TY - GEN A1 - Abramowski, Attila A1 - Aharonian, Felix A. A1 - Benkhali, Faical Ait A1 - Akhperjanian, A. G. A1 - Angüner, Ekrem Oǧuzhan A1 - Backes, Michael A1 - Balenderan, Shangkari A1 - Balzer, Arnim A1 - Barnacka, Anna A1 - Becherini, Yvonne A1 - Tjus, Julia Becker A1 - Berge, David A1 - Bernhard, Sabrina A1 - Bernlöhr, Konrad A1 - Birsin, E. A1 - Biteau, Jonathan A1 - Böttcher, Markus A1 - Boisson, Catherine A1 - Bolmont, J. A1 - Bordas, Pol A1 - Bregeon, Johan A1 - Brun, Francois A1 - Brun, Pierre A1 - Bryan, Mark A1 - Bulik, Tomasz A1 - Carrigan, Svenja A1 - Casanova, Sabrina A1 - Chadwick, Paula M. A1 - Chakraborty, Nachiketa A1 - Chalme-Calvet, R. A1 - Chaves, Ryan C. G. A1 - Chretien, M. A1 - Colafrancesco, Sergio A1 - Cologna, Gabriele A1 - Conrad, Jan A1 - Couturier, Claire A1 - Cui, Yudong A1 - Davids, Isak Delberth A1 - Degrange, Bernhard A1 - Deil, Christoph A1 - deWilt, P. A1 - Djannati-Ataï, A. A1 - Domainko, Wilfried A1 - Donath, Axel A1 - Dubus, G. A1 - Dutson, K. A1 - Dyks, J. A1 - Dyrda, M. A1 - Edwards, Tanya A1 - Egberts, Kathrin A1 - Eger, Peter A1 - Espigat, P. A1 - Farnier, C. A1 - Fegan, Stephen A1 - Feinstein, Fabrice A1 - Fernandes, Milton Virgilio A1 - Fernandez, Diane A1 - Fiasson, A. A1 - Fontaine, Gerard A1 - Förster, Andreas A1 - Fuessling, M. A1 - Gabici, S. A1 - Gajdus, M. A1 - Gallant, Yves A. A1 - Garrigoux, Tania A1 - Giavitto, G. A1 - Giebels, Berrie A1 - Glicenstein, Jean-Francois A1 - Gottschall, Daniel A1 - Grondin, M. -H. A1 - Grudzinska, M. A1 - Hadasch, Daniela A1 - Haeffner, S. A1 - Hahn, Joachim A1 - Harris, Jonathan A1 - Heinzelmann, Götz A1 - Henri, G. A1 - Hermann, German A1 - Hervet, O. A1 - Hillert, Andreas A1 - Hinton, James Anthony A1 - Hofmann, Werner A1 - Hofverberg, Petter A1 - Holler, Markus A1 - Horns, Dieter A1 - Ivascenko, Alex A1 - Jacholkowska, A. A1 - Jahn, C. A1 - Jamrozy, Marek A1 - Janiak, M. A1 - Jankowsky, F. A1 - Jung-Richardt, I. A1 - Kastendieck, Max Anton A1 - Katarzynski, K. A1 - Katz, U. A1 - Kaufmann, S. A1 - Khelifi, B. A1 - Kieffer, Michel A1 - Klepser, S. A1 - Klochkov, Dmitry A1 - Kluzniak, W. A1 - Kolitzus, David A1 - Komin, Nu A1 - Kosack, Karl A1 - Krakau, Steffen A1 - Krayzel, F. A1 - Krueger, Pat P. A1 - Laffon, H. A1 - Lamanna, G. A1 - Lefaucheur, J. A1 - Lefranc, Valentin A1 - Lemiere, A. A1 - Lemoine-Goumard, M. A1 - Lenain, J. -P. A1 - Lohse, Thomas A1 - Lopatin, A. A1 - Lu, Chia-Chun A1 - Marandon, Vincent A1 - Marcowith, Alexandre A1 - Marx, Ramin A1 - Maurin, G. A1 - Maxted, Nigel A1 - Mayer, Michael A1 - McComb, T. J. Lowry A1 - Mehault, J. A1 - Meintjes, P. J. A1 - Menzler, Ulf A1 - Meyer, M. A1 - Mitchell, Alison M. W. A1 - Moderski, R. A1 - Mohamed, M. A1 - Mora, K. A1 - Moulin, Emmanuel A1 - Murach, Thomas A1 - de Naurois, Mathieu A1 - Niemiec, J. A1 - Nolan, Sam J. A1 - Oakes, Louise A1 - Odaka, Hirokazu A1 - Ohm, S. A1 - Optiz, Björn A1 - Ostrowski, Michal A1 - Oya, I. A1 - Panter, Michael A1 - Parsons, R. Daniel A1 - Arribas, M. Paz A1 - Pekeur, Nikki W. A1 - Pelletier, G. A1 - Petrucci, P. -O. A1 - Peyaud, B. A1 - Pita, S. A1 - Poon, Helen A1 - Pühlhofer, Gerd A1 - Punch, M. A1 - Quirrenbach, A. A1 - Raab, S. A1 - Reichardt, I. A1 - Reimer, Anita A1 - Reimer, Olaf A1 - Renaud, Metz A1 - de los Reyes, Raquel A1 - Rieger, Frank A1 - Romoli, C. A1 - Rosier-Lees, S. A1 - Rowell, G. A1 - Rudak, B. A1 - Rulten, C. B. A1 - Sahakian, Vardan A1 - Salek, D. A1 - Sanchez, David M. A1 - Santangelo, Andrea A1 - Schlickeiser, Reinhard A1 - Schuessler, F. A1 - Schulz, A. A1 - Schwanke, Ullrich A1 - Schwarzburg, S. A1 - Schwemmer, S. A1 - Sol, H. A1 - Spanier, Felix A1 - Spengler, G. A1 - Spies, Franziska A1 - Stawarz, Lukasz A1 - Steenkamp, Riaan A1 - Stegmann, Christian A1 - Stinzing, F. A1 - Stycz, K. A1 - Sushch, Iurii A1 - Tavernet, J. -P. A1 - Tavernier, T. A1 - Taylor, A. M. A1 - Terrier, R. A1 - Tluczykont, Martin A1 - Trichard, C. A1 - Valerius, K. A1 - van Eldik, C. A1 - van Soelen, B. A1 - Vasileiadis, Georges A1 - Veh, J. A1 - Venter, Christo A1 - Viana, Aion A1 - Vincent, P. A1 - Vink, Jacco A1 - Völk, Heinrich J. A1 - Volpe, Francesca A1 - Vorster, Martine A1 - Vuillaume, T. A1 - Wagner, S. J. A1 - Wagner, P. A1 - Wagner, R. M. A1 - Ward, Martin A1 - Weidinger, Matthias A1 - Weitzel, Quirin A1 - White, R. A1 - Wierzcholska, A. A1 - Willmann, P. A1 - Woernlein, A. A1 - Wouters, D. A1 - Yang, Ruizhi A1 - Zabalza, Victor A1 - Zaborov, Dmitry A1 - Zacharias, M. A1 - Zdziarski, A. A. A1 - Zech, Alraune A1 - Zechlin, Hannes -S. T1 - H.E.S.S. detection of TeV emission from the interaction region between the supernova remnant G349.7+0.2 and a molecular cloud (vol 574, A100, 2015) T2 - Astronomy and astrophysics : an international weekly journal KW - gamma rays: general KW - ISM: supernova remnants KW - ISM: clouds KW - errata, addenda Y1 - 2015 U6 - https://doi.org/10.1051/0004-6361/201425070e SN - 1432-0746 VL - 580 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Abramowski, Attila A1 - Acero, F. A1 - Aharonian, Felix