Heino Falcke - Department of Astrophysics/IMAPP Radboud University Nijmegen The Netherlands

Heino Falcke
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Name
Heino Falcke
Affiliation
Department of Astrophysics/IMAPP Radboud University Nijmegen The Netherlands
City
Nijmegen
Country
Netherlands

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High Energy Astrophysical Phenomena (38)
 
Astrophysics of Galaxies (16)
 
Instrumentation and Methods for Astrophysics (15)
 
Cosmology and Nongalactic Astrophysics (13)
 
General Relativity and Quantum Cosmology (4)
 
High Energy Physics - Experiment (3)
 
Solar and Stellar Astrophysics (2)
 
Physics - Classical Physics (1)
 
Earth and Planetary Astrophysics (1)

Publications Authored By Heino Falcke

Non-VLBI measurements of Faraday rotation at mm wavelengths have been used to constrain mass accretion rates ($\mdot$) onto supermassive black holes in the centre of the Milky Way and in the centre of M87. We constructed general relativistic magnetohydrodynamics models for these sources that qualitatively well describe their spectra and radio/mm images invoking a coupled jet-disk system. Using general relativistic polarized radiative transfer, we now also model the observed mm rotation measure (RM) of M87. Read More

2017Jan
Affiliations: 1Department of Astrophysics/IMAPP, Radboud University, Nijmegen, The Netherlands, 2Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, USA, 3Leiden Observatory, Leiden University, Leiden, The Netherlands, 4Department of Astrophysics/IMAPP, Radboud University, Nijmegen, The Netherlands, 5FÖMI Satellite Geodetic Observatory, Budapest, Hungary, 6Department of Astrophysics/IMAPP, Radboud University, Nijmegen, The Netherlands, 7Department of Astrophysics/IMAPP, Radboud University, Nijmegen, The Netherlands, 8School of Physics, Astronomy and Mathematics, University of Hertfordshire, Hatfield, UK, 9Department of Astrophysics/IMAPP, Radboud University, Nijmegen, The Netherlands, 10Department of Astrophysics/IMAPP, Radboud University, Nijmegen, The Netherlands, 11Netherlands Institute for Radio Astronomy, 12Joint Institute for VLBI ERIC, Dwingeloo, The Netherlands, and, 13FÖMI Satellite Geodetic Observatory, Budapest, Hungary

High-redshift quasars are important to study galaxy and active galactic nuclei (AGN) evolution, test cosmological models, and study supermassive black hole growth. Optical searches for high-redshift sources have been very successful, but radio searches are not hampered by dust obscuration and should be more effective at finding sources at even higher redshifts. Identifying high-redshift sources based on radio data is, however, not trivial. Read More

We present the black hole accretion code (BHAC), a new multidimensional general-relativistic magnetohydrodynamics module for the MPI-AMRVAC framework. BHAC has been designed to solve the equations of ideal general-relativistic magnetohydrodynamics in arbitrary spacetimes and exploits adaptive mesh refinement techniques with an efficient block-based approach. Several spacetimes have already been implemented and tested. Read More

Compact radio cores associated with relativistic jets are often observed in both active galactic nuclei and X-ray binaries. Their radiative properties follow some general scaling laws which primarily depend on their masses and accretion rates. However, it has been suggested that the black hole spin can also strongly influence the power and radio flux of these. Read More

2016Sep
Affiliations: 1Department of Astrophysics/IMAPP, Radboud University, The Netherlands, 2FÖMI Satellite Geodetic Observatory, Hungary, 3Department of Astrophysics/IMAPP, Radboud University, The Netherlands, 4Department of Astrophysics/IMAPP, Radboud University, The Netherlands, 5Joint Institute for VLBI ERIC, The Netherlands, 6Department of Astrophysics/IMAPP, Radboud University, The Netherlands, 7FÖMI Satellite Geodetic Observatory, Hungary, 8Joint Institute for VLBI ERIC, The Netherlands, 9Shanghai Astronomical Observatory, Chinese Academy of Sciences, P. R. China, 10Geoscience Australia, Australia

High-redshift radio-loud quasars are used to, among other things, test the predictions of cosmological models, set constraints on black hole growth in the early universe and understand galaxy evolution. Prior to this paper, 20 extragalactic radio sources at redshifts above 4.5 have been imaged with very long baseline interferometry (VLBI). Read More

As of 2023, the low-frequency part of the Square Kilometre Array will go online in Australia. It will constitute the largest and most powerful low-frequency radio-astronomical observatory to date, and will facilitate a rich science programme in astronomy and astrophysics. With modest engineering changes, it will also be able to measure cosmic rays via the radio emission from extensive air showers. Read More

We present the results of a closure phase analysis of 3 mm very long baseline interferometry (VLBI) measurements performed on Sagittarius A* (Sgr A*). We have analyzed observations made in May 2015 using the Very Long Baseline Array, the Robert C. Byrd Green Bank Telescope and the Large Millimeter Telescope Alfonso Serrano and obtained non-zero closure phase measurements on several station triangles - indicative of a non-point-symmetric source structure. Read More

The lunar Askaryan technique is a method to study the highest-energy cosmic rays, and their predicted counterparts, the ultra-high-energy neutrinos. By observing the Moon with a radio telescope, and searching for the characteristic nanosecond-scale Askaryan pulses emitted when a high-energy particle interacts in the outer layers of the Moon, the visible lunar surface can be used as a detection area. Several previous experiments, at Parkes, Goldstone, Kalyazin, Westerbork, the ATCA, Lovell, LOFAR, and the VLA, have developed the necessary techniques to search for these pulses, but existing instruments have lacked the necessary sensitivity to detect the known flux of cosmic rays from such a distance. Read More

Blazar radiation is dominated by a relativistic jet which can be modeled at first approximation using just two intrinsic parameters - the Lorentz factor $\Gamma$ and the viewing angle $\theta$. Blazar jet observations are often beamed due to relativistic effects, complicating the understanding of these intrinsic properties. The most common way to estimate blazar Lorentz factors needs the estimation of apparent jet speeds and Doppler beaming factors. Read More

Our aim is to characterize the polarized continuum emission properties including intensity, polarization position angle, and polarization percentage of Sgr A* at $\sim$100 (3.0 mm), $\sim$230 (1.3 mm), $\sim$345 (0. Read More

