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38 results on '"Astronomy and Astrophysics Research Group"'

1. The relationship of lightning radio pulse amplitudes and source altitudes as observed by LOFAR

Author

A. Nelles, Arthur Corstanje, Heino Falcke, Brian Hare, Stijn Buitink, Katie Mulrey, H. Pandya, J. G. O. Machado, T. Huege, Olaf Scholten, Satyendra Thoudam, G. K. Krampah, Pragati Mitra, S. ter Veen, Tobias Winchen, T. N. G. Trinh, Jörg P. Rachen, Jörg R. Hörandel, Astronomy, Astronomy and Astrophysics Research Group, Physics, and Faculty of Sciences and Bioengineering Sciences

Subjects
Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics, Environmental Science (miscellaneous), radio astronomy, Atmosphere, Flash (photography), Altitude, ddc:550, ddc:530, Physics::Atmospheric and Oceanic Physics, amplitude, Physics, pulse detection, Astrophysics::Instrumentation and Methods for Astrophysics, LOFAR, Lightning, Pulse (physics), Amplitude, Physics::Space Physics, General Earth and Planetary Sciences, lightning, Radio astronomy, altitude
Abstract

Earth and Space Science 9(4), e2021EA001958 (2022). doi:10.1029/2021EA001958, When a lightning flash is propagating in the atmosphere it is known that especially the negative leaders emit a large number of very high frequency (VHF) radio pulses. It is thought that this is due to streamer activity at the tip of the growing negative leader. In this work, we have investigated the dependence of the strength of this VHF emission on the altitude of such emission for two lightning flashes as observed by the Low Frequency ARray (LOFAR) radio telescope. We find for these two flashes that the extracted amplitude distributions are consistent with a power-law, and that the amplitude of the radio emissions decreases very strongly with source altitude, by more than a factor of 2 from 1 km altitude up to 5 km altitude. In addition, we do not find any dependence on the extracted power-law with altitude, and that the extracted power-law slope has an average around 3, for both flashes., Published by American Geophysical Union, Malden, Mass.

Published
2021
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2. Deep-learning based reconstruction of the shower maximum X max using the water-Cherenkov detectors of the Pierre Auger Observatory

Author

A. Segreto, Günter Sigl, Orazio Zapparrata, P. Stassi, Radomir Smida, A. Machado Payeras, G. Cataldi, V. Scherini, Carola Dobrigkeit, M. Muzio, Marcio Aparecido Muller, Srijan Sehgal, Fernando Gollan, Carla Bleve, Rodrigo Guedes Lang, M. E. Bertaina, F. de Palma, Alan Watson, M. Perlin, Mihai Niculescu-Oglinzanu, L. Valore, Belén Andrada, Marina Scornavacche, V. de Souza, G. Golup, Violet M. Harvey, D. Harari, N. Kunka, T. Bister, F. Riehn, P. Tobiska, Jonathan Biteau, M. I. Micheletti, A. Insolia, Jesús Peña-Rodríguez, Matías J. Roncoroni, Sullivan Marafico, M. Kleifges, D. Zavrtanik, Marco Giammarchi, R.J. Barreira Luz, D. Melo, G. P. Guedes, F. Salamida, N. Fazzini, Jonas Glombitza, F. C. T. Barbato, A. Yushkov, Alina Mihaela Badescu, Ioana Codrina Maris, R. Sato, Lourenco Lopes, Toshihiro Fujii, S. Schröder, Italo Epicoco, Marvin Gottowik, Cristina Galea, M. Prouza, Brian Fick, Xavier Bertou, A. Di Matteo, Julian Kemp, Eric Mayotte, D. Nitz, Esteban Roulet, P. Abreu, D. Ravignani, R. M. de Almeida, K. H. Kampert, J. C. Arteaga Velázquez, J. Kleinfeller, A. Zepeda, M. Gómez Berisso, R. C. Shellard, Roberto Mussa, A. Puyleart, Jakub Juryšek, Petr Hamal, Steffen Hahn, Juan Carlos D'Olivo, Julien Manshanden, Lorenzo Caccianiga, Pedro Assis, H. Martinez, A. Etchegoyen, G. C. Hill, Corinne Berat, M. Giller, Jan Pękala, Rúben Conceição, Valerio Verzi, B. Tome, J. Chudoba, L. Lu, H. J. Mathes, Stanislav Michal, B. Wundheiler, Andres Travaini, K. Choi, Alex Kääpä, Ralph Engel, Flavia Gesualdi, J. Perez Armand, E. Varela, D. Correia dos Santos, J. Ridky, L. R. Wiencke, T. Pierog, François Montanet, Justin M. Albury, P. L. Ghia, Marcel Köpke, M. Platino, J.D. Sanabria Gomez, Rodrigo Pelayo, Jose J. Gonzalez, Stijn Buitink, Katie Mulrey, Carlos Escobar, G. De Mauro, Kevin-Druis Merenda, Vladimir Lenok, L. Perrone, H. Schieler, C. J. Todero Peixoto, Mario Buscemi, D. Nosek, E. Santos, Niklas Langner, Antonella Castellina, Eleonora Guido, Antonio Condorelli, M. Risse, Jörg R. Hörandel, J. F. Valdés Galicia, I. De Mitri, Jonathan Blazek, Jose Chinellato, J. Rodriguez Rojo, Fridtjof Feldbusch, A.L. Garcia Vegas, Enrique Zas, I. Lhenry-Yvon, C. Trimarelli, Gaia Silli, A. Filipčič, A.D. Supanitsky, Philipp Papenbreer, Claudio Galelli, A. Weindl, M. Suárez-Durán, J. Stasielak, T. Huege, Hernán Gonzalo Asorey, L. Nellen, L. Anchordoqui, Alena Bakalova, C. Morello, Miroslav Hrabovský, Petr Travnicek, Trent D. Grubb, G. Parente, Fabrizia Canfora, Fernando Contreras, A. Haungs, Juan Manuel Figueira, Roberta Colalillo, Paul Sommers, Clara Keiko Oliveira Watanabe, B. García, M. Schimp, A. G. Mariazzi, R. López, Karen S. Caballero-Mora, H. Wilczyński, Ioana Caracas, A. Letessier-Selvon, Lorenzo Cazon, C. Pérez Bertolli, F. Sanchez, F. Sarazin, S. Petrera, Marc Weber, David Schmidt, G. Farrar, L. Zehrer, J. de Oliveira, Alejandro Almela, P. Mantsch, Z. Szadkowski, M. Schimassek, C. Hojvat, Jan Ebr, Jacco Vink, Peter L. Biermann, L. Bonneau Arbeletche, Maximilian Reininghaus, Paolo Privitera, M. A. Leigui de Oliveira, Jaime Alvarez-Muñiz, Alexandru Gherghel-Lascu, Martin Erdmann, J. de Jesús, A. Taboada, G. Marsella, E. M. Santos, A. Gorgi, H.O. Klages, B. C. Manning, Dariusz Gora, Bjarni Pont, Thomas Bretz, Petr Janecek, Corbin Covault, Matías Rolf Hampel, Frank G. Schröder, R. Squartini, Alfred Müller, P.F. Gómez Vitale, A. Streich, Gioacchino Alex Anastasi, M. Wirtz, David Wittkowski, G. Salina, Roger W Clay, Olivier Deligny, W. M. Namasaka, M. Mastrodicasa, A. C. Rovero, Alexandru Balaceanu, A. A. Nucita, Alan Coleman, Lino Miramonti, S. J. Saffi, Lukáš Vaclavek, J. F. Soriano, D. de Oliveira Franco, R. Alves Batista, Bruce R. Dawson, Octavian Sima, Ana Martina Botti, Jeffrey Brack, Olaf Scholten, P.O. Mazur, K.-H. Becker, Maria Rita Coluccia, Dusan Mandat, Francesco Fenu, Humberto Ibarguen Salazar, M. Pimenta, Tomáš Fodran, Alina Nasr-Esfahani, P.R. Araújo Ferreira, Tobias Winchen, G. Mancarella, B. Keilhauer, Florian Lukas Briechle, Darko Veberič, Ugo Giaccari, S. J. Sciutto, F. Pedreira, Christian Sarmiento-Cano, Raul Sarmento, G. Medina-Tanco, Felix Schlüter, P. Ruehl, Carla Aramo, Vincenzo Rizi, C. J.W.P. Timmermans, Julien Souchard, Jon Paul Lundquist, A. Menshikov, D. Martello, Juan Miguel Carceller, C. M. Schäfer, Markus Roth, Silvia Mollerach, O. Martínez Bravo, Isabel Goos, D. Heck, A. Tapia, Josina Schulte, Peter Hansen, M. del Río, H. Gemmeke, Fabian Gobbi, B. L. Lago, P. Savina, W. Rodrigues de Carvalho, Denise Boncioli, M. Unger, F. Guarino, John Matthews, Peter Buchholz, Marco Aglietta, Miguel Mostafa, E.E. Pereira Martins, Serguei Vorobiov, Martina Bohacova, Miroslav Pech, M. Pothast, J. Hulsman, J. Rautenberg, Pavel Horvath, Q. Luce, Marcus Niechciol, Juan Pablo Gongora, Paula Gina Isar, Sofia Andringa, Maximilian Stadelmaier, Nataliia Borodai, Marcos Cerda, D. Lo Presti, S. J. De Jong, Samo Stanič, Jarryd A. Day, A. Saftoiu, A.C. Cobos Cerutti, Martin Vacula, J. R. T. de Mello Neto, V. Novotny, V. K.C. Varma, Rossella Caruso, A. Lucero, Fernando Catalani, N. González, Kai Daumiller, Heino Falcke, S. Querchfeld, Olena Tkachenko, Thomas Hebbeker, Sergio Dasso, Tristan Sudholz, J. Šupík, Carlo Ventura, Martín Miguel Freire, V. Pirronello, J. Vicha, Ladislav Chytka, A. Aab, Carla Taricco, Matias Tueros, Luis A. Nunez, T. Suomijärvi, J. Pallotta, Hernan Wahlberg, A. Parra, A. Fuster, M. Trini, P.G. Brichetto Orchera, I. Allekotte, A. C. Fauth, Carla Bonifazi, Jose A. Bellido, Fabio Convenga, I.D. Vergara Quispe, M. Zavrtanik, E. De Vito, Giovanni Consolati, Petr Schovanek, Denis Stanca, Ralf Ulrich, L. Nožka, G. Matthiae, Antonio Bueno, Gualberto Avila, John Farmer, Maria-Teresa Dova, R.C. dos Anjos, Adriana Vásquez-Ramírez, M. Palatka, Jeffrey A. Johnsen, Aab, A., Abreu, P., Aglietta, M., Albury, J. M., Allekotte, I., Almela, A., Alvarez-Mu??iz, J., Alves Batista, R., Anastasi, G. A., Anchordoqui, L., Andrada, B., Andringa, S., Aramo, C., Ara??jo Ferreira, P. R., Arteaga Vel??zquez, J. C., Asorey, H., Assis, P., Avila, G., Badescu, A. M., Bakalova, A., Balaceanu, A., Barbato, F., Barreira Luz, R. J., Becker, K. H., Bellido, J. A., Berat, C., Bertaina, M. E., Bertou, X., Biermann, P. L., Bister, T., Biteau, J., Blazek, J., Bleve, C., Boh????ov??, M., Boncioli, D., Bonifazi, C., Bonneau Arbeletche, L., Borodai, N., Botti, A. M., Brack, J., Bretz, T., Brichetto Orchera, P. G., Briechle, F. L., Buchholz, P., Bueno, A., Buitink, S., Buscemi, M., Caballero-Mora, K. S., Caccianiga, L., Canfora, F., Caracas, I., Carceller, J. M., Caruso, R., Castellina, A., Catalani, F., Cataldi, G., Cazon, L., Cerda, M., Chinellato, J. A., Choi, K., Chudoba, J., Chytka, L., Clay, R. W., Cobos Cerutti, A. C., Colalillo, R., Coleman, A., Coluccia, M. R., Concei????o, R., Condorelli, A., Consolati, G., Contreras, F., Convenga, F., Correia dos Santos, D., Covault, C. E., Dasso, S., Daumiller, K., Dawson, B. R., Day, J. A., de Almeida, R. M., de Jes??s, J., de Jong, S. J., De Mauro, G., de Mello Neto, J. R. T., De Mitri, I., de Oliveira, J., de Oliveira Franco, D., de Palma, F., de Souza, V., De Vito, E., del R??o, M., Deligny, O., Di Matteo, A., Dobrigkeit, C., D'Olivo, J. C., dos Anjos, R. C., Dova, M. T., Ebr, J., Engel, R., Epicoco, I., Erdmann, M., Escobar, C. O., Etchegoyen, A., Falcke, H., Farmer, J., Farrar, G., Fauth, A. C., Fazzini, N., Feldbusch, F., Fenu, F., Fick, B., Figueira, J. M., Filip??i??, A., Fodran, T., Freire, M. M., Fujii, T., Fuster, A., Galea, C., Galelli, C., Garc??a, B., Garcia Vegas, A. L., Gemmeke, H., Gesualdi, F., Gherghel-Lascu, A., Ghia, P. L., Giaccari, U., Giammarchi, M., Giller, M., Glombitza, J., Gobbi, F., Gollan, F., Golup, G., G??mez Berisso, M., G??mez Vitale, P. F., Gongora, J. P., Gonz??lez, J. M., Gonz??lez, N., Goos, I., G??ra, D., Gorgi, A., Gottowik, M., Grubb, T. D., Guarino, F., Guedes, G. P., Guido, E., Hahn, S., Hamal, P., Hampel, M. R., Hansen, P., Harari, D., Harvey, V. M., Haungs, A., Hebbeker, T., Heck, D., Hill, G. C., Hojvat, C., H??randel, J. R., Horvath, P., Hrabovsk??, M., Huege, T., Hulsman, J., Insolia, A., Isar, P. G., Janecek, P., Johnsen, J. A., Jurysek, J., K????p??, A., Kampert, K. H., Keilhauer, B., Kemp, J., Klages, H. O., Kleifges, M., Kleinfeller, J., K??pke, M., Kunka, N., Lago, B. L., Lang, R. G., Langner, N., Leigui de Oliveira, M. A., Lenok, V., Letessier-Selvon, A., Lhenry-Yvon, I., Lo Presti, D., Lopes, L., L??pez, R., Lu, L., Luce, Q., Lucero, A., Lundquist, J. P., Machado Payeras, A., Mancarella, G., Mandat, D., Manning, B. C., Manshanden, J., Mantsch, P., Marafico, S., Mariazzi, A. G., Mari??, I. C., Marsella, G., Martello, D., Martinez, H., Mart??nez Bravo, O., Mastrodicasa, M., Mathes, H. J., Matthews, J., Matthiae, G., Mayotte, E., Mazur, P. O., Medina-Tanco, G., Melo, D., Menshikov, A., Merenda, K. -D., Michal, S., Micheletti, M. I., Miramonti, L., Mollerach, S., Montanet, F., Morello, C., Mostaf??, M., M??ller, A. L., Muller, M. A., Mulrey, K., Mussa, R., Muzio, M., Namasaka, W. M., Nasr-Esfahani, A., Nellen, L., Niculescu-Oglinzanu, M., Niechciol, M., Nitz, D., Nosek, D., Novotny, V., No??ka, L., Nucita, A., N????ez, L. A., Palatka, M., Pallotta, J., Papenbreer, P., Parente, G., Parra, A., Pech, M., Pedreira, F., P??kala, J., Pelayo, R., Pe??a-Rodriguez, J., Pereira Martins, E. E., Perez Armand, J., P??rez Bertolli, C., Perlin, M., Perrone, L., Petrera, S., Pierog, T., Pimenta, M., Pirronello, V., Platino, M., Pont, B., Pothast, M., Privitera, P., Prouza, M., Puyleart, A., Querchfeld, S., Rautenberg, J., Ravignani, D., Reininghaus, M., Ridky, J., Riehn, F., Risse, M., Rizi, V., Rodrigues de Carvalho, W., Rodriguez Rojo, J., Roncoroni, M. J., Roth, M., Roulet, E., Rovero, A. C., Ruehl, P., Saffi, S. J., Saftoiu, A., Salamida, F., Salazar, H., Salina, G., Sanabria Gomez, J. D., S??nchez, F., Santos, E. M., Santos, E., Sarazin, F., Sarmento, R., Sarmiento-Cano, C., Sato, R., Savina, P., Sch??fer, C. M., Scherini, V., Schieler, H., Schimassek, M., Schimp, M., Schl??ter, F., Schmidt, D., Scholten, O., Schov??nek, P., Schr??der, F. G., Schr??der, S., Schulte, J., Sciutto, S. J., Scornavacche, M., Segreto, A., Sehgal, S., Shellard, R. C., Sigl, G., Silli, G., Sima, O., m??da, R., Sommers, P., Soriano, J. F., Souchard, J., Squartini, R., Stadelmaier, M., Stanca, D., Stani??, S., Stasielak, J., Stassi, P., Streich, A., Su??rez-Dur??n, M., Sudholz, T., Suomij??rvi, T., Supanitsky, A. D., up??k, J., Szadkowski, Z., Taboada, A., Tapia, A., Taricco, C., Timmermans, C., Tkachenko, O., Tobiska, P., Todero Peixoto, C. J., Tom??, B., Travaini, A., Travnicek, P., Trimarelli, C., Trini, M., Tueros, M., Ulrich, R., Unger, M., Vaclavek, L., Vacula, M., Galicia, J. F. Vald??s., Valore, L., Varela, E., Varma K. C., V., V??squez-Ram??rez, A., Veberi??, D., Ventura, C., Vergara Quispe, I. D., Verzi, V., Vicha, J., Vink, J., Vorobiov, S., Wahlberg, H., Watanabe, C., Watson, A. A., Weber, M., Weindl, A., Wiencke, L., Wilczy??ski, H., Winchen, T., Wirtz, M., Wittkowski, D., Wundheiler, B., Yushkov, A., Zapparrata, O., Zas, E., Zavrtanik, D., Zavrtanik, M., Zehrer, L., Zepeda, A., High Energy Astrophys. & Astropart. Phys (API, FNWI), Gravitation and Astroparticle Physics Amsterdam, Astronomy and Astrophysics Research Group, Physics, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Pierre Auger, Aab A., Abreu P., Aglietta M., Albury J.M., Allekotte I., Almela A., Alvarez-Muniz J., Batista R.A., Anastasi G.A., Anchordoqui L., Andrada B., Andringa S., Aramo C., Ferreira P.R.A., Velazquez J.C.A., Asorey H., Assis P., Avila G., Badescu A.M., Bakalova A., Balaceanu A., Barbato F., Luz R.J.B., Becker K.H., Bellido J.A., Berat C., Bertaina M.E., Bertou X., Biermann P.L., Bister T., Biteau J., Blazek J., Bleve C., Bohacova M., Boncioli D., Bonifazi C., Arbeletche L.B., Borodai N., Botti A.M., Brack J., Bretz T., Orchera P.G.B., Briechle F.L., Buchholz P., Bueno A., Buitink S., Buscemi M., Caballero-Mora K.S., Caccianiga L., Canfora F., Caracas I., Carceller J.M., Caruso R., Castellina A., Catalani F., Cataldi G., Cazon L., Cerda M., Chinellato J.A., Choi K., Chudoba J., Chytka L., Clay R.W., Cerutti A.C.C., Colalillo R., Coleman A., Coluccia M.R., Conceicao R., Condorelli A., Consolati G., Contreras F., Convenga F., dos Santos D.C., Covault C.E., Dasso S., Daumiller K., Dawson B.R., Day J.A., de Almeida R.M., de Jesus J., de Jong S.J., de Mauro G., de Mello Neto J.R.T., de Mitri I., de Oliveira J., de Oliveira Franco D., de Palma F., de Souza V., de Vito E., del Rio M., Deligny O., Di Matteo A., Dobrigkeit C., D'Olivo J.C., dos Anjos R.C., Dova M.T., Ebr J., Engel R., Epicoco I., Erdmann M., Escobar C.O., Etchegoyen A., Falcke H., Farmer J., Farrar G., Fauth A.C., Fazzini N., Feldbusch F., Fenu F., Fick B., Figueira J.M., Filipcic A., Fodran T., Freire M.M., Fujii T., Fuster A., Galea C., Galelli C., Garcia B., Vegas A.L.G., Gemmeke H., Gesualdi F., Gherghel-Lascu A., Ghia P.L., Giaccari U., Giammarchi M., Giller M., Glombitza J., Gobbi F., Gollan F., Golup G., Berisso M.G., Vitale P.F.G., Gongora J.P., Gonzalez J.M., Gonzalez N., Goos I., Gora D., Gorgi A., Gottowik M., Grubb T.D., Guarino F., Guedes G.P., Guido E., Hahn S., Hamal P., Hampel M.R., Hansen P., Harari D., Harvey V.M., Haungs A., Hebbeker T., Heck D., Hill G.C., Hojvat C., Horandel J.R., Horvath P., Hrabovsky M., Huege T., Hulsman J., Insolia A., Isar P.G., Janecek P., Johnsen J.A., Jurysek J., Kaapa A., Kampert K.H., Keilhauer B., Kemp J., Klages H.O., Kleifges M., Kleinfeller J., Kopke M., Kunka N., Lago B.L., Lang R.G., Langner N., de Oliveira M.A.L., Lenok V., Letessier-Selvon A., Lhenry-Yvon I., Presti D.L., Lopes L., Lopez R., Lu L., Luce Q., Lucero A., Lundquist J.P., Payeras A.M., Mancarella G., Mandat D., Manning B.C., Manshanden J., Mantsch P., Marafico S., Mariazzi A.G., Maris I.C., Marsella G., Martello D., Martinez H., Bravo O.M., Mastrodicasa M., Mathes H.J., Matthews J., Matthiae G., Mayotte E., Mazur P.O., Medina-Tanco G., Melo D., Menshikov A., Merenda K.-D., Michal S., Micheletti M.I., Miramonti L., Mollerach S., Montanet F., Morello C., Mostafa M., Muller A.L., Muller M.A., Mulrey K., Mussa R., Muzio M., Namasaka W.M., Nasr-Esfahani A., Nellen L., Niculescu-Oglinzanu M., Niechciol M., Nitz D., Nosek D., Novotny V., Nozka L., Nucita A., Nunez L.A., Palatka M., Pallotta J., Papenbreer P., Parente G., Parra A., Pech M., Pedreira F., Pekala J., Pelayo R., Pena-Rodriguez J., Martins E.E.P., Armand J.P., Bertolli C.P., Perlin M., Perrone L., Petrera S., Pierog T., Pimenta M., Pirronello V., Platino M., Pont B., Pothast M., Privitera P., Prouza M., Puyleart A., Querchfeld S., Rautenberg J., Ravignani D., Reininghaus M., Ridky J., Riehn F., Risse M., Rizi V., Rodrigues de Carvalho W., Rojo J.R., Roncoroni M.J., Roth M., Roulet E., Rovero A.C., Ruehl P., Saffi S.J., Saftoiu A., Salamida F., Salazar H., Salina G., Gomez J.D.S., Sanchez F., Santos E.M., Santos E., Sarazin F., Sarmento R., Sarmiento-Cano C., Sato R., Savina P., Schafer C.M., Scherini V., Schieler H., Schimassek M., Schimp M., Schluter F., Schmidt D., Scholten O., Schovanek P., Schroder F.G., Schroder S., Schulte J., Sciutto S.J., Scornavacche M., Segreto A., Sehgal S., Shellard R.C., Sigl G., Silli G., Sima O., Smida R., Sommers P., Soriano J.F., Souchard J., Squartini R., Stadelmaier M., Stanca D., Stanic S., Stasielak J., Stassi P., Streich A., Suarez-Duran M., Sudholz T., Suomijarvi T., Supanitsky A.D., Supik J., Szadkowski Z., Taboada A., Tapia A., Taricco C., Timmermans C., Tkachenko O., Tobiska P., Peixoto C.J.T., Tome B., Travaini A., Travnicek P., Trimarelli C., Trini M., Tueros M., Ulrich R., Unger M., Vaclavek L., Vacula M., Galicia J.F.V., Valore L., Varela E., Varma V.K.C., Vasquez-Ramirez A., Veberic D., Ventura C., Quispe I.D.V., Verzi V., Vicha J., Vink J., Vorobiov S., Wahlberg H., Watanabe C., Watson A.A., Weber M., Weindl A., Wiencke L., Wilczynski H., Winchen T., Wirtz M., Wittkowski D., Wundheiler B., Yushkov A., Zapparrata O., Zas E., Zavrtanik D., Zavrtanik M., Zehrer L., Zepeda A., Research unit Astroparticle Physics, Alvarez-Muniz, J., Batista, R. A., Ferreira, P. R. A., Velazquez, J. C. A., Luz, R. J. B., Bohacova, M., Arbeletche, L. B., Orchera, P. G. B., Cerutti, A. C. C., Conceicao, R., dos Santos, D. C., de Jesus, J., de Mauro, G., de Mitri, I., de Vito, E., del Rio, M., Filipcic, A., Garcia, B., Vegas, A. L. G., Berisso, M. G., Vitale, P. F. G., Gonzalez, J. M., Gonzalez, N., Gora, D., Horandel, J. R., Hrabovsky, M., Kaapa, A., Kopke, M., de Oliveira, M. A. L., Presti, D. L., Lopez, R., Payeras, A. M., Maris, I. C., Bravo, O. M., Mostafa, M., Muller, A. L., Nozka, L., Nunez, L. A., Pekala, J., Pena-Rodriguez, J., Martins, E. E. P., Armand, J. P., Bertolli, C. P., Rojo, J. R., Gomez, J. D. S., Sanchez, F., Schafer, C. M., Schluter, F., Schovanek, P., Schroder, F. G., Schroder, S., Smida, R., Stanic, S., Suarez-Duran, M., Suomijarvi, T., Supik, J., Peixoto, C. J. T., Tome, B., Galicia, J. F. V., Varma, V. K. C., Vasquez-Ramirez, A., Veberic, D., Quispe, I. D. V., and Wilczynski, H.

