-11) TeV-1 cm(-2) s(-1) with E-0 = 300 GeV. No VHE variability is detected during VERITAS observations of RX J0648.7+1516 between 2010 March 4 and April 15. Following the VHE discovery, the optical identification and spectroscopic redshift were obtained using the Shane 3 m Telescope at the Lick Observatory, showing the unidentified object to be a BL Lac type with a redshift of z = 0.179. Broadband multiwavelength observations contemporaneous with the VERITAS exposure period can be used to subclassify the blazar as an HBL object, including data from the MDM observatory, Swift-UVOT, and X-Ray Telescope, and continuous monitoring at photon energies above 1 GeV from the Fermi Large Area Telescope (LAT). We find that in the absence of undetected, high-energy rapid variability, the one-zone synchrotron self-Compton (SSC) model overproduces the high-energy gamma-ray emission measured by the Fermi-LAT over 2.3 years. The spectral energy distribution can be parameterized satisfactorily with an external-Compton or lepto-hadronic model, which have two and six additional free parameters, respectively, compared to the one-zone SSC model. KW - BL Lacertae objects: individual (RX J0648.7+1516, 1FGL J0648.8+1516, VER J0648+152) KW - gamma rays: galaxies Y1 - 2011 U6 - https://doi.org/10.1088/0004-637X/742/2/127 SN - 0004-637X VL - 742 IS - 2 PB - IOP Publ. Ltd. CY - Bristol ER - TY - JOUR A1 - Aliu, E. A1 - Arlen, T. A1 - Aune, T. A1 - Beilicke, M. A1 - Benbow, W. A1 - Bouvier, A. A1 - Bradbury, S. M. A1 - Buckley, J. H. A1 - Bugaev, V. A1 - Byrum, K. A1 - Cannon, A. A1 - Cesarini, A. A1 - Christiansen, J. L. A1 - Ciupik, L. A1 - Collins-Hughes, E. A1 - Connolly, M. P. A1 - Cui, W. A1 - Dickherber, R. A1 - Duke, C. A1 - Errando, M. A1 - Falcone, A. A1 - Finley, J. P. A1 - Finnegan, G. A1 - Fortson, L. A1 - Furniss, A. A1 - Galante, N. A1 - Gall, D. A1 - Gibbs, K. A1 - Gillanders, G. H. A1 - Godambe, S. A1 - Griffin, S. A1 - Grube, J. A1 - Guenette, R. A1 - Gyuk, G. A1 - Hanna, D. A1 - Holder, J. A1 - Huan, H. A1 - Hughes, G. A1 - Hui, C. M. A1 - Humensky, T. B. A1 - Imran, A. A1 - Kaaret, P. A1 - Karlsson, N. A1 - Kertzman, M. A1 - Kieda, D. A1 - Krawczynski, H. A1 - Krennrich, F. A1 - Lang, M. J. A1 - Lyutikov, M. A1 - Madhavan, A. S. A1 - Maier, G. A1 - Majumdar, P. A1 - McArthur, S. A1 - McCann, A. A1 - McCutcheon, M. A1 - Moriarty, P. A1 - Mukherjee, R. A1 - Nunez, P. A1 - Ong, R. A. A1 - Orr, M. A1 - Otte, A. N. A1 - Park, N. A1 - Perkins, J. S. A1 - Pizlo, F. A1 - Pohl, Martin A1 - Prokoph, H. A1 - Quinn, J. A1 - Ragan, K. A1 - Reyes, L. C. A1 - Reynolds, P. T. A1 - Roache, E. A1 - Rose, H. J. A1 - Ruppel, J. A1 - Saxon, D. B. A1 - Schroedter, M. A1 - Sembroski, G. H. A1 - Sentuerk, G. D. A1 - Smith, A. W. A1 - Staszak, D. A1 - Tesic, G. A1 - Theiling, M. A1 - Thibadeau, S. A1 - Tsurusaki, K. A1 - Tyler, J. A1 - Varlotta, A. A1 - Vassiliev, V. V. A1 - Vincent, S. A1 - Vivier, M. A1 - Wakely, S. P. A1 - Ward, J. E. A1 - Weekes, T. C. A1 - Weinstein, A. A1 - Weisgarber, T. A1 - Williams, D. A. A1 - Zitzer, B. T1 - Detection of pulsed Gamma Rays Above 100 GeV from the Crab Pulsar JF - Science N2 - We report the detection of pulsed gamma rays from the Crab pulsar at energies above 100 giga-electron volts (GeV) with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) array of atmospheric Cherenkov telescopes. The detection cannot be explained on the basis of current pulsar models. The photon spectrum of pulsed emission between 100 mega-electron volts and 400 GeV is described by a broken power law that is statistically preferred over a power law with an exponential cutoff. It is unlikely that the observation can be explained by invoking curvature radiation as the origin of the observed gamma rays above 100 GeV. Our findings require that these gamma rays be produced more than 10 stellar radii from the neutron star. Y1 - 2011 U6 - https://doi.org/10.1126/science.1208192 SN - 0036-8075 VL - 334 IS - 6052 SP - 69 EP - 72 PB - American Assoc. for the Advancement of Science CY - Washington ER - TY - JOUR A1 - Aliu, E. A1 - Arlen, T. A1 - Aune, T. A1 - Beilicke, M. A1 - Benbow, W. A1 - Boettcher, Markus A1 - Bouvier, A. A1 - Bradbury, S. M. A1 - Buckley, J. H. A1 - Bugaev, V. A1 - Cannon, A. A1 - Cesarini, A. A1 - Ciupik, L. A1 - Collins-Hughes, E. A1 - Connolly, M. P. A1 - Cui, W. A1 - Dickherber, R. A1 - Errando, M. A1 - Falcone, A. A1 - Finley, J. P. A1 - Fortson, L. A1 - Furniss, A. A1 - Galante, N. A1 - Gall, D. A1 - Gillanders, G. H. A1 - Godambe, S. A1 - Griffin, S. A1 - Grube, J. A1 - Gyuk, G. A1 - Hanna, D. A1 - Holder, J. A1 - Huan, H. A1 - Hughes, G. A1 - Hui, C. M. A1 - Humensky, T. B. A1 - Kaaret, P. A1 - Karlsson, N. A1 - Kertzman, M. A1 - Kieda, D. A1 - Krawczynski, H. A1 - Krennrich, F. A1 - Madhavan, A. S. A1 - Maier, G. A1 - Majumdar, P. A1 - McArthur, S. A1 - McCann, A. A1 - Moriarty, P. A1 - Mukherjee, R. A1 - Ong, R. A. A1 - Orr, M. A1 - Otte, A. N. A1 - Park, N. A1 - Perkins, J. S. A1 - Pichel, A. A1 - Pohl, Martin A1 - Prokoph, H. A1 - Quinn, J. A1 - Ragan, K. A1 - Reyes, L. C. A1 - Reynolds, P. T. A1 - Roache, E. A1 - Rose, H. J. A1 - Ruppel, J. A1 - Saxon, D. B. A1 - Schroedter, M. A1 - Sembroski, G. H. A1 - Skole, C. A1 - Smith, A. W. A1 - Staszak, D. A1 - Tesic, G. A1 - Theiling, M. A1 - Thibadeau, S. A1 - Tsurusaki, K. A1 - Tyler, J. A1 - Varlotta, A. A1 - Vincent, S. A1 - Vivier, M. A1 - Wakely, S. P. A1 - Ward, J. E. A1 - Weinstein, A. A1 - Weisgarber, T. A1 - Williams, D. A. T1 - Veritas observations of unusual extragalactic transient swift J164449.3+573451 JF - The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters N2 - We report on very