Jose L. Gomez - Instituto de Astrofisica de Andalucia, Spain

Jose L. Gomez
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Name
Jose L. Gomez
Affiliation
Instituto de Astrofisica de Andalucia, Spain
Country
Spain

Pubs By Year

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High Energy Astrophysical Phenomena (22)
 
Solar and Stellar Astrophysics (15)
 
Astrophysics of Galaxies (14)
 
Cosmology and Nongalactic Astrophysics (13)
 
Instrumentation and Methods for Astrophysics (7)
 
Mathematics - Algebraic Topology (5)
 
Nonlinear Sciences - Chaotic Dynamics (2)
 
Mathematics - Probability (2)
 
Earth and Planetary Astrophysics (2)
 
Physics - Statistical Mechanics (1)
 
Mathematical Physics (1)
 
Mathematics - Mathematical Physics (1)
 
Physics - Data Analysis; Statistics and Probability (1)
 
Mathematics - Representation Theory (1)
 
Mathematics - Combinatorics (1)
 
Mathematics - K-Theory and Homology (1)
 
General Relativity and Quantum Cosmology (1)
 
Computer Science - Artificial Intelligence (1)
 
High Energy Physics - Experiment (1)
 
Computer Science - Computer Vision and Pattern Recognition (1)

Publications Authored By Jose L. Gomez

We carried out multiwavelength (0.7-5 cm), multiepoch (1994-2015) Very Large Array (VLA) observations toward the region enclosing the bright far-IR sources FIR 3 (HOPS 370) and FIR 4 (HOPS 108) in OMC-2. We report the detection of 10 radio sources, seven of them identified as young stellar objects. Read More

Water fountain stars (WFs) are evolved objects with water masers tracing high-velocity jets (up to several hundreds of km s$^{-1}$). They could represent one of the first manifestations of collimated mass-loss in evolved objects and thus, be a key to understanding the shaping mechanisms of planetary nebulae. Only 13 objects had been confirmed so far as WFs with interferometer observations. Read More

We present a survey for water maser emission toward a sample of 44 low-luminosity young objects, comprising (proto-)brown dwarfs, first hydrostatic cores (FHCs), and other young stellar objects (YSOs) with bolometric luminosities lower than 0.4 L$_\odot$. Water maser emission is a good tracer of energetic processes, such as mass-loss and/or accretion, and is a useful tool to study this processes with very high angular resolution. Read More

We report Very Large Array observations at 7 mm, 9 mm, and 3 cm toward the pre-transitional disk of the Herbig Ae star HD 169142. These observations have allowed us to study the mm emission of this disk with the highest angular resolution so far ($0\rlap."12\times0\rlap. Read More

Supervised learning tends to produce more accurate classifiers than unsupervised learning in general. This implies that training data is preferred with annotations. When addressing visual perception challenges, such as localizing certain object classes within an image, the learning of the involved classifiers turns out to be a practical bottleneck. Read More

In this paper we describe a new approach for mm-VLBI calibration that provides bona-fide astrometric alignment of the mm-wavelength images from a single source, for the measurement of frequency dependent effects, such as `core-shifts' near the black hole of AGN jets. We achieve our astrometric alignment by solving firstly for the ionospheric (dispersive) contributions using wide-band cm-wavelength observations. Secondly we solve for the tropospheric (non-dispersive) contributions by using fast frequency-switching at the target mm-wavelengths. Read More

We report on high spatial resolution observations, using the Australia Telescope Compact Array (ATCA), of ground-state OH masers. These observations were carried out toward 196 pointing centres previously identified in the Southern Parkes Large-Area Survey in Hydroxyl (SPLASH) pilot region, between Galactic longitudes of $334^{\circ}$ and $344^{\circ}$ and Galactic latitudes of $-2^{\circ}$ and $+2^{\circ}$. Supplementing our data with data from the MAGMO (Mapping the Galactic Magnetic field through OH masers) survey, we find maser emission towards 175 of the 196 target fields. Read More

We study the interaction of relativistic jets with their environment, using 3-dimensional relativistic particle-in-cell simulations for two cases of jet composition: (i) electron-proton ($e^{-}-p^{+}$) and (ii) electron-positron ($e^{\pm}$) plasmas containing helical magnetic fields. We have performed simulations of "global" jets containing helical magnetic fields in order to examine how helical magnetic fields affect kinetic instabilities such as the Weibel instability, the kinetic Kelvin-Helmholtz instability and the Mushroom instability. We have found that these kinetic instabilities are suppressed and new types of instabilities can grow. Read More