Subjects
showers: energy, longitudinal [showers], interaction: model, Physics::Instrumentation and Detectors, Astronomy, Calibration and fitting methods, Cluster finding, Data analysis, Large detector systems for particle and astroparticle physics, Particle identification methods, Pattern recognition, 01 natural sciences, High Energy Physics - Experiment, Auger, High Energy Physics - Experiment (hep-ex), cluster finding, surface [detector], Observatory, Large detector systems, Instrumentation, Mathematical Physics, High Energy Astrophysical Phenomena (astro-ph.HE), astro-ph.HE, Physics, Pattern recognition, cluster finding, calibration and fitting methods, Settore FIS/01 - Fisica Sperimentale, model [interaction], Detector, Astrophysics::Instrumentation and Methods for Astrophysics, Data analysi, calibration and fitting methods, energy [showers], observatory, Pattern recognition, cluster finding, calibration and fitting method, astroparticle physics, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, atmosphere [showers], air, neural network, Astrophysics::High Energy Astrophysical Phenomena, UHE [cosmic radiation], FOS: Physical sciences, Cosmic ray, detector: fluorescence, 0103 physical sciences, ddc:530, High Energy Physics, ddc:610, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], cosmic radiation: UHE, structure, particle physics, network: performance, 010306 general physics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Ciencias Exactas, Cherenkov radiation, fluorescence [detector], Pierre Auger Observatory, mass spectrum [nucleus], showers: atmosphere, detector: surface, hep-ex, 010308 nuclear & particles physics, Física, resolution, calibration, Computational physics, performance [network], Cherenkov counter, Air shower, Large detector systems for particle and astroparticle physic, Experimental High Energy Physics, High Energy Physics::Experiment, nucleus: mass spectrum, showers: longitudinal, RAIOS CÓSMICOS, Energy (signal processing), astro-ph.IM
Abstract

The atmospheric depth of the air shower maximum $X_{\mathrm{max}}$ is an observable commonly used for the determination of the nuclear mass composition of ultra-high energy cosmic rays. Direct measurements of $X_{\mathrm{max}}$ are performed using observations of the longitudinal shower development with fluorescence telescopes. At the same time, several methods have been proposed for an indirect estimation of $X_{\mathrm{max}}$ from the characteristics of the shower particles registered with surface detector arrays. In this paper, we present a deep neural network (DNN) for the estimation of $X_{\mathrm{max}}$. The reconstruction relies on the signals induced by shower particles in the ground based water-Cherenkov detectors of the Pierre Auger Observatory. The network architecture features recurrent long short-term memory layers to process the temporal structure of signals and hexagonal convolutions to exploit the symmetry of the surface detector array. We evaluate the performance of the network using air showers simulated with three different hadronic interaction models. Thereafter, we account for long-term detector effects and calibrate the reconstructed $X_{\mathrm{max}}$ using fluorescence measurements. Finally, we show that the event-by-event resolution in the reconstruction of the shower maximum improves with increasing shower energy and reaches less than $25~\mathrm{g/cm^{2}}$ at energies above $2\times 10^{19}~\mathrm{eV}$., Published version, 29 pages, 12 figures

Published
2021
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3. Properties of the Lunar Detection Mode for ZeV-Scale Particles with LOFAR

Author

Anna Nelles, Arthur Corstanje, Olaf Scholten, Heino Falcke, Tobias Winchen, A. Hörandel, Pragati Mitra, T. N. G. Trinh, Brian Hare, Antonio Bonardi, Satyendra Thoudam, Jörg P. Rachen, S. ter Veen, Laura Rossetto, Stijn Buitink, Katie Mulrey, Pim Schellart, Astronomy and Astrophysics Research Group, Physics, and Faculty of Sciences and Bioengineering Sciences

Subjects
Physics, 010308 nuclear & particles physics, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, QC1-999, Detector, Mode (statistics), Astrophysics::Instrumentation and Methods for Astrophysics, Flux, Cosmic ray, LOFAR, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Physics::Geophysics, Radio telescope, Particle shower, 0103 physical sciences, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Energy (signal processing)
Abstract

The steep decrease of the flux of ultra-high energy cosmic rays (UHECR) provides a challenge to answer the long standing question about their origin and nature. A significant increase in detector volume may be achieved byemploying Earth’s moon as a detector that is read out using existing Earth-bound radio telescopes by searching for the radio pulses emitted by the particle shower in the lunar rock. In this contribution we will report on the properties of a corresponding detection mode currently under development for the LOFAR Radio telescope.

Published
2019
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4. Cosmic Ray Mass Measurements with LOFAR

Author

Anna Nelles, Antonio Bonardi, Laura Rossetto, Olaf Scholten, Satyendra Thoudam, Pragati Mitra, Tobias Winchen, Sander ter Veen, Jörg P. Rachen, Jörg R. Hörandel, Heino Falcke, Stijn Buitink, Katie Mulrey, Arthur Corstanje, Pim Schellart, Gia Trinh, J. Emilio Enriquez, Research unit Astroparticle Physics, Physics, Astronomy and Astrophysics Research Group, and Faculty of Sciences and Bioengineering Sciences

Subjects
Physics, Range (particle radiation), 010308 nuclear & particles physics, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, QC1-999, Astrophysics::Instrumentation and Methods for Astrophysics, Cosmic ray, LOFAR, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Physics and Astronomy(all), 01 natural sciences, law.invention, law, 0103 physical sciences, Dipole antenna, Mass analysis, Particle density, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), 010303 astronomy & astrophysics, Energy (signal processing), Dense core
Abstract

In the dense core of LOFAR individual air showers are detected by hundreds of dipole antennas simultaneously. We reconstruct X max by using a hybrid technique that combines a two-dimensional fit of the radio profile to CoREAS simulations and a one-dimensional fit of the particle density distribution. For high-quality detections, the statistical uncertainty on X max is smaller than 20 g/cm 2 . We present results of cosmic-ray mass analysis in the energy regime of 10 17 - 10 17.5 eV. This range is of particular interest as it may harbor the transition from a Galactic to an extragalactic origin of cosmic rays.