2016May
Authors: The Pierre Auger Collaboration, Alexander Aab, Pedro Abreu, Marco Aglietta, Eun-Joo Ahn, Imen Al Samarai, Ivone Albuquerque, Ingomar Allekotte, Patrick Allison, Alejandro Almela, Jesus Alvarez Castillo, Jaime Alvarez-Muñiz, Rafael Alves Batista, Michelangelo Ambrosio, Amin Aminaei, Gioacchino Alex Anastasi, Luis Anchordoqui, Sofia Andringa, Carla Aramo, Fernando Arqueros, Nicusor Arsene, Hernán Gonzalo Asorey, Pedro Assis, Julien Aublin, Gualberto Avila, Nafiun Awal, Alina Mihaela Badescu, Colin Baus, Jim Beatty, Karl Heinz Becker, Jose A. Bellido, Corinne Berat, Mario Edoardo Bertaina, Xavier Bertou, Peter Biermann, Pierre Billoir, Simon G. Blaess, Alberto Blanco, Miguel Blanco, Jiri Blazek, Carla Bleve, Hans Blümer, Martina Boháčová, Denise Boncioli, Carla Bonifazi, Nataliia Borodai, Jeffrey Brack, Iliana Brancus, Thomas Bretz, Ariel Bridgeman, Pedro Brogueira, Peter Buchholz, Antonio Bueno, Stijn Buitink, Mario Buscemi, Karen S. Caballero-Mora, Barbara Caccianiga, Lorenzo Caccianiga, Marina Candusso, Laurentiu Caramete, Rossella Caruso, Antonella Castellina, Gabriella Cataldi, Lorenzo Cazon, Rosanna Cester, Alan G. Chavez, Andrea Chiavassa, Jose Augusto Chinellato, Jiri Chudoba, Marco Cilmo, Roger W Clay, Giuseppe Cocciolo, Roberta Colalillo, Alan Coleman, Laura Collica, Maria Rita Coluccia, Ruben Conceição, Fernando Contreras, Mathew J. Cooper, Alain Cordier, Stephane Coutu, Corbin Covault, James Cronin, Richard Dallier, Bruno Daniel, Sergio Dasso, Kai Daumiller, Bruce R. Dawson, Rogerio M. de Almeida, Sijbrand J. de Jong, Giuseppe De Mauro, Joao de Mello Neto, Ivan De Mitri, Jaime de Oliveira, Vitor de Souza, Luis del Peral, Olivier Deligny, Niraj Dhital, Claudio Di Giulio, Armando Di Matteo, Johana Chirinos Diaz, Mary Lucia Díaz Castro, Francisco Diogo, Carola Dobrigkeit, Wendy Docters, Juan Carlos D'Olivo, Alexei Dorofeev, Qader Dorosti Hasankiadeh, Rita dos Anjos, Maria Teresa Dova, Jan Ebr, Ralph Engel, Martin Erdmann, Mona Erfani, Carlos O. Escobar, Joao Espadanal, Alberto Etchegoyen, Heino Falcke, Ke Fang, Glennys Farrar, Anderson Fauth, Norberto Fazzini, Andrew P. Ferguson, Brian Fick, Juan Manuel Figueira, Alberto Filevich, Andrej Filipčič, Octavian Fratu, Martín Miguel Freire, Toshihiro Fujii, Beatriz García, Diego Garcia-Gamez, Diego Garcia-Pinto, Florian Gate, Hartmut Gemmeke, Alexandru Gherghel-Lascu, Piera Luisa Ghia, Ugo Giaccari, Marco Giammarchi, Maria Giller, Dariusz Głas, Christian Glaser, Henry Glass, Geraldina Golup, Mariano Gómez Berisso, Primo F. Gómez Vitale, Nicolás González, Ben Gookin, Jacob Gordon, Alessio Gorgi, Peter Gorham, Philippe Gouffon, Nathan Griffith, Aurelio Grillo, Trent D. Grubb, Fausto Guarino, Germano Guedes, Matías Rolf Hampel, Patricia Hansen, Diego Harari, Thomas A. Harrison, Sebastian Hartmann, John Harton, Andreas Haungs, Thomas Hebbeker, Dieter Heck, Philipp Heimann, Alexander E. Herve, Gary C. Hill, Carlos Hojvat, Nicholas Hollon, Ewa Holt, Piotr Homola, Jörg Hörandel, Pavel Horvath, Miroslav Hrabovský, Daniel Huber, Tim Huege, Antonio Insolia, Paula Gina Isar, Ingolf Jandt, Stefan Jansen, Cecilia Jarne, Jeffrey A. Johnsen, Mariela Josebachuili, Alex Kääpä, Olga Kambeitz, Karl Heinz Kampert, Peter Kasper, Igor Katkov, Bianca Keilhauer, Ernesto Kemp, Roger Kieckhafer, Hans Klages, Matthias Kleifges, Jonny Kleinfeller, Raphael Krause, Nicole Krohm, Daniel Kuempel, Gasper Kukec Mezek, Norbert Kunka, Alaa Metwaly Kuotb Awad, Danielle LaHurd, Luca Latronico, Robert Lauer, Markus Lauscher, Pascal Lautridou, Sandra Le Coz, Didier Lebrun, Paul Lebrun, Marcelo Augusto Leigui de Oliveira, Antoine Letessier-Selvon, Isabelle Lhenry-Yvon, Katrin Link, Luis Lopes, Rebeca López, Aida López Casado, Karim Louedec, Agustin Lucero, Max Malacari, Manuela Mallamaci, Jennifer Maller, Dusan Mandat, Paul Mantsch, Analisa Mariazzi, Vincent Marin, Ioana Mariş, Giovanni Marsella, Daniele Martello, Humberto Martinez, Oscar Martínez Bravo, Diane Martraire, Jimmy Masías Meza, Hermann-Josef Mathes, Sebastian Mathys, James Matthews, John Matthews, Giorgio Matthiae, Daniela Maurizio, Eric Mayotte, Peter Mazur, Carlos Medina, Gustavo Medina-Tanco, Rebecca Meissner, Victor Mello, Diego Melo, Alexander Menshikov, Stefano Messina, Maria Isabel Micheletti, Lukas Middendorf, Ignacio A. Minaya, Lino Miramonti, Bogdan Mitrica, Laura Molina-Bueno, Silvia Mollerach, François Montanet, Carlo Morello, Miguel Mostafá, Celio A. Moura, Marcio Aparecido Muller, Gero Müller, Sarah Müller, Sergio Navas, Petr Necesal, Lukas Nellen, Anna Nelles, Jens Neuser, Phong H. Nguyen, Mihai Niculescu-Oglinzanu, Marcus Niechciol, Lukas Niemietz, Tim Niggemann, Dave Nitz, Dalibor Nosek, Vladimir Novotny, Lyberis Nožka, Luis Núñez, Livingstone Ochilo, Foteini Oikonomou, Angela Olinto, Noelia Pacheco, Daniel Pakk Selmi-Dei, Miroslav Palatka, Juan Pallotta, Philipp Papenbreer, Gonzalo Parente, Alejandra Parra, Thomas Paul, Miroslav Pech, Jan Pękala, Rodrigo Pelayo, Iuri Pepe, Lorenzo Perrone, Emily Petermann, Christine Peters, Sergio Petrera, Yevgeniy Petrov, Jamyang Phuntsok, Ricardo Piegaia, Tanguy Pierog, Pablo Pieroni, Mário Pimenta, Valerio Pirronello, Manuel Platino, Matthias Plum, Alessio Porcelli, Czeslaw Porowski, Raul Ribeiro Prado, Paolo Privitera, Michael Prouza, Eduardo J Quel, Sven Querchfeld, Sean Quinn, Julian Rautenberg, Olivier Ravel, Diego Ravignani, Darius Reinert, Benoît Revenu, Jan Ridky, Markus Risse, Pablo Ristori, Vincenzo Rizi, Washington Rodrigues de Carvalho, Jorge Rubén Rodriguez Rojo, Maria Dolores Rodríguez-Frías, Dmytro Rogozin, Jaime Rosado, Markus Roth, Esteban Roulet, Adrian Rovero, Steven J. Saffi, Alexandra Saftoiu, Humberto Salazar, Ahmed Saleh, Francisco Salesa Greus, Gaetano Salina, Jose Sanabria Gomez, Federico Sánchez, Patricia Sanchez-Lucas, Edivaldo Moura Santos, Eva Santos, Fred Sarazin, Biswaijt Sarkar, Raul Sarmento, Christian Sarmiento-Cano, Ricardo Sato, Carlos Scarso, Markus Schauer, Viviana Scherini, Harald Schieler, David Schmidt, Olaf Scholten, Harm Schoorlemmer, Petr Schovánek, Frank G. Schröder, Alexander Schulz, Johannes Schulz, Johannes Schumacher, Sergio Sciutto, Alberto Segreto, Mariangela Settimo, Amir Shadkam, Ronald C. Shellard, Guenter Sigl, Octavian Sima, Andrzej Śmiałkowski, Radomir Šmída, Gregory Snow, Paul Sommers, Sebastian Sonntag, J. Sorokin, Ruben Squartini, Yogendra N. Srivastava, Denis Stanca, Samo Stanič, James Stapleton, Jaroslaw Stasielak, Maurice Stephan, Anne Stutz, Federico Suarez, Mauricio Suarez Durán, Tiina Suomijärvi, A. Daniel Supanitsky, Michael Sutherland, John Swain, Zbigniew Szadkowski, Oscar Alejandro Taborda, Alex Tapia, Andreas Tepe, Vanessa Menezes Theodoro, Charles Timmermans, Carlos J. Todero Peixoto, Gabriel Toma, Lenka Tomankova, Bernardo Tomé, Aurelio Tonachini, Guillermo Torralba Elipe, Diego Torres Machado, Petr Travnicek, Marta Trini, Ralf Ulrich, Michael Unger, Martin Urban, Jose F. Valdés Galicia, Ines Valiño, Laura Valore, Guus van Aar, Patrick van Bodegom, Ad M. van den Berg, Sjoert van Velzen, Arjen van Vliet, Enrique Varela, Bernardo Vargas Cárdenas, Gary Varner, Rafael Vasquez, Jose R. Vázquez, Ricardo Vázquez, Darko Veberič, Valerio Verzi, Jakub Vicha, Mariela Videla, Luis Villaseñor, Brian Vlcek, Serguei Vorobiov, Hernan Wahlberg, Oscar Wainberg, David Walz, Alan Watson, Marc Weber, Klaus Weidenhaupt, Andreas Weindl, Christoph Welling, Felix Werner, Allan Widom, Lawrence Wiencke, Henryk Wilczyński, Tobias Winchen, David Wittkowski, Brian Wundheiler, Sarka Wykes, Lili Yang, Tolga Yapici, Alexey Yushkov, Enrique Zas, Danilo Zavrtanik, Marko Zavrtanik, Arnulfo Zepeda, Benedikt Zimmermann, Michael Ziolkowski, Francesca Zuccarello

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0. Read More

We report linearly polarized continuum emission properties of Sgr A* at $\sim$492 GHz, based on the Atacama Large Millimeter Array (ALMA) observations. We used the observations of the likely unpolarized continuum emission of Titan, and the observations of C\textsc{i} line emission, to gauge the degree of spurious polarization. The Stokes I flux of 3. Read More

2016Apr
Affiliations: 1Department of Astrophysics/IMAPP, Radboud University Nijmegen, 2Department of Astrophysics/IMAPP, Radboud University Nijmegen, 3Department of Physics and Astronomy, The Johns Hopkins University, 4Department of Astrophysics/IMAPP, Radboud University Nijmegen, 5Leiden Observatory, Leiden University, 6Joint Institute for VLBI ERIC, 7Department of Astrophysics/IMAPP, Radboud University Nijmegen, 8School of Physics, Astronomy and Mathematics, University of Hertfordshire, 9FOMI Satellite Geodetic Observatory, 10Joint Institute for VLBI ERIC, 11Department of Astrophysics/IMAPP, Radboud University Nijmegen

Megahertz peaked-spectrum (MPS) sources have spectra that peak at frequencies below 1 GHz in the observer's frame and are believed to be radio-loud active galactic nuclei (AGN). We recently presented a new method to search for high-redshift AGN by identifying unusually compact MPS sources. In this paper, we present European VLBI Network (EVN) observations of 11 MPS sources which we use to determine their sizes and investigate the nature of the sources with ~10 mas resolution. Read More

The Galactic Center black hole Sagittarius A* (Sgr A*) is a prime observing target for the Event Horizon Telescope (EHT), which can resolve the 1.3 mm emission from this source on angular scales comparable to that of the general relativistic shadow. Previous EHT observations have used visibility amplitudes to infer the morphology of the millimeter-wavelength emission. Read More

2015Dec
Affiliations: 1MIT Haystack Observatory, 2Radboud University, 3MIT Haystack Observatory, 4University of Illinois, Urbana-Champaign, 5MIT Haystack Observatory, 6University of Illinois, Urbana-Champaign, 7Radboud University, 8MPIfR, 9MPIfR

The black hole in the center of the Galaxy, associated with the compact source Sagittarius A* (Sgr A*), is predicted to cast a shadow upon the emission of the surrounding plasma flow, which encodes the influence of general relativity in the strong-field regime. The Event Horizon Telescope (EHT) is a Very Long Baseline Interferometry (VLBI) network with a goal of imaging nearby supermassive black holes (in particular Sgr A* and M87) with angular resolution sufficient to observe strong gravity effects near the event horizon. General relativistic magnetohydrodynamic (GRMHD) simulations show that radio emission from Sgr A* exhibits vari- ability on timescales of minutes, much shorter than the duration of a typical VLBI imaging experiment, which usually takes several hours. Read More