We present the results of our survey of 1612 MHz circumstellar OH maser emission from asymptotic giant branch (AGB) stars and red supergiants (RSGs) in the Large Magellanic Cloud. We have discovered four new circumstellar maser sources in the LMC, and increased the number of reliable wind speeds from IR stars in the LMC from 5 to 13. Using our new wind speeds, as well as those from Galactic sources, we have derived an updated relation for dust driven winds: $v_{exp} \propto Z L^{0. Read More

In the study of relativistic jets one of the key open questions is their interaction with the environment on the microscopic level. Here, we study the initial evolution of both electron$-$proton ($e^{-}-p^{+}$) and electron$-$positron ($e^{\pm}$) relativistic jets containing helical magnetic fields, focusing on their interaction with an ambient plasma. We have performed simulations of "global" jets containing helical magnetic fields in order to examine how helical magnetic fields affect kinetic instabilities such as the Weibel instability, the kinetic Kelvin-Helmholtz instability (kKHI) and the Mushroom instability (MI). Read More

This work presents the first characterization of the internal structure of overpressured steady superfast magnetosonic relativistic jets in connection with their dominant type of energy. To this aim, relativistic magnetohydrodynamic simulations of different jet models threaded by a helical magnetic field have been analyzed covering a wide region in the magnetosonic Mach number - specific internal energy plane. The merit of this plane is that models dominated by different types of energy (internal energy: hot jets; rest-mass energy: kinetically dominated jets; magnetic energy: Poynting-flux dominated jets) occupy well separated regions. Read More

Photoevaporation is probably the main agent for gas dispersal during the last stages of protoplanetary disk evolution. However, the overall mass loss rate in the photoevaporative wind and its driving mechanism are still not well understood. Here we report multi-configuration Very Large Array observations at 0. Read More

We present the interferometric, full-polarisation observations of the four ground-state transitions of OH, toward five confirmed and one candidate OH-emitting planetary nebulae (OHPNe). OHPNe are believed to be very young PNe, and information on their magnetic fields (provided by their polarisation) could be key to understand the early evolution of PNe. We detect significant circular and linear polarisation in four and two objects, respectively. Read More

We report the discovery of a dwarf protoplanetary disk around the star XZ Tau B that shows all the features of a classical transitional disk but on a much smaller scale. The disk has been imaged with the Atacama Large Millimeter/Submillimeter Array (ALMA), revealing that its dust emission has a quite small radius of ~ 3.4 au and presents a central cavity of ~ 1. 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

For G a finite group and X a G-space on which a normal subgroup A acts trivially, we show that the G-equivariant K-theory of X decomposes as a direct sum of twisted equivariant K-theories of X parametrized by the orbits of the conjugation action of G on the irreducible representations of A. The twists are group 2-cocycles which encode the obstruction of lifting an irreducible representation of A to the subgroup of G which fixes the isomorphism class of the irreducible representation. Read More

We present the first polarimetric space VLBI imaging observations at 22 GHz. BL Lacertae was observed in 2013 November 10 with the RadioAstron space VLBI mission, including a ground array of 15 radio telescopes. The instrumental polarization of the space radio telescope is found to be within 9%, demonstrating the polarimetric imaging capabilities of RadioAstron at 22 GHz. 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

We prove central limit theorems (CLT) for empirical processes of extreme values cluster functionals as in Drees and Rootz\'en (2010). We use coupling properties enlightened for Dedecker \& Prieur's $\tau-$dependence coefficients in order to improve the conditions of dependence and continue to obtain these CLT. The assumptions are precisely set for particular processes and cluster functionals of interest. Read More

We present the analysis of the radio jet evolution of the radio galaxy 3C 120 during a period of prolonged gamma-ray activity detected by the Fermi satellite between December 2012 and October 2014. We find a clear connection between the gamma-ray and radio emission, such that every period of gamma-ray activity is accompanied by the flaring of the mm-VLBI core and subsequent ejection of a new superluminal component. However, not all ejections of components are associated with gamma-ray events detectable by Fermi. Read More

We have performed two-dimensional special-relativistic magnetohydrodynamic simulations of non-equilibrium over-pressured relativistic jets in cylindrical geometry. Multiple stationary recollimation shock and rarefaction structures are produced along the jet by the nonlinear interaction of shocks and rarefaction waves excited at the interface between the jet and the surrounding ambient medium. Although initially the jet is kinematically dominated, we have considered axial, toroidal and helical magnetic fields to investigate the effects of different magnetic-field topologies and strengths on the recollimation structures. Read More

The beginning of photoionization marks the transition between the post-Asymptotic Giant Branch (post-AGB) and planetary nebula (PN) phases of stars with masses < 8 M_sun. This critical phase is difficult to observe, as it lasts only a few decades. The combination of jets and magnetic fields, the key agents of PNe shaping, could give rise to synchrotron emission, but this has never been observed before in any PNe, since free-free emission from the ionized gas is expected to dominate its radio spectrum. Read More