Published
2017

5. TEC, Trigger and Check, preparing LOFAR for Lunar observations

Author

Jörg P. Rachen, Pim Schellart, Jörg R. Hörandel, Sander ter Veen, Olaf Scholten, Laura Rossetto, Katey Mulrey, Heino Falcke, J. Emilio Enriquez, Antonio Bonardi, Satyendra Thoudam, Gia Trinh, Anna Nelles, Stijn Buitink, Pragati Mitra, Tobias Winchen, Arthur Corstanje, Maaijke Mevius, Physics, Astronomy and Astrophysics Research Group, Faculty of Sciences and Bioengineering Sciences, and Research unit Astroparticle Physics

Subjects
Physics, Total electron content, 010308 nuclear & particles physics, Aperture, QC1-999, TEC, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Cosmic ray, LOFAR, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Low frequency, Physics and Astronomy(all), 01 natural sciences, Radio telescope, 0103 physical sciences, Neutrino, 010303 astronomy & astrophysics, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries)
Abstract

One of the main ways to use radio to detect Ultra High Energy Neutrinos and Cosmic Rays is the Lunar Askaryan technique, that uses the Moon as a target and searches for nanosecond pulses with large radio telescopes. To use low frequency aperture arrays, such as LOFAR and the SKA, pose new challenges and possibilities in detection techniques of short radio pulses and to measure the Total Electron Content (TEC). As a prepatory work, we have used other measurements that use similar techniques, or that can answer a specific question, with the LOFAR radio telescope. This contribution reports on our work on triggering on short radio signals, post-event imaging of radio signals from buffered data and methods to determine the TEC-value.

Published
2017
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6. Towards real-time identification of cosmic rays with LOw-Frequency ARray radio antennas

Author

Arthur Corstanje, Jörg P. Rachen, Jörg R. Hörandel, Olaf Scholten, Heino Falcke, Antonio Bonardi, Anna Nelles, Pragati Mitra, Pim Schellart, Satyendra Thoudam, Gia Trinh, Tobias Winchen, J. Emilio Enriquez, Sander ter Veen, Stijn Buitink, Katie Mulrey, Laura Rossetto, Research unit Astroparticle Physics, Physics, Astronomy and Astrophysics Research Group, and Faculty of Sciences and Bioengineering Sciences

Subjects
Astronomy, Astrophysics::High Energy Astrophysical Phenomena, QC1-999, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, Physics and Astronomy(all), Radiation, Low frequency, 01 natural sciences, Atmosphere, Background noise, 0103 physical sciences, 010303 astronomy & astrophysics, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), Remote sensing, Physics, 010308 nuclear & particles physics, business.industry, Electrical engineering, Astrophysics::Instrumentation and Methods for Astrophysics, LOFAR, Identification (information), Experimental High Energy Physics, Antenna (radio), business
Abstract

Cosmic rays entering the Earth's atmosphere produce Extensive Air Showers, which emit a radio signal through Geo-magnetic radiation and Askaryan emission. At the present time, one of the biggest challenges for assessing the Radio detection as a valuable technique for Cosmic-ray observation is to identify in real-time the very short (less than 100 ns) radio signals over the background noise. In this work, we present the latest updates on the real-time identification of radio signals from Extensive Air Showers by using the data from LOFAR Low Band Antenna stations, which are sensitive in the 30-80 MHz region.

Published
2017
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7. Calibration of the LOFAR low-band antennas using the Galaxy and a model of the signal chain

Author

Olaf Scholten, Heino Falcke, Antonio Bonardi, Tobias Winchen, S. ter Veen, Stijn Buitink, Katie Mulrey, Arthur Corstanje, Pim Schellart, Laura Rossetto, T. N. G. Trinh, Anna Nelles, Satyendra Thoudam, Brian Hare, Jörg R. Hörandel, Pragati Mitra, Jörg P. Rachen, T. Huege, Astronomy and Astrophysics Research Group, Physics, and Elementary Particle Physics

Subjects
Astroparticle physics, Physics, Spectral shape analysis, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astronomy and Astrophysics, Cosmic ray, LOFAR, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, 7. Clean energy, Signal, Signal chain, Computational physics, 0103 physical sciences, ddc:540, Calibration, Astrophysics - Instrumentation and Methods for Astrophysics, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Energy (signal processing), astro-ph.IM
Abstract

The LOw-Frequency ARray (LOFAR) is used to make precise measurements of radio emission from extensive air showers, yielding information about the primary cosmic ray. Interpreting the measured data requires an absolute and frequency-dependent calibration of the LOFAR system response. This is particularly important for spectral analyses, because the shape of the detected signal holds information about the shower development. We revisit the calibration of the LOFAR antennas in the range of 30 - 80 MHz. Using the Galactic emission and a detailed model of the LOFAR signal chain, we find an improved calibration that provides an absolute energy scale and allows for the study of frequency-dependent features in measured signals. With the new calibration, systematic uncertainties of 13% are reached, and comparisons of the spectral shape of calibrated data with simulations show promising agreement., Comment: 23 pages, 10 figures

Published
2019
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8. Status of the Lunar Detection Mode for Cosmic Particles of LOFAR

Author

T. N. G. Trinh, Brian Hare, Satyendra Thoudam, Stijn Buitink, Olaf Scholten, Katharine Mulrey, Anna Nelles, Heino Falcke, Pragati Mitra, Tobias Winchen, Arthur Corstanje, A. Bonardi, S. ter Veen, Laura Rossetto, Pim Schellart, Jörg P. Rachen, Jörg R. Hörandel, Physics, Astronomy and Astrophysics Research Group, Faculty of Sciences and Bioengineering Sciences, Elementary Particle Physics, and Faculty of Economic and Social Sciences and Solvay Business School

Subjects
History, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Low frequency, 01 natural sciences, Education, Askaryan effect, Radio telescope, 0103 physical sciences, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Astroparticle physics, Physics, astro-ph.HE, COSMIC cancer database, 010308 nuclear & particles physics, Mode (statistics), Astrophysics::Instrumentation and Methods for Astrophysics, LOFAR, Computer Science Applications, Orders of magnitude (time), Astrophysics::Earth and Planetary Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, astro-ph.IM
Abstract

Cosmic particles hitting Earth's moon produce radio emission via the Askaryan effect. If the resulting radio ns-pulse can be detected by radio telescopes, this technique potentially increases the available collective area for ZeV scale particles by several orders of magnitude compared to current experiments. The LOw Frequency ARray (LOFAR) is the largest radio telescope operating in the optimum frequency regime for this technique. In this contribution, we report on the status of the implementation of the lunar detection mode at LOFAR., Comment: Proceedings of the 26th Extended European Cosmic Ray Symposium (ECRS), Barnaul/Belokurikha, 2018

Published
2019

9. The cosmic-ray air-shower signal in Askaryan radio detectors

Author

A. O Murchadha, Stijn Buitink, Olaf Scholten, Krijn D. de Vries, Nick van Eijndhoven, Thomas Meures, Research unit Astroparticle Physics, Physics, Elementary Particle Physics, and Astronomy and Astrophysics Research Group

Subjects
Coherent transition radiation, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Flux, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Askaryan effect, Atmosphere, 0103 physical sciences, Neutrinos, Radio detection, 010306 general physics, Cosmic rays, Askaryan radiation, Physics::Atmospheric and Oceanic Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, 010308 nuclear & particles physics, Detector, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, Air shower, Transition radiation, Astrophysics::Earth and Planetary Astrophysics, Neutrino, Astrophysics - High Energy Astrophysical Phenomena
Abstract

We discuss the radio emission from high-energy cosmic-ray induced air showers hitting Earth’s surface before the cascade has died out in the atmosphere. The induced emission gives rise to a radio signal which should be detectable in the currently operating Askaryan radio detectors built to search for the GZK neutrino flux in ice. The in-air emission, the in-ice emission, as well as a new component, the coherent transition radiation when the particle bunch crosses the air–ice boundary, are included in the calculations.

Published
2016
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10. Cosmic-ray energy spectrum and composition up to the ankle: the case for a second Galactic component

Author

Abraham Achterberg, A. van Vliet, Satyendra Thoudam, Stijn Buitink, Jörg P. Rachen, Jörg R. Hörandel, Heino Falcke, Physics, and Astronomy and Astrophysics Research Group

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astronomy, FOS: Physical sciences, chemistry.chemical_element, Cosmic ray, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, outflows, Auger, Diffusion, cosmic rays, Observatory, 0103 physical sciences, Energy spectrum, 010303 astronomy & astrophysics, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), Helium, Astrophysics::Galaxy Astrophysics, ISM: supernova remnants, High Energy Astrophysical Phenomena (astro-ph.HE), Astroparticle physics, Physics, 010308 nuclear & particles physics, Component (thermodynamics), Astronomy and Astrophysics, Supernova, chemistry, Space and Planetary Science, stars: winds, Astrophysics - High Energy Astrophysical Phenomena, galaxies: ISM
Abstract

We have carried out a detailed study to understand the observed energy spectrum and composition of cosmic rays with energies up to ~10^18 eV. Our study shows that a single Galactic component with subsequent energy cut-offs in the individual spectra of different elements, optimised to explain the observed spectra below ~10^14 eV and the knee in the all-particle spectrum, cannot explain the observed all-particle spectrum above ~2x10^16 eV. We discuss two approaches for a second component of Galactic cosmic rays -- re-acceleration at a Galactic wind termination shock, and supernova explosions of Wolf-Rayet stars, and show that the latter scenario can explain almost all observed features in the all-particle spectrum and the composition up to ~10^18 eV, when combined with a canonical extra-galactic spectrum expected from strong radio galaxies or a source population with similar cosmological evolution. In this two-component Galactic model, the knee at ~ 3x10^15 eV and the second knee at ~10^17 eV in the all-particle spectrum are due to the cut-offs in the first and second components, respectively. We also discuss several variations of the extra-galactic component, from a minimal contribution to scenarios with a significant component below the ankle (at ~4x10^18 eV), and find that extra-galactic contributions in excess of regular source evolution are neither indicated nor in conflict with the existing data. Our main result is that the second Galactic component predicts a composition of Galactic cosmic rays at and above the second knee that largely consists of helium or a mixture of helium and CNO nuclei, with a weak or essentially vanishing iron fraction, in contrast to most common assumptions. This prediction is in agreement with new measurements from LOFAR and the Pierre Auger Observatory which indicate a strong light component and a rather low iron fraction between ~10^17 and 10^18 eV., Added Table 4; Published in A&A, 595 (2016) A33 (Highlight paper)

Published
2016
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11. Large-scale Cosmic-Ray Anisotropies above 4 EeV Measured by the Pierre Auger Observatory