(abridged) The connection between black hole, accretion disk, and radio jet can be best constrained by fitting models to observations of nearby low luminosity galactic nuclei, in particular the well studied sources Sgr~A* and M87. There has been considerable progress in modeling the central engine of active galactic nuclei by an accreting supermassive black hole coupled to a relativistic plasma jet. However, can a single model be applied to a range of black hole masses and accretion rates? Here we want to compare the latest three-dimensional numerical model, originally developed for Sgr A* in the center of the Milky Way, to radio observations of the much more powerful and more massive black hole in M87. Read More

2015Aug
Authors: The Pierre Auger Collaboration, Alexander Aab, Pedro Abreu, Marco Aglietta, Eun-Joo Ahn, Imen Al Samarai, Ivone Albuquerque, Ingomar Allekotte, Patrick Allison, Alejandro Almela, Jesus Alvarez Castillo, Jaime Alvarez-Muñiz, Rafael Alves Batista, Michelangelo Ambrosio, Amin Aminaei, Gioacchino Alex Anastasi, Luis Anchordoqui, Sofia Andringa, Carla Aramo, Fernando Arqueros, Nicusor Arsene, Hernán Gonzalo Asorey, Pedro Assis, Julien Aublin, Gualberto Avila, Nafiun Awal, Alina Mihaela Badescu, Colin Baus, Jim Beatty, Karl Heinz Becker, Jose A. Bellido, Corinne Berat, Mario Edoardo Bertaina, Xavier Bertou, Peter Biermann, Pierre Billoir, Simon G. Blaess, Alberto Blanco, Miguel Blanco, Jiri Blazek, Carla Bleve, Hans Blümer, Martina Boháčová, Denise Boncioli, Carla Bonifazi, Nataliia Borodai, Jeffrey Brack, Iliana Brancus, Thomas Bretz, Ariel Bridgeman, Pedro Brogueira, Peter Buchholz, Antonio Bueno, Stijn Buitink, Mario Buscemi, Karen S. Caballero-Mora, Barbara Caccianiga, Lorenzo Caccianiga, Marina Candusso, Laurentiu Caramete, Rossella Caruso, Antonella Castellina, Gabriella Cataldi, Lorenzo Cazon, Rosanna Cester, Alan G. Chavez, Andrea Chiavassa, Jose Augusto Chinellato, Jiri Chudoba, Marco Cilmo, Roger W Clay, Giuseppe Cocciolo, Roberta Colalillo, Alan Coleman, Laura Collica, Maria Rita Coluccia, Ruben Conceição, Fernando Contreras, Mathew J. Cooper, Alain Cordier, Stephane Coutu, Corbin Covault, James Cronin, Richard Dallier, Bruno Daniel, Sergio Dasso, Kai Daumiller, Bruce R. Dawson, Rogerio M. de Almeida, Sijbrand J. de Jong, Giuseppe De Mauro, Joao de Mello Neto, Ivan De Mitri, Jaime de Oliveira, Vitor de Souza, Luis del Peral, Olivier Deligny, Niraj Dhital, Claudio Di Giulio, Armando Di Matteo, Johana Chirinos Diaz, Mary Lucia Díaz Castro, Francisco Diogo, Carola Dobrigkeit, Wendy Docters, Juan Carlos D'Olivo, Alexei Dorofeev, Qader Dorosti Hasankiadeh, Rita dos Anjos, Maria Teresa Dova, Jan Ebr, Ralph Engel, Martin Erdmann, Mona Erfani, Carlos O. Escobar, Joao Espadanal, Alberto Etchegoyen, Heino Falcke, Ke Fang, Glennys Farrar, Anderson Fauth, Norberto Fazzini, Andrew P. Ferguson, Brian Fick, Juan Manuel Figueira, Alberto Filevich, Andrej Filipčič, Octavian Fratu, Martín Miguel Freire, Toshihiro Fujii, Beatriz García, Diego Garcia-Gamez, Diego Garcia-Pinto, Florian Gate, Hartmut Gemmeke, Alexandru Gherghel-Lascu, Piera Luisa Ghia, Ugo Giaccari, Marco Giammarchi, Maria Giller, Dariusz Głas, Christian Glaser, Henry Glass, Geraldina Golup, Mariano Gómez Berisso, Primo F. Gómez Vitale, Nicolás González, Ben Gookin, Jacob Gordon, Alessio Gorgi, Peter Gorham, Philippe Gouffon, Nathan Griffith, Aurelio Grillo, Trent D. Grubb, Fausto Guarino, Germano Guedes, Matías Rolf Hampel, Patricia Hansen, Diego Harari, Thomas A. Harrison, Sebastian Hartmann, John Harton, Andreas Haungs, Thomas Hebbeker, Dieter Heck, Philipp Heimann, Alexander E. Herve, Gary C. Hill, Carlos Hojvat, Nicholas Hollon, Ewa Holt, Piotr Homola, Jörg Hörandel, Pavel Horvath, Miroslav Hrabovský, Daniel Huber, Tim Huege, Antonio Insolia, Paula Gina Isar, Ingolf Jandt, Stefan Jansen, Cecilia Jarne, Jeffrey A. Johnsen, Mariela Josebachuili, Alex Kääpä, Olga Kambeitz, Karl Heinz Kampert, Peter Kasper, Igor Katkov, Bianca Keilhauer, Ernesto Kemp, Roger Kieckhafer, Hans Klages, Matthias Kleifges, Jonny Kleinfeller, Raphael Krause, Nicole Krohm, Daniel Kuempel, Gasper Kukec Mezek, Norbert Kunka, Alaa Metwaly Kuotb Awad, Danielle LaHurd, Luca Latronico, Robert Lauer, Markus Lauscher, Pascal Lautridou, Sandra Le Coz, Didier Lebrun, Paul Lebrun, Marcelo Augusto Leigui de Oliveira, Antoine Letessier-Selvon, Isabelle Lhenry-Yvon, Katrin Link, Luis Lopes, Rebeca López, Aida López Casado, Karim Louedec, Agustin Lucero, Max Malacari, Manuela Mallamaci, Jennifer Maller, Dusan Mandat, Paul Mantsch, Analisa Mariazzi, Vincent Marin, Ioana Mariş, Giovanni Marsella, Daniele Martello, Humberto Martinez, Oscar Martínez Bravo, Diane Martraire, Jimmy Masías Meza, Hermann-Josef Mathes, Sebastian Mathys, James Matthews, John Matthews, Giorgio Matthiae, Daniela Maurizio, Eric Mayotte, Peter Mazur, Carlos Medina, Gustavo Medina-Tanco, Rebecca Meissner, Victor Mello, Diego Melo, Alexander Menshikov, Stefano Messina, Maria Isabel Micheletti, Lukas Middendorf, Ignacio A. Minaya, Lino Miramonti, Bogdan Mitrica, Laura Molina-Bueno, Silvia Mollerach, François Montanet, Carlo Morello, Miguel Mostafá, Celio A. Moura, Marcio Aparecido Muller, Gero Müller, Sarah Müller, Sergio Navas, Petr Necesal, Lukas Nellen, Anna Nelles, Jens Neuser, Phong H. Nguyen, Mihai Niculescu-Oglinzanu, Marcus Niechciol, Lukas Niemietz, Tim Niggemann, Dave Nitz, Dalibor Nosek, Vladimir Novotny, Lyberis Nožka, Luis Núñez, Livingstone Ochilo, Foteini Oikonomou, Angela Olinto, Noelia Pacheco, Daniel Pakk Selmi-Dei, Miroslav Palatka, Juan Pallotta, Philipp Papenbreer, Gonzalo Parente, Alejandra Parra, Thomas Paul, Miroslav Pech, Jan Pękala, Rodrigo Pelayo, Iuri Pepe, Lorenzo Perrone, Emily Petermann, Christine Peters, Sergio Petrera, Yevgeniy Petrov, Jamyang Phuntsok, Ricardo Piegaia, Tanguy Pierog, Pablo Pieroni, Mário Pimenta, Valerio Pirronello, Manuel Platino, Matthias Plum, Alessio Porcelli, Czeslaw Porowski, Raul Ribeiro Prado, Paolo Privitera, Michael Prouza, Eduardo J Quel, Sven Querchfeld, Sean Quinn, Julian Rautenberg, Olivier Ravel, Diego Ravignani, Darius Reinert, Benoît Revenu, Jan Ridky, Markus Risse, Pablo Ristori, Vincenzo Rizi, Washington Rodrigues de Carvalho, Jorge Rubén Rodriguez Rojo, Maria Dolores Rodríguez-Frías, Dmytro Rogozin, Jaime Rosado, Markus Roth, Esteban Roulet, Adrian Rovero, Steven J. Saffi, Alexandra Saftoiu, Humberto Salazar, Ahmed Saleh, Francisco Salesa Greus, Gaetano Salina, Jose Sanabria Gomez, Federico Sánchez, Patricia Sanchez-Lucas, Edivaldo Moura Santos, Eva Santos, Fred Sarazin, Biswaijt Sarkar, Raul Sarmento, Christian Sarmiento-Cano, Ricardo Sato, Carlos Scarso, Markus Schauer, Viviana Scherini, Harald Schieler, David Schmidt, Olaf Scholten, Harm Schoorlemmer, Petr Schovánek, Frank G. Schröder, Alexander Schulz, Johannes Schulz, Johannes Schumacher, Sergio Sciutto, Alberto Segreto, Mariangela Settimo, Amir Shadkam, Ronald C. Shellard, Guenter Sigl, Octavian Sima, Andrzej Śmiałkowski, Radomir Šmída, Gregory Snow, Paul Sommers, Sebastian Sonntag, J. Sorokin, Ruben Squartini, Yogendra N. Srivastava, Denis Stanca, Samo Stanič, James Stapleton, Jaroslaw Stasielak, Maurice Stephan, Anne Stutz, Federico Suarez, Mauricio Suarez Durán, Tiina Suomijärvi, A. Daniel Supanitsky, Michael Sutherland, John Swain, Zbigniew Szadkowski, Oscar Alejandro Taborda, Alex Tapia, Andreas Tepe, Vanessa Menezes Theodoro, Omar Tibolla, Charles Timmermans, Carlos J. Todero Peixoto, Gabriel Toma, Lenka Tomankova, Bernardo Tomé, Aurelio Tonachini, Guillermo Torralba Elipe, Diego Torres Machado, Petr Travnicek, Marta Trini, Ralf Ulrich, Michael Unger, Martin Urban, Jose F. Valdés Galicia, Ines Valiño, Laura Valore, Guus van Aar, Patrick van Bodegom, Ad M. van den Berg, Sjoert van Velzen, Arjen van Vliet, Enrique Varela, Bernardo Vargas Cárdenas, Gary Varner, Rafael Vasquez, Jose R. Vázquez, Ricardo Vázquez, Darko Veberič, Valerio Verzi, Jakub Vicha, Mariela Videla, Luis Villaseñor, Brian Vlcek, Serguei Vorobiov, Hernan Wahlberg, Oscar Wainberg, David Walz, Alan Watson, Marc Weber, Klaus Weidenhaupt, Andreas Weindl, Christoph Welling, Felix Werner, Allan Widom, Lawrence Wiencke, Henryk Wilczyński, Tobias Winchen, David Wittkowski, Brian Wundheiler, Sarka Wykes, Lili Yang, Tolga Yapici, Alexey Yushkov, Enrique Zas, Danilo Zavrtanik, Marko Zavrtanik, Arnulfo Zepeda, Benedikt Zimmermann, Michael Ziolkowski, Francesca Zuccarello