A. A1 - Akhperjanian, A. G. A1 - Anton, Gisela A1 - Balenderan, Shangkari A1 - Balzer, Arnim A1 - Barnacka, Anna A1 - Becherini, Yvonne A1 - Tjus, J. Becker A1 - Behera, B. A1 - Bernlöhr, K. A1 - Birsin, E. A1 - Biteau, Jonathan A1 - Bochow, A. A1 - Boisson, Catherine A1 - Bolmont, J. A1 - Bordas, Pol A1 - Brucker, J. A1 - Brun, Francois A1 - Brun, Pierre A1 - Bulik, Tomasz A1 - Carrigan, Svenja A1 - Casanova, Sabrina A1 - Cerruti, M. A1 - Chadwick, Paula M. A1 - Chaves, Ryan C. G. A1 - Cheesebrough, A. A1 - Colafrancesco, Sergio A1 - Cologna, Gabriele A1 - Conrad, Jan A1 - Couturier, C. A1 - Dalton, M. A1 - Daniel, M. K. A1 - Davids, I. D. A1 - Degrange, B. A1 - Deil, C. A1 - deWilt, P. A1 - Dickinson, H. J. A1 - Djannati-Ataï, A. A1 - Domainko, W. A1 - Drury, L. O'C. A1 - Dubus, G. A1 - Dutson, K. A1 - Dyks, J. A1 - Dyrda, M. A1 - Egberts, Kathrin A1 - Eger, P. A1 - Espigat, P. A1 - Fallon, L. A1 - Farnier, C. A1 - Fegan, S. A1 - Feinstein, F. A1 - Fernandes, M. V. A1 - Fernandez, D. A1 - Fiasson, A. A1 - Fontaine, G. A1 - Foester, A. A1 - Fuessling, M. A1 - Gajdus, M. A1 - Gallant, Y. A. A1 - Garrigoux, T. A1 - Gast, H. A1 - Giebels, B. A1 - Glicenstein, J. F. A1 - Glueck, B. A1 - Goeing, D. A1 - Grondin, M. -H. A1 - Grudzinska, M. A1 - Haeffner, S. A1 - Hague, J. D. A1 - Hahn, J. A1 - Hampf, D. A1 - Harris, J. A1 - Hauser, M. A1 - Heinz, S. A1 - Heinzelmann, G. A1 - Henri, G. A1 - Hermann, G. A1 - Hillert, A. A1 - Hinton, James Anthony A1 - Hofmann, W. A1 - Hofverberg, P. A1 - Holler, Markus A1 - Horns, D. A1 - Jacholkowska, A. A1 - Jahn, C. A1 - Jamrozy, M. A1 - Jung, I. A1 - Kastendieck, M. A. A1 - Katarzynski, K. A1 - Katz, U. A1 - Kaufmann, S. A1 - Khelifi, B. A1 - Klepser, S. A1 - Klochkov, D. A1 - Kluzniak, W. A1 - Kneiske, T. A1 - Komin, Nu. A1 - Kosack, K. A1 - Kossakowski, R. A1 - Krayzel, F. A1 - Krueger, P. P. A1 - Laffon, H. A1 - Lamanna, G. A1 - Lefaucheur, J. A1 - Lemoine-Goumard, M. A1 - Lenain, J. -P. A1 - Lennarz, D. A1 - Lohse, T. A1 - Lopatin, A. A1 - Lu, C. -C. A1 - Marandon, V. A1 - Marcowith, Alexandre A1 - Masbou, J. A1 - Maurin, G. A1 - Maxted, N. A1 - Mayer, M. A1 - McComb, T. J. L. A1 - Medina, M. C. A1 - Mehault, J. A1 - Menzler, U. A1 - Moderski, R. A1 - Mohamed, M. A1 - Moulin, Emmanuel A1 - Naumann, C. L. A1 - Naumann-Godo, M. A1 - de Naurois, M. A1 - Nedbal, D. A1 - Nguyen, N. A1 - Niemiec, J. A1 - Nolan, S. J. A1 - Ohm, S. A1 - Wilhelmi, E. de Ona A1 - Opitz, B. A1 - Ostrowski, M. A1 - Oya, I. A1 - Panter, M. A1 - Parsons, R. D. A1 - Arribas, M. Paz A1 - Pekeur, N. W. A1 - Pelletier, G. A1 - Perez, J. A1 - Petrucci, P. -O. A1 - Peyaud, B. A1 - Pita, S. A1 - Puehlhofer, G. A1 - Punch, M. A1 - Quirrenbach, A. A1 - Raab, S. A1 - Raue, M. A1 - Reimer, A. A1 - Reimer, O. A1 - Renaud, M. A1 - de los Reyes, R. A1 - Rieger, F. A1 - Ripken, J. A1 - Rob, L. A1 - Rosier-Lees, S. A1 - Rowell, G. A1 - Rudak, B. A1 - Rulten, C. B. A1 - Sahakian, V. A1 - Sanchez, David M. A1 - Santangelo, Andrea A1 - Schlickeiser, R. A1 - Schulz, A. A1 - Schwanke, U. A1 - Schwarzburg, S. A1 - Schwemmer, S. A1 - Sheidaei, F. A1 - Skilton, J. L. A1 - Sol, H. A1 - Spengler, G. A1 - Stawarz, L. A1 - Steenkamp, R. A1 - Stegmann, Christian A1 - Stinzing, F. A1 - Stycz, K. A1 - Sushch, Iurii A1 - Szostek, A. A1 - Tavernet, J. -P. A1 - Terrier, R. A1 - Tluczykont, M. A1 - Trichard, C. A1 - Valerius, K. A1 - van Eldik, C. A1 - Vasileiadis, G. A1 - Venter, C. A1 - Viana, A. A1 - Vincent, P. A1 - Voelk, H. J. A1 - Volpe, F. A1 - Vorobiov, S. A1 - Vorster, M. A1 - Wagner, S. J. A1 - Ward, M. A1 - White, R. A1 - Wierzcholska, A. A1 - Wouters, D. A1 - Zacharias, M. A1 - Zajczyk, A. A1 - Zdziarski, A. A. A1 - Zech, Alraune A1 - Zechlin, H. S. T1 - HESS discovery of VHE gamma-rays from the quasar PKS 1510-089 JF - Astronomy and astrophysics : an international weekly journal N2 - The quasar PKS 1510-089 (z = 0.361) was observed with the H.E.S.S. array of imaging atmospheric Cherenkov telescopes during high states in the optical and GeV bands, to search for very high energy (VHE, defined as E >= 0.1 TeV) emission. VHE gamma-rays were detected with a statistical significance of 9.2 standard deviations in 15.8 h of H. E. S. S. data taken during March and April 2009. A VHE integral flux of I(0.15 TeV < E < 1.0TeV) = (1.0 +/- 0.2(stat) +/- 0.2(sys)) x 10(-11) cm(-2) s(-1) is measured. The best-fit power law to the VHE data has a photon index of G = 5.4 +/- 0.7(stat) +/- 0.3(sys). The GeV and optical light curves show pronounced variability during the period of H.E.S.S. observations. However, there is insufficient evidence to claim statistically significant variability in the VHE data. Because of its relatively high redshift, the VHE flux from PKS 1510-089 should suffer considerable attenuation in the intergalactic space due to the extragalactic background light (EBL). Hence, the measured gamma-ray spectrum is used to derive upper limits on the opacity due to EBL, which are found to be comparable with the previously derived limits from