Author

Aab, A., Abreu, P., AGLIETTA, MARCO, Albuquerque, I. F. M., Albury, J. M., Allekotte, I., Almela, A., Alvarez Castillo, J., Alvarez-Muñiz, J., Anastasi, G. A., Anchordoqui, L., Andrada, B., Andringa, S., Aramo, C., Asorey, H., Assis, P., Avila, G., Badescu, A. M., Balaceanu, A., Barbato, F., Barreira Luz, R. J., Baur, S., Becker, K. H., Bellido, J. A., Berat, C., Bertaina, M. E., Bertou, X., Biermann, P. L., Biteau, J., Blaess, S. G., Blanco, A., Blazek, J., Bleve, C., Boháčová, M., Bonifazi, C., Borodai, N., Botti, A. M., Brack, J., Bretz, T., Bridgeman, A., Briechle, F. L., Buchholz, P., Bueno, A., Buitink, S., Buscemi, M., Caballero-Mora, K. S., Caccianiga, L., Calcagni, L., Cancio, A., Canfora, F., Carceller, J. M., Caruso, R., CASTELLINA, ANTONELLA, Catalani, F., Cataldi, G., Cazon, L., Chinellato, J. A., Chudoba, J., Chytka, L., Clay, R. W., Cobos Cerutti, A. C., Colalillo, R., Coleman, A., Coluccia, M. R., Conceição, R., Consolati, G., Contreras, F., Cooper, M. J., Coutu, S., Covault, C. E., Daniel, B., Dasso, S., Daumiller, K., Dawson, B. R., Day, J. A., de Almeida, R. M., de Jong, S. J., De Mauro, G., de Mello Neto, J. R. T., De Mitri, I., de Oliveira, J., de Souza, V., Debatin, J., Deligny, O., Dhital, N., Díaz Castro, M. L., Diogo, F., Dobrigkeit, C., D'Olivo, J. C., Dorosti, Q., dos Anjos, R. C., Dova, M. T., Dundovic, A., Ebr, J., Engel, R., Erdmann, M., Escobar, C. O., Etchegoyen, A., Falcke, H., Farmer, J., Farrar, G., Fauth, A. C., Fazzini, N., Feldbusch, F., Fenu, F., Ferreyro, L. P., Figueira, J. M., Filipčič, A., Freire, M. M., Fujii, T., Fuster, A., García, B., Gemmeke, H., Gherghel-Lascu, A., Ghia, P. L., Giaccari, U., Giammarchi, M., Giller, M., Głas, D., Glombitza, J., Golup, G., Gómez Berisso, M., Gómez Vitale, P. F., González, N., Goos, I., Góra, D., GORGI, Alessio, Gottowik, M., Grubb, T. D., Guarino, F., Guedes, G. P., Guido, E., Halliday, R., Hampel, M. R., Hansen, P., Harari, D., Harrison, T. A., Harvey, V. M., Haungs, A., Hebbeker, T., Heck, D., Heimann, P., Hill, G. C., Hojvat, C., Holt, E. M., Homola, P., Hörandel, J. R., Horvath, P., Hrabovský, M., Huege, T., Hulsman, J., Insolia, A., Isar, P. G., Jandt, I., Johnsen, J. A., Josebachuili, M., Jurysek, J., Kääpä, A., Kampert, K. H., Keilhauer, B., Kemmerich, N., Kemp, J., Klages, H. O., Kleifges, M., Kleinfeller, J., Krause, R., Kuempel, D., Kukec Mezek, G., Kuotb Awad, A., Lago, B. L., LaHurd, D., Lang, R. G., Legumina, R., Leigui de Oliveira, M. A., Lenok, V., Letessier-Selvon, A., Lhenry-Yvon, I., Lo Presti, D., Lopes, L., López, R., López Casado, A., Lorek, R., Luce, Q., Lucero, A., Malacari, M., Mallamaci, M., Mancarella, G., Mandat, D., Mantsch, P., Mariazzi, A. G., Mariș, I. C., Marsella, G., Martello, D., Martinez, H., Martínez Bravo, O., Mathes, H. J., Mathys, S., Matthews, J., Matthiae, G., Mayotte, E., Mazur, P. O., Medina-Tanco, G., Melo, D., Menshikov, A., Merenda, K. -D., Michal, S., Micheletti, M. I., Middendorf, L., Miramonti, L., Mitrica, B., Mockler, D., Mollerach, S., Montanet, F., Morello, C., MORLINO, GIOVANNI, Mostafá, M., Müller, A. L., Muller, M. A., Müller, S., Mussa, R., Nellen, L., Nguyen, P. H., Niculescu-Oglinzanu, M., Niechciol, M., Nitz, D., Nosek, D., Novotny, V., Nožka, L., Nucita, A., Núñez, L. A., Olinto, A., Palatka, M., Pallotta, J., Papenbreer, P., Parente, G., Parra, A., Pech, M., Pedreira, F., Pȩkala, J., Pelayo, R., Peña-Rodriguez, J., Pereira, L. A. S., Perlin, M., Perrone, L., Peters, C., Petrera, S., Phuntsok, J., Pierog, T., Pimenta, M., Pirronello, V., Platino, M., Poh, J., Pont, B., Porowski, C., Prado, R. R., Privitera, P., Prouza, M., Puyleart, A., Querchfeld, S., Quinn, S., Ramos-Pollan, R., Rautenberg, J., Ravignani, D., Reininghaus, M., Ridky, J., Riehn, F., Risse, M., Ristori, P., Rizi, V., Rodrigues de Carvalho, W., Rodriguez Rojo, J., Roncoroni, M. J., Roth, M., Roulet, E., Rovero, A. C., Ruehl, P., Saffi, S. J., Saftoiu, A., Salamida, F., Salazar, H., Saleh, A., Salina, G., Sánchez, F., Santos, E. M., Santos, E., Sarazin, F., Sarmento, R., Sarmiento-Cano, C., Sato, R., Savina, P., Schauer, M., Scherini, V., Schieler, H., Schimassek, M., Schimp, M., Schmidt, D., Scholten, O., Schovánek, P., Schröder, F. G., Schröder, S., Schumacher, J., Sciutto, S. J., Shellard, R. C., Sigl, G., Silli, G., Sima, O., Šmída, R., Snow, G. R., Sommers, P., Soriano, J. F., Souchard, J., Squartini, R., Stanca, D., Stanič, S., Stasielak, J., Stassi, P., Stolpovskiy, M., Streich, A., Suarez, F., Suárez-Durán, M., Sudholz, T., Suomijärvi, T., Supanitsky, A. D., Šupík, J., Szadkowski, Z., Taboada, A., Taborda, O. A., Tapia, A., Timmermans, C., Todero Peixoto, C. J., Tomé, B., Torralba Elipe, G., Travnicek, P., Trini, M., Tueros, M., Ulrich, R., Unger, M., Urban, M., Valdés Galicia, J. F., Valiño, I., Valore, L., van Bodegom, P., van den Berg, A. M., van Vliet, A., Varela, E., Vargas Cárdenas, B., Vázquez, R. A., Veberič, D., Ventura, C., Vergara Quispe, I. D., Verzi, V., Vicha, J., Villaseñor, L., Vorobiov, S., Wahlberg, H., Wainberg, O., Watson, A. A., Weber, M., Weindl, A., Wiedeński, M., Wiencke, L., Wilczyński, H., Wirtz, M., Wittkowski, D., Wundheiler, B., Yang, L., Yushkov, A., Zas, E., Zavrtanik, D., Zavrtanik, M., Zehrer, L., Zepeda, A., Zimmermann, B., Ziolkowski, M., Zong, Z., Zuccarello, Francesca, Pierre Auger Collaboration, Aab, A., Abreu, P., Aglietta, M., Albuquerque, I. F. M., Albury, J. M., Allekotte, I., Almela, A., Castillo, J. Alvarez, Alvarez-Muñiz, J., Anastasi, G. A., Anchordoqui, L., Andrada, B., Andringa, S., Aramo, C., Asorey, H., Assis, P., Avila, G., Badescu, A. M., Balaceanu, A., Barbato, F., Luz, R. J. Barreira, Baur, S., Becker, K. H., Bellido, J. A., Berat, C., Bertaina, M. E., Bertou, X., Biermann, P. L., Biteau, J., Blaess, S. G., Blanco, A., Blazek, J., Bleve, C., Boháčová, M., Bonifazi, C., Borodai, N., Botti, A. M., Brack, J., Bretz, T., Bridgeman, A., Briechle, F. L., Buchholz, P., Bueno, A., Buitink, S., Buscemi, M., Caballero-Mora, K. S., Caccianiga, L., Calcagni, L., Cancio, A., Canfora, F., Carceller, J. M., Caruso, R., Castellina, A., Catalani, F., Cataldi, G., Cazon, L., Chinellato, J. A., Chudoba, J., Chytka, L., Clay, R. W., Cerutti, A. C. Cobo, Colalillo, R., Coleman, A., Coluccia, M. R., Conceição, R., Consolati, G., Contreras, F., Cooper, M. J., Coutu, S., Covault, C. E., Daniel, B., Dasso, S., Daumiller, K., Dawson, B. R., Day, J. A., Almeida, R. M. De, Jong, S. J. De, De Mauro, G., Neto, J. R. T. De Mello, De Mitri, I., Deoliveira, J., De Souza, V., Debatin, J., Deligny, O., Dhital, N., Díaz Castro, M. L., Diogo, F., Dobrigkeit, C., D'Olivo, J. C., Dorosti, Q., Anjos, R. C. Do, Dova, M. T., Dundovic, A., Ebr, J., Engel, R., Erdmann, M., Escobar, C. O., Etchegoyen, A., Falcke, H., Farmer, J., Farrar, G., Fauth, A. C., Fazzini, N., Feldbusch, F., Fenu, F., Ferreyro, L. P., Figueira, J. M., Filipčič, A., Freire, M. M., Fujii, T., Fuster, A., García, B., Gemmeke, H., Gherghel-Lascu, A., Ghia, P. L., Giaccari, U., Giammarchi, M., Giller, M., Głas, D., Glombitza, J., Golup, G., Berisso, M. Gómez, Vitale, P. F. Gómez, González, N., Goos, I., Góra, D., Gorgi, A., Gottowik, M., Grubb, T. D., Guarino, F., Guedes, G. P., Guido, E., Halliday, R., Hampel, M. R., Hansen, P., Harari, D., Harrison, T. A., Harvey, V. M., Haungs, A., Hebbeker, T., Heck, D., Heimann, P., Hill, G. C., Hojvat, C., Holt, E. M., Homola, P., Hörandel, J. R., Horvath, P., Hrabovský, M., Huege, T., Hulsman, J., Insolia, A., Isar, P. G., Jandt, I., Johnsen, J. A., Josebachuili, M., Jurysek, J., Käpä, A., Kampert, K. H., Keilhauer, B., Kemmerich, N., Kemp, J., Klages, H. O., Kleifges, M., Kleinfeller, J., Krause, R., Kuempel, D., Mezek, G. Kukec, Awad, A. Kuotb, Lago, B. L., Lahurd, D., Lang, R. G., Legumina, R., De Oliveira, M. A. Leigui, Lenok, V., Letessier-Selvon, A., Lhenry-Yvon, I., Lo Presti, D., Lopes, L., López, R., Casado, A. López, Lorek, R., Luce, Q., Lucero, A., Malacari, M., Mallamaci, M., Mancarella, G., Mandat, D., Mantsch, P., Mariazzi, A. G., Mariş, I. C., Marsella, G., Martello, D., Martinez, H., Martínez Bravo, O., Mathes, H. J., Mathys, S., Matthews, J., Matthiae, G., Mayotte, E., Mazur, P. O., Medina-Tanco, G., Melo, D., Menshikov, A., Merenda, K. -D., Michal, S., Micheletti, M. I., Middendorf, L., Miramonti, L., Mitrica, B., Mockler, D., Mollerach, S., Montanet, F., Morello, C., Morlino, G., Mostafá, M., Müller, A. L., Muller, M. A., Müller, S., Mussa, R., Nellen, L., Nguyen, P. H., Niculescu-Oglinzanu, M., Niechciol, M., Nitz, D., Nosek, D., Novotny, V., Nožka, L., Nucita, A., Nñez, L. A., Olinto, A., Palatka, M., Pallotta, J., Papenbreer, P., Parente, G., Parra, A., Pech, M., Pedreira, F., Pkala, J., Pelayo, R., Peña-Rodriguez, J., Pereira, L. A. S., Perlin, M., Perrone, L., Peters, C., Petrera, S., Phuntsok, J., Pierog, T., Pimenta, M., Pirronello, V., Platino, M., Poh, J., Pont, B., Porowski, C., Prado, R. R., Privitera, P., Prouza, M., Puyleart, A., Querchfeld, S., Quinn, S., Ramos-Pollan, R., Rautenberg, J., Ravignani, D., Reininghaus, M., Ridky, J., Riehn, F., Risse, M., Ristori, P., Rizi, V., De Carvalho, W. Rodrigue, Rojo, J. Rodriguez, Roncoroni, M. J., Roth, M., Roulet, E., Rovero, A. C., Ruehl, P., Saffi, S. J., Saftoiu, A., Salamida, F., Salazar, H., Saleh, A., Salina, G., Sánchez, F., Santos, E. M., Santos, E., Sarazin, F., Sarmento, R., Sarmiento-Cano, C., Sato, R., Savina, P., Schauer, M., Scherini, V., Schieler, H., Schimassek, M., Schimp, M., Schmidt, D., Scholten, O., Schovánek, P., Schröder, F. G., Schröder, S., Schumacher, J., Sciutto, S. J., Shellard, R. C., Sigl, G., Silli, G., Sima, O., Šmída, R., Snow, G. R., Sommers, P., Soriano, J. F., Souchard, J., Squartini, R., Stanca, D., Stanič, S., Stasielak, J., Stassi, P., Stolpovskiy, M., Streich, A., Suarez, F., Suárez-Durán, M., Sudholz, T., Suomijärvi, T., Supanitsky, A. D., Šupík, J., Szadkowski, Z., Taboada, A., Taborda, O. A., Tapia, A., Timmermans, C., Peixoto, C. J. Todero, Tomé, B., Elipe, G. Torralba, Travnicek, P., Trini, M., Tueros, M., Ulrich, R., Unger, M., Urban, M., Galicia, J. F. Valdé, Valiño, I., Valore, L., Bodegom, P. Van, Berg, A. M. Van Den, Vliet, A. Van, Varela, E., Cárdenas, B. Varga, Vázquez, R. A., Veberič, D., Ventura, C., Quispe, I. D. Vergara, Verzi, V., Vicha, J., Villaseñor, L., Vorobiov, S., Wahlberg, H., Wainberg, O., Watson, A. A., Weber, M., Weindl, A., Wiedeński, M., Wiencke, L., Wilczyński, H., Wirtz, M., Wittkowski, D., Wundheiler, B., Yang, L., Yushkov, A., Zas, E., Zavrtanik, D., Zavrtanik, M., Zehrer, L., Zepeda, A., Zimmermann, B., Ziolkowski, M., Zong, Z., Zuccarello, F., Physics, Astronomy and Astrophysics Research Group, Elementary Particle Physics, Research unit Astroparticle Physics, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Pierre Auger, Almeida, R. M. de, Jong, S. J. de, Mauro, G. De, Neto, J. R. T. de Mello, Mitri, I. De, Oliveira, J. de, Souza, V. de, D’Olivo, J. C., Anjos, R. C. do, Kääpä, A., de Oliveira, M. A. Leigui, Presti, D. Lo, Nucita, A, Núñez, L. A., Pȩkala, J., de Carvalho, W. Rodrigue, Savina, Pierpaolo, Bodegom, P. van, Berg, A. M. van den, Vliet, A. van, LaHurd, D., SAVINA, PIERPAOLO, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Astronomy, magnetic field, Astrophysics, 01 natural sciences, Amplitude, astroparticle physics, cosmic rays, Anisotropy, 010303 astronomy & astrophysics, cosmic ray, astroparticle physics, cosmic rays, Right ascension, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, astro-ph.HE, COSMIC cancer database, ORIGIN, OBSERVATÓRIOS, Settore FIS/01 - Fisica Sperimentale, Astrophysics::Instrumentation and Methods for Astrophysics, astroparticle physic, Auger, Astronomy and Astrophysics, Space and Planetary Science, observatory, modulation, Cosmic cancer database, Astrophysics - High Energy Astrophysical Phenomena, large scale anysotropy, splitting, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Cosmic ray, Context (language use), cosmic radiation: anisotropy, 0103 physical sciences, High Energy Physics, cosmic radiation: UHE, Pierre auger observatory, Pierre Auger Observatory, extragalactic origin, 010308 nuclear & particles physics, Física, Astronomy and Astrophysic, Dipole, Experimental High Energy Physics, Observatory, Astroparticle physics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], large scale anysotropy, extragalactic origin, dipole
Abstract

We present a detailed study of the large-scale anisotropies of cosmic rays with energies above 4 EeV measured using the Pierre Auger Observatory. For the energy bins [4,8] EeV and $E\geq 8$ EeV, the most significant signal is a dipolar modulation in right ascension at energies above 8 EeV, as previously reported. In this paper we further scrutinize the highest-energy bin by splitting it into three energy ranges. We find that the amplitude of the dipole increases with energy above 4 EeV. The growth can be fitted with a power law with index $\beta=0.79\pm 0.19$. The directions of the dipoles are consistent with an extragalactic origin of these anisotropies at all the energies considered. Additionally we have estimated the quadrupolar components of the anisotropy: they are not statistically significant. We discuss the results in the context of the predictions from different models for the distribution of ultrahigh-energy sources and cosmic magnetic fields., Comment: Published version, 16 pages, 7 figures, 8 tables

Published
2018
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12. Understanding AGB evolution in Galactic bulge stars from high-resolution infrared spectroscopy

Author

Mathias Schultheis, S. Uttenthaler, Peter R. Wood, Nils Ryde, J. A. D. L. Blommaert, Thomas Lebzelter, Bernhard Aringer, Physics, Astrophysics, and Astronomy and Astrophysics Research Group

Subjects
010504 meteorology & atmospheric sciences, Metallicity, K-type main-sequence star, FOS: Physical sciences, stars: AGB and post-AGB, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Galaxy: bulge, Bulge, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Asymptotic giant branch, stars: evolution, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Spiral galaxy, stars: late-type, Astronomy, Astronomy and Astrophysics, Galaxy, Radial velocity, Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics
Abstract

An analysis of high-resolution near-infrared spectra of a sample of 45 asymptotic giant branch (AGB) stars towards the Galactic bulge is presented. The sample consists of two subsamples, a larger one in the inner and intermediate bulge, and a smaller one in the outer bulge. The data are analysed with the help of hydrostatic model atmospheres and spectral synthesis. We derive the radial velocity of all stars, and the atmospheric chemical mix ([Fe/H], C/O, $^{12}$C/$^{13}$C, Al, Si, Ti, and Y) where possible. Our ability to model the spectra is mainly limited by the (in)completeness of atomic and molecular line lists, at least for temperatures down to $T_{\rm eff}\approx3100$ K. We find that the subsample in the inner and intermediate bulge is quite homogeneous, with a slightly sub-solar mean metallicity and only few stars with super-solar metallicity, in agreement with previous studies of non-variable M-type giants in the bulge. All sample stars are oxygen-rich, C/O$, Comment: 21 pages, 13 figures, 6 tables (incl. appendix), years of work, published in MNRAS

Published
2015
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13. A first search for cosmogenic neutrinos with the ARIANNA Hexagonal Radio Array

Author

D. Z. Besson, R. G. Bose, G. Yodh, A. Samanta, Ulrik I. Uggerhøj, E. C. Berg, Stijn Buitink, Kenneth L. Ratzlaff, J. H. Buckley, Jordan C. Hanson, G. Binder, K. Dookayka, J. Walker, S. Euler, Hans Niederhausen, Brian Rauch, L. Gerhardt, Leif Gustafsson, Steven W. Barwick, G. E. Simburger, C. Reed, W. R. Binns, T. Duffin, M. H. Israel, S. R. Klein, C. Persichelli, P. F. Dowkontt, D. J. Boersma, Stuart A. Kleinfelder, V. Bugaev, Allan Hallgren, M. A. Olevitch, R. Young, M. Roumi, D. L. Braun, J. Tatar, T. Stezelberger, J. Kiryluk, Physics, and Astronomy and Astrophysics Research Group

Subjects
Physics::Instrumentation and Detectors, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Antartica, Flux, FOS: Physical sciences, Astrophysics, Atomic, ARIANNA Experiment, Nuclear physics, Particle and Plasma Physics, Neutrino, Cosmogenic, Nuclear, Instrumentation and Methods for Astrophysics (astro-ph.IM), Cherenkov radiation, Physics, astro-ph.HE, High Energy Astrophysical Phenomena (astro-ph.HE), Detector, Molecular, Astronomy and Astrophysics, Solar neutrino problem, GZK, Radio, Nuclear & Particles Physics, radio, Neutrino detector, High energy, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Antarctica, High Energy Physics::Experiment, Radio frequency, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, physics, Astronomical and Space Sciences, astro-ph.IM
Abstract

The ARIANNA experiment seeks to observe the diffuse flux of neutrinos in the 10^8 - 10^10 GeV energy range using a grid of radio detectors at the surface of the Ross Ice Shelf of Antarctica. The detector measures the coherent Cherenkov radiation produced at radio frequencies, from about 100 MHz to 1 GHz, by charged particle showers generated by neutrino interactions in the ice. The ARIANNA Hexagonal Radio Array (HRA) is being constructed as a prototype for the full array. During the 2013-14 austral summer, three HRA stations collected radio data which was wirelessly transmitted off site in nearly real-time. The performance of these stations is described and a simple analysis to search for neutrino signals is presented. The analysis employs a set of three cuts that reject background triggers while preserving 90% of simulated cosmogenic neutrino triggers. No neutrino candidates are found in the data and a model-independent 90% confidence level Neyman upper limit is placed on the all flavor neutrino+antineutrino flux in a sliding decade-wide energy bin. The limit reaches a minimum of 1.9x10^-23 GeV^-1 cm^-2 s^-1 sr^-1 in the 10^8.5 - 10^9.5 GeV energy bin. Simulations of the performance of the full detector are also described. The sensitivity of the full ARIANNA experiment is presented and compared with current neutrino flux models., 22 pages, 22 figures. Published in Astroparticle Physics