The relativistic jet in M87 offers a unique opportunity for understanding the detailed jet structure and emission processes due to its proximity. In particular, the peculiar jet region HST-1 at ~1 arcsecond (or 80 pc, projected) from the nucleus has attracted a great deal of interest in the last decade because of its superluminal motion and broadband radio-to-X-ray outbursts, which may be further connected to the gamma-ray productions up to TeV energies. Over the last five years, we have been doing an intensive monitoring of HST-1 with EVN at 5GHz in order to examine the detailed structural evolution and its possible connection to high-energy activities. Read More

Using a construction derived from the descending central series of the free groups, we produce filtrations by infinite loop spaces of the classical infinite loop spaces $BSU$, $BU$, $BSO$, $BO$, $BSp$, $BGL_{\infty}(R)^{+}$ and $Q_0(\mathbb{S}^{0})$. We show that these infinite loop spaces are the zero spaces of non-unital $E_\infty$-ring spectra. We introduce the notion of $q$-nilpotent K-theory of a CW-complex $X$ for any $q\ge 2$, which extends the notion of commutative K-theory defined by Adem-G\'omez, and show that it is represented by $\mathbb Z\times B(q,U)$, were $B(q,U)$ is the $q$-th term of the aforementioned filtration of $BU$. 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 blazar 1156+295 was active at gamma-ray energies, exhibiting three prominent flares during the year 2010. Here, we present results using the combination of broadband (X-ray through mm single dish) monitoring data and radio band imaging data at 43 GHz on the connection of gamma-ray events to the ejections of superluminal components and other changes in the jet of 1156+295. The kinematics of the jet over the interval 2007. Read More

We present Very Large Array observations at 7 mm that trace the thermal emission of large dust grains in the HD 169142 protoplanetary disk. Our images show a ring of enhanced emission of radius ~25-30 AU, whose inner region is devoid of detectable 7 mm emission. We interpret this ring as tracing the rim of an inner cavity or gap, possibly created by a planet or a substellar companion. Read More

We present $\gamma$-ray, X-ray, ultraviolet, optical, and near-infrared light curves of 33 $\gamma$-ray bright blazars over four years that we have been monitoring since 2008 August with multiple optical, ground-based telescopes and the Swift satellite, and augmented by data from the Fermi Gamma-ray Space Telescope and other publicly available data from Swift. The sample consists of 21 flat-spectrum radio quasars (FSRQs) and 12 BL Lac objects (BL Lacs). We identify quiescent and active states of the sources based on their $\gamma$-ray behavior. Read More

2014Apr
Affiliations: 1Instituto de Astrofísica de Andalucía, CSIC, 2Instituto de Astrofísica de Andalucía, CSIC, 3Instituto de Astrofísica de Andalucía, CSIC, 4Max-Planck-Institut für Radioastronomie, 5Chalmers University of Technology, 6Max-Planck-Institut für Radioastronomie

The source NRAO150 is a very prominent millimeter to radio emitting quasar at redshift z=1.52 for which previous millimeter VLBI observations revealed a fast counterclockwise rotation of the innermost regions of the jet. Here we present new polarimetric multi-epoch VLBI-imaging observations of NRAO150 performed at 8, 15, 22, 43, and 86GHz with the VLBA and GMVA between 2006 and 2010. Read More

Drees and Rootz\'en [2010] have proven central limit theorems (CLT) for empirical processes of extreme values cluster functionals built from $\beta$-mixing processes. The problem with this family of $\beta$-mixing processes is that it is quite restrictive, as has been shown by Andrews [1984]. We expand this result to a more general dependent processes family, known as weakly dependent processes in the sense of Doukhan and Louhichi [1999], but in finite-dimensional convergence (fidis). Read More

To obtain a better understanding of the location and mechanisms for the production of the gamma-ray emission in jets of AGN we present a detailed study of the HST-1 structure, 0.8 arcsec downstream the jet of M87, previously identified as a possible candidate for TeV emission. HST-1 shows a very peculiar structure with superluminal as well as possible stationary sub-components, and appears to be located in the transition from a parabolic to a conical jet shape, presumably leading to the formation of a recollimation shock. Read More

In this contribution we study the onset of chaos via type-II intermittency within the framework of Horizontal Visibility graph theory. We construct graphs associated to time series generated by an iterated map close to a Neimark-Sacker bifurcation and study, both numerically and analytically, their main topological properties. We find well defined equivalences between the main statistical properties of intermittent series (scaling of laminar trends and Lyapunov exponent) and those of the resulting graphs, and accordingly construct a graph theoretical description of type-II intermittency. 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