relatively-nearby BL Lac objects. Unlike typical VHE-detected blazars where the broadband spectrum is dominated by nonthermal radiation at all wavelengths, the quasar PKS 1510-089 has a bright thermal component in the optical to UV frequency band. Among all VHE detected blazars, PKS 1510-089 has the most luminous broad line region. The detection of VHE emission from this quasar indicates a low level of gamma - gamma absorption on the internal optical to UV photon field. KW - gamma rays: galaxies KW - quasars: individual: PKS 1510-089 KW - infrared: diffuse background Y1 - 2013 U6 - https://doi.org/10.1051/0004-6361/201321135 SN - 0004-6361 VL - 554 IS - 6 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Abramowski, Attila A1 - Acero, F. A1 - Aharonian, Felix A. A1 - Akhperjanian, A. G. A1 - Anton, Gisela A1 - Balenderan, Shangkari A1 - Balzer, Arnim A1 - Barnacka, Anna A1 - Becherini, Yvonne A1 - Tjus, J. Becker A1 - Bernlöhr, K. A1 - Birsin, E. A1 - Biteau, Jonathan A1 - Bochow, A. A1 - Boisson, Catherine A1 - Bolmont, J. A1 - Bordas, Pol A1 - Brucker, J. A1 - Brun, Francois A1 - Brun, Pierre A1 - Bulik, Tomasz A1 - Carrigan, Svenja A1 - Casanova, Sabrina A1 - Cerruti, M. A1 - Chadwick, Paula M. A1 - Chaves, Ryan C. G. A1 - Cheesebrough, A. A1 - Colafrancesco, Sergio A1 - Cologna, Gabriele A1 - Conrad, Jan A1 - Couturier, C. A1 - Dalton, M. A1 - Daniel, M. K. A1 - Davids, I. D. A1 - Degrange, B. A1 - Deil, C. A1 - deWilt, P. A1 - Dickinson, H. J. A1 - Djannati-Ataï, A. A1 - Domainko, W. A1 - Drury, L. O'C. A1 - Dubus, G. A1 - Dutson, K. A1 - Dyks, J. A1 - Dyrda, M. A1 - Egberts, Kathrin A1 - Eger, P. A1 - Espigat, P. A1 - Fallon, L. A1 - Farnier, C. A1 - Fegan, S. A1 - Feinstein, F. A1 - Fernandes, M. V. A1 - Fernandez, D. A1 - Fiasson, A. A1 - Fontaine, G. A1 - Foerster, A. A1 - Fussling, Matthias A1 - Gajdus, M. A1 - Gallant, Y. A. A1 - Garrigoux, T. A1 - Gast, H. A1 - Giebels, B. A1 - Glicenstein, J. F. A1 - Glueck, B. A1 - Goering, D. A1 - Grondin, M. -H. A1 - Haeffner, S. A1 - Hague, J. D. A1 - Hahn, J. A1 - Hampf, D. A1 - Harris, J. A1 - Heinz, S. A1 - Heinzelmann, G. A1 - Henri, G. A1 - Hermann, G. A1 - Hillert, A. A1 - Hinton, James Anthony A1 - Hofmann, W. A1 - Hofverberg, P. A1 - Holler, M. A1 - Horns, D. A1 - Jacholkowska, A. A1 - Jahn, C. A1 - Jamrozy, M. A1 - Jung, I. A1 - Kastendieck, M. A. A1 - Katarzynski, K. A1 - Katz, U. A1 - Kaufmann, S. A1 - Khelifi, B. A1 - Klepser, S. A1 - Klochkov, D. A1 - Kluzniak, W. A1 - Kneiske, T. A1 - Komin, Nu A1 - Kosack, K. A1 - Kossakowski, R. A1 - Krayzel, F. A1 - Krueger, P. P. A1 - Laffon, H. A1 - Lamanna, G. A1 - Lefaucheur, J. A1 - Lemoine-Goumard, M. A1 - Lenain, J. -P. A1 - Lennarz, D. A1 - Lohse, T. A1 - Lopatin, A. A1 - Lu, C. -C. A1 - Marandon, V. A1 - Marcowith, Alexandre A1 - Masbou, J. A1 - Maurin, G. A1 - Maxted, N. A1 - Mayer, M. A1 - McComb, T. J. L. A1 - Medina, M. C. A1 - Mehault, J. A1 - Menzler, U. A1 - Moderski, R. A1 - Mohamed, M. A1 - Moulin, Emmanuel A1 - Naumann, C. L. A1 - Naumann-Godo, M. A1 - de Naurois, M. A1 - Nedbal, D. A1 - Nekrassov, D. A1 - Nguyen, N. A1 - Niemiec, J. A1 - Nolan, S. J. A1 - Ohm, S. A1 - Awilhelmi, E. de Ona A1 - Opitz, B. A1 - Ostrowski, M. A1 - Oya, I. A1 - Panter, M. A1 - Parsons, R. D. A1 - Arribas, M. Paz A1 - Pekeur, N. W. A1 - Pelletier, G. A1 - Perez, J. A1 - Petrucci, P. -O. A1 - Peyaud, B. A1 - Pita, S. A1 - Puehlhofer, G. A1 - Punch, M. A1 - Quirrenbach, A. A1 - Raue, M. A1 - Reimer, A. A1 - Reimer, O. A1 - Renaud, M. A1 - de los Reyes, R. A1 - Rieger, F. A1 - Ripken, J. A1 - Rob, L. A1 - Rosier-Lees, S. A1 - Rowell, G. A1 - Rudak, B. A1 - Rulten, C. B. A1 - Sahakian, V. A1 - Sanchez, David M. A1 - Santangelo, Andrea A1 - Schlickeiser, R. A1 - Schulz, A. A1 - Schwanke, U. A1 - Schwarzburg, S. A1 - Schwemmer, S. A1 - Sheidaei, F. A1 - Skilton, J. L. A1 - Sol, H. A1 - Spengler, G. A1 - Stawarz, L. A1 - Steenkamp, R. A1 - Stegmann, Christian A1 - Stinzing, F. A1 - Stycz, K. A1 - Sushch, Iurii A1 - Szostek, A. A1 - Tavernet, J. -P. A1 - Terrier, R. A1 - Tluczykont, M. A1 - Trichard, C. A1 - Valerius, K. A1 - van Eldik, C. A1 - Vasileiadis, G. A1 - Venter, C. A1 - Viana, A. A1 - Vincent, P. A1 - Voelk, H. J. A1 - Volpe, F. A1 - Vorobiov, S. A1 - Vorster, M. A1 - Wagner, S. J. A1 - Ward, M. A1 - White, R. A1 - Wierzcholska, A. A1 - Wouters, D. A1 - Zacharias, M. A1 - Zajczyk, A. A1 - Zdziarski, A. A. A1 - Zech, Alraune A1 - Zechlin, H. -S. T1 - Search for Photon-Linelike Signatures from Dark Matter Annihilations with H.E.S.S. JF - Physical review letters N2 - Gamma-ray line signatures can be expected in the very-high-energy (E-gamma > 100 GeV) domain due to self-annihilation or decay of dark matter (DM) particles in space. Such a signal would be readily distinguishable from astrophysical gamma-ray sources that in most cases produce continuous spectra that span over several orders of magnitude in energy. Using data collected with the H. E. S. S. gamma-ray instrument, upper limits on linelike emission are obtained