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. Read More

2015Apr
Authors: The Pierre Auger Collaboration, Alexander Aab, Pedro Abreu, Marco Aglietta, Eun-Joo Ahn, Imen Al Samarai, Ivone Albuquerque, Ingomar Allekotte, Patrick Allison, Alejandro Almela, Jesus Alvarez Castillo, Jaime Alvarez-Muñiz, Rafael Alves Batista, Michelangelo Ambrosio, Amin Aminaei, Luis Anchordoqui, Sofia Andringa, Carla Aramo, Victor Manuel Aranda, Fernando Arqueros, Nicusor Arsene, Hernán Gonzalo Asorey, Pedro Assis, Julien Aublin, Maximo Ave, Michel Avenier, Gualberto Avila, Nafiun Awal, Alina Mihaela Badescu, Kerri B Barber, Julia Bäuml, Colin Baus, Jim Beatty, Karl Heinz Becker, Jose A Bellido, Corinne Berat, Mario Edoardo Bertaina, Xavier Bertou, Peter Biermann, Pierre Billoir, Simon G Blaess, Alberto Blanco, Miguel Blanco, Carla Bleve, Hans Blümer, Martina Boháčová, Denise Boncioli, Carla Bonifazi, Nataliia Borodai, Jeffrey Brack, Iliana Brancus, Ariel Bridgeman, Pedro Brogueira, William C Brown, Peter Buchholz, Antonio Bueno, Stijn Buitink, Mario Buscemi, Karen S Caballero-Mora, Barbara Caccianiga, Lorenzo Caccianiga, Marina Candusso, Laurentiu Caramete, Rossella Caruso, Antonella Castellina, Gabriella Cataldi, Lorenzo Cazon, Rosanna Cester, Alan G Chavez, Andrea Chiavassa, Jose Augusto Chinellato, Jiri Chudoba, Marco Cilmo, Roger W Clay, Giuseppe Cocciolo, Roberta Colalillo, Alan Coleman, Laura Collica, Maria Rita Coluccia, Ruben Conceição, Fernando Contreras, Mathew J Cooper, Alain Cordier, Stephane Coutu, Corbin Covault, James Cronin, Richard Dallier, Bruno Daniel, Sergio Dasso, Kai Daumiller, Bruce R Dawson, Rogerio M de Almeida, Sijbrand J de Jong, Giuseppe De Mauro, Joao de Mello Neto, Ivan De Mitri, Jaime de Oliveira, Vitor de Souza, Luis del Peral, Olivier Deligny, Hans Dembinski, Niraj Dhital, Claudio Di Giulio, Armando Di Matteo, Johana Chirinos Diaz, Mary Lucia Díaz Castro, Francisco Diogo, Carola Dobrigkeit, Wendy Docters, Juan Carlos D'Olivo, Alexei Dorofeev, Qader Dorosti Hasankiadeh, Maria Teresa Dova, Jan Ebr, Ralph Engel, Martin Erdmann, Mona Erfani, Carlos O Escobar, Joao Espadanal, Alberto Etchegoyen, Heino Falcke, Ke Fang, Glennys Farrar, Anderson Fauth, Norberto Fazzini, Andrew P Ferguson, Mateus Fernandes, Brian Fick, Juan Manuel Figueira, Alberto Filevich, Andrej Filipčič, Brendan Fox, Octavian Fratu, Martín Miguel Freire, Benjamin Fuchs, Toshihiro Fujii, Beatriz García, Diego Garcia-Pinto, Florian Gate, Hartmut Gemmeke, Alexandru Gherghel-Lascu, Piera Luisa Ghia, Ugo Giaccari, Marco Giammarchi, Maria Giller, Dariusz Głas, Christian Glaser, Henry Glass, Geraldina Golup, Mariano Gómez Berisso, Primo F Gómez Vitale, Nicolás González, Ben Gookin, Jacob Gordon, Alessio Gorgi, Peter Gorham, Philippe Gouffon, Nathan Griffith, Aurelio Grillo, Trent D Grubb, Yann Guardincerri, Fausto Guarino, Germano Guedes, Matías Rolf Hampel, Patricia Hansen, Diego Harari, Thomas A Harrison, Sebastian Hartmann, John Harton, Andreas Haungs, Thomas Hebbeker, Dieter Heck, Philipp Heimann, Alexander E Herve, Gary C Hill, Carlos Hojvat, Nicholas Hollon, Ewa Holt, Piotr Homola, Jörg Hörandel, Pavel Horvath, Miroslav Hrabovský, Daniel Huber, Tim Huege, Antonio Insolia, Paula Gina Isar, Ingolf Jandt, Stefan Jansen, Cecilia Jarne, Jeffrey A Johnsen, Mariela Josebachuili, Alex Kääpä, Olga Kambeitz, Karl Heinz Kampert, Peter Kasper, Igor Katkov, Balazs Kégl, Bianca Keilhauer, Azadeh Keivani, Ernesto Kemp, Roger Kieckhafer, Hans Klages, Matthias Kleifges, Jonny Kleinfeller, Raphael Krause, Nicole Krohm, Oliver Krömer, Daniel Kuempel, Norbert Kunka, Danielle LaHurd, Luca Latronico, Robert Lauer, Markus Lauscher, Pascal Lautridou, Sandra Le Coz, Didier Lebrun, Paul Lebrun, Marcelo Augusto Leigui de Oliveira, Antoine Letessier-Selvon, Isabelle Lhenry-Yvon, Katrin Link, Luis Lopes, Rebeca López, Aida López Casado, Karim Louedec, Lu Lu, Agustin Lucero, Max Malacari, Simone Maldera, Manuela Mallamaci, Jennifer Maller, Dusan Mandat, Paul Mantsch, Analisa Mariazzi, Vincent Marin, Ioana Mariş, Giovanni Marsella, Daniele Martello, Lilian Martin, Humberto Martinez, Oscar Martínez Bravo, Diane Martraire, Jimmy Masías Meza, Hermann-Josef Mathes, Sebastian Mathys, James Matthews, John Matthews, Giorgio Matthiae, Detlef Maurel, Daniela Maurizio, Eric Mayotte, Peter Mazur, Carlos Medina, Gustavo Medina-Tanco, Rebecca Meissner, Victor Mello, Diego Melo, Alexander Menshikov, Stefano Messina, Rishi Meyhandan, Maria Isabel Micheletti, Lukas Middendorf, Ignacio A Minaya, Lino Miramonti, Bogdan Mitrica, Laura Molina-Bueno, Silvia Mollerach, François Montanet, Carlo Morello, Miguel Mostafá, Celio A Moura, Marcio Aparecido Muller, Gero Müller, Sarah Müller, Roberto Mussa, Gianni Navarra, Jose Luis Navarro, Sergio Navas, Petr Necesal, Lukas Nellen, Anna Nelles, Jens Neuser, Phong H Nguyen, Mihai Niculescu-Oglinzanu, Marcus Niechciol, Lukas Niemietz, Tim Niggemann, Dave Nitz, Dalibor Nosek, Vladimir Novotny, Lyberis Nožka, Livingstone Ochilo, Foteini Oikonomou, Angela Olinto, Noelia Pacheco, Daniel Pakk Selmi-Dei, Miroslav Palatka, Juan Pallotta, Philipp Papenbreer, Gonzalo Parente, Alejandra Parra, Thomas Paul, Miroslav Pech, Jan Pękala, Rodrigo Pelayo, Iuri Pepe, Lorenzo Perrone, Emily Petermann, Christine Peters, Sergio Petrera, Yevgeniy Petrov, Jamyang Phuntsok, Ricardo Piegaia, Tanguy Pierog, Pablo Pieroni, Mário Pimenta, Valerio Pirronello, Manuel Platino, Matthias Plum, Alessio Porcelli, Czeslaw Porowski, Raul Ribeiro Prado, Paolo Privitera, Michael Prouza, Victor Purrello, Eduardo J Quel, Sven Querchfeld, Sean Quinn, Julian Rautenberg, Olivier Ravel, Diego Ravignani, Benoît Revenu, Jan Ridky, Simone Riggi, Markus Risse, Pablo Ristori, Vincenzo Rizi, Washington Rodrigues de Carvalho, Gonzalo Rodriguez Fernandez, Jorge Rubén Rodriguez Rojo, Maria Dolores Rodríguez-Frías, Dmytro Rogozin, Jaime Rosado, Markus Roth, Esteban Roulet, Adrian Rovero, Steven J Saffi, Alexandra Saftoiu, Francesco Salamida, Humberto Salazar, Ahmed Saleh, Francisco Salesa Greus, Gaetano Salina, Federico Sánchez, Patricia Sanchez-Lucas, Edivaldo Moura Santos, Eva Santos, Fred Sarazin, Biswaijt Sarkar, Raul Sarmento, Ricardo Sato, Carlos Scarso, Markus Schauer, Viviana Scherini, Harald Schieler, Peter Schiffer, David Schmidt, Olaf Scholten, Harm Schoorlemmer, Petr Schovánek, Frank G Schröder, Alexander Schulz, Johannes Schulz, Johannes Schumacher, Sergio Sciutto, Alberto Segreto, Mariangela Settimo, Amir Shadkam, Ronald C Shellard, Iván Sidelnik, Guenter Sigl, Octavian Sima, Andrzej Śmiałkowski, Radomir Šmída, Gregory Snow, Paul Sommers, J Sorokin, Ruben Squartini, Yogendra N Srivastava, Denis Stanca, Samo Stanič, James Stapleton, Jaroslaw Stasielak, Maurice Stephan, Anne Stutz, Federico Suarez, Tiina Suomijärvi, A Daniel Supanitsky, Michael Sutherland, John Swain, Zbigniew Szadkowski, Oscar Alejandro Taborda, Alex Tapia, Andreas Tepe, Vanessa Menezes Theodoro, Javier Tiffenberg, Charles Timmermans, Carlos J Todero Peixoto, Gabriel Toma, Lenka Tomankova, Bernardo Tomé, Aurelio Tonachini, Guillermo Torralba Elipe, Diego Torres Machado, Petr Travnicek, Ralf Ulrich, Michael Unger, Martin Urban, Jose F Valdés Galicia, Ines Valiño, Laura Valore, Guus van Aar, Patrick van Bodegom, Ad M van den Berg, Sjoert van Velzen, Arjen van Vliet, Enrique Varela, Bernardo Vargas Cárdenas, Gary Varner, Rafael Vasquez, Jose R Vázquez, Ricardo Vázquez, Darko Veberič, Valerio Verzi, Jakub Vicha, Mariela Videla, Luis Villaseñor, Brian Vlcek, Serguei Vorobiov, Hernan Wahlberg, Oscar Wainberg, David Walz, Alan Watson, Marc Weber, Klaus Weidenhaupt, Andreas Weindl, Felix Werner, Allan Widom, Lawrence Wiencke, Henryk Wilczyński, Tobias Winchen, David Wittkowski, Brian Wundheiler, Sarka Wykes, Lili Yang, Tolga Yapici, Alexey Yushkov, Enrique Zas, Danilo Zavrtanik, Marko Zavrtanik, Arnulfo Zepeda, Yue Zhu, Benedikt Zimmermann, Michael Ziolkowski, Francesca Zuccarello