Published
2015
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14. Search for Cosmic Particles with the Moon and LOFAR

Author

T. N. G. Trinh, Olaf Scholten, S. ter Veen, Jörg P. Rachen, Jörg R. Hörandel, Laura Rossetto, Arthur Corstanje, Anna Nelles, Satyendra Thoudam, Pragati Mitra, Tobias Winchen, J. E. Enriquez, Katharine Mulrey, A. Bonardi, Heino Falcke, Pim Schellart, Stijn Buitink, Research unit Astroparticle Physics, Physics, Astronomy and Astrophysics Research Group, and Faculty of Sciences and Bioengineering Sciences

Subjects
Physics, COSMIC cancer database, 010308 nuclear & particles physics, QC1-999, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Dark matter, Detector, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, LOFAR, Physics and Astronomy(all), 01 natural sciences, Radio telescope, 0103 physical sciences, Particle, Neutrino, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries)
Abstract

The low flux of the ultra-high energy cosmic rays (UHECR) at the highest energies provides a challenge to answer the long standing question about their origin and nature. A significant increase in the number of detected UHECR is expected to be achieved by employing Earth's moon as detector, and search for short radio pulses that are emitted when a particle interacts in the lunar rock. Observation of these short pulses with current and future radio telescopes also allows to search for the even lower fluxes of neutrinos with energies above $10^{22}$ eV, that are predicted in certain Grand-Unifying-Theories (GUTs), and e.g. models for super-heavy dark matter (SHDM). In this contribution we present the initial design for such a search with the LOFAR radio telescope., Comment: To be published in the Proceedings of the ARENA2016 conference, Groningen, The Netherlands

Published
2017

15. Towards real-time cosmic-ray identification with the LOw Frequency ARay

Author

Anna Nelles, Antonio Bonardi, Brian Hare, Stijn Buitink, Katie Mulrey, Sander ter Veen, Jörg P. Rachen, Jörg R. Hörandel, Pragati Mitra, Satyendra Thoudam, Heino Falcke, Pim Schellart, Gia Trinh, Olaf Scholten, Laura Rossetto, Tobias Winchen, Arthur Corstanje, Astronomy and Astrophysics Research Group, Physics, and Faculty of Sciences and Bioengineering Sciences

Subjects
Physics, 010308 nuclear & particles physics, business.industry, QC1-999, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, Limiting, LOFAR, Low frequency, 01 natural sciences, Particle detector, Identification (information), Optics, 0103 physical sciences, Recognition system, Antenna (radio), 010306 general physics, business
Abstract

The radio signals emitted by Extensive Air Showers have been successfully used for the last decade by LOFAR to reconstruct the properties of the primary cosmic rays. Since an effective real-time recognition system for the very short radio pulses is lacking, cosmic-ray acquisition is currently triggered by an external array of particle detector, called LORA, limiting the LOFAR collecting area to the area covered by LORA. A new algorithm for the real-time cosmic-ray detection has been developed for the LOFAR Low Band Antenna, which are sensitive between 10 and 90 MHz, and is here presented together with the latest results.

Published
2019
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16. A new parametrization for the radio emission of air showers applied to LOFAR data

Author

Brian Hare, Arthur Corstanje, Antonio Bonardi, Pim Schellart, Pragati Mitra, Tobias Winchen, Jörg R. Hörandel, Heino Falcke, J. P. Rachen, T. N. G. Trinh, I. Plaisier, Satyendra Thoudam, S. ter Veen, Laura Rossetto, Anna Nelles, Stijn Buitink, Katie Mulrey, Olaf Scholten, S. J. De Jong, Astronomy and Astrophysics Research Group, Physics, and Faculty of Sciences and Bioengineering Sciences

Subjects
Physics, QC1-999, Astronomy, Computer Science::Information Retrieval, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, LOFAR, Mass composition, Computational physics, Earth's magnetic field, Primary (astronomy), Energy density, High Energy Physics, Parametrization, Energy (signal processing)
Abstract

The energy and mass composition of cosmic rays influence how the energy density of the radio emission of air showers is distributed on the ground. A precise description of the radio profiles can, therefore, be used to reconstruct the properties of the primary cosmic rays. Here, such a description is presented, using a separate treatment of the two radio-emission mechanisms, the geomagnetic effect and the charge excess effect. The model is parametrized as a function that depends only on the shower parameters, allowing for a precise reconstruction of the properties of the primary cosmic rays. This model is applied to cosmic-ray events measured with LOFAR and it is capable of reconstructing the properties of air showers correctly.

Published
2019
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17. Constraints on the H2O formation mechanism in the wind of carbon-rich AGB stars

Author

Bart Vandenbussche, Joris Blommaert, Theo Khouri, C. Waelkens, Martin Groenewegen, Nick L. J. Cox, Pierre Royer, Franz Kerschbaum, Marcelino Agúndez, J. De Ridder, David A. Neufeld, A. de Koter, José Cernicharo, Leen Decin, Eduardo González-Alfonso, Robin Lombaert, Research Foundation - Flanders, University of Leuven, Belgian Science Policy Office, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia e Innovación (España), Hercules Foundation, Federal Ministry for Transport, Innovation and Technology (Austria), European Space Agency, Centre National D'Etudes Spatiales (France), German Centre for Air and Space Travel, Agenzia Spaziale Italiana, Astronomy and Astrophysics Research Group, Physics, Astrophysics, Faculty of Science, and Low Energy Astrophysics (API, FNWI)

Subjects
astro-ph.SR, 010504 meteorology & atmospheric sciences, astro-ph.GA, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Radiation, medicine.disease_cause, 01 natural sciences, 7. Clean energy, Spectral line, law.invention, Telescope, law, 0103 physical sciences, medicine, Asymptotic giant branch, Astrophysics::Solar and Stellar Astrophysics, Stars: mass-loss, winds, outflows [stars], 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, carbon [stars], Photodissociation, Stars: AGB and post-AGB, Stars: abundances, Astronomy and Astrophysics, mass-loss [stars], Astrophysics - Astrophysics of Galaxies, AGB and post-AGB [stars], abundances [stars], Stars, Stars: carbon, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Outflow, Stars: winds, outflows, Astrophysics::Earth and Planetary Astrophysics, Ultraviolet
Abstract

[Context] Context. The recent detection of warm H2O vapor emission from the outflows of carbon-rich asymptotic giant branch (AGB) stars challenges the current understanding of circumstellar chemistry. Two mechanisms have been invoked to explain warm H2O vapor formation. In the first, periodic shocks passing through the medium immediately above the stellar surface lead to H2O formation. In the second, penetration of ultraviolet interstellar radiation through a clumpy circumstellar medium leads to the formation of H2O molecules in the intermediate wind., [Aims] We aim to determine the properties of H2O emission for a sample of 18 carbon-rich AGB stars and subsequently constrain which of the above mechanisms provides the most likely warm H2O formation pathway., [Methods] Using far-infrared spectra taken with the PACS instrument onboard the Herschel telescope, we combined two methods to identify H2O emission trends and interpreted these in terms of theoretically expected patterns in the H2O abundance. Through the use of line-strength ratios, we analyzed the correlation between the strength of H2O emission and the mass-loss rate of the objects, as well as the radial dependence of the H2O abundance in the circumstellar outflow per individual source. We computed a model grid to account for radiative-transfer effects in the line strengths., [Results] We detect warm H2O emission close to or inside the wind acceleration zone of all sample stars, irrespective of their stellar or circumstellar properties. The predicted H2O abundances in carbon-rich environments are in the range of 10-6 up to 10-4 for Miras and semiregular-a objects, and cluster around 10-6 for semiregular-b objects. These predictions are up to three orders of magnitude greater than what is predicted by state-of-the-art chemical models. We find a negative correlation between the H2O/CO line-strength ratio and gas mass-loss rate for Ṁg> 5 × 10-7 M⊙ yr-1, regardless of the upper-level energy of the relevant transitions. This implies that the H2O formation mechanism becomes less efficient with increasing wind density. The negative correlation breaks down for the sources of lowest mass-loss rate, the semiregular-b objects., [Conclusions] Observational constraints suggest that pulsationally induced shocks play an important role in warm H2O formation in carbon-rich AGB stars, although photodissociation by interstellar UV photons may still contribute. Both mechanisms fail in predicting the high H2O abundances we infer in Miras and semiregular-a sources, while our results for the semiregular-b objects are inconclusive., R.L. acknowledges financial support from the Fund for Scientific Research – Flanders (FWO) under grant number ZKB5757-04-W01, from the Department of Physics and Astronomy of the KU Leuven, and from the Belgian Federal Science Policy Office via the PRODEX Program of ESA under grant number C90371. L.D. acknowledges financial support from the FWO. P.R., N.C., J.D., J.B., M.G., and B.V. acknowledge support from the Belgian Federal Science Policy Office via the PRODEX Programme of ESA. F.K. is supported by the FWF project P23586 and the ffg ASAP project HIL. E.G-A is a Research Associate at the Harvard-Smithsonian CfA, and thanks the Spanish Ministerio de Economía y Competitividad for support under projects AYA2010-21697-C05-0 and FIS2012-39162-C06-01 and partial support from NHSC/JPL RSA 1455432. This development has been supported by the funding agencies BMVIT (Austria), ESA-PRODEX (Belgium), CEA/CNES (France), DLR (Germany), ASI (Italy), and CICT/MCT (Spain). For the computations we used the infrastructure of the VSC – Flemish Supercomputer Center, funded by the Hercules Foundation and the Flemish Government – department EWI.

Published
2016

18. The interstellar medium in Andromeda's dwarf spheroidal galaxies: II. Multi-phase gas content and ISM conditions

Author

George J. Bendo, Maarten Baes, Robert C. Kennicutt, Médéric Boquien, Suzanne C. Madden, Nario Kuno, Gianfranco Gentile, Christine D. Wilson, Lisa M. Young, Diane Cormier, Hiroyuki Kaneko, Jacopo Fritz, Ilse De Looze, Matthew Smith, Astrophysics, Physics, Astronomy and Astrophysics Research Group, Faculty of Medicine and Pharmacy, Kennicutt, Robert [0000-0001-5448-1821], and Apollo - University of Cambridge Repository

Subjects
C-II, 010504 meteorology & atmospheric sciences, dwarf [galaxies], NGC 205, FOURIER-TRANSFORM SPECTROMETER, FOS: Physical sciences, galaxies: individual: NGC 147, Astrophysics, evolution [ISM], galaxies: individual: NGC 205, 01 natural sciences, Hubble sequence, NGC 185, symbols.namesake, ISM: evolution, 0103 physical sciences, LOCAL GROUP GALAXIES, ATOMIC CARBON, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, individual: NGC 147 [galaxies], infrared: ISM, Physics, ISM: evolution, galaxies: dwarf, galaxies: individual: NGC 147, NGC 185, NGC 205, Local Group, infrared: ISM, Astronomy, Local Group, ISM [infrared], Astronomy and Astrophysics, galaxies: dwarf, STAR-FORMATION HISTORY, VIRGO CLUSTER, Astrophysics - Astrophysics of Galaxies, Virgo Cluster, Planetary nebula, Galaxy, MOLECULAR GAS, Andromeda, Interstellar medium, Supernova, Physics and Astronomy, galaxies: individual: NGC 185, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), symbols, PLANETARY-NEBULAE, FAR-INFRARED SPECTROSCOPY
Abstract

We make an inventory of the interstellar medium material in three low-metallicity dwarf spheroidal galaxies of the Local Group (NGC147, NGC185 and NGC205). Ancillary Hi, CO, \textit{Spitzer} IRS spectra, H$\alpha$ and X-ray observations are combined to trace the atomic, cold and warm molecular, ionised and hot gas phases. We present new Nobeyama CO(1-0) observations and \textit{Herschel} SPIRE FTS [Ci] observations of NGC205 to revise its molecular gas content. We derive total gas masses of Mg = 1.9-5.5x10$^5$ M$\odot$ for NGC185 and Mg = 8.6-25.0x10^5 M$\odot$ for NGC205. Non-detections combine to an upper limit on the gas mass of Mg =< 0.3-2.2x10^5 M$\odot$ for NGC147. The observed gas reservoirs are significantly lower compared to the expected gas masses based on a simple closed-box model that accounts for the gas mass returned by planetary nebulae and supernovae. The gas-to-dust mass ratios GDR~37-107 and GDR~48-139 are also considerably lower compared to the expected GDR~370 and GDR~520 for the low metal abundances in NGC 185 (0.36 Z$\odot$) and NGC205 (0.25 Z$\odot$), respectively. To simultaneously account for the gas deficiency and low gas-to-dust ratios, we require an efficient removal of a large gas fraction and a longer dust survival time (~1.6 Gyr). We believe that efficient galactic winds (combined with heating of gas to sufficiently high temperatures in order for it to escape from the galaxy) and/or environmental interactions with neighbouring galaxies are responsible for the gas removal from NGC147, NGC185 and NGC205., Science and Technology Facilities Council (STFC); Flemish Fund for Scientific Research (FWO-Vlaanderen); BMVIT (Austria); ESA-PRODEX (Belgium); CEA/CNES (France); DLR (Germany); ASI/INAF (Italy); CICYT/ MCYT (Spain); CSA (Canada); NAOC (China); CEA, CNES, CNRS (France); ASI (Italy); MCINN (Spain); SNSB (Sweden); STFC, UKSA (UK); NASA (USA)

Published
2016
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19. The potential role of NGC 205 in generating Andromeda's vast thin co-rotating plane of satellite galaxies

Author

Paul Coppin, Antonaldo Diaferio, Gianfranco Gentile, Garry W. Angus, Faculty of Sciences and Bioengineering Sciences, Physics, Astrophysics, and Astronomy and Astrophysics Research Group

Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO), Andromeda Galaxy, Astrophysics::High Energy Astrophysical Phenomena, Dwarf galaxy problem, Dark matter, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Hubble sequence, symbols.namesake, 0103 physical sciences, Satellite galaxy, Local group, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, Methods: numerical, 010308 nuclear & particles physics, Galaxies: kinematics and dynamics, Local Group, Astronomy, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Space and Planetary Science, Andromeda, Astrophysics of Galaxies (astro-ph.GA), symbols, Dark galaxy, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The Andromeda galaxy is observed to have a system of two large dwarf ellipticals and ~13 smaller satellite galaxies that are currently co-rotating in a thin plane, in addition to 2 counter-rotating satellite galaxies. We explored the consistency of those observations with a scenario where the majority of the co-rotating satellite galaxies originated from a subhalo group, where NGC 205 was the host and the satellite galaxies occupied dark matter sub-subhalos. We ran N-body simulations of a close encounter between NGC 205 and M31. In the simulations, NGC 205 was surrounded by massless particles to statistically sample the distribution of the sub-subhalos expected in a subhalo that has a mass similar to NGC 205. We made Monte Carlo samplings and found that, using a set of reference parameters, the probability of producing a thinner distribution of sub-subhalos than the observed NGC 205 + 15 smaller satellites (thus including the 2 counter-rotators, but excluding M32) increased from, 19 pages, 15 figures, to be published in MNRAS

Published
2016
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20. Spin rates and spin evolution of O components in WR+O binaries

Author

Dany Vanbeveren, A. F. J. Moffat, N. Mennekens, Michael M. Shara, Physics, and Astronomy and Astrophysics Research Group

Subjects
Physics, Condensed matter physics, 010308 nuclear & particles physics, Space and Planetary Science, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astronomy and Astrophysics, Astrophysics, 010303 astronomy & astrophysics, 01 natural sciences, Astrophysics::Galaxy Astrophysics, Spin-½
Abstract

Context.Despite 50 yr of extensive binary research, we must conclude that the Roche lobe overflow/mass transfer process that governs close binary evolution is still poorly understood.Aims.It is the scope of the present paper to lift the edge of the veil by studying the spin-up and spin-down processes of the O-type components of WR+O binaries.Methods.We critically analyzed the available observational data of rotation speeds of the O-type components in WR+O binaries. By combining a binary evolutionary code and a formalism that describes the effects of tides in massive stars with an envelope in radiative equilibrium, we computed the corresponding rotational velocities during the Roche lobe overflow of the progenitor binaries.Results.In all the WR+O binaries studied, we find that the O-type stars were affected by accretion of matter during Roche lobe overflow (RLOF) of the progenitor. This means that common envelope evolution, which excludes any accretion onto the secondary O star, has not played an important role in explaining WR+O binaries. Moreover, although it is very likely that the O-type star progenitors were spun up by mass transfer, many ended the RLOF (and mass transfer) phase with a rotational velocity that is significantly smaller than the critical rotation speed. This may indicate that during the mass transfer phase there is a spin-down process that is of the same order, although significantly less, than that of the spin-up process. We propose a Spruit–Tayler type dynamo spin-down suggested in the past to explain the rotation speeds of the mass gainers in long-period Algols.