in the energy range between similar to 500 GeV and similar to 25 TeV for the central part of the Milky Way halo and for extragalactic observations, complementing recent limits obtained with the Fermi-LAT instrument at lower energies. No statistically significant signal could be found. For monochromatic gamma-ray line emission, flux limits of (2 x 10(-7)-2 x 10(-5)) m(-2)s(-1)sr(-1) and (1 x 10(-8)- 2 x 10(-6)) m(-2)s(-1)sr(-1) are obtained for the central part of the Milky Way halo and extragalactic observations, respectively. For a DM particle mass of 1 TeV, limits on the velocity- averaged DM annihilation cross section (chi chi ->gamma gamma) reach similar to 10(-27)cm(3)s(-1), based on the Einasto parametrization of the Galactic DM halo density profile. DOI: 10.1103/PhysRevLett.110.041301 Y1 - 2013 U6 - https://doi.org/10.1103/PhysRevLett.110.041301 SN - 0031-9007 VL - 110 IS - 4 PB - American Physical Society CY - College Park ER - TY - JOUR A1 - Abramowski, Attila A1 - Acero, F. A1 - Akhperjanian, A. G. A1 - Anton, Gisela A1 - Balenderan, Shangkari A1 - Balzer, Arnim A1 - Barnacka, Anna A1 - Becherini, Yvonne A1 - Tjus, J. Becker A1 - Behera, B. A1 - Bernlöhr, K. A1 - Birsin, E. A1 - Biteau, Jonathan A1 - Bochow, A. A1 - Boisson, Catherine A1 - Bolmont, J. A1 - Bordas, Pol A1 - Brucker, J. A1 - Brun, Francois A1 - Brun, Pierre A1 - Bulik, Tomasz A1 - Carrigan, Svenja A1 - Casanova, Sabrina A1 - Cerruti, M. A1 - Chadwick, Paula M. A1 - Chaves, Ryan C. G. A1 - Cheesebrough, A. A1 - Colafrancesco, Sergio A1 - Cologna, Gabriele A1 - Conrad, Jan A1 - Couturier, C. A1 - Dalton, M. A1 - Daniel, M. K. A1 - Davids, I. D. A1 - Degrange, B. A1 - Deil, C. A1 - deWilt, P. A1 - Dickinson, H. J. A1 - Djannati-Ataï, A. A1 - Domainko, W. A1 - Drury, L. O&rsquo A1 - C., A1 - Dubus, G. A1 - Dutson, K. A1 - Dyks, J. A1 - Dyrda, M. A1 - Egberts, Kathrin A1 - Eger, P. A1 - Espigat, P. A1 - Fallon, L. A1 - Farnier, C. A1 - Fegan, S. A1 - Feinstein, F. A1 - Fernandes, M. V. A1 - Fernandez, D. A1 - Fiasson, A. A1 - Fontaine, G. A1 - Foerster, A. A1 - Fussling, Matthias A1 - Gajdus, M. A1 - Gallant, Y. A. A1 - Garrigoux, T. A1 - Gast, H. A1 - Giebels, B. A1 - Glicenstein, J. F. A1 - Glueck, B. A1 - Goering, D. A1 - Grondin, M. -H. A1 - Grudzinska, M. A1 - Haeffner, S. A1 - Hague, J. D. A1 - Hahn, J. A1 - Hampf, D. A1 - Harris, J. A1 - Heinz, S. A1 - Heinzelmann, G. A1 - Henri, G. A1 - Hermann, G. A1 - Hillert, A. A1 - Hinton, James Anthony A1 - Hofmann, W. A1 - Hofverberg, P. A1 - Holler, M. A1 - Horns, D. A1 - Jacholkowska, A. A1 - Jahn, C. A1 - Jamrozy, M. A1 - Jung, I. A1 - Kastendieck, M. A. A1 - Katarzynski, K. A1 - Katz, U. A1 - Kaufmann, S. A1 - Khelifi, B. A1 - Klepser, S. A1 - Klochkov, D. A1 - Kluzniak, W. A1 - Kneiske, T. A1 - Kolitzus, D. A1 - Komin, Nu A1 - Kosack, K. A1 - Kossakowski, R. A1 - Krayzel, F. A1 - Krueger, P. P. A1 - Laffon, H. A1 - Lamanna, G. A1 - Lefaucheur, J. A1 - Lemoine-Goumard, M. A1 - Lenain, J. -P. A1 - Lennarz, D. A1 - Lohse, T. A1 - Lopatin, A. A1 - Lu, C. -C. A1 - Marandon, V. A1 - Marcowith, Alexandre A1 - Masbou, J. A1 - Maurin, G. A1 - Maxted, N. A1 - Mayer, M. A1 - McComb, T. J. L. A1 - Medina, M. C. A1 - Mehault, J. A1 - Menzler, U. A1 - Moderski, R. A1 - Mohamed, M. A1 - Moulin, Emmanuel A1 - Naumann, C. L. A1 - Naumann-Godo, M. A1 - de Naurois, M. A1 - Nedbal, D. A1 - Nguyen, N. A1 - Niemiec, J. A1 - Nolan, S. J. A1 - Ohm, S. A1 - Wilhelmi, E. de Ona A1 - Opitz, B. A1 - Ostrowski, M. A1 - Oya, I. A1 - Panter, M. A1 - Parsons, R. D. A1 - Arribas, M. Paz A1 - Pekeur, N. W. A1 - Pelletier, G. A1 - Perez, J. A1 - Petrucci, P. -O. A1 - Peyaud, B. A1 - Pita, S. A1 - Puehlhofer, G. A1 - Punch, M. A1 - Quirrenbach, A. A1 - Raab, S. A1 - Raue, M. A1 - Reimer, A. A1 - Reimer, O. A1 - Renaud, M. A1 - de los Reyes, R. A1 - Rieger, F. A1 - Ripken, J. A1 - Rob, L. A1 - Rosier-Lees, S. A1 - Rowell, G. A1 - Rudak, B. A1 - Rulten, C. B. A1 - Sahakian, V. A1 - Sanchez, David M. A1 - Santangelo, Andrea A1 - Schlickeiser, R. A1 - Schulz, A. A1 - Schwanke, U. A1 - Schwarzburg, S. A1 - Schwemmer, S. A1 - Sheidaei, F. A1 - Skilton, J. L. A1 - Sol, H. A1 - Spengler, G. A1 - Stawarz, L. A1 - Steenkamp, R. A1 - Stegmann, Christian A1 - Stinzing, F. A1 - Stycz, K. A1 - Sushch, Iurii A1 - Szostek, A. A1 - Tavernet, J. -P. A1 - Terrier, R. A1 - Tluczykont, M. A1 - Trichard, C. A1 - Valerius, K. A1 - van Eldik, C. A1 - Vasileiadis, G. A1 - Venter, C. A1 - Viana, A. A1 - Vincent, P. A1 - Voelk, H. J. A1 - Volpe, F. A1 - Vorobiov, S. A1 - Vorster, M. A1 - Wagner, S. J. A1 - Ward, M. A1 - White, R. A1 - Wierzcholska, A. A1 - Wouters, D. A1 - Zacharias, M. A1 - Zajczyk, A. A1 - Zdziarski, A. A. A1 - Zech, Alraune A1 - Zechlin, H. -S. A1 - Pelat, D. T1 - Discovery of TeV gamma-ray emission from PKS 0447-439 and derivation of an upper limit on its redshift JF - ASTRONOMY & ASTROPHYSICS N2 - Very high-energy gamma-ray emission from PKS 0447-439 was detected with the H. E. S. S. Cherenkov telescope array in December 2009. This