Neutrinos in the cosmic ray flux with energies near 1 EeV and above are detectable with the Surface Detector array of the Pierre Auger Observatory. We report here on searches through Auger data from 1 January 2004 until 20 June 2013. No neutrino candidates were found, yielding a limit to the diffuse flux of ultra-high energy neutrinos that challenges the Waxman-Bahcall bound predictions. Read More

Black hole accretion and jet formation have long been thought to be scale invariant. One empirical relation suggesting scale invariance is the Fundamental Plane of Black Hole activity, which is a plane in the space given by black hole mass and the radio/X-ray luminosities. We search for an alternative version of this plane using the luminosity of [OIII] emission line instead of X-ray luminosity. Read More

2015Mar
Affiliations: 1Department of Astrophysics/IMAPP Radboud University Nijmegen The Netherlands, 2Department of Astrophysics/IMAPP Radboud University Nijmegen The Netherlands, 3Leiden Observatory Leiden University The Netherlands, 4Department of Physics and Astronomy The Johns Hopkins University USA, 5Department of Astrophysics/IMAPP Radboud University Nijmegen The Netherlands

We present a 324.5MHz image of the NOAO Bo\"otes field that was made using Very Large Array (VLA) P-band observations. The image has a resolution of 5. Read More

2015Mar
Authors: The Pierre Auger Collaboration, Alexander Aab, Pedro Abreu, Marco Aglietta, Eun-Joo Ahn, Imen Al Samarai, Ivone Albuquerque, Ingomar Allekotte, Patrick Allison, Alejandro Almela, Jesus Alvarez Castillo, Jaime Alvarez-Muñiz, Rafael Alves Batista, Michelangelo Ambrosio, Amin Aminaei, Luis Anchordoqui, Sofia Andringa, Carla Aramo, Victor Manuel Aranda, Fernando Arqueros, Nicusor Arsene, Hernán Gonzalo Asorey, Pedro Assis, Julien Aublin, Maximo Ave, Michel Avenier, Gualberto Avila, Nafiun Awal, Alina Mihaela Badescu, Kerri B Barber, Julia Bäuml, Colin Baus, Jim Beatty, Karl Heinz Becker, Jose A Bellido, Corinne Berat, Mario Edoardo Bertaina, Xavier Bertou, Peter Biermann, Pierre Billoir, Simon G Blaess, Alberto Blanco, Miguel Blanco, Carla Bleve, Hans Blümer, Martina Boháčová, Denise Boncioli, Carla Bonifazi, Nataliia Borodai, Jeffrey Brack, Iliana Brancus, Ariel Bridgeman, Pedro Brogueira, William C Brown, Peter Buchholz, Antonio Bueno, Stijn Buitink, Mario Buscemi, Karen S Caballero-Mora, Barbara Caccianiga, Lorenzo Caccianiga, Marina Candusso, Laurentiu Caramete, Rossella Caruso, Antonella Castellina, Gabriella Cataldi, Lorenzo Cazon, Rosanna Cester, Alan G Chavez, Andrea Chiavassa, Jose Augusto Chinellato, Jiri Chudoba, Marco Cilmo, Roger W Clay, Giuseppe Cocciolo, Roberta Colalillo, Alan Coleman, Laura Collica, Maria Rita Coluccia, Ruben Conceição, Fernando Contreras, Mathew J Cooper, Alain Cordier, Stephane Coutu, Corbin Covault, James Cronin, Richard Dallier, Bruno Daniel, Sergio Dasso, Kai Daumiller, Bruce R Dawson, Rogerio M de Almeida, Sijbrand J de Jong, Giuseppe De Mauro, Joao de Mello Neto, Ivan De Mitri, Jaime de Oliveira, Vitor de Souza, Luis del Peral, Olivier Deligny, Hans Dembinski, Niraj Dhital, Claudio Di Giulio, Armando Di Matteo, Johana Chirinos Diaz, Mary Lucia Díaz Castro, Francisco Diogo, Carola Dobrigkeit, Wendy Docters, Juan Carlos D'Olivo, Alexei Dorofeev, Qader Dorosti Hasankiadeh, Maria Teresa Dova, Jan Ebr, Ralph Engel, Martin Erdmann, Mona Erfani, Carlos O Escobar, Joao Espadanal, Alberto Etchegoyen, Heino Falcke, Ke Fang, Glennys Farrar, Anderson Fauth, Norberto Fazzini, Andrew P Ferguson, Mateus Fernandes, Brian Fick, Juan Manuel Figueira, Alberto Filevich, Andrej Filipčič, Brendan Fox, Octavian Fratu, Martín Miguel Freire, Benjamin Fuchs, Toshihiro Fujii, Beatriz García, Diego Garcia-Pinto, Florian Gate, Hartmut Gemmeke, Alexandru Gherghel-Lascu, Piera Luisa Ghia, Ugo Giaccari, Marco Giammarchi, Maria Giller, Dariusz Głas, Christian Glaser, Henry Glass, Geraldina Golup, Mariano Gómez Berisso, Primo F Gómez Vitale, Nicolás González, Ben Gookin, Jacob Gordon, Alessio Gorgi, Peter Gorham, Philippe Gouffon, Nathan Griffith, Aurelio Grillo, Trent D Grubb, Fausto Guarino, Germano Guedes, Matías Rolf Hampel, Patricia Hansen, Diego Harari, Thomas A Harrison, Sebastian Hartmann, John Harton, Andreas Haungs, Thomas Hebbeker, Dieter Heck, Philipp Heimann, Alexander E Herve, Gary C Hill, Carlos Hojvat, Nicholas Hollon, Ewa Holt, Piotr Homola, Jörg Hörandel, Pavel Horvath, Miroslav Hrabovský, Daniel Huber, Tim Huege, Antonio Insolia, Paula Gina Isar, Ingolf Jandt, Stefan Jansen, Cecilia Jarne, Jeffrey A Johnsen, Mariela Josebachuili, Alex Kääpä, Olga Kambeitz, Karl Heinz Kampert, Peter Kasper, Igor Katkov, Balazs Kégl, Bianca Keilhauer, Azadeh Keivani, Ernesto Kemp, Roger Kieckhafer, Hans Klages, Matthias Kleifges, Jonny Kleinfeller, Raphael Krause, Nicole Krohm, Oliver Krömer, Daniel Kuempel, Norbert Kunka, Danielle LaHurd, Luca Latronico, Robert Lauer, Markus Lauscher, Pascal Lautridou, Sandra Le Coz, Didier Lebrun, Paul Lebrun, Marcelo Augusto Leigui de Oliveira, Antoine Letessier-Selvon, Isabelle Lhenry-Yvon, Katrin Link, Luis Lopes, Rebeca López, Aida López Casado, Karim Louedec, Lu Lu, Agustin Lucero, Max Malacari, Simone Maldera, Manuela Mallamaci, Jennifer Maller, Dusan Mandat, Paul Mantsch, Analisa Mariazzi, Vincent Marin, Ioana Mariş, Giovanni Marsella, Daniele Martello, Lilian Martin, Humberto Martinez, Oscar Martínez Bravo, Diane Martraire, Jimmy Masías Meza, Hermann-Josef Mathes, Sebastian Mathys, James Matthews, John Matthews, Giorgio Matthiae, Detlef Maurel, Daniela Maurizio, Eric Mayotte, Peter Mazur, Carlos Medina, Gustavo Medina-Tanco, Rebecca Meissner, Victor Mello, Diego Melo, Alexander Menshikov, Stefano Messina, Rishi Meyhandan, Maria Isabel Micheletti, Lukas Middendorf, Ignacio A Minaya, Lino Miramonti, Bogdan Mitrica, Laura Molina-Bueno, Silvia Mollerach, François Montanet, Carlo Morello, Miguel Mostafá, Celio A Moura, Marcio Aparecido Muller, Gero Müller, Sarah Müller, Roberto Mussa, Gianni Navarra, Sergio Navas, Petr Necesal, Lukas Nellen, Anna Nelles, Jens Neuser, David Newton, Phong H Nguyen, Mihai Niculescu-Oglinzanu, Marcus Niechciol, Lukas Niemietz, Tim Niggemann, Dave Nitz, Dalibor Nosek, Vladimir Novotny, Lyberis Nožka, Livingstone Ochilo, Foteini Oikonomou, Angela Olinto, Victor Olmos-Gilbaja, Noelia Pacheco, Daniel Pakk Selmi-Dei, Miroslav Palatka, Juan Pallotta, Philipp Papenbreer, Gonzalo Parente, Alejandra Parra, Thomas Paul, Miroslav Pech, Jan Pękala, Rodrigo Pelayo, Iuri Pepe, Lorenzo Perrone, Emily Petermann, Christine Peters, Sergio Petrera, Yevgeniy Petrov, Jamyang Phuntsok, Ricardo Piegaia, Tanguy Pierog, Pablo Pieroni, Mário Pimenta, Valerio Pirronello, Manuel Platino, Matthias Plum, Alessio Porcelli, Czeslaw Porowski, Raul Ribeiro Prado, Paolo Privitera, Michael Prouza, Victor Purrello, Eduardo J Quel, Sven Querchfeld, Sean Quinn, Julian Rautenberg, Olivier Ravel, Diego Ravignani, Benoît Revenu, Jan Ridky, Simone Riggi, Markus Risse, Pablo Ristori, Vincenzo Rizi, Washington Rodrigues de Carvalho, Gonzalo Rodriguez