Published
2018
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21. Mass models of disk galaxies from the DiskMass Survey in MOND

Author

Angus, Garry W., Gentile, Gianfranco, Swaters, Robert A., Famaey, Benoit, Diaferio, Antonaldo, McGaugh, Stacy S., Heyden, Kurt J. van der, Physics, Astrophysics, and Astronomy and Astrophysics Research Group

Subjects
astro-ph.GA, Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics::Galaxy Astrophysics
Abstract

This article explores the agreement between the predictions of Modified Newtonian Dynamics (MOND) and the rotation curves and stellar velocity dispersion profiles measured by the DiskMass Survey. A bulge-disk decomposition was made for each of the thirty published galaxies, and a MOND Poisson solver was used to simultaneously compute, from the baryonic mass distributions, model rotation curves and vertical velocity dispersion profiles, which were compared to the measured values. The two main free parameters, the stellar disk's mass-to-light ratio ($M/L$) and its exponential scale-height ($h_z$), were estimated by Markov Chain Monte Carlo modelling. The average best-fit K-band stellar mass-to-light ratio was $M/L \simeq 0.55 \pm 0.15$. However, to match the DiskMass Survey data, the vertical scale-heights would have to be in the range $h_z=200$ to $400$ pc which is a factor of two lower than those derived from observations of edge-on galaxies with a similar scale-length. The reason is that modified gravity versions of MOND characteristically require a larger $M/L$ to fit the rotation curve in the absence of dark matter and therefore predict a stronger vertical gravitational field than Newtonian models. It was found that changing the MOND acceleration parameter, the shape of the velocity dispersion ellipsoid, the adopted vertical distribution of stars, as well as the galaxy inclination, within any realistic range, all had little impact on these results., Comment: 13 pages, 26 figures, accepted for publication in MNRAS

Published
2015
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22. Measuring a Cherenkov ring in the radio emission from air showers at 110–190 MHz with LOFAR

Author

Aris Karastergiou, Gianni Bernardi, Jörg R. Hörandel, Adam Deller, A. Nelles, A. Horneffer, Jochen Eislöffel, Heino Falcke, Stefan J. Wijnholds, Gottfried Mann, J. E. Enriquez, Maaijke Mevius, B. Ciardi, Ben Stappers, Matthias Steinmetz, C. Tasse, Sarod Yatawatta, Olaf Scholten, Oleg Smirnov, Stijn Buitink, A. G. Polatidis, Arthur Corstanje, E. Juette, Adam Stewart, Christian Vocks, P. Zarka, M. Kuniyoshi, Rene C. Vermeulen, P. Maat, M. J. Norden, Harvey Butcher, Tim Hassall, Dominik J. Schwarz, V. I. Kondratiev, Joel N. Bregman, J. W. Broderick, Marcus Brüggen, M. Pandey-Pommier, George Heald, W. Reich, Michel Tagger, S. Duscha, J. Anderson, R. J. van Weeren, W. N. Brouw, M. van den Akker, G. Pietka, Wilfred Frieswijk, Philip Best, Pim Schellart, Y. Tang, Anna M. M. Scaife, K. D. de Vries, Ashish Asgekar, Martin Bell, S. ter Veen, A. W. Gunst, Marco Iacobelli, M. A. Garrett, G. Kuper, Frank Breitling, Richard Fallows, H. J. A. Röttgering, Mark J. Bentum, Olaf Wucknitz, Michael Kramer, H. Paas, Roberto Pizzo, Satyendra Thoudam, Physics, Elementary Particle Physics, Astronomy and Astrophysics Research Group, Radboud university [Nijmegen], SETI Institute, Netherlands Institute for Radio Astronomy (ASTRON), Max-Planck-Institut für Radioastronomie (MPIFR), Kernfysisch Versneller Instituut, Univ. of Groningen (KVI), University of Groningen [Groningen], Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), University of Southampton, Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, University of Edinburgh, Leibniz-Institut für Astrophysik Potsdam (AIP), Kapteyn Astronomical Institute [Groningen], Jacobs University [Bremen], Max Planck Institute for Astrophysics, Max-Planck-Gesellschaft, Thüringer Landessternwarte Tautenburg (TLS), Institute of Mathematical and Physical Sciences, Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Centre de Mathématiques Laurent Schwartz (CMLS), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Dipartimento di Matematica 'Guido Castelnuovo' [Roma I] (Sapienza University of Rome), Università degli Studi di Roma 'La Sapienza' [Rome], Ruhr-Universität Bochum [Bochum], Oxford Astrophysics, University of Oxford [Oxford], Vrije Universiteit Medical Centre (VUMC), Vrije Universiteit Amsterdam [Amsterdam] (VU), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), School of Physics and Astronomy [Southampton], Interactions Son Musique Mouvement, Sciences et Technologies de la Musique et du Son (STMS), Université Pierre et Marie Curie - Paris 6 (UPMC)-IRCAM-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-IRCAM-Centre National de la Recherche Scientifique (CNRS), Rhodes University, Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH / Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures (DSMZ), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Sun Yat-Sen University (SYSU), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Argelander-Institut für Astronomie (AlfA), Rheinische Friedrich-Wilhelms-Universität Bonn, the Netherlands Research School for Astronomy (NOVA), the Samenwerkingsverband Noord-Nederland (SNN), the Foundation for Fundamental Research on Matter (FOM) and the Netherlands Organization for Scientific Research (NWO), VENI Grant 639-041-130., European Project: 227610,EC:FP7:ERC,ERC-2008-AdG,LOFAR-AUGER(2009), Radboud University [Nijmegen], Harvard University-Smithsonian Institution, Universiteit Leiden, Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA), University of Oxford, École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Rhodes University, Grahamstown, Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Sun Yat-Sen University [Guangzhou] (SYSU), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Research unit Astroparticle Physics, Astronomy, ITA, GBR, FRA, DEU, and NLD

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astronomy, FOS: Physical sciences, Cosmic ray, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Radiation, Radio telescope, Optics, cosmic rays, Extensive air showers, Radio emission, Instrumentation and Methods for Astrophysics (astro-ph.IM), Cherenkov radiation, High Energy Astrophysical Phenomena (astro-ph.HE), Astroparticle physics, Physics, astro-ph.HE, Range (particle radiation), business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Radio emissions, Astronomy and Astrophysics, LOFAR, Time-compression, [SDU]Sciences of the Universe [physics], Experimental High Energy Physics, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, business, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Refractive index, astro-ph.IM
Abstract

Measuring radio emission from air showers offers a novel way to determine properties of the primary cosmic rays such as their mass and energy. Theory predicts that relativistic time compression effects lead to a ring of amplified emission which starts to dominate the emission pattern for frequencies above ~100 MHz. In this article we present the first detailed measurements of this structure. Ring structures in the radio emission of air showers are measured with the LOFAR radio telescope in the frequency range of 110 - 190 MHz. These data are well described by CoREAS simulations. They clearly confirm the importance of including the index of refraction of air as a function of height. Furthermore, the presence of the Cherenkov ring offers the possibility for a geometrical measurement of the depth of shower maximum, which in turn depends on the mass of the primary particle., 20 pages, 10 figures, accpeted for publication in Astroparticle Physics

Published
2015
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23. Large dust grains in the wind of VY Canis Majoris

Author

Nikolai V. Voshchinnikov, Joris Blommaert, Peter Scicluna, Ralf Siebenmorgen, Markus Kasper, Roger Wesson, Sebastian Wolf, Astrophysics, Physics, and Astronomy and Astrophysics Research Group

Subjects
Physics, astrophysics, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, supergiants, Astrophysics, Radius, Astrophysics::Cosmology and Extragalactic Astrophysics, stars: winds, outflows, supergiants, circumstellar matter, stars: individual: VY Canis Majoris, stars: mass-loss, polarization, Interstellar medium, Stars, Supernova, stars : winds, outflows, Astrophysics - Solar and Stellar Astrophysics, Radiation pressure, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, Red supergiant, Ejecta, physics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Envelope (waves)
Abstract

Massive stars live short lives, losing large amounts of mass through their stellar wind. Their mass is a key factor determining how and when they explode as supernovae, enriching the interstellar medium with heavy elements and dust. During the red supergiant phase, mass-loss rates increase prodigiously, but the driving mechanism has proven elusive. Here we present high-contrast optical polarimetric-imaging observations of the extreme red supergiant VY Canis Majoris and its clumpy, dusty, mass-loss envelope, using the new extreme-adaptive-optics instrument SPHERE at the VLT. These observations allow us to make the first direct and unambiguous detection of submicron dust grains in the ejecta; we derive an average grain radius $\sim$ 0.5 $\mu$m, 50 times larger than in the diffuse ISM, large enough to receive significant radiation pressure by photon scattering. We find evidence for varying grain sizes throughout the ejecta, highlighting the dynamical nature of the envelope. Grains with 0.5 $\mu$m sizes are likely to reach a safe distance from the eventual explosion of VY Canis Majoris; hence it may inject upwards of 10$^{-2}$ M$_\odot$ of dust into the ISM., Comment: 5 pages, 3 figures. Accepted as a letter to A&A. Press release available at: http://www.eso.org/public/news/eso1546/

Published
2015
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24. Probing Atmospheric Electric Fields in Thunderstorms through Radio Emission from Cosmic-Ray-Induced Air Showers

Author

A. Alexov, M. Serylak, M. A. Garrett, E. Juette, B. Ciardi, C. Tasse, C. Koehn, M. Kuniyoshi, Dominik J. Schwarz, M. C. Toribio, A. Nelles, F. Breitling, Jean-Mathias Grießmeier, John McKean, John D. Swinbank, Jochen Eislöffel, W. Reich, J. Moldon, Maaijke Mevius, Marcus Brüggen, Casper Rutjes, R. J. van Weeren, Emanuela Orrú, J. W. Broderick, A. G. Polatidis, Rebecca McFadden, D. McKay-Bukowski, E. de Geus, Heino Falcke, M. J. Norden, V. I. Kondratiev, Harvey Butcher, M. Pandey-Pommier, Philip Best, Pim Schellart, Jason W. T. Hessels, Philippe Zarka, S. Duscha, Richard Fallows, Arthur Corstanje, Matthias Steinmetz, H. Paas, Ute Ebert, G. Kuper, Olaf Scholten, H. J. A. Röttgering, Oleg Smirnov, R. Vermeulen, Annalisa Bonafede, Mark J. Bentum, Michel Tagger, Michael W. Wise, Jörg P. Rachen, Gianni Bernardi, Jörg R. Hörandel, H. A. Holties, Olaf Wucknitz, T. N. G. Trinh, J. E. Enriquez, S. ter Veen, A. W. Gunst, M. de Vos, I. M. Avruch, Laura Rossetto, James M. Anderson, Gottfried Mann, Stijn Buitink, Roberto Pizzo, Wilfred Frieswijk, Christian Vocks, Satyendra Thoudam, Anna M. M. Scaife, Matthias Hoeft, George Heald, Department of Astrophysics [Nijmegen], Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud University [Nijmegen]-Radboud University [Nijmegen], KVI Center for Advanced Radiation Technology, University of Groningen [Groningen], Netherlands Institute for Radio Astronomy (ASTRON), Max-Planck-Institut für Radioastronomie (MPIFR), National Institute for Subatomic Physics [Amsterdam] (NIKHEF), Vrije Universiteit Brussel (VUB), Centrum Wiskunde & Informatica (CWI), Space Telescope Science Institute (STSci), GeoForschungsZentrum - Helmholtz-Zentrum Potsdam (GFZ), SRON Netherlands Institute for Space Research (SRON), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University-Smithsonian Institution, Institute for Astronomy [Edinburgh] (IfA), University of Edinburgh, University of Hamburg, Leibniz-Institut für Astrophysik Potsdam (AIP), Oxford Astrophysics, University of Oxford, University of Southampton, Research School of Astronomy and Astrophysics [Canberra] (RSAA), Australian National University (ANU), Max Planck Institute for Astrophysics, Max-Planck-Gesellschaft, Thüringer Landessternwarte Tautenburg (TLS), Unité Scientifique de la Station de Nançay (USN), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Astronomisches Institut der Ruhr-Universität Bochum, Ruhr-Universität Bochum [Bochum], National Astronomical Observatory of Japan (NAOJ), University of Oulu, Center for Information Technology CIT, Université de Groningen, Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Leiden Observatory [Leiden], Universiteit Leiden, Universität Bielefeld = Bielefeld University, SKA South Africa, Ska South Africa, Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), NOVA, SNN and FOM as well as from NWO, VENI Grant No. 639-041-130, European Project: 227610,EC:FP7:ERC,ERC-2008-AdG,LOFAR-AUGER(2009), High Energy Astrophys. & Astropart. Phys (API, FNWI), Schellart, P., Trinh, T.N.G., Buitink, S., Corstanje, A., Enriquez, J.E., Falcke, H., Hörandel, J.R., Nelles, A., Rachen, J.P., Rossetto, L., Scholten, O., Ter Veen, S., Thoudam, S., Ebert, U., Koehn, C., Rutjes, C., Alexov, A., Anderson, J.M., Avruch, I.M., Bentum, M.J., Bernardi, G., Best, P., Bonafede, A., Breitling, F., Broderick, J.W., Brüggen, M., Butcher, H.R., Ciardi, B., De Geus, E., De Vos, M., Duscha, S., Eislöffel, J., Fallows, R.A., Frieswijk, W., Garrett, M.A., Grießmeier, J., Gunst, A.W., Heald, G., Hessels, J.W.T., Hoeft, M., Holties, H.A., Juette, E., Kondratiev, V.I., Kuniyoshi, M., Kuper, G., Mann, G., McFadden, R., McKay-Bukowski, D., McKean, J.P., Mevius, M., Moldon, J., Norden, M.J., Orru, E., Paas, H., Pandey-Pommier, M., Pizzo, R., Polatidis, A.G., Reich, W., Röttgering, H., Scaife, A.M.M., Schwarz, D.J., Serylak, M., Smirnov, O., Steinmetz, M., Swinbank, J., Tagger, M., Tasse, C., Toribio, M.C., Van Weeren, R.J., Vermeulen, R., Vocks, C., Wise, M.W., Wucknitz, O., Zarka, P., Kapteyn Astronomical Institute, Elementary Processes in Gas Discharges, Center for Wireless Technology Eindhoven, Physics, Astronomy and Astrophysics Research Group, Elementary Particle Physics, Multiscale Dynamics, Radboud university [Nijmegen]-Radboud university [Nijmegen], Harvard University [Cambridge]-Smithsonian Institution, University of Oxford [Oxford], Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Universiteit Leiden [Leiden], Fakultät für Physik, Universität Bielefeld, Universität Bielefeld, ITA, GBR, FRA, DEU, and NLD

Subjects
Astronomy, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, General Physics and Astronomy, Cosmic ray, Astrophysics, Neutrino muon pion and other elementary particles, Physics and Astronomy (all), cosmic rays, IR-99169, Atmospheric electricity lightning, Electric field, Extensive air showers, Instrumentation and Methods for Astrophysics (astro-ph.IM), METIS-315601, Physics::Atmospheric and Oceanic Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Earth and Planetary Astrophysics (astro-ph.EP), Astroparticle physics, Physics, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, EWI-26542, LOFAR, Polarization (waves), SIMULATIONS, COREAS, 13. Climate action, Experimental High Energy Physics, Thunderstorm, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, ARRAY, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

We present measurements of radio emission from cosmic ray air showers that took place during thunderstorms. The intensity and polarization patterns of these air showers are radically different from those measured during fair-weather conditions. With the use of a simple two-layer model for the atmospheric electric field, these patterns can be well reproduced by state-of-the-art simulation codes. This in turn provides a novel way to study atmospheric electric fields., 6 pages, 3 figures, accepted for publication in Physical Review Letters

Published
2015
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25. The influence of the atmospheric refractive index on radioXmaxmeasurements of air showers

Author

Arthur Corstanje, Jörg P. Rachen, Jörg R. Hörandel, Olaf Scholten, Satyendra Thoudam, Pim Schellart, Tobias Winchen, Heino Falcke, Anna Nelles, Pragati Mitra, Antonio Bonardi, Stijn Buitink, Katie Mulrey, Sander ter Veen, Laura Rossetto, Gia Trinh, Physics, Astronomy and Astrophysics Research Group, Faculty of Sciences and Bioengineering Sciences, and Research unit Astroparticle Physics

Subjects
Physics, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Astronomy, QC1-999, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Humidity, Physics and Astronomy(all), Atmospheric sciences, 01 natural sciences, Atmosphere, Altitude, 0103 physical sciences, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), 010303 astronomy & astrophysics, Refractive index, Physics::Atmospheric and Oceanic Physics, Sea level, Intensity (heat transfer), Cherenkov radiation, Zenith
Abstract

The refractive index of the atmosphere, which is n ≈ 1:0003 at sea level, varies with altitude and with local temperature, pressure and humidity. When performing radio measurements of air showers, natural variations in n will change the radio lateral intensity distribution, by changing the Cherenkov angle. Using CoREAS simulations, we have evaluated the systematic error on measurements of the shower maximum X max due to variations in n . It was found that a 10% increase in refractivity ( n – 1) leads to an underestimation of X max between 8 and 22 g/cm 2 for proton-induced showers at zenith angles from 15 to 45 degrees, respectively.