In this article we consider a space B_{com}G assembled from commuting elements in a Lie group G first defined in [Adem, Cohen, Torres-Giese 2012]. We describe homotopy-theoretic properties of these spaces using homotopy colimits, and their role as a classifying space for transitionally commutative bundles. We prove that ZxB_{com}U is a loop space and define a notion of commutative K-theory for bundles over a finite complex X which is isomorphic to [X,ZxB_{com}U]. Read More

Let n>0 be an integer and let B_{n} denote the hyperoctahedral group of rank n. The group B_{n} acts on the polynomial ring Q[x_{1},.. Read More

We present observations of a major outburst at centimeter, millimeter, optical, X-ray, and gamma-ray wavelengths of the BL Lacertae object AO 0235+164 in 2008. We analyze the timing of multi-waveband variations in the flux and linear polarization, as well as changes in Very Long Baseline Array (VLBA) images at 7mm with ~0.15 milliarcsecond resolution. Read More

The type-I intermittency route to (or out of) chaos is investigated within the Horizontal Visibility graph theory. For that purpose, we address the trajectories generated by unimodal maps close to an inverse tangent bifurcation and construct, according to the Horizontal Visibility algorithm, their associated graphs. We show how the alternation of laminar episodes and chaotic bursts has a fingerprint in the resulting graph structure. Read More

Relativistic jets in AGN in general, and in blazars in particular, are the most energetic and among the most powerful astrophysical objects known so far. Their relativistic nature provides them with the ability to emit profusely at all spectral ranges from radio wavelengths to gamma-rays, as well as to vary extremely at time scales from hours to years. Since the birth of gamma-ray astronomy, locating the origin of gamma-ray emission has been a fundamental problem for the knowledge of the emission processes involved. Read More

VLBI multi-epoch water maser observations are a powerful tool to study the gas very close to the central engine responsible for the phenomena associated with the early evolution of massive protostars. In this paper we present a summary of the main observational results obtained toward the massive star-forming regions of Cepheus A and W75N. These observations revealed unexpected phenomena in the earliest stages of evolution of massive objects (e. Read More

In this note we study topological invariants of the spaces of homomorphisms Hom(\pi,G), where \pi\ is a finitely generated abelian group and G is a compact Lie group arising as an arbitrary finite product of the classical groups SU(r), U(q) and Sp(k). Read More

Let G denote a compact connected Lie group with torsion-free fundamental group acting on a compact space X such that all the isotropy subgroups are connected subgroups of maximal rank. Let $T\subset G$ be a maximal torus with Weyl group W. If the fixed-point set $X^T$ has the homotopy type of a finite W-CW complex, we prove that the rationalized complex equivariant K-theory of X is a free module over the representation ring of G. Read More

We present Very Long Baseline Array observations of the radio galaxy 3C120 at 5, 8, 12, and 15 GHz designed to study a peculiar stationary jet feature (hereafter C80) located ~80 mas from the core, which was previously shown to display a brightness temperature ~600 times lager than expected at such distances. The high sensitivity of the images -- obtained between December 2009 and June 2010 -- has revealed that C80 corresponds to the eastern flux density peak of an arc of emission (hereafter A80), downstream of which extends a large (~20 mas in size) bubble-like structure that resembles an inverted bow shock. The linearly polarized emission closely follows that of the total intensity in A80, with the electric vector position angle distributed nearly perpendicular to the arc-shaped structure. Read More

(Context.) A number of millimeter and submillimeter facilities with linear polarization observing capabilities have started operating during last years. These facilities, as well as other previous millimeter telescopes and interferometers, require bright and stable linear polarization calibrators to calibrate new instruments and to monitor their instrumental polarization. Read More

We present the results from an ultra-high-resolution 7mm Very Long Baseline Array (VLBA) study of the relativistic jet in the BL Lacertae object OJ287 from 1995 to 2011 containing 136 total intensity images. Analysis of the image sequence reveals a sharp jet-position-angle swing by >100 deg. during [2004,2006], as viewed in the plane of the sky, that we interpret as the crossing of the jet from one side of the line of sight to the other during a softer and longer term swing of the inner jet. Read More

We locate the gamma-ray and lower frequency emission in flares of the BL Lac object AO 0235+164 at >12pc in the jet of the source from the central engine. We employ time-dependent multi-spectral-range flux and linear polarization monitoring observations, as well as ultra-high resolution (~0.15 milliarcsecond) imaging of the jet structure at lambda=7mm. Read More

We introduce MAPCAT, a long-term observing program for "Monitoring of AGN with Polarimetry at the Calar Alto Telescopes". Multi-spectral-range studies are critical to understand some of the most relevant current problems of high energy astrophysics of blazars such as their high energy emission mechanisms and the location of their gamma-ray emission region through event associations across the spectrum. Adding multi-spectral-range polarimetry allows for even more reliable identification of polarized flares across the spectrum in these kind of objects, as well as for more accurate modeling of their magnetic field. Read More