Fernandez, Jorge Rubén Rodriguez Rojo, Maria Dolores Rodríguez-Frías, Dmytro Rogozin, Jaime Rosado, Markus Roth, Esteban Roulet, Adrian Rovero, Steven J Saffi, Alexandra Saftoiu, Francesco Salamida, Humberto Salazar, Ahmed Saleh, Francisco Salesa Greus, Gaetano Salina, Federico Sánchez, Patricia Sanchez-Lucas, Edivaldo Moura Santos, Eva Santos, Fred Sarazin, Biswaijt Sarkar, Raul Sarmento, Ricardo Sato, Carlos Scarso, Markus Schauer, Viviana Scherini, Harald Schieler, Peter Schiffer, David Schmidt, Olaf Scholten, Harm Schoorlemmer, Petr Schovánek, Frank G Schröder, Alexander Schulz, Johannes Schulz, Johannes Schumacher, Sergio Sciutto, Alberto Segreto, Mariangela Settimo, Amir Shadkam, Ronald C Shellard, Iván Sidelnik, Guenter Sigl, Octavian Sima, Andrzej Śmiałkowski, Radomir Šmída, Gregory Snow, Paul Sommers, J Sorokin, Ruben Squartini, Yogendra N Srivastava, Denis Stanca, Samo Stanič, James Stapleton, Jaroslaw Stasielak, Maurice Stephan, Anne Stutz, Federico Suarez, Tiina Suomijärvi, A Daniel Supanitsky, Michael Sutherland, John Swain, Zbigniew Szadkowski, Oscar Alejandro Taborda, Alex Tapia, Andreas Tepe, Vanessa Menezes Theodoro, Charles Timmermans, Carlos J Todero Peixoto, Gabriel Toma, Lenka Tomankova, Bernardo Tomé, Aurelio Tonachini, Guillermo Torralba Elipe, Diego Torres Machado, Petr Travnicek, Ralf Ulrich, Michael Unger, Martin Urban, Jose F Valdés Galicia, Ines Valiño, Laura Valore, Guus van Aar, Patrick van Bodegom, Ad M van den Berg, Sjoert van Velzen, Arjen van Vliet, Enrique Varela, Bernardo Vargas Cárdenas, Gary Varner, Rafael Vasquez, Jose R Vázquez, Ricardo Vázquez, Darko Veberič, Valerio Verzi, Jakub Vicha, Mariela Videla, Luis Villaseñor, Brian Vlcek, Serguei Vorobiov, Hernan Wahlberg, Oscar Wainberg, David Walz, Alan Watson, Marc Weber, Klaus Weidenhaupt, Andreas Weindl, Felix Werner, Allan Widom, Lawrence Wiencke, Henryk Wilczyński, Tobias Winchen, David Wittkowski, Brian Wundheiler, Sarka Wykes, Lili Yang, Tolga Yapici, Alexey Yushkov, Enrique Zas, Danilo Zavrtanik, Marko Zavrtanik, Arnulfo Zepeda, Yue Zhu, Benedikt Zimmermann, Michael Ziolkowski, Francesca Zuccarello

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5. Read More

Current and future astronomical survey facilities provide a remarkably rich opportunity for transient astronomy, combining unprecedented fields of view with high sensitivity and the ability to access previously unexplored wavelength regimes. This is particularly true of LOFAR, a recently-commissioned, low-frequency radio interferometer, based in the Netherlands and with stations across Europe. The identification of and response to transients is one of LOFAR's key science goals. Read More

We report new observations with the Very Large Array, Atacama Large Millimeter Array, and Submillimeter Array at frequencies from 1.0 to 355 GHz of the Galactic Center black hole, Sagittarius A*. These observations were conducted between October 2012 and November 2014. Read More

Radio and mm-wavelength observations of Sagittarius A* (Sgr A*), the radio source associated with the supermassive black hole at the center of our Galaxy, show that it behaves as a partially self-absorbed synchrotron-emitting source. The measured size of Sgr A* shows that the mm-wavelength emission comes from a small region and consists of the inner accretion flow and a possible collimated outflow. Existing observations of Sgr A* have revealed a time lag between light curves at 43 GHz and 22 GHz, which is consistent with a rapidly expanding plasma flow and supports the presence of a collimated outflow from the environment of an accreting black hole. Read More

Relativistic jets in active galactic nuclei (AGN) are among the most powerful astrophysical objects discovered to date. Indeed, jetted AGN studies have been considered a prominent science case for SKA, and were included in several different chapters of the previous SKA Science Book (Carilli & Rawlings 2004). Most of the fundamental questions about the physics of relativistic jets still remain unanswered, and await high-sensitivity radio instruments such as SKA to solve them. Read More

2014Dec

Adding VLBI capability to the SKA arrays will greatly broaden the science of the SKA, and is feasible within the current specifications. SKA-VLBI can be initially implemented by providing phased-array outputs for SKA1-MID and SKA1-SUR and using these extremely sensitive stations with other radio telescopes, and in SKA2 by realising a distributed configuration providing baselines up to thousands of km, merging it with existing VLBI networks. The motivation for and the possible realization of SKA-VLBI is described in this paper. Read More

The vast collecting area of the Square Kilometre Array (SKA), harnessed by sensitive receivers, flexible digital electronics and increased computational capacity, could permit the most sensitive and exhaustive search for technologically-produced radio emission from advanced extraterrestrial intelligence (SETI) ever performed. For example, SKA1-MID will be capable of detecting a source roughly analogous to terrestrial high-power radars (e.g. Read More

Current wide-area radio surveys are dominated by active galactic nuclei, yet many of these sources have no identified optical counterparts. Here we investigate whether one can constrain the nature and properties of these sources, using Fanaroff-Riley type II (FRII) radio galaxies as probes. These sources are easy to identify since the angular separation of their lobes remains almost constant at some tens of arcseconds for z>1. Read More

We measure the proper motion of the pulsar PSR J1745-2900 relative to the Galactic Center massive black hole, Sgr A*, using the Very Long Baseline Array (VLBA). The pulsar has a transverse velocity of 236 +/- 11 km s^-1 at position angle 22 +/- 2 deg East of North at a projected separation of 0.097 pc from Sgr A*. Read More

Radiatively inefficient accretion flows (RIAFs) are believed to power supermassive black holes (SMBH) in the underluminous cores of galaxies. Such black holes are typically accompanied by flat-spectrum radio cores indicating the presence of moderately relativistic jets. One of the best constrained RIAFs is associated with the SMBH in the Galactic center, Sgr A*. Read More

We report the detection of the two-dimensional structure of the radio source associated with the Galactic Center black hole, Sagittarius A*, obtained from Very Long Baseline Array (VLBA) observations at a wavelength of 7mm. The intrinsic source is modeled as an elliptical Gaussian with major axis size 35.4 x 12. Read More

Measuring radio emission from air showers provides excellent opportunities to directly measure all air shower properties, including the shower development. To exploit this in large-scale experiments, a simple and analytic parameterization of the distribution of the radio signal at ground level is needed. Data taken with the Low-Frequency Array (LOFAR) show a complex two-dimensional pattern of pulse powers, which is sensitive to the shower geometry. Read More