Published
2017
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26. Morphology parameters: substructure identification in X-ray galaxy clusters

Author

Chiara Ferrari, Benne W. Holwerda, Kurt van der Heyden, Garry W. Angus, Viral Parekh, Department of Astronomy, Faculty of Science, Physics, Astrophysics, and Astronomy and Astrophysics Research Group

Subjects
Physics, Smoothness (probability theory), galaxies: clusters: intracluster medium, Cosmology and Nongalactic Astrophysics (astro-ph.CO), media_common.quotation_subject, Order (ring theory), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Asymmetry, Redshift, Moment (mathematics), Space and Planetary Science, X-rays: galaxies: clusters, Cluster (physics), astro-ph.CO, Substructure, Galaxy cluster, media_common, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

In recent years multi-wavelength observations have shown the presence of substructures related to merging events in a high fraction of galaxy clusters. Clusters can be roughly grouped into two categories -- relaxed and non-relaxed -- and a proper characterisation of the dynamical state of these systems is of crucial importance both for astrophysical and cosmological studies. In this paper we investigate the use of a number of morphological parameters (Gini, $M_{20}$, Concentration, Asymmetry, Smoothness, Ellipticity and Gini of the second order moment, $G_{M}$) introduced to automatically classify clusters as relaxed or dynamically disturbed systems. We apply our method to a sample of clusters at different redshifts extracted from the {\it Chandra} archive and we investigate possible correlations between morphological parameters and other X-ray gas properties. We conclude that a combination of the adopted parameters is a very useful tool to properly characterise the X-ray cluster morphology. According to our results three parameters -- Gini, $M_{20}$ and Concentration -- are very promising for identifying cluster mergers. The Gini coefficient is a particularly powerful tool, especially at high redshift, being independent from the choice of the position of the cluster centre. We find that high Gini ($>$ 0.65), high Concentration ($>$ 1.55) and low $M_{20}$ ($$ -1.4) characterise dynamically perturbed systems. We also estimate the X-ray cluster morphological parameters in the case of {\it radio loud} clusters. In excellent agreement with previous analyses we confirm that diffuse intracluster radio sources are associated with major mergers., Comment: 31 pages, 20 figures; accepted for publication in A&A

Published
2014
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27. Search for Dark Matter Annihilations in the Sun with the 79-String IceCube Detector

Author

A. O'Murchadha, O. Engdegård, S. Hussain, D. J. Koskinen, Chris Wendt, Elisa Resconi, J. Berdermann, S. Schöneberg, Ignacio Taboada, A. Haj Ismail, J. Blumenthal, M. Wellons, Dariusz Gora, A. Goldschmidt, Peter Mészáros, M. Usner, Olga Botner, R. Bruijn, S. C. Nowicki, Allan Hallgren, C. Finley, K. Frantzen, B. Riedel, S. Schoenen, J. J. Beatty, L. Köpke, J. Auffenberg, A. Obertacke, Hans Niederhausen, M. Merck, A. Bernhard, M. Schmitz, K. Jero, W. Huelsnitz, S. Cohen, N. Kurahashi, K. Mase, Ch. Weaver, S. Bechet, K. Hoshina, J. A. Pepper, D. Heereman, A. Schukraft, O. Fadiran, Gerald Przybylski, H. S. Matis, A. Zilles, J. Posselt, M. Zoll, K. Rawlins, S. Böser, D. Bindig, M. W. E. Smith, K. Helbing, Mike Richman, M. Lesiak-Bzdak, P. Redl, E. A. Strahler, K. Schatto, G. Kohnen, A. Stößl, O. Jlelati, M. Scheel, S. Tilav, M. Krasberg, Glenn Spiczak, U. Naumann, K. H. Becker, Reina H. Maruyama, James Madsen, M. L. Benabderrahmane, M. Kowalski, T. Meures, Rasha Abbasi, R. W. Ellsworth, R. Nahnhauer, J. Miller, M. Vraeghe, Donglian Xu, P. B. Price, Hermann Kolanoski, L. Rädel, T. Ruhe, N. Whitehorn, C. De Clercq, O. Schulz, T. Waldenmaier, Juanan Aguilar, L. Brayeur, M. Soiron, D. Bertrand, J. Casey, Teresa Montaruli, B. Ruzybayev, M. Olivo, S. Yoshida, L. Schönherr, E. Jacobi, R. Ström, M. Wolf, Francis Halzen, P. Zarzhitsky, J. Becker Tjus, C. Pfendner, Christian Spiering, E. Middell, Elisa Bernardini, M. Ribordy, D. Z. Besson, Michael S. Bell, Kirill Filimonov, Markus Ackermann, B. Christy, M. Danninger, L. Paul, A. Tamburro, J. van Santen, A. Van Overloop, M. Casier, L. Schulte, L. Mohrmann, J. Eisch, V. Baum, J. Feintzeig, F. McNally, Christian Bohm, T. Schmidt, C. Pérez de los Heros, N. Pirk, T. Fischer-Wasels, Kael Hanson, Segev BenZvi, Spencer Klein, S. Seunarine, M. J. Carson, Fabian Kislat, J. C. Díaz-Vélez, S. Kopper, M. Baker, J. Lünemann, G. de Vries-Uiterweerd, H. G. Sander, Todor Stanev, Dawn Williams, M. Gurtner, Jenni Adams, K. Beattie, R. C. Bay, Steven W. Barwick, A. Franckowiak, G. C. Hill, Axel Groß, R. Hoffmann, L. Gladstone, F. Clevermann, R. Franke, D. Seckel, S. Miarecki, M. Voge, R. Eagan, H. Taavola, Kara Hoffman, A. H. Cruz Silva, J.-H. Köhne, H. Wissing, A. R. Fazely, Tyce DeYoung, P. A. Toale, T. Feusels, Paolo Desiati, S. Bohaichuk, Y. Sestayo, M. Dunkman, S. Hickford, D. Soldin, C. Kopper, G. Golup, Thomas K. Gaisser, G. B. Yodh, R. G. Stokstad, B. Eberhardt, Xinhua Bai, K. Wiebe, J. P. Yanez, N. van Eijndhoven, R. Morse, Wolfgang Rhode, J. E. Jacobsen, Marcos Santander, J. L. Kelley, E. Blaufuss, J. C. Davis, K. Clark, P. Berghaus, A. Homeier, T. Glüsenkamp, J. Kläs, M. Wallraff, Carsten Rott, Dave Nygren, Jürgen Brunner, P. Heimann, S. Euler, L. Gerhardt, Markus Ahlers, M. Bissok, D. Berley, M. G. Aartsen, J. Kunnen, Christopher Wiebusch, J. Daughhetee, B. Kaminsky, G. Kroll, J. Leute, S. Odrowski, F. Scheriau, Michael Stamatikos, Damian Pieloth, P. O. Hulth, Xianwu Xu, S. Toscano, A. M. Brown, J. A. Goodman, T. Fuchs, J. Ziemann, Albrecht Karle, Samvel Ter-Antonyan, A. Stasik, A. Schönwald, D. Ryckbosch, S. Zierke, G. W. Sullivan, K. Meagher, D. Heinen, S. H. Seo, Aya Ishihara, Darren Grant, Chun Xu, T. Salameh, S. De Ridder, C. Walck, D. Altmann, M. Labare, M. Vehring, D. F. Cowen, C. Ha, Stijn Buitink, C. Sheremata, S. Westerhoff, T. R. Wood, Kurt Woschnagg, Paul Evenson, Dmitry Chirkin, D. Bose, Alexander Kappes, T. Karg, T. Kuwabara, Klas Hultqvist, J. Kiryluk, A. Fedynitch, J. P. Rodrigues, T. Stezelberger, S. M. Saba, R. Hellauer, S. Flis, J. Dreyer, Y. Abdou, Jay Gallagher, M. J. Larson, A. Olivas, D. van der Drift, R. Wasserman, H. Landsman, D. J. Boersma, Subir Sarkar, N. Milke, George Japaridze, Aguilar Sanchez, Juan, Montaruli, Teresa, Physics, Elementary Particle Physics, and Astronomy and Astrophysics Research Group

Subjects
Particle physics, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Dark matter, FOS: Physical sciences, General Physics and Astronomy, Cosmic ray, ddc:500.2, MASSIVE PARTICLES, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 7. Clean energy, 01 natural sciences, IceCube, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), LIMITS, WIMP, 0103 physical sciences, ddc:550, 010306 general physics, Light dark matter, CANDIDATES, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, 010308 nuclear & particles physics, Astrophysics::Instrumentation and Methods for Astrophysics, CONSTRAINTS, CAPTURE, NEUTRINOS, Physics and Astronomy, Neutrino detector, 13. Climate action, Weakly interacting massive particles, High Energy Physics::Experiment, Cryogenic Dark Matter Search, Neutrino, Astrophysics - High Energy Astrophysical Phenomena
Abstract

We have performed a search for muon neutrinos from dark matter annihilation in the center of the Sun with the 79-string configuration of the IceCube neutrino telescope. For the first time, the DeepCore sub-array is included in the analysis, lowering the energy threshold and extending the search to the austral summer. The 317 days of data collected between June 2010 and May 2011 are consistent with the expected background from atmospheric muons and neutrinos. Upper limits are therefore set on the dark matter annihilation rate, with conversions to limits on spin-dependent and spin-independent WIMP-proton cross-sections for WIMP masses in the range 20 - 5000 GeV. These are the most stringent spin-dependent WIMP-proton cross-sections limits to date above 35 GeV., 7 pages, 3 figues

Published
2013
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28. Spatially-resolved dust properties of the GRB 980425 host galaxy

Author

Darach Watson, S. D. Vergani, Stefano Covino, Dong Xu, Silvia Piranomonte, Maarten Baes, J. Juul Rasmussen, Gianfranco Gentile, Andrea Rossi, Eliana Palazzi, Michał J. Michałowski, A. de Ugarte Postigo, Valerio D'Elia, S. Berta, Nial R. Tanvir, E. Le Floc'h, Diego Götz, Patrizia Ferrero, D. Malesani, Leslie K. Hunt, Jesper Sollerman, P. van der Werf, Jens Hjorth, D. Burlon, Sandra Savaglio, Simone Bianchi, J. M. Castro Cerón, D. Le Borgne, M. P. Koprowski, S. Basa, Tara Murphy, Jean-Gabriel Cuby, Elena Pian, Ghent University [Belgium] (UGENT), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), European Project: 322307,EC:FP7:PEOPLE,FP7-PEOPLE-2012-CIG,HETRANSIENTS(2012), Universiteit Gent = Ghent University [Belgium] (UGENT), Astrophysics, Astronomy and Astrophysics Research Group, Universiteit Gent = Ghent University (UGENT), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
HERSCHEL REFERENCE SURVEY, submillimeter: galaxies, galaxies: individual: ESO 184-G82, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Stellar population, MASS-METALLICITY RELATION, Metallicity, Astrophysics::High Energy Astrophysical Phenomena, individual: ESO 184-G82 [galaxies], galaxies [submillimeter], gamma-ray burst: individual: 980425, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, GAMMA-RAY BURST, CORE-COLLAPSE SUPERNOVAE, COMPACT DWARF GALAXIES, STAR-FORMING GALAXIES, Astrophysics::Solar and Stellar Astrophysics, NEARBY GALAXIES, Astrophysics::Galaxy Astrophysics, SPITZER-SPACE-TELESCOPE, Dwarf galaxy, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), GRB 980425, ISM [galaxies], extinction, Star formation, Astronomy and Astrophysics, Atacama Large Millimeter Array, Galaxy, SPECTRAL ENERGY-DISTRIBUTION, Physics and Astronomy, 13. Climate action, Space and Planetary Science, galaxies: star formation, individual: 980425 [gamma-ray burst], LARGE-MAGELLANIC-CLOUD, dust, extinction, dust, Astrophysics::Earth and Planetary Astrophysics, star formation [galaxies], Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Gamma-ray burst, galaxies: ISM, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

Gamma-ray bursts (GRBs) have been proposed as a tool for studying star formation in the Universe, so it is crucial to investigate whether their host galaxies and immediate environments are in any way special compared with other star-forming galaxies. Here we present spatially resolved maps of dust emission of the host galaxy of the closest known GRB 980425 at z=0.0085 using our new high-resolution observations from Herschel, Atacama Pathfinder Experiment (APEX), Atacama Large Millimeter Array (ALMA) and Australia Telescope Compact Array (ATCA). We modelled the spectral energy distributions of the host and of the star-forming region displaying the Wolf-Rayet signatures in the spectrum (WR region), located 800 pc from the GRB position. The host is characterised by low dust content and a high fraction of UV-visible star formation, similar to other dwarf galaxies. These galaxies are abundant in the local universe, so it is not surprising to find a GRB in one of them, assuming the correspondence between the GRB rate and star formation. The WR region contributes substantially to the host emission at the far-infrared, millimetre, and radio wavelengths and we propose that this is a consequence of its high gas density. If dense environments are also found close to the positions of other GRBs, then the ISM density should also be considered, along with metallicity, an important factor influencing whether a given stellar population can produce a GRB., Comment: Accepted by A&A. 14 pages, 7 figures, 2 tables. V2: minor updates to match the published version

Published
2013
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29. POPCORN: A comparison of binary population synthesis codes

Author

Claeys, J.S.W.A., Toonen, S., Mennekens, N., Pugliese, G., Pugliese, G., Physics, Astrophysics, and Astronomy and Astrophysics Research Group

Subjects
binary stars, Astrophysics - Solar and Stellar Astrophysics, Astronomy, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, FOS: Physical sciences, Astronomical Society of the Pacific Conference Series, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

We compare the results of three binary population synthesis codes to understand the differences in their results. As a first result we find that when equalizing the assumptions the results are similar. The main differences arise from deviating physical input., Comment: 2 pages, Proceedings of the conference: "370 Years of Astronomy in Utrecht"

Published
2013

30. Massive double compact object mergers: gravitational wave sources and r-process-element production sites

Author

Dany Vanbeveren, Nicki Mennekens, Physics, Astrophysics, and Astronomy and Astrophysics Research Group

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Population, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Compact star, Galaxy formation and evolution, Astrophysics::Solar and Stellar Astrophysics, education, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Physics, Galaxy: evolution, education.field_of_study, binaries: close, Gravitational wave, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Black hole, stars: massive, Neutron star, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), r-process
Abstract