blazar is one of the brightest extragalactic objects in the Fermi bright source list and has a hard spectrum in the MeV to GeV range. In the TeV range, a photon index of 3.89 +/- 0.37 (stat) +/- 0.22 (sys) and a flux normalisation at 1 TeV, phi(1) (TeV) = (3.5 +/- 1.1(stat) +/- 0.9(sys)) x 10(-13) cm(-2) s(-1) TeV-1 were found. The detection with H. E. S. S. triggered observations in the X-ray band with the Swift and RXTE telescopes. Simultaneous UV and optical data from Swift UVOT and data from the optical telescopes ATOM and ROTSE are also available. The spectrum and light curve measured with H. E. S. S. are presented and compared to the multi-wavelength data at lower energies. A rapid flare is seen in the Swift XRT and RXTE data, together with a flux variation in the UV band, at a time scale of the order of one day. A firm upper limit of z < 0.59 on the redshift of PKS 0447-439 is derived from the combined Fermi-LAT and H. E. S. S. data, given the assumptions that there is no upturn in the intrinsic spectrum above the Fermi-LAT energy range and that absorption on the extragalactic background light (EBL) is not weaker than the lower limit provided by current models. The spectral energy distribution is well described by a simple one-zone synchrotron self-Compton scenario, if the redshift of the source is less than z less than or similar to 0.4. KW - galaxies: active KW - BL Lacertae objects: individual: PKS 0447-439 KW - radiation mechanisms: non-thermal KW - gamma rays: galaxies Y1 - 2013 U6 - https://doi.org/10.1051/0004-6361/201321108 SN - 0004-6361 VL - 552 IS - 4 PB - EDP SCIENCES S A CY - LES ULIS CEDEX A ER - TY - JOUR A1 - Abramowski, Attila A1 - Acero, F. A1 - Aharonian, Felix A. A1 - Akhperjanian, A. G. A1 - Anton, Gisela A1 - Balenderan, Shangkari A1 - Balzer, Arnim A1 - Barnacka, Anna A1 - Becherini, Yvonne A1 - Tjus, J. Becker A1 - Bernlöhr, K. A1 - Birsin, E. A1 - Biteau, Jonathan A1 - Bochow, A. A1 - Boisson, Catherine A1 - Bolmont, J. A1 - Bordas, Pol A1 - Brucker, J. A1 - Brun, Francois A1 - Brun, Pierre A1 - Bulik, Tomasz A1 - Carrigan, Svenja A1 - Casanova, Sabrina A1 - Cerruti, M. A1 - Chadwick, Paula M. A1 - Chaves, Ryan C. G. A1 - Cheesebrough, A. A1 - Colafrancesco, Sergio A1 - Cologna, Gabriele A1 - Conrad, Jan A1 - Couturier, C. A1 - Dalton, M. A1 - Daniel, M. K. A1 - Davids, I. D. A1 - Degrange, B. A1 - Deil, C. A1 - deWilt, P. A1 - Dickinson, H. J. A1 - Djannati-Ataï, A. A1 - Domainko, W. A1 - Drury, L. O&rsquo A1 - C., A1 - Dubus, G. A1 - Dutson, K. A1 - Dyks, J. A1 - Dyrda, M. A1 - Egberts, Kathrin A1 - Eger, P. A1 - Espigat, P. A1 - Fallon, L. A1 - Farnier, C. A1 - Fegan, S. A1 - Feinstein, F. A1 - Fernandes, M. V. A1 - Fernandez, D. A1 - Fiasson, A. A1 - Fontaine, G. A1 - Foerster, A. A1 - Fuessling, M. A1 - Gajdus, M. A1 - Gallant, Y. A. A1 - Garrigoux, T. A1 - Gast, H. A1 - Giebels, B. A1 - Glicenstein, J. F. A1 - Glueck, B. A1 - Goering, D. A1 - Grondin, M-H. A1 - Grudzinska, M. A1 - Haeffner, S. A1 - Hague, J. D. A1 - Hahn, J. A1 - Hampf, D. A1 - Harris, J. A1 - Heinz, S. A1 - Heinzelmann, G. A1 - Henri, G. A1 - Hermann, G. A1 - Hillert, A. A1 - Hinton, James Anthony A1 - Hofmann, W. A1 - Hofverberg, P. A1 - Holler, M. A1 - Horns, D. A1 - Jacholkowska, A. A1 - Jahn, C. A1 - Jamrozy, M. A1 - Jung, I. A1 - Kastendieck, M. A. A1 - Katarzynski, K. A1 - Katz, U. A1 - Kaufmann, S. A1 - Khelifi, B. A1 - Klepser, S. A1 - Klochkov, D. A1 - Kluzniak, W. A1 - Kneiske, T. A1 - Kolitzus, D. A1 - Komin, Nu. A1 - Kosack, K. A1 - Kossakowski, R. A1 - Krayzel, F. A1 - Krueger, P. P. A1 - Laffon, H. A1 - Lamanna, G. A1 - Lefaucheur, J. A1 - Lemoine-Goumard, M. A1 - Lenain, J-P A1 - Lennarz, D. A1 - Lohse, T. A1 - Lopatin, A. A1 - Lu, C-C. A1 - Marandon, V. A1 - Marcowith, Alexandre A1 - Masbou, J. A1 - Maurin, G. A1 - Maxted, N. A1 - Mayer, M. A1 - McComb, T. J. L. A1 - Medina, M. C. A1 - Mehault, J. A1 - Menzler, U. A1 - Moderski, R. A1 - Mohamed, M. A1 - Moulin, Emmanuel A1 - Naumann, C. L. A1 - Naumann-Godo, M. A1 - de Naurois, M. A1 - Nedbal, D. A1 - Nguyen, N. A1 - Niemiec, J. A1 - Nolan, S. J. A1 - Ohm, S. A1 - de Ona Wilhelmi, E. A1 - Opitz, B. A1 - Ostrowski, M. A1 - Oya, I. A1 - Panter, M. A1 - Parsons, R. D. A1 - Arribas, M. Paz A1 - Pekeur, N. W. A1 - Pelletier, G. A1 - Perez, J. A1 - Petrucci, P-O A1 - Peyaud, B. A1 - Pita, S. A1 - Puehlhofer, G. A1 - Punch, M. A1 - Quirrenbach, A. A1 - Raab, S. A1 - Raue, M. A1 - Reimer, A. A1 - Reimer, O. A1 - Renaud, M. A1 - de los Reyes, R. A1 - Rieger, F. A1 - Ripken, J. A1 - Rob, L. A1 - Rosier-Lees, S. A1 - Rowell, G. A1 - Rudak, B. A1 - Rulten, C. B. A1 - Sahakian, V. A1 - Sanchez, David M. A1 - Santangelo, Andrea A1 - Schlickeiser, R. A1 - Schulz, A. A1 - Schwanke, U. A1 - Schwarzburg, S. A1 - Schwemmer, S. A1 - Sheidaei, F. A1 - Skilton, J. L. A1 - Sol, H. A1 - Spengler, G. A1 - Stawarz, L. A1 - Steenkamp, R. A1 - Stegmann, Christian A1 - Stinzing, F. A1 - Stycz, K. A1 - Sushch, Iurii A1 - Szostek, A. A1 - Tavernet, J-P A1 - Terrier, R. A1 - Tluczykont, M. A1 - Trichard, C. A1 - Valerius, K. A1 - van Eldik, C. A1 - Vasileiadis, G. A1 - Venter, C. A1 - Viana, A. A1 - Vincent, P. A1 - Voelk, H. J. A1 - Volpe, F. A1 - Vorobiov, S. A1 - Vorster, M. A1 - Wagner, S. J. A1 - Ward, M. A1 - White, R. A1 - Wierzcholska, A. A1 - Wouters, D. A1 - Zacharias, M. A1 - Zajczyk, A. A1 - Zdziarski, A. A. A1 - Zech, Alraune A1 - Zechlin, H-S T1 - Search for very-high-energy gamma-ray emission from Galactic globular clusters with HESS JF - ASTRONOMY & ASTROPHYSICS N2 - Context. Globular clusters (GCs) are established emitters of high-energy (HE, 100 MeV < E < 100 GeV) gamma-ray radiation which could originate from the cumulative emission of the numerous millisecond pulsars (msPSRs) in the clusters’ cores or from inverse Compton (IC) scattering of relativistic leptons accelerated in the GC environment. These stellar clusters could also constitute a new class of sources in the very-high-energy (VHE, E > 100 GeV) gamma-ray regime, judging from the recent detection of a signal from the direction of Terzan 5 with the H.E.S.S. telescope array. Aims. To search for VHE gamma-ray sources associated with other GCs, and to put constraints on leptonic emission models, we systematically analyzed the observations towards 15 GCs taken with the H. E. S. S. array of imaging atmospheric Cherenkov telescopes. Methods. We searched for point-like and extended VHE gamma-ray emission from each GC in our sample and also performed a stacking analysis combining the data from all GCs to investigate the hypothesis of a population of faint emitters. Assuming IC emission as the origin of the VHE gamma-ray signal from the direction of Terzan 5, we calculated the expected gamma-ray flux from each of the 15 GCs, based on their number of millisecond pulsars, their optical brightness and the energy density of background photon fields. Results. We did not detect significant VHE gamma-ray emission from any of the 15 GCs in either of the two analyses. Given the uncertainties related to the parameter determinations, the obtained flux upper limits allow to rule out the simple IC/msPSR scaling model for NGC6388 and NGC7078. The upper limits derived from the stacking analyses are factors between 2 and 50 below the flux predicted by the simple leptonic scaling model, depending on the assumed source extent and the dominant target photon fields. Therefore, Terzan 5 still remains exceptional among all GCs, as the VHE gamma-ray emission either arises from extra-ordinarily efficient leptonic processes, or from a recent catastrophic event, or is even unrelated to the GC itself. KW - globular clusters: general KW - radiation mechanisms: non-thermal KW - pulsars: general KW - gamma rays: general Y1 - 2013 U6 - https://doi.org/10.1051/0004-6361/201220719 SN - 0004-6361 VL - 551 PB - EDP SCIENCES S A CY - LES ULIS CEDEX A ER - TY - JOUR A1 - Srama, Ralf A1 - Krueger, H. A1 - Yamaguchi, T. A1 - Stephan, T. A1 - Burchell, M. A1 - Kearsley, A. T. A1 - Sterken, V. A1 - Postberg, F. A1 - Kempf, S. A1 - Grün, Eberhard A1 - Altobelli, Nicolas A1 - Ehrenfreund, P. A1 - Dikarev, V. A1 - Horanyi, M. A1 - Sternovsky, Zoltan A1 - Carpenter, J. D. A1 - Westphal, A. A1 - Gainsforth, Z. A1 - Krabbe, A. A1 - Agarwal, Jessica A1 - Yano, H. A1 - Blum, J. A1 - Henkel, H. A1 - Hillier, J. A1 - Hoppe, P. A1 - Trieloff, M. A1 - Hsu, S. A1 - Mocker, A. A1 - Fiege, K. A1 - Green, S. F. A1 - Bischoff, A. A1 - Esposito, F. A1 - Laufer, R. A1 - Hyde, T. W. A1 - Herdrich, G. A1 - Fasoulas, S. A1 - Jaeckel, A. A1 - Jones, G. A1 - Jenniskens, P. A1 - Khalisi, E. A1 - Moragas-Klostermeyer, Georg A1 - Spahn, Frank A1 - Keller, H. U. A1 - Frisch, P. A1 - Levasseur-Regourd, A. C. A1 - Pailer, N. A1 - Altwegg, K. A1 - Engrand, C. A1 - Auer, S. A1 - Silen, J. A1 - Sasaki, S. A1 - Kobayashi, M. A1 - Schmidt, J. A1 - Kissel, J. A1 - Marty, B. A1 - Michel, P. A1 - Palumbo, P. A1 - Vaisberg, O. A1 - Baggaley, J. A1 - Rotundi, A. A1 - Roeser, H. P. T1 - SARIM PLUS-sample return of comet 67P/CG and of interstellar matter JF - EXPERIMENTAL ASTRONOMY N2 - The Stardust mission returned cometary, interplanetary and (probably) interstellar dust in 2006 to Earth that have been analysed in Earth laboratories worldwide. Results of this mission have changed our view and knowledge on the early solar nebula. The Rosetta mission is on its way to land on comet 67P/Churyumov-Gerasimenko and will investigate for the first time in great detail the comet nucleus and its environment starting in 2014. Additional astronomy and planetary space missions will further contribute to our understanding of dust generation, evolution and destruction in interstellar and interplanetary space and provide constraints on solar system formation and processes that led to the origin of life on Earth. One of these missions, SARIM-PLUS, will provide a unique perspective by measuring interplanetary and interstellar dust with high accuracy and sensitivity in our inner solar system between 1 and 2 AU. SARIM-PLUS