The center of our Galaxy hosts the best constrained supermassive black hole in the universe, Sagittarius A* (Sgr A*). Its mass and distance have been accurately determined from stellar orbits and proper motion studies, respectively, and its high-frequency radio, and highly variable near-infrared and X-ray emission originate from within a few Schwarzschild radii of the event horizon. The theory of general relativity (GR) predicts the appearance of a black hole shadow, which is a lensed image of the event horizon. Read More

The pulsed radio emission from the Galactic Center (GC) magnetar SGR J1745-29 probes the turbulent, magnetized plasma of the GC hyperstrong scattering screen through both angular and temporal broadening. We present the first measurements of the angular size of SGR J1745-29, obtained with the Very Long Baseline Array and the phased Very Large Array at 8.7 and 15. Read More

An international consortium is presently constructing a beamformer for the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile that will be available as a facility instrument. The beamformer will aggregate the entire collecting area of the array into a single, very large aperture. The extraordinary sensitivity of phased ALMA, combined with the extremely fine angular resolution available on baselines to the Northern Hemisphere, will enable transformational new very long baseline interferometry (VLBI) observations in Bands 6 and 7 (1. Read More

The spin of supermassive black holes could power jets from active galactic nuclei (AGN), although direct observational evidence for this conjecture is sparse. The accretion disk luminosity and jet power, on the other hand, have long been observed to follow a linear correlation. If jet power is coupled to black hole spin, deviations from the jet-disk correlation for a sample of AGN can be used to probe the dispersion of the spin parameter within this sample. Read More

2013Jul
Authors: The Pierre Auger Collaboration, Alexander Aab, Pedro Abreu, Marco Aglietta, Markus Ahlers, Eun-Joo Ahn, Ivone Albuquerque, Ingomar Allekotte, Jeff Allen, Patrick Allison, Alejandro Almela, Jesus Alvarez Castillo, Jaime Alvarez-Muñiz, Rafael Alves Batista, Michelangelo Ambrosio, Amin Aminaei, Luis Anchordoqui, Sofia Andringa, Tome Antičić, Carla Aramo, Fernando Arqueros, Hernán Gonzalo Asorey, Pedro Assis, Julien Aublin, Maximo Ave, Michel Avenier, Gualberto Avila, Alina Mihaela Badescu, Kerri B. Barber, Remi Bardenet, Julia Bäuml, Colin Baus, Jim Beatty, Karl Heinz Becker, Jose A. Bellido, Segev BenZvi, Corinne Berat, Xavier Bertou, Peter Biermann, Pierre Billoir, Francisco Blanco, Miguel Blanco, Carla Bleve, Hans Blümer, Martina Boháčová, Denise Boncioli, Carla Bonifazi, Raffaella Bonino, Nataliia Borodai, Jeffrey Brack, Iliana Brancus, Pedro Brogueira, William C. Brown, Peter Buchholz, Antonio Bueno, Mario Buscemi, Karen S. Caballero-Mora, Barbara Caccianiga, Lorenzo Caccianiga, Marina Candusso, Laurentiu Caramete, Rossella Caruso, Antonella Castellina, Gabriella Cataldi, Lorenzo Cazon, Rosanna Cester, Shih-Ho Cheng, Andrea Chiavassa, Jose Augusto Chinellato, Jiri Chudoba, Marco Cilmo, Roger W Clay, Giuseppe Cocciolo, Roberta Colalillo, Laura Collica, Maria Rita Coluccia, Ruben Conceição, Fernando Contreras, Mathew J. Cooper, Stephane Coutu, Corbin Covault, Adrienne Criss, James Cronin, Alex Curutiu, Richard Dallier, Bruno Daniel, Sergio Dasso, Kai Daumiller, Bruce R. Dawson, Rogerio M. de Almeida, Manlio De Domenico, Sijbrand J. de Jong, Gonzalo De La Vega, Walter J. M. de Mello Junior, Joao de Mello Neto, Ivan De Mitri, Vitor de Souza, Krijn de Vries, Luis del Peral, Olivier Deligny, Hans Dembinski, Niraj Dhital, Claudio Di Giulio, Armando Di Matteo, Johana Chirinos Diaz, Mary Lucia Díaz Castro, Pham Ngoc Diep, Francisco Diogo, Carola Dobrigkeit, Wendy Docters, Juan Carlos D'Olivo, Pham Ngoc Dong, Alexei Dorofeev, Joao dos Anjos, Maria Teresa Dova, Jan Ebr, Ralph Engel, Martin Erdmann, Carlos O. Escobar, Joao Espadanal, Alberto Etchegoyen, Pedro Facal San Luis, Heino Falcke, Ke Fang, Glennys Farrar, Anderson Fauth, Norberto Fazzini, Andrew P. Ferguson, Brian Fick, Juan Manuel Figueira, Alberto Filevich, Andrej Filipčič, Nadine Foerster, Brendan Fox, Claudia Fracchiolla, Eric Daniel Fraenkel, Octavian Fratu, Uwe Fröhlich, Benjamin Fuchs, Romain Gaior, Rodolfo Federico Gamarra, Silvia Gambetta, Beatriz García, Sayri Tupac Garcia Roca, Diego Garcia-Gamez, Diego Garcia-Pinto, Gianpaolo Garilli, Alberto Gascon Bravo, Hartmut Gemmeke, Piera Luisa Ghia, Marco Giammarchi, Maria Giller, Javier Gitto, Christian Glaser, Henry Glass, Flavia Gomez Albarracin, Mariano Gómez Berisso, Primo F. Gómez Vitale, Patrícia Gonçalves, Javier G. Gonzalez, Ben Gookin, Alessio Gorgi, Peter Gorham, Philippe Gouffon, Stefan Grebe, Nathan Griffith, Aurelio Grillo, Trent D. Grubb, Yann Guardincerri, Fausto Guarino, Germano Guedes, Patricia Hansen, Diego Harari, Thomas A. Harrison, John Harton, Andreas Haungs, Thomas Hebbeker, Dieter Heck, Alexander E. Herve, Gary C. Hill, Carlos Hojvat, Nicholas Hollon, Ewa Holt, Piotr Homola, Joerg Hörandel, Pavel Horvath, Miroslav Hrabovský, Daniel Huber, Tim Huege, Antonio Insolia, Paula Gina Isar, Stefan Jansen, Cecilia Jarne, Mariela Josebachuili, Krešo Kadija, Olga Kambeitz, Karl Heinz Kampert, Pavel Karhan, Peter Kasper, Igor Katkov, Balazs Kégl, Bianca Keilhauer, Azadeh Keivani, Ernesto Kemp, Roger Kieckhafer, Hans Klages, Matthias Kleifges, Jonny Kleinfeller, Johannes Knapp, Raphael Krause, Nicole Krohm, Oliver Krömer, Daniel Kruppke-Hansen, Daniel Kuempel, Norbert Kunka, Giovanni La Rosa, Danielle LaHurd, Luca Latronico, Robert Lauer, Markus Lauscher, Pascal Lautridou, Sandra Le Coz, Milton Leão, Paul Lebrun, Didier Lebrun, Marcelo Augusto Leigui de Oliveira, Antoine Letessier-Selvon, Isabelle Lhenry-Yvon, Katrin Link, Rebeca López, Angeles Lopez Agüera, Karim Louedec, Julio Lozano Bahilo, Lu Lu, Agustin Lucero, Marianne Ludwig, Haris Lyberis, Maria Concetta Maccarone, Max Malacari, Simone Maldera, Jennifer Maller, Dusan Mandat, Paul Mantsch, Analisa Mariazzi, Vincent Marin, Ioana Mariş, Hugo R. Marquez Falcon, Giovanni Marsella, Daniele Martello, Lilian Martin, Humberto Martinez, Oscar Martínez Bravo, Diane Martraire, Jimmy Masías Meza, Hermann-Josef Mathes, James Matthews, John A. J. Matthews, Giorgio Matthiae, Detlef Maurel, Daniela Maurizio, Eric Mayotte, Peter Mazur, Carlos Medina, Gustavo Medina-Tanco, Maximilien Melissas, Diego Melo, Ezio Menichetti, Alexander Menshikov, Stefano Messina, Rishi Meyhandan, Saša Mićanović, Maria Isabel Micheletti, Lukas Middendorf, Ignacio A. Minaya, Lino Miramonti, Bogdan Mitrica, Laura Molina-Bueno, Silvia Mollerach, Maria Monasor, Delphine Monnier Ragaigne, François Montanet, Benjamin Morales, Carlo Morello, Juan Cruz Moreno, Miguel Mostafá, Celio A. Moura, Marcio Aparecido Muller, Gero Müller, Moritz Münchmeyer, Roberto Mussa, Gianni Navarra, Jose Luis Navarro, Sergio Navas, Petr Necesal, Lukas Nellen, Anna Nelles, Jens Neuser, Pham Thi Tuyet Nhung, Marcus Niechciol, Lukas Niemietz, Tim Niggemann, Dave Nitz, Dalibor Nosek, Libor Nožka, Juergen Oehlschläger, Angela Olinto, Micael Oliveira, Montserrat Ortiz, Noelia Pacheco, Daniel Pakk Selmi-Dei, Miroslav Palatka, Juan Pallotta, Nunzia Palmieri, Gonzalo Parente, Alejandra Parra, Sergio Pastor, Thomas Paul, Miroslav Pech, Jan Pękala, Rodrigo Pelayo, Iuri Pepe, Lorenzo Perrone, Roberto Pesce, Emily Petermann, Sergio Petrera, Alessandro Petrolini, Yevgeniy Petrov, Ricardo Piegaia, Tanguy Pierog, Pablo Pieroni, Mário Pimenta, Valerio Pirronello, Manuel Platino, Matthias Plum, Michael Pontz, Alessio Porcelli, Titi Preda, Paolo Privitera, Michael Prouza, Eduardo J Quel, Sven Querchfeld, Sean Quinn, Julian Rautenberg, Olivier Ravel, Diego Ravignani, Benoît Revenu, Jan Ridky, Simone Riggi, Markus Risse, Pablo Ristori, Hugo M. Rivera, Vincenzo Rizi, Jonathan Roberts, Washington Rodrigues de Carvalho, Iago Rodriguez Cabo, Gonzalo Rodriguez Fernandez, Julio Rodriguez Martino, Jorge Rubén Rodriguez Rojo, Maria Dolores Rodríguez-Frías, Germán Ros, Jaime Rosado, Tomas Rossler, Markus Roth, Benjamin Rouillé-d'Orfeuil, Esteban Roulet, Adrian Rovero, Christoph Rühle, Steven J. Saffi, Alexandra Saftoiu, Francesco Salamida, Humberto Salazar, Francisco Salesa Greus, Gaetano Salina, Federico Sánchez, Patricia Sanchez-Lucas, Catarina E. Santo, Eva Santos, Edivaldo Moura Santos, Fred Sarazin, Biswaijt Sarkar, Raul Sarmento, Ricardo Sato, Nils Scharf, Viviana Scherini, Harald Schieler, Peter Schiffer, Adrian Schmidt, Olaf Scholten, Harm Schoorlemmer, Petr Schovánek, Frank G. Schröder, Alexander Schulz, Johannes Schulz, Sergio Sciutto, Mario Scuderi, Alberto Segreto, Mariangela Settimo, Amir Shadkam, Ronald C. Shellard, Iván Sidelnik, Guenter Sigl, Octavian Sima, Andrzej Śmiałkowski, Radomir Šmída, Gregory Snow, Paul Sommers, J. Sorokin, Hal Spinka, Ruben Squartini, Yogendra N. Srivastava, Samo Stanič, James Stapleton, Jaroslaw Stasielak, Maurice Stephan, Marcel Straub, Anne Stutz, Federico Suarez, Tiina Suomijärvi, A. Daniel Supanitsky, Tatjana Šuša, Michael Sutherland, John Swain, Zbigniew Szadkowski, Marek Szuba, Alex Tapia, Mathieu Tartare, Oana Taşcău, Nguyen Thi Thao, Javier Tiffenberg, Charles Timmermans, Wieslaw Tkaczyk, Carlos J. Todero Peixoto, Gabriel Toma, Lenka Tomankova, Bernardo Tomé, Aurelio Tonachini, Guillermo Torralba Elipe, Diego Torres Machado, Petr Travnicek, Diogo Tridapalli, Enrica Trovato, Matias Tueros, Ralf Ulrich, Michael Unger, Jose F. Valdés Galicia, Ines Valiño, Laura Valore, Guus van Aar, Ad M. van den Berg, Sjoert van Velzen, Arjen van Vliet, Enrique Varela, Bernardo Vargas Cárdenas, Gary Varner, Jose R. Vázquez, Ricardo Vázquez, Darko Veberič, Valerio Verzi, Jakub Vicha, Mariela Videla, Luis Villaseñor, Hernan Wahlberg, Philip Wahrlich, Oscar Wainberg, David Walz, Alan Watson, Marc Weber, Klaus Weidenhaupt, Andreas Weindl, Felix Werner, Stefan Westerhoff, Ben J. Whelan, Allan Widom, Grzegorz Wieczorek, Lawrence Wiencke, Barbara Wilczyńska, Henryk Wilczyński, Martin Will, Christopher Williams, Tobias Winchen, Brian Wundheiler, Sarka Wykes, Tokonatsu Yamamoto, Tolga Yapici, Patrick Younk, Guofeng Yuan, Alexey Yushkov, Bruno Zamorano, Gabriel Zarza, Enrique Zas, Danilo Zavrtanik, Marko Zavrtanik, Ingyin Zaw, Arnulfo Zepeda, Jing Zhou, Yue Zhu, Marcelo Zimbres Silva, Michael Ziolkowski