With our galactic evolutionary code that contains a detailed intermediate mass and massive binary population model, we study the temporal evolution of the galactic population of double neutron star binaries, mixed systems with a neutron star and black hole component and double black hole binaries. We compute the merger rates of these relativistic binaries and we translate them into LIGO II detection rates. We demonstrate that accounting for the uncertainties in the relation 'initial mass-final mass' predicted by massive close binary evolution and due to the possible effect of large stellar wind mass loss during the luminous blue variable phase of a star with initial mass larger than 30-40 Mo and during the red supergiant phase of a star with initial mass smaller than 30-40 Mo when such a star is a binary component, the double black hole merger rate may be very small, contrary to predictions made by other groups. Hydrodynamic computations of r-process chemical yields ejected during the relativistic binary merger process have recently become available. With our galactic code that includes binaries it is then straightforward to calculate the temporal galactic evolution of the r-process elements ejected by these mergers. We conclude that except for the earliest evolutionary phase of the Galaxy (~the first 100 Myr) double compact star mergers may be the major production sites of r-process elements and it is probable that the mixed systems dominate this production over double neutron star binary mergers., Comment: 12 pages, 7 figures, accepted for publication in A&A; accepted version

Published
2013
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31. TheHerschelExploitation of Local Galaxy Andromeda (HELGA)

Author

Maarten Baes, Médéric Boquien, Elmo Tempel, Laure Ciesla, O. Ł. Karczewski, Thomas Jarrett, Joris Verstappen, Walter Kieran Gear, I. De Looze, George J. Bendo, Jacopo Fritz, Matthew Smith, David A. Thilker, Sébastien Viaene, L. Spinoglio, Gianfranco Gentile, Antti Tamm, Luca Cortese, Joris Blommaert, Alessandro Boselli, T. M. Hughes, Astrophysics, Astronomy and Astrophysics Research Group, and Kapteyn Astronomical Institute

Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO), H II REGIONS, Andromeda Galaxy, Stellar mass, INFRARED-EMISSION, media_common.quotation_subject, observational [methods], FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, individual: M 31 [galaxies], Bulge, VIRGO CLUSTER GALAXIES, STAR-FORMING GALAXIES, fundamental parameters [galaxies], Astrophysics::Solar and Stellar Astrophysics, TO-GAS RATIO, Astrophysics::Galaxy Astrophysics, SPITZER-SPACE-TELESCOPE, QB, media_common, infrared: ISM, Physics, ISM [galaxies], extinction, Star formation, ISM [infrared], galaxies: fundamental parameters, Astronomy and Astrophysics, galaxies: individual: M 31, Astrophysics - Astrophysics of Galaxies, Galaxy, Universe, Andromeda, SPECTRAL ENERGY-DISTRIBUTION, Physics and Astronomy, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), MULTIBAND IMAGING PHOTOMETER, DIGITAL SKY SURVEY, Spectral energy distribution, dust, dust, extinction, Astrophysics::Earth and Planetary Astrophysics, methods: observational, NEARBY SPIRAL GALAXIES, galaxies: ISM, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The imprints of dust-starlight interactions are visible in scaling relations between stellar characteristics, star formation parameters and dust properties. We aim to examine dust scaling relations on a sub-kpc resolution in the Andromeda galaxy (M31) by comparing the properties on a local and global scale to other galaxies of the local universe. New Herschel observations are combined with available data from GALEX, SDSS, WISE and Spitzer to construct a dataset covering UV to submm wavelengths. We work at the resolution of the SPIRE $500\; \mu$m beam, with pixels corresponding to physical regions of 137 x 608 pc in the galaxy's disk. A panchromatic spectral energy distribution was modelled for each pixel and several dust scaling relations are investigated. We find, on a sub-kpc scale, strong correlations between $M_d/M_\star$ and NUV-r, and between $M_d/M_\star$ and $\mu_\star$ (the stellar mass surface density). Striking similarities with corresponding relations based on integrated galaxies are found. We decompose M31 in four macro-regions based on their FIR morphology; the bulge, inner disk, star forming ring and the outer disk. All regions closely follow the galaxy-scale average trends. The specific star formation characteristics we derive for these macro-regions give strong hints of an inside-out formation of the bulge-disk geometry, as well as an internal downsizing process. However, within each macro-region, a great diversity in individual micro-regions is found. Furthermore, we confirm that dust in the bulge of M31 is heated only by the old stellar populations. In general, the local dust scaling relations indicate that the dust content in M31 is maintained by a subtle interplay of past and present star formation. The similarity with galaxy-based relations strongly suggests that they are in situ correlations, with underlying processes that must be local in nature. (Abriged), Comment: 23 pages, 12 figures, Published in Astronomy & Astrophysics

Published
2014
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32. DISCOVERY OF A RED QUASAR WITH RECURRENT ACTIVITY

Author

Rupak Roy, D. J. Saikia, Maarten Baes, Mahadev Patgiri, S. Nandi, Gianfranco Gentile, Mahendra Pratap Singh, Ravi Joshi, H. C. Chandola, Astrophysics, and Astronomy and Astrophysics Research Group

Subjects
GALACTIC NUCLEI, Cosmology and Nongalactic Astrophysics (astro-ph.CO), IMAGES, Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, galaxies: active, nuclei [galaxies], FOS: Physical sciences, DUST, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Spectral line, DOUBLE RADIO GALAXIES, Radio telescope, OPTICAL MICROVARIABILITY, Astrophysics::Solar and Stellar Astrophysics, Emission spectrum, BLACK-HOLES, Astrophysics::Galaxy Astrophysics, media_common, High Energy Astrophysical Phenomena (astro-ph.HE), radio continuum: galaxies, Physics, Giant Metrewave Radio Telescope, Line-of-sight, individual (J0746+4526) [galaxies], Astronomy and Astrophysics, Quasar, 1ST SURVEY, Astrophysics - Astrophysics of Galaxies, galaxies [radio continuum], Galaxy, Physics and Astronomy, Space and Planetary Science, Sky, REDSHIFT QUASARS, Astrophysics of Galaxies (astro-ph.GA), active [galaxies], LUMINOSITY, galaxies: nuclei, EMISSION, galaxies: individual (J0746+4526), Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We report a new double-double radio quasar, DDRQ, J0746$+$4526 which exhibits two cycles of episodic activity. From radio continuum observations at 607 MHz using the GMRT and 1400 MHz from the FIRST survey we confirm its episodic nature. We examine the SDSS optical spectrum and estimate the black hole mass to be (8.2$\pm$0.3)$\times$10$^7$M$_\odot$ from its observed MgII emission line, and the Eddington ratio to be 0.03. The black hole mass is significantly smaller than for the other reported DDRQ, J0935+0204, while the Eddington ratios are comparable. The SDSS spectrum is significantly red continuum dominated suggesting that it is highly obscured with ${E(B-V)}_{host}=0.70\pm0.16$ mag. This high obscuration further indicates the existence of a large quantity of dust and gas along the line of sight, which may have a key role in triggering the recurrent jet activity in such objects., 5 pages, 3 figures, 1 table. Accepted for publication in ApJ

Published
2014
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33. Dusty shells surrounding the carbon variables S Scuti and RT Capricorni

Author

A. Mayer, M. Mecina, A. Luntzer, Leen Decin, C. Waelkens, Franz Kerschbaum, Bart Vandenbussche, Joris Blommaert, Martin Groenewegen, Roland Ottensamer, Th. Posch, Astrophysics, and Astronomy and Astrophysics Research Group

Subjects
Shell (structure), FOS: Physical sciences, stars: individual: RT Cap, stars: AGB and post-AGB, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, individual: RT Cap [stars], Radiative transfer, Astrophysics::Solar and Stellar Astrophysics, Asymptotic giant branch, Red supergiant, infrared: stars, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Physics, carbon [stars], stars [infrared], mass-loss [stars], Astronomy and Astrophysics, AGB and post-AGB [stars], Interstellar medium, stars: carbon, Wavelength, Stars, Astrophysics - Solar and Stellar Astrophysics, individual: S Sct [stars], 13. Climate action, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Circular symmetry, stars: mass-loss, stars: individual: S Sct
Abstract

For the Mass-loss of Evolved StarS (MESS) programme, the unprecedented spatial resolution of the PACS photometer on board the Herschel Space Observatory was employed to map the dusty environments of asymptotic giant branch (AGB) and red supergiant (RSG) stars. Among the morphologically heterogeneous sample, a small fraction of targets is enclosed by spherically symmetric detached envelopes. Based on observations in the 70 μm and 160 μm wavelength bands, we investigated the surroundings of the two carbon semiregular variables S Sct and RT Cap, which both show evidence for a history of highly variable mass-loss. S Sct exhibits a bright, spherically symmetric detached shell, 138″ in diameter and co-spatial with an already known CO structure. Moreover, weak emission is detected at the outskirts, where the morphology seems indicative of a mild shaping by interaction of the wind with the interstellar medium, which is also supported by the stellar space motion. Two shells are found around RT Cap that were not known so far in either dust emission or from molecular line observations. The inner shell with a diameter of 188″ shows an almost immaculate spherical symmetry, while the outer ~5′ structure is more irregularly shaped. MoD, a modification of the DUSTY radiative transfer code, was used to model the detached shells. Dust temperatures, shell dust masses, and mass-loss rates are derived for both targets. © ESO, 2014. keywords: stars: AGB and post-AGB, stars: carbon, stars: mass-loss, infrared: stars, stars: individual: S Sct, stars: individual: RT Cap, Astrophysics - Solar and Stellar Astrophysics eid: A69 adsurl: https://ui.adsabs.harvard.edu/#abs/2014A&A...566A..69M adsnote: Provided by the SAO/NASA Astrophysics Data System ispartof: ASTRONOMY & ASTROPHYSICS vol:566 status: published

Published
2014
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34. The debris disc of solar analogue τ Ceti: Herschel observations and dynamical simulations of the proposed multiplanet system

Author

Joris Blommaert, Physics, Astrophysics, and Astronomy and Astrophysics Research Group

Subjects
Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, circumstellar matter, Astrophysics::Galaxy Astrophysics
Abstract

Ceti is a nearby, mature G-type star very similar to our Sun, with a massive Kuiper Belt analogue and possible multiplanet system that has been compared to our Solar system. We present Herschel Space Observatory images of the debris disc, finding the disc is resolved at 70??m and 160??m, and marginally resolved at 250??m. The Herschel images and infrared photometry from the literature are best modelled using a wide dust annulus with an inner edge between 1 and 10 au and an outer edge at ?55 au, inclined from face-on by 35° ± 10°, and with no significant azimuthal structure. We model the proposed tightly packed planetary system of five super-Earths and find that the innermost dynamically stable disc orbits are consistent with the inner edge found by the observations. The photometric modelling, however, cannot rule out a disc inner edge as close to the star as 1 au, though larger distances produce a better fit to the data. Dynamical modelling shows that the five-planet system is stable with the addition of a Neptune or smaller mass planet on an orbit outside 5 au, where the radial velocity data analysis would not have detected a planet of this mass.

35. The problematically short superwind of OH/IR stars. Probing the outflow with the 69 micrometer spectral band of forsterite

Author

Joris Blommaert, Physics, Astrophysics, and Astronomy and Astrophysics Research Group

Subjects
Radiative transfer
Abstract

Aims. Spectra of OH/IR stars show prominent spectral bands of crystalline olivine (Mg(2-2x)Fe(2x)SiO4). To learn more about the timescale of the outflows of OH/IR stars, we study the spectral band of crystalline olivine at 69 mircometer. Methods. The 69 micrometer band is of interest because its width and peak wavelength position are sensitive to the grain temperature and to the exact composition of the crystalline olivine. With Herschel/PACS, we observed the 69 ?m band in the outflow of 14 OH/IR stars. By comparing the crystalline olivine features of our sample with those of model spectra, we determined the size of the outflow and its crystalline olivine abundance. Results. The temperature indicated by the observed 69 micrometer bands can only be reproduced by models with a geometrically compact superwind (RSW

36. Infrared spectoscopy of asymptotic giant branch stars in the Galactic bulge

Author

Joris Blommaert, Physics, Astrophysics, and Astronomy and Astrophysics Research Group

Subjects
Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, circumstellar matter, Astrophysics::Galaxy Astrophysics
Abstract

We have selected a homogeneous sample of asymptotic giant branch (AGB) stars in the Galactic bulge population from the ISOGAL survey. Our target stars cover a wide range of mass-loss rates (?10?8-10?4 M? yr?1) and differ primarily by their age on the AGB. This homogeneous sample is thus ideally suited to study the dust formation process as a function of age on the AGB. We observed our sample with Spitzer-Infrared Spectrograph, and studied the overall properties of the infrared spectra of these targets. The analysis is complicated by the presence of strong and variable background emission, and the extracted infrared AGB star spectra are affected by interstellar extinction. Several stars in our sample have no detectable dust emission, and we used these 'naked stars' to characterize the stellar and molecular contributions to the infrared spectra of our target stars. The resulting dust spectra of our targets do indeed show significant variety in their spectral appearance, pointing to differing dust compositions for the targets. We classify the spectra based on the shape of their 10-?m emission following the scheme by Sloan & Price. We find that the early silicate emission classes associated with oxide dust are generally under-represented in our sample due to extinction effects. We also find a weak 13-?m dust feature in two of our otherwise naked star spectra, suggesting that the carrier of this feature could potentially be the first condensate in the sequence of dust condensation.

37. Searches for high-energy neutrino emission in the Galaxy with the combined IceCube-AMANDA detector

Author

IceCube Collaboration, Debanjan Bose, Lionel Brayeur, Stijn Buitink, Martin Casier, Catherine De Clercq, Jan Kunnen, Mathieu Labare, Jonathan Miller, Erik Strahler, Nick van Eijndhoven, Physics, Elementary Particle Physics, and Astronomy and Astrophysics Research Group

Subjects
Astrophysics::High Energy Astrophysical Phenomena, High Energy Physics::Experiment, Astrophysics::Galaxy Astrophysics, IceCube
Abstract

We report on searches for neutrino sources at energies above 200 GeV in the Northern sky of the galactic plane, using the data collected by the South Pole neutrino telescopes IceCube and AMANDA. The galactic region considered here includes the Local Arm towards the Cygnus region and our closest approach to the Perseus Arm. The data have been collected between 2007 and 2009 when AMANDA was an integrated part of IceCube, which was still under construction and operated with 22-strings (2007-8) and 40-strings (2008-9) of optical modules deployed in the ice. By combining the larger IceCube detector with the lower energy threshold of the more compact AMANDA detector, we obtain an improved sensitivity at energies below ?10 TeV with respect to previous searches. The analyses presented here are: a scan for point sources within the galactic plane/ a search optimized for multiple and extended sources in the Cygnus region, which might be below the sensitivity of the point source scan/ and studies of seven pre-selected neutrino source candidates. For one of them, Cygnus X-3, a time-dependent search for neutrinos in coincidence with observed radio and X-ray flares has been performed. No evidence of a signal is found, and upper limits are reported for each of the searches. We investigate neutrino spectra proportional to E?2 and E?3 to cover the entire range of possible spectra. The soft E?3 spectrum results in an energy distribution similar to a source with cut-off below ?50 TeV. For the considered region of the galactic plane, the 90% confidence level muon neutrino flux upper limits are in the range E3dN/dE?5.4?19.5×10?11TeV2cm?2s?1 for point-like neutrino sources in the energy region [180.0 GeV - 20.5 TeV]. These represent the most stringent upper limits for soft-spectra neutrino sources within the Galaxy reported to date.

38. Carbon Monoxide in the Cold Debris of Supernova 1987A

Author

Joris Blommaert, Physics, Astrophysics, and Astronomy and Astrophysics Research Group

Subjects
ISM : supernova remnants
Abstract

We report spectroscopic and imaging observations of rotational transitions of cold CO and SiO in the ejecta of SN1987A, the first such emission detected in a supernova remnant. In addition to line luminosities for the CO J = 1-0, 2-1, 6-5, and 7-6 transitions, we present upper limits for all other transitions up to J = 13-12, collectively measured from the Atacama Large Millimeter Array, the Atacama Pathfinder EXperiment, and the Herschel Spectral and Photometric Imaging REceiver. Simple models show the lines are emitted from at least 0.01 M ? of CO at a temperature >14 K, confined within at most 35% of a spherical volume expanding at ~2000 km s-1. Moreover, we locate the emission within 1'' of the central debris. These observations, along with a partial observation of SiO, confirm the presence of cold molecular gas within supernova remnants and provide insight into the physical conditions and chemical processes in the ejecta. Furthermore, we demonstrate the powerful new window into supernova ejecta offered by submillimeter observations.

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