employs latest in-situ techniques for a full characterisation of individual micrometeoroids (flux, mass, charge, trajectory, composition()) and collects and returns these samples to Earth for a detailed analysis. The opportunity to visit again the target comet of the Rosetta mission 67P/Churyumov-Gerasimeenternko, and to investigate its dusty environment six years after Rosetta with complementary methods is unique and strongly enhances and supports the scientific exploration of this target and the entire Rosetta mission. Launch opportunities are in 2020 with a backup window starting early 2026. The comet encounter occurs in September 2021 and the reentry takes place in early 2024. An encounter speed of 6 km/s ensures comparable results to the Stardust mission. KW - Interstellar dust KW - Cometary dust KW - Churyumov Gerasimenko KW - Interplanetary dust KW - IMF KW - Cosmic vision KW - Sample return KW - Dust collector KW - Mass spectrometry Y1 - 2012 U6 - https://doi.org/10.1007/s10686-011-9285-7 SN - 0922-6435 SN - 1572-9508 VL - 33 IS - 2-3 SP - 723 EP - 751 PB - SPRINGER CY - DORDRECHT ER - TY - JOUR A1 - Tubiana, C. A1 - Rinaldi, G. A1 - Guettler, C. A1 - Snodgrass, C. A1 - Shi, X. A1 - Hu, X. A1 - Marschall, R. A1 - Fulle, M. A1 - Bockeele-Morvan, D. A1 - Naletto, G. A1 - Capaccioni, F. A1 - Sierks, H. A1 - Arnold, G. A1 - Barucci, M. A. A1 - Bertaux, J-L A1 - Bertini, I A1 - Bodewits, D. A1 - Capria, M. T. A1 - Ciarniello, M. A1 - Cremonese, G. A1 - Crovisier, J. A1 - Da Deppo, V A1 - Debei, S. A1 - De Cecco, M. A1 - Deller, J. A1 - De Sanctis, M. C. A1 - Davidsson, B. A1 - Doose, L. A1 - Erard, S. A1 - Filacchione, G. A1 - Fink, U. A1 - Formisano, M. A1 - Fornasier, S. A1 - Gutierrez, P. J. A1 - Ip, W-H A1 - Ivanovski, S. A1 - Kappel, David A1 - Keller, H. U. A1 - Kolokolova, L. A1 - Koschny, D. A1 - Krueger, H. A1 - La Forgia, F. A1 - Lamy, P. L. A1 - Lara, L. M. A1 - Lazzarin, M. A1 - Levasseur-Regourd, A. C. A1 - Lin, Z-Y A1 - Longobardo, A. A1 - Lopez-Moreno, J. J. A1 - Marzari, F. A1 - Migliorini, A. A1 - Mottola, S. A1 - Rodrigo, R. A1 - Taylor, F. A1 - Toth, I A1 - Zakharov, V T1 - Diurnal variation of dust and gas production in comet 67P/Churyumov-Gerasimenko at the inbound equinox as seen by OSIRIS and VIRTIS-M on board Rosetta JF - Astronomy and astrophysics : an international weekly journal N2 - Context. On 27 April 2015, when comet 67P/Churyumov-Gerasimenko was at 1.76 au from the Sun and moving toward perihelion, the OSIRIS and VIRTIS-M instruments on board the Rosetta spacecraft simultaneously observed the evolving dust and gas coma during a complete rotation of the comet. Aims. We aim to characterize the spatial distribution of dust, H2O, and CO2 gas in the inner coma. To do this, we performed a quantitative analysis of the release of dust and gas and compared the observed H2O production rate with the rate we calculated using a thermophysical model. Methods. For this study we selected OSIRIS WAC images at 612 nm (dust) and VIRTIS-M image cubes at 612 nm, 2700 nm (H2O emission band), and 4200 nm (CO2 emission band). We measured the average signal in a circular annulus to study the spatial variation around the comet, and in a sector of the annulus to study temporal variation in the sunward direction with comet rotation, both at a fixed distance of 3.1 km from the comet center. Results. The spatial correlation between dust and water, both coming from the sunlit side of the comet, shows that water is the main driver of dust activity in this time period. The spatial distribution of CO2 is not correlated with water and dust. There is no strong temporal correlation between the dust brightness and water production rate as the comet rotates. The dust brightness shows a peak at 0 degrees subsolar longitude, which is not pronounced in the water production. At the same epoch, there is also a maximum in CO2 production. An excess of measured water production with respect to the value calculated using a simple thermophysical model is observed when the head lobe and regions of the southern hemisphere with strong seasonal variations are illuminated (subsolar longitude 270 degrees-50 degrees). A drastic decrease in dust production when the water production (both measured and from the model) displays a maximum occurs when typical northern consolidated regions are illuminated and the southern hemisphere regions with strong seasonal variations are instead in shadow (subsolar longitude 50 degrees-90 degrees). Possible explanations of these observations are presented and discussed. KW - comets: general KW - comets: individual: 67P/Churyumov-Gerasimenko KW - methods: data analysis Y1 - 2019 U6 - https://doi.org/10.1051/0004-6361/201834869 SN - 1432-0746 VL - 630 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Green-Saxena, A. A1 - Feyzullayev, A. A1 - Hubert, C. R. J. A1 - Kallmeyer, Jens A1 - Krueger, M. A1 - Sauer, P. A1 - Schulz, Hans-Martin A1 - Orphan, V. J. T1 - Active sulfur cycling by diverse mesophilic and