Contributions of the Pierre Auger Collaboration to the 33rd International Cosmic Ray Conference, Rio de Janeiro, Brazil, July 2013 Read More

Several fast radio bursts have been discovered recently, showing a bright, highly dispersed millisecond radio pulse. The pulses do not repeat and are not associated with a known pulsar or gamma-ray burst. The high dispersion suggests sources at cosmological distances, hence implying an extremely high radio luminosity, far larger than the power of single pulses from a pulsar. Read More

LOFAR (the Low Frequency Array) is the largest radio telescope in the world for observing low frequency radio emission from 10 to 240 MHz. In addition to its use as an interferometric array, LOFAR is now routinely used to detect cosmic ray induced air showers by their radio emission. The LOFAR core in the Netherlands has a higher density of antennas than any dedicated cosmic ray experiment in radio. Read More

Ultra-high-energy neutrinos and cosmic rays produce short radio flashes through the Askaryan effect when they impact on the Moon. Earthbound radio telescopes can search the Lunar surface for these signals. A new generation of low- frequency, digital radio arrays, spearheaded by LOFAR, will allow for searches with unprecedented sensitivity. Read More

The Square Kilometre Array (SKA) will have a low frequency component (SKA-low) which has as one of its main science goals the study of the redshifted 21cm line from the earliest phases of star and galaxy formation in the Universe. This 21cm signal provides a new and unique window on both the formation of the first stars and accreting black holes and the later period of substantial ionization of the intergalactic medium. The signal will teach us fundamental new things about the earliest phases of structure formation, cosmology and even has the potential to lead to the discovery of new physical phenomena. Read More

Many decades of observations of active galactic nuclei and X-ray binaries have shown that relativistic jets are ubiquitous when compact objects accrete. One could therefore anticipate the launch of a jet after a star is disrupted and accreted by a massive black hole. This birth of a relativistic jet may have been observed recently in two stellar tidal disruption flares (TDFs), which were discovered in gamma-rays by Swift. Read More

The active broadband (1 kHz-100 MHz) tripole antenna now envisaged to be placed on the European Lunar Lander located at the Lunar South Pole allows for sensitive measurements of the exosphere and ionosphere, and their interaction with the Earths magnetosphere, solar particles, wind and CMEs and studies of radio communication on the moon, that are essential for future lunar human and science exploration. In addition, the lunar South pole provides an excellent opportunity for radio astronomy. Placing a single radio antenna in an eternally dark crater or behind a mountain at the south (or north) pole would potentially provide perfect shielding from man-made radio interference (RFI), absence of ionospheric distortions, and high temperature and antenna gain stability that allows detection of the 21 cm wave emission from pristine hydrogen formed after the big bang and into the period where the first stars formed. Read More

To understand the feedback of black holes on their environment or the acceleration of ultra-high energy cosmic rays in the present cosmic epoch, a systematic, all-sky inventory of radio galaxies in the local universe is needed. Here we present the first catalog of radio-emitting galaxies that meets this requirement. Our catalog allows the selection of volume-limited subsamples containing all low-power radio galaxies, similar to the prototypical low-power radio galaxies Cen A or M87, within some hundred Mpc. Read More

We present the "endpoint" formalism for the calculation of electromagnetic radiation and illustrate its applications in astroparticle physics. We use the formalism to explain why the coherent radiation from the Askaryan effect is not in general Cherenkov radiation, as the emission directly results from the time-variation of the net charge in the particle shower. Secondly, we illustrate how the formalism has been applied in the air shower radio emission code REAS3 to unify the microscopic and macroscopic views of radio emission from extensive air showers. Read More

A star that passes too close to a massive black hole will be torn apart by tidal forces. The flare of photons emitted during the accretion of the stellar debris is predicted to be observable and candidates of such events have been observed at optical to X-ray frequencies. If a fraction of the accreted material is fed into a jet, tidal flares should be detectable at radio frequencies too, thus comprising a new class of rare radio transients. Read More

2010Oct
Affiliations: 1Department of Astrophysics, IMAPP, Radboud University, Nijmegen, The Netherlands, 2Astronomical Institute "Anton Pannekoek'', University of Amsterdam, The Netherlands, 3Astronomy Department & Radio Astronomy Lab, UC Berkeley, USA, 4Department of Physics, University of Illinois, Urbana, Illinois, USA, 5Department of Physics, University of Illinois, Urbana, Illinois, USA, 6Department of Astronomy, University of Michigan, Ann Arbor, Michigan, USA

In this paper we review and discuss some of the intriguing properties of the Galactic Center supermassive black hole candidate Sgr A*. Of all possible black hole sources, the event horizon of Sgr A*, subtends the largest angular scale on the sky. It is therefore a prime candidate to study and image plasma processes in strong gravity and it even allows imaging of the shadow cast by the event horizon. Read More

2010Oct
Affiliations: 1U. Michigan, 2Yale U, 3U. Amsterdam, 4Radboud U. Nijmegen, 5U. Michigan, 6Yale U

We present results of recent observations and theoretical modeling of data from black holes accreting at very low luminosities (L/L_Edd ~ 10^{-8}). We discuss our newly developed time-dependent model for episodic ejection of relativistic plasma within a jet framework, and a successful application of this model to describe the origin of radio flares seen in Sgr A*, the Galactic center black hole. Both the observed time lags and size-frequency relationships are reproduced well by the model. Read More

We present a new methodology for calculating the electromagnetic radiation from accelerated charged particles. Our formulation --- the `endpoint formulation' --- combines numerous results developed in the literature in relation to radiation arising from particle acceleration using a complete, and completely general, treatment. We do this by describing particle motion via a series of discrete, instantaneous acceleration events, or `endpoints', with each such event being treated as a source of emission. Read More

2009Nov
Affiliations: 1Univ. of Amsterdam, 2Univ. of Amsterdam, 3Radboud University, Nijmegen

The source of emission from Sgr A*, the supermassive black hole at the Galactic Center, is still unknown. Flares and data from multiwavelength campaigns provide important clues about the nature of Sgr A* itself. Here we attempt to constrain the physical origin of the broadband emission and the radio flares from Sgr A*. Read More