high energy (>100 GeV) gamma-ray observations of Swift J164449.3+573451, an unusual transient object first detected by the Swift Observatory and later detected by multiple radio, optical, and X-ray observatories. A total exposure of 28 hr was obtained on Swift J164449.3+573451 with the Very Energetic Radiation Imaging Telescope Array System ( VERITAS) during 2011 March 28-April 15. We do not detect the source and place a differential upper limit on the emission at 500 GeV during these observations of 1.4 x 10(-12) erg cm(-2) s(-1) (99% confidence level). We also present time-resolved upper limits and use a flux limit averaged over the X-ray flaring period to constrain various emission scenarios that can accommodate both the radio-through-X-ray emission detected from the source and the lack of detection by VERITAS. KW - accretion, accretion disks KW - galaxies: active KW - gamma rays: galaxies KW - radiation mechanisms: non-thermal Y1 - 2011 U6 - https://doi.org/10.1088/2041-8205/738/2/L30 SN - 2041-8205 VL - 738 IS - 2 PB - IOP Publ. Ltd. CY - Bristol ER - TY - JOUR A1 - Actis, M. A1 - Agnetta, G. A1 - Aharonian, Felix A. A1 - Akhperjanian, A. G. A1 - Aleksic, J. A1 - Aliu, E. A1 - Allan, D. A1 - Allekotte, I. A1 - Antico, F. A1 - Antonelli, L. A. A1 - Antoranz, P. A1 - Aravantinos, A. A1 - Arlen, T. A1 - Arnaldi, H. A1 - Artmann, S. A1 - Asano, K. A1 - Asorey, H. G. A1 - Baehr, J. A1 - Bais, A. A1 - Baixeras, C. A1 - Bajtlik, S. A1 - Balis, D. A1 - Bamba, A. A1 - Barbier, C. A1 - Barcelo, M. A1 - Barnacka, Anna A1 - Barnstedt, Jürgen A1 - de Almeida, U. Barres A1 - Barrio, J. A. A1 - Basso, S. A1 - Bastieri, D. A1 - Bauer, C. A1 - Becerra Gonzalez, J. A1 - Becherini, Yvonne A1 - Bechtol, K. C. A1 - Becker, J. A1 - Beckmann, Volker A1 - Bednarek, W. A1 - Behera, B. A1 - Beilicke, M. A1 - Belluso, M. A1 - Benallou, M. A1 - Benbow, W. A1 - Berdugo, J. A1 - Berger, K. A1 - Bernardino, T. A1 - Bernlöhr, K. A1 - Biland, A. A1 - Billotta, S. A1 - Bird, T. A1 - Birsin, E. A1 - Bissaldi, E. A1 - Blake, S. A1 - Blanch Bigas, O. A1 - Bobkov, A. A. A1 - Bogacz, L. A1 - Bogdan, M. A1 - Boisson, Catherine A1 - Boix Gargallo, J. A1 - Bolmont, J. A1 - Bonanno, G. A1 - Bonardi, A. A1 - Bonev, T. A1 - Borkowski, Janett A1 - Botner, O. A1 - Bottani, A. A1 - Bourgeat, M. A1 - Boutonnet, C. A1 - Bouvier, A. A1 - Brau-Nogue, S. A1 - Braun, I. A1 - Bretz, T. A1 - Briggs, M. S. A1 - Brun, Pierre A1 - Brunetti, L. A1 - Buckley, H. A1 - Bugaev, V. A1 - Buehler, R. A1 - Bulik, Tomasz A1 - Busetto, G. A1 - Buson, S. A1 - Byrum, K. A1 - Cailles, M. A1 - Cameron, R. A. A1 - Canestrari, R. A1 - Cantu, S. A1 - Carmona, E. A1 - Carosi, A. A1 - Carr, John A1 - Carton, P. H. A1 - Casiraghi, M. A1 - Castarede, H. A1 - Catalano, O. A1 - Cavazzani, S. A1 - Cazaux, S. A1 - Cerruti, B. A1 - Cerruti, M. A1 - Chadwick, M. A1 - Chiang, J. A1 - Chikawa, M. A1 - Cieslar, M. A1 - Ciesielska, M. A1 - Cillis, A. N. A1 - Clerc, C. A1 - Colin, P. A1 - Colome, J. A1 - Compin, M. A1 - Conconi, P. A1 - Connaughton, V. A1 - Conrad, Jan A1 - Contreras, J. L. A1 - Coppi, P. A1 - Corlier, M. A1 - Corona, P. A1 - Corpace, O. A1 - Corti, D. A1 - Cortina, J. A1 - Costantini, H. A1 - Cotter, G. A1 - Courty, B. A1 - Couturier, S. A1 - Covino, S. A1 - Croston, J. A1 - Cusumano, G. A1 - Daniel, M. K. A1 - Dazzi, F. A1 - Deangelis, A. A1 - de Cea del Pozo, E. A1 - Dal Pino, E. M. de Gouveia A1 - de Jager, O. A1 - de la Calle Perez, I. A1 - De La Vega, G. A1 - De Lotto, B. A1 - de Naurois, M. A1 - Wilhelmi, E. de Ona A1 - de Souza, V. A1 - Decerprit, B. A1 - Deil, C. A1 - Delagnes, E. A1 - Deleglise, G. A1 - Delgado, C. A1 - Dettlaff, T. A1 - Di Paolo, A. A1 - Di Pierro, F. A1 - Diaz, C. A1 - Dick, J. A1 - Dickinson, H. A1 - Digel, S. W. A1 - Dimitrov, D. A1 - Disset, G. A1 - Djannati-Ataï, A. A1 - Doert, M. A1 - Domainko, W. A1 - Dorner, D. A1 - Doro, M. A1 - Dournaux, J. -L. A1 - Dravins, D. A1 - Drury, L. A1 - Dubois, F. A1 - Dubois, R. A1 - Dubus, G. A1 - Dufour, C. A1 - Durand, D. A1 - Dyks, J. A1 - Dyrda, M. A1 - Edy, E. A1 - Egberts, Kathrin A1 - Eleftheriadis, C. A1 - Elles, S. A1 - Emmanoulopoulos, D. A1 - Enomoto, R. A1 - Ernenwein, J. -P. A1 - Errando, M. A1 - Etchegoyen, A. A1 - Falcone, A. D. A1 - Farakos, K. A1 - Farnier, C. A1 - Federici, S. A1 - Feinstein, F. A1 - Ferenc, D. A1 - Fillin-Martino, E. A1 - Fink, D. A1 - Finley, C. A1 - Finley, J. P. A1 - Firpo, R. A1 - Florin, D. A1 - Foehr, C. A1 - Fokitis, E. A1 - Font, Ll. A1 - Fontaine, G. A1 - Fontana, A. A1 - Foerster, A. A1 - Fortson, L. A1 - Fouque, N. A1 - Fransson, C. A1 - Fraser, G. W. A1 - Fresnillo, L. A1 - Fruck, C. A1 - Fujita, Y. A1 - Fukazawa, Y. A1 - Funk, S. A1 - Gaebele, W. A1 - Gabici, S. A1 - Gadola, A. A1 - Galante, N. A1 - Gallant, Y. A1 - Garcia, B. A1 - Garcia Lopez, R. J. A1 - Garrido, D. A1 - Garrido, L. A1 - Gascon, D. A1 - Gasq, C. A1 - Gaug, M. A1 - Gaweda, J. A1 - Geffroy, N. A1 - Ghag, C. A1 - Ghedina, A. A1 - Ghigo, M. A1 - Gianakaki, E. A1 - Giarrusso, S. A1 - Giavitto, G. A1 - Giebels, B. A1 - Giro, E. A1 - Giubilato, P. A1 - Glanzman, T. A1 - Glicenstein, J. -F. A1 - Gochna, M. A1 - Golev, V. A1 - Gomez Berisso, M. A1 - Gonzalez, A. A1 - Gonzalez, F. A1 - Granena, F. A1 - Graciani, R. A1 - Granot, J. A1 - Gredig, R. A1 - Green, A. A1 - Greenshaw, T. A1 - Grimm, O. A1 - Grube, J. A1 - Grudzinska, M. A1 - Grygorczuk, J. A1 - Guarino, V. A1 - Guglielmi, L. A1 - Guilloux, F. A1 - Gunji, S. A1 - Gyuk, G. A1 - Hadasch, D. A1 - Haefner, D. A1 - Hagiwara, R. A1 - Hahn, J. A1 - Hallgren, A. A1 - Hara, S. A1 - Hardcastle, M. J. A1 - Hassan, T. A1 - Haubold, T. A1 - Hauser, M. A1 - Hayashida, M. A1 - Heller, R. A1 - Henri, G. A1 - Hermann, G. A1 - Herrero, A. A1 - Hinton, James Anthony A1 - Hoffmann, D. A1 - Hofmann, W. A1 - Hofverberg, P. A1 - Horns, D. A1 - Hrupec, D. A1 - Huan, H. A1 - Huber, B. A1 - Huet, J. -M. A1 - Hughes, G. A1 - Hultquist, K. A1 - Humensky, T. B. A1 - Huppert, J. -F. A1 - Ibarra, A. A1 - Illa, J. M. A1 - Ingjald, J. A1 - Inoue, S. A1 - Inoue, Y. A1 - Ioka, K. A1 - Jablonski, C. A1 - Jacholkowska, A. A1 - Janiak, M. A1 - Jean, P. A1 - Jensen, H. A1 - Jogler, T. A1 - Jung, I. A1 - Kaaret, P. A1 - Kabuki, S. A1 - Kakuwa, J. A1 - Kalkuhl, C. A1 - Kankanyan, R. A1 - Kapala, M. A1 - Karastergiou, A. A1 - Karczewski, M. A1 - Karkar, S. A1 - Karlsson, N. A1 - Kasperek, J. A1 - Katagiri, H. A1 - Katarzynski, K. A1 - Kawanaka, N. A1 - Kedziora, B. A1 - Kendziorra, E. A1 - Khelifi, B. A1 - Kieda, D. A1 - Kifune, T. A1 - Kihm, T. A1 - Klepser, S. A1 - Kluzniak, W. A1 - Knapp, J. A1 - Knappy, A. R. A1 - Kneiske, T. A1 - Knoedlseder, J. A1 - Koeck, F. A1 - Kodani, K. A1 - Kohri, K. A1 - Kokkotas, K. A1 - Komin, N. A1 - Konopelko, A. A1 - Kosack, K. A1 - Kossakowski, R. A1 - Kostka, P. A1 - Kotula, J. A1 - Kowal, G. A1 - Koziol, J. A1 - Kraehenbuehl, T. A1 - Krause, J. A1 - Krawczynski, H. A1 - Krennrich, F. A1 - Kretzschmann, A. A1 - Kubo, H. A1 - Kudryavtsev, V. A. A1 - Kushida, J. A1 - La Barbera, N. A1 - La Parola, V. A1 - La Rosa, G. A1 - Lopez, A. A1 - Lamanna, G. A1 - Laporte, P. A1 - Lavalley, C. A1 - Le Flour, T. A1 - Le Padellec, A. A1 - Lenain, J. -P. A1 - Lessio, L. A1 - Lieunard, B. A1 - Lindfors, E. A1 - Liolios, A. A1 - Lohse, T. A1 - Lombardi, S. A1 - Lopatin, A. A1 - Lorenz, E. A1 - Lubinski, P. A1 - Luz, O. A1 - Lyard, E. A1 - Maccarone, M. C. A1 - Maccarone, T. A1 - Maier, G. A1 - Majumdar, P. A1 - Maltezos, S. A1 - Malkiewicz, P. A1 - Mana, C. A1 - Manalaysay, A. A1 - Maneva, G. A1 - Mangano, A. A1 - Manigot, P. A1 - Marin, J. A1 - Mariotti, M. A1 - Markoff, S. A1 - Martinez, G. A1 - Martinez, M. A1 - Mastichiadis, A. A1 - Matsumoto, H. A1 - Mattiazzo, S. A1 - Mazin, D. A1 - McComb, T. J. L. A1 - McCubbin, N. A1 - McHardy, I. A1 - Medina, C. A1 - Melkumyan, D. A1 - Mendes, A. A1 - Mertsch, P. A1 - Meucci, M. A1 - Michalowski, J. A1 - Micolon, P. A1 - Mineo, T. A1 - Mirabal, N. A1 - Mirabel, F. A1 - Miranda, J. M. A1 - Mirzoyan, R. A1 - Mizuno, T. A1 - Moal, B. A1 - Moderski, R. A1 - Molinari, E. A1 - Monteiro, I. A1 - Moralejo, A. A1 - Morello, C. A1 - Mori, K. A1 - Motta, G. A1 - Mottez, F. A1 - Moulin, Emmanuel A1 - Mukherjee, R. A1 - Munar, P. A1 - Muraishi, H. A1 - Murase, K. A1 - Murphy, A. Stj. A1 - Nagataki, S. A1 - Naito, T. A1 - Nakamori, T. A1 - Nakayama, K. A1 - Naumann, C. L. A1 - Naumann, D. A1 - Nayman, P. A1 - Nedbal, D. A1 - Niedzwiecki, A. A1 - Niemiec, J. A1 - Nikolaidis, A. A1 - Nishijima, K. A1 - Nolan, S. J. A1 - Nowak, N. A1 - O'Brien, P. T. A1 - Ochoa, I. A1 - Ohira, Y. A1 - Ohishi, M. A1 - Ohka, H. A1 - Okumura, A. A1 - Olivetto, C. A1 - Ong, R. A. A1 - Orito, R. A1 - Orr, M. A1 - Osborne, J. P. A1 - Ostrowski, M. A1 - Otero, L. A1 - Otte, A. N. A1 - Ovcharov, E. A1 - Oya, I. A1 - Ozieblo, A. A1 - Paiano, S. A1 - Pallota, J. A1 - Panazol, J. L. A1 - Paneque, D. A1 - Panter, M. A1 - Paoletti, R. A1 - Papyan, G. A1 - Paredes, J. M. A1 - Pareschi, G. A1 - Parsons, R. D. A1 - Arribas, M. Paz A1 - Pedaletti, G. A1 - Pepato, A. A1 - Persic, M. A1 - Petrucci, P. O. A1 - Peyaud, B. A1 - Piechocki, W. A1 - Pita, S. A1 - Pivato, G. A1 - Platos, L. A1 - Platzer, R. A1 - Pogosyan, L. A1 - Pohl, Martin A1 - Pojmanski, G. A1 - Ponz, J. D. A1 - Potter, W. A1 - Prandini, E. A1 - Preece, R. A1 - Prokoph, H. A1 - Puehlhofer, G. A1 - Punch, M. A1 - Quel, E. A1 - Quirrenbach, A. A1 - Rajda, P. A1 - Rando, R. A1 - Rataj, M. A1 - Raue, M. A1 - Reimann, C. A1 - Reimann, O. A1 - Reimer, A. A1 - Reimer, O. A1 - Renaud, M. A1 - Renner, S. A1 - Reymond, J. -M. A1 - Rhode, W. A1 - Ribo, M. A1 - Ribordy, M. A1 - Rico, J. A1 - Rieger, F. A1 - Ringegni, P. A1 - Ripken, J. A1 - Ristori, P. A1 - Rivoire, S. A1 - Rob, L. A1 - Rodriguez, S. A1 - Roeser, U. A1 - Romano, Patrizia A1 - Romero, G. E. A1 - Rosier-Lees, S. A1 - Rovero, A. C. A1 - Roy, F. A1 - Royer, S. A1 - Rudak, B. A1 - Rulten, C. B. A1 - Ruppel, J. A1 - Russo, F. A1 - Ryde, F. A1 - Sacco, B. A1 - Saggion, A. A1 - Sahakian, V. A1 - Saito, K. A1 - Saito, T. A1 - Sakaki, N. A1 - Salazar, E. A1 - Salini, A. A1 - Sanchez, F. A1 - Sanchez Conde, M. A. A1 - Santangelo, Andrea A1 - Santos, E. M. A1 - Sanuy, A. A1 - Sapozhnikov, L. A1 - Sarkar, S. A1 - Scalzotto, V. A1 - Scapin, V. A1 - Scarcioffolo, M. A1 - Schanz, T. A1 - Schlenstedt, S. A1 - Schlickeiser, R. A1 - Schmidt, T. A1 - Schmoll, J. A1 - Schroedter, M. A1 - Schultz, C. A1 - Schultze, J. A1 - Schulz, A. A1 - Schwanke, U. A1 - Schwarzburg, S. A1 - Schweizer, T. A1 - Seiradakis, J. A1 - Selmane, S. A1 - Seweryn, K. A1 - Shayduk, M. A1 - Shellard, R. C. A1 - Shibata, T. A1 - Sikora, M. A1 - Silk, J. A1 - Sillanpaa, A. A1 - Sitarek, J. A1 - Skole, C. A1 - Smith, N. A1 - Sobczynska, D. A1 - Sofo Haro, M. A1 - Sol, H. A1 - Spanier, F. A1 - Spiga, D. A1 - Spyrou, S. A1 - Stamatescu, V. A1 - Stamerra, A. A1 - Starling, R. L. C. A1 - Stawarz, L. A1 - Steenkamp, R. A1 - Stegmann, Christian A1 - Steiner, S. A1 - Stergioulas, N. A1 - Sternberger, R. A1 - Stinzing, F. A1 - Stodulski, M. A1 - Straumann, U. A1 - Suarez, A. A1 - Suchenek, M. A1 - Sugawara, R. A1 - Sulanke, K. H. A1 - Sun, S. A1 - Supanitsky, A. D. A1 - Sutcliffe, P. A1 - Szanecki, M. A1 - Szepieniec, T. A1 - Szostek, A. A1 - Szymkowiak, A. A1 - Tagliaferri, G. A1 - Tajima, H. A1 - Takahashi, H. A1 - Takahashi, K. A1 - Takalo, L. A1 - Takami, H. A1 - Talbot, R. G. A1 - Tam, P. H. A1 - Tanaka, M. A1 - Tanimori, T. A1 - Tavani, M. A1 - Tavernet, J. -P. A1 - Tchernin, C. A1 - Tejedor, L. A. A1 - Telezhinsky, Igor O. A1 - Temnikov, P. A1 - Tenzer, C. A1 - Terada, Y. A1 - Terrier, R. A1 - Teshima, M. A1 - Testa, V. A1 - Tibaldo, L. A1 - Tibolla, O. A1 - Tluczykont, M. A1 - Peixoto, C. J. Todero A1 - Tokanai, F. A1 - Tokarz, M. A1 - Toma, K. A1 - Torres, D. F. A1 - Tosti, G. A1 - Totani, T. A1 - Toussenel, F. A1 - Vallania, P. A1 - Vallejo, G. A1 - van der Walt, J. A1 - van Eldik, C. A1 - Vandenbroucke, J. A1 - Vankov, H. A1 - Vasileiadis, G. A1 - Vassiliev, V. V. A1 - Vegas, I. A1 - Venter, L. A1 - Vercellone, S. A1 - Veyssiere, C. A1 - Vialle, J. P. A1 - Videla, M. A1 - Vincent, P. A1 - Vink, J. A1 - Vlahakis, N. A1 - Vlahos, L. A1 - Vogler, P. A1 - Vollhardt, A. A1 - Volpe, F. A1 - Von Gunten, H. P. A1 - Vorobiov, S. A1 - Wagner, S. A1 - Wagner, R. M. A1 - Wagner, B. A1 - Wakely, S. P. A1 - Walter, P. A1 - Walter, R. A1 - Warwick, R. A1 - Wawer, P. A1 - Wawrzaszek, R. A1 - Webb, N. A1 - Wegner, P. A1 - Weinstein, A. A1 - Weitzel, Q. A1 - Welsing, R. A1 - Wetteskind, H. A1 - White, R. A1 - Wierzcholska, A. A1 - Wilkinson, M. I. A1 - Williams, D. A. A1 - Winde, M. A1 - Wischnewski, R. A1 - Wisniewski, L. A1 - Wolczko, A. A1 - Wood, M. A1 - Xiong, Q. A1 - Yamamoto, T. A1 - Yamaoka, K. A1 - Yamazaki, R. A1 - Yanagita, S. A1 - Yoffo, B. A1 - Yonetani, M. A1 - Yoshida, A. A1 - Yoshida, T. A1 - Yoshikoshi, T. A1 - Zabalza, V. A1 - Zagdanski, A. A1 - Zajczyk, A. A1 - Zdziarski, A. A1 - Zech, Alraune A1 - Zietara, K. A1 - Ziolkowski, P. A1 - Zitelli, V. A1 - Zychowski, P. T1 - Design concepts for the Cherenkov Telescope Array CTA an advanced facility for ground-based high-energy gamma-ray astronomy JF - Experimental astronomy : an international journal on astronomical instrumentation and data analysis N2 - Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA. KW - Ground based gamma ray astronomy KW - Next generation Cherenkov telescopes KW - Design concepts Y1 - 2011 U6 - https://doi.org/10.1007/s10686-011-9247-0 SN - 0922-6435 SN - 1572-9508 VL - 32 IS - 3 SP - 193 EP - 316 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Ackermann, Margit A1 - Ajello, M. A1 - Allafort, A. J. A1 - Baldini, L. A1 - Ballet, J. A1 - Barbiellini, G. A1 - Bastieri, D. A1 - Belfiore, A. A1 - Bellazzini, R. A1 - Berenji, B. A1 - Blandford, R. D. A1 - Bloom, E. D. A1 - Bonamente, E. A1 - Borgland, A. W. A1 - Bottacini, E. A1 - Brigida, M. A1 - Bruel, P. A1 - Buehler, R. A1 - Buson, S. A1 - Caliandro, G. A. A1 - Cameron, R. A. A1 - Caraveo, P. A. A1 - Casandjian, J. M. A1 - Cecchi, C. A1 - Chekhtman, A. A1 - Cheung, C. C. A1 - Chiang, J. A1 - Ciprini, S. A1 - Claus, R. A1 - Cohen-Tanugi, J. A1 - de Angelis, A. A1 - de Palma, F. A1 - Dermer, C. D. A1 - do Couto e Silva, E. A1 - Drell, P. S. A1 - Dumora, D. A1 - Favuzzi, C. A1 - Fegan, S. J. A1 - Focke, W. B. A1 - Fortin, P. A1 - Fukazawa, Y. A1 - Fusco, P. A1 - Gargano, F. A1 - Germani, S. A1 - Giglietto, N. A1 - Giordano, F. A1 - Giroletti, M. A1 - Glanzman, T. A1 - Godfrey, G. A1 - Grenier, I. A. A1 - Guillemot, L. A1 - Guiriec, S. A1 - Hadasch, D. A1 - Hanabata, Y. A1 - Harding, A. K. A1 - Hayashida, M. A1 - Hayashi, K. A1 - Hays, E. A1 - Johannesson, G. A1 - Johnson, A. S. A1 - Kamae, T. A1 - Katagiri, H. A1 - Kataoka, J. A1 - Kerr, M. A1 - Knoedlseder, J. A1 - Kuss, M. A1 - Lande, J. A1 - Latronico, L. A1 - Lee, S. -H. A1 - Longo, F. A1 - Loparco, F. A1 - Lott, B. A1 - Lovellette, M. N. A1 - Lubrano, P. A1 - Martin, P. A1 - Mazziotta, Mario Nicola A1 - McEnery, J. E. A1 - Mehault, J. A1 - Michelson, P. F. A1 - Mitthumsiri, W. A1 - Mizuno, T. A1 - Monte, C. A1 - Monzani, M. E. A1 - Morselli, A. A1 - Moskalenko, I. V. A1 - Murgia, S. A1 - Naumann-Godo, M. A1 - Nolan, P. L. A1 - Norris, J. P. A1 - Nuss, E. A1 - Ohsugi, T. A1 - Okumura, A. A1 - Orlando, E. A1 - Ormes, J. F. A1 - Ozaki, M. A1 - Paneque, D. A1 - Parent, D. A1 - Pesce-Rollins, M. A1 - Pierbattista, M. A1 - Piron, F. A1 - Pohl, Martin A1 - Prokhorov, D. A1 - Raino, S. A1 - Rando, R. A1 - Razzano, M. A1 - Reposeur, T. A1 - Ritz, S. A1 - Parkinson, P. M. Saz A1 - Sgro, C. A1 - Siskind, E. J. A1 - Smith, P. D. A1 - Spinelli, P. A1 - Strong, A. W. A1 - Takahashi, H. A1 - Tanaka, T. A1 - Thayer, J. G. A1 - Thayer, J. B. A1 - Thompson, D. J. A1 - Tibaldo, L. A1 - Torres, D. F. A1 - Tosti, G. A1 - Tramacere, A. A1 - Troja, E. A1 - Uchiyama, Y. A1 - Vandenbroucke, J. A1 - Vasileiou, V. A1 - Vianello, G. A1 - Vitale, V. A1 - Waite, A. P. A1 - Wang, P. A1 - Winer, B. L. A1 - Wood, K. S. A1 - Yang, Z. A1 - Zimmer, S. A1 - Bontemps, S. T1 - A cocoon of freshly accelerated cosmic rays detected by fermi in the cygnus superbubble JF - Science N2 - The origin of Galactic cosmic rays is a century-long puzzle. Indirect evidence points to their acceleration by supernova shockwaves, but we know little of their escape from the shock and their evolution through the turbulent medium surrounding massive stars. Gamma rays can probe their spreading through the ambient gas and radiation fields. The Fermi Large Area Telescope (LAT) has observed the star-forming region of Cygnus X. The 1- to 100-gigaelectronvolt images reveal a 50-parsec-wide cocoon of freshly accelerated cosmic rays that flood the cavities carved by the stellar winds and ionization fronts from young stellar clusters. It provides an example to study the youth of cosmic rays in a superbubble environment before they merge into the older Galactic population. Y1 - 2011 U6 - https://doi.org/10.1126/science.1210311 SN - 0036-8075 VL - 334 IS - 6059 SP - 1103 EP - 1107 PB - American Assoc. for the Advancement of Science CY - Washington ER -