thermophilic microorganisms in terrestrial mud volcanoes of Azerbaijan JF - Environmental microbiology N2 - Terrestrial mud volcanoes (TMVs) represent geochemically diverse habitats with varying sulfur sources and yet sulfur cycling in these environments remains largely unexplored. Here we characterized the sulfur-metabolizing microorganisms and activity in four TMVs in Azerbaijan. A combination of geochemical analyses, biological rate measurements and molecular diversity surveys (targeting metabolic genes aprA and dsrA and SSU ribosomal RNA) supported the presence of active sulfur-oxidizing and sulfate-reducing guilds in all four TMVs across a range of physiochemical conditions, with diversity of these guilds being unique to each TMV. The TMVs varied in potential sulfate reduction rates (SRR) by up to four orders of magnitude with highest SRR observed in sediments where in situ sulfate concentrations were highest. Maximum temperatures at which SRR were measured was 60 degrees C in two TMVs. Corresponding with these trends in SRR, members of the potentially thermophilic, spore-forming, Desulfotomaculum were detected in these TMVs by targeted 16S rRNA analysis. Additional sulfate-reducing bacterial lineages included members of the Desulfobacteraceae and Desulfobulbaceae detected by aprA and dsrA analyses and likely contributing to the mesophilic SRR measured. Phylotypes affiliated with sulfide-oxidizing Gamma- and Betaproteobacteria were abundant in aprA libraries from low sulfate TMVs, while the highest sulfate TMV harboured 16S rRNA phylotypes associated with sulfur-oxidizing Epsilonproteobacteria. Altogether, the biogeochemical and microbiological data indicate these unique terrestrial habitats support diverse active sulfur-cycling microorganisms reflecting the in situ geochemical environment. Y1 - 2012 U6 - https://doi.org/10.1111/1462-2920.12015 SN - 1462-2912 VL - 14 IS - 12 SP - 3271 EP - 3286 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Giewekemeyer, K. A1 - Krueger, S. P. A1 - Kalbfleisch, S. A1 - Bartels, Meike A1 - Beta, Carsten A1 - Salditt, T. T1 - X-ray propagation microscopy of biological cells using waveguides as a quasipoint source JF - Physical review : A, Atomic, molecular, and optical physics N2 - We have used x-ray waveguides as highly confining optical elements for nanoscale imaging of unstained biological cells using the simple geometry of in-line holography. The well-known twin-image problem is effectively circumvented by a simple and fast iterative reconstruction. The algorithm which combines elements of the classical Gerchberg-Saxton scheme and the hybrid-input-output algorithm is optimized for phase-contrast samples, well-justified for imaging of cells at multi-keV photon energies. The experimental scheme allows for a quantitative phase reconstruction from a single holographic image without detailed knowledge of the complex illumination function incident on the sample, as demonstrated for freeze-dried cells of the eukaryotic amoeba Dictyostelium discoideum. The accessible resolution range is explored by simulations, indicating that resolutions on the order of 20 nm are within reach applying illumination times on the order of minutes at present synchrotron sources. Y1 - 2011 U6 - https://doi.org/10.1103/PhysRevA.83.023804 SN - 1050-2947 VL - 83 IS - 2 PB - American Physical Society CY - College Park ER - TY - JOUR A1 - Levermann, Anders A1 - Bamber, Jonathan L. A1 - Drijfhout, Sybren A1 - Ganopolski, Andrey A1 - Haeberli, Winfried A1 - Harris, Neil R. P. A1 - Huss, Matthias A1 - Krueger, Kirstin A1 - Lenton, Timothy M. A1 - Lindsay, Ronald W. A1 - Notz, Dirk A1 - Wadhams, Peter A1 - Weber, Susanne T1 - Potential climatic transitions with profound impact on Europe Review of the current state of six 'tipping elements of the climate system' JF - Climatic change : an interdisciplinary, intern. journal devoted to the description, causes and implications of climatic change N2 - We discuss potential transitions of six climatic subsystems with large-scale impact on Europe, sometimes denoted as tipping elements. These are the ice sheets on Greenland and West Antarctica, the Atlantic thermohaline circulation, Arctic sea ice, Alpine glaciers and northern hemisphere stratospheric ozone. Each system is represented by co-authors actively publishing in the corresponding field. For each subsystem we summarize the mechanism of a potential transition in a warmer climate along with its impact on Europe and assess the likelihood for such a transition based on published scientific literature. As a summary, the 'tipping' potential for each system is provided as a function of global mean temperature increase which required some subjective interpretation of scientific facts by the authors and should be considered as a snapshot of our current understanding. Y1 - 2012 U6 - https://doi.org/10.1007/s10584-011-0126-5 SN - 0165-0009 SN - 1573-1480 VL - 110 IS - 3-4 SP - 845 EP - 878 PB - Springer CY - Dordrecht ER -