Author: "HAJIME TAKAMI" / Topic: astrophysics - high energy astrophysical phenomena - Searchworks@Jio Institute Digital Library Search Results

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35 results on '"HAJIME TAKAMI"'

1. Propagation of ultra-high-energy cosmic ray nuclei in cosmic magnetic fields and implications for anisotropy measurements

Author: Tokonatsu Yamamoto, Hajime Takami, and Susumu Inoue
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Pierre Auger Observatory, Cosmology and Nongalactic Astrophysics (astro-ph.CO), COSMIC cancer database, Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, Centaurus A, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astronomy, Astronomy and Astrophysics, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Universe, Photodisintegration, Ultra-high-energy cosmic ray, Astrophysics - High Energy Astrophysical Phenomena, Anisotropy, Astrophysics - Cosmology and Nongalactic Astrophysics, media_common
Abstract: (Abridged) Recent results from the Pierre Auger Observatory (PAO) indicate that the composition of ultra-high-energy cosmic rays (UHECRs) with energies above $10^{19}$ eV may be dominated by heavy nuclei. An important question is whether the distribution of arrival directions for such UHECR nuclei can exhibit observable anisotropy or positional correlations with their astrophysical source objects despite the expected strong deflections by intervening magnetic fields. For this purpose, we have simulated the propagation of UHECR nuclei including models for both the extragalactic magnetic field and the Galactic magnetic field. Assuming that only iron nuclei are injected steadily from sources with equal luminosity and spatially distributed according to the observed large scale structure in the local Universe, at the number of events published by the PAO so far, the arrival distribution of UHECRs would be consistent with no auto-correlation at 95% confidence if the mean number density of UHECR sources $n_s >~ 10^{-6}$ Mpc$^{-3}$, and consistent with no cross-correlation with sources within 95% errors for $n_s >~ 10^{-5}$ Mpc$^{-3}$. On the other hand, with 1000 events above $5.5 \times 10^{19}$ eV in the whole sky, next generation experiments can reveal auto-correlation with more than 99% probability even for $n_s, Comment: 17 pages, 15 figures
Published: 2012

2. The production of ultra high energy cosmic rays during the early epochs of radio-loud AGN

Author: Hajime Takami and Shunsaku Horiuchi
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Active galactic nucleus, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy, Astronomy and Astrophysics, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Galaxy, 0103 physical sciences, Ultra-high-energy cosmic ray, Astrophysics - High Energy Astrophysical Phenomena, 010306 general physics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Powerful radio-loud active galactic nuclei (AGN) with large Mpc-scale jets have been theoretically motivated as emitters of high-energy cosmic rays. Recent radio observations have established a populous class of young radio-loud galaxies with compact ($< 1$ kpc) symmetric jets that are morphologically similar to large-scale AGNs. We show that these compact AGNs, so-called compact symmetric objects (CSOs), can accelerate protons up to $10^{20}$ eV at their hot spots via a Fermi type mechanism on the assumption of efficient acceleration. The required magnetic field strengths are comparable to those derived from the minimum energy condition. We further show that the accelerated protons can escape through the photon fields of the cocoon without significant energy loss. However, the local number density of powerful CSOs is insufficient for CSOs to power the entire observed flux of ultra-high-energy cosmic rays, providing maximally only a few percent. A heavy composition of UHECRs allows more CSOs to accelerate particles to UHECR energies, but escaping the cocoon is difficult. We comment on a method that may test CSOs as UHECR sources., 7 pages, 3 figures
Published: 2011

3. Black hole lightning due to particle acceleration at subhorizon scales

Author: J. Kushida, Jose Luis Contreras, Juan Cortina, J. Hose, R. Reinthal, D. Elsaesser, Michele Palatiello, P. Munar-Adrover, Elina Lindfors, Damir Lelas, Dario Hrupec, R. Zanin, Daniel Mazin, D. Nakajima, Victor Stamatescu, M. A. Lopez, Dorota Sobczyńska, Adrian Biland, K. Nishijima, M. Uellenbeck, D. Garrido Terrats, D. Dominis Prester, J. Rico, V. Scalzotto, Christian Fruck, E. Prandini, Stefano Covino, P. G. Prada Moroni, Francesco Longo, F. Borracci, P. Da Vela, Nikola Godinovic, Benito Marcote, Patrick Vogler, Ana Babić, D. Galindo, Yusuke Konno, O. Tibolla, I. Snidaric, M. Makariev, D. Tescaro, P. Temnikov, Ivica Puljak, M. V. Fonseca, A. Sillanpää, Jörn Wilms, G. Bonnoli, L. Maraschi, Pierre Colin, C. Delgado Mendez, S. R. Gozzini, E. de Oña Wilhelmi, Konstancja Satalecka, Julian Sitarek, Michele Doro, A. Treves, Kari Nilsson, Tomislav Terzić, N. Mankuzhiyil, Daniela Hadasch, Jelena Aleksić, Oscar Blanch, Alessandro Carosi, E. Lorenz, Ruben Lopez-Coto, T. Toyama, A. Niedzwiecki, I. Lozano, G. De Caneva, M. Hayashida, David Paneque, S. Bonnefoy, A. González Muñoz, T. Schweizer, Jose Miguel Miranda, E. Colombo, Francesco Dazzi, Masahiro Teshima, G. Maneva, Felix Spanier, Y. Hanabata, Daniela Dorner, C. Schultz, V. Scapin, Miriam Lucio Martinez, S. Rügamer, Juan Abel Barrio, M. Gaug, W. Bednarek, Fabrizio Tavecchio, Ll. Font, Juri Poutanen, Stefano Ansoldi, J. Herrera, Koji Noda, B. Biasuzzi, U. Bach, Marc Ribó, Riccardo Paoletti, P. Antoranz, Elisa Bernardini, Hajime Takami, P. Bangale, J. M. Paredes, Felicia Krauß, Hidetoshi Kubo, Antonio Stamerra, Julia Thaele, K. Kodani, E. Carmona, L. O. Takalo, Louis Antonelli, J. Storz, A. De Angelis, D. Hildebrand, Mosè Mariotti, A.-K. Overkemping, Sabrina Einecke, Saverio Lombardi, J. Rodriguez Garcia, K. Saito, W. Idec, K. Frantzen, V. Kadenius, S. Paiano, Karl Mannheim, Alicia López-Oramas, Natalia Lewandowska, R. Mirzoyan, A. La Barbera, D. Eisenacher, Markus Garczarczyk, X. Paredes-Fortuny, J. Becerra González, Abelardo Moralejo, T. Steinbring, Hanna Kellermann, U. Menzel, Diego F. Torres, J. Krause, B. De Lotto, Takashi Saito, Reiko Orito, Eduardo Ros, Marcel Strzys, Matthias Kadler, K. Mallot, R. J. García López, Massimo Persic, R. Schulz, Thomas Bretz, S. N. Shore, Wolfgang Rhode, Aleksić, J, Ansoldi, S., Antonelli, L. A., Antoranz, P., Babic, A., Bangale, P., Barrio, J. A., González, J. Becerra, Bednarek, W., Bernardini, E., Biasuzzi, B., Bil, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carmona, E., Carosi, A., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Da Vela, P., Dazzi, F., De Angelis, A., De Caneva, G., De Lotto, B., De Oña Wilhelmi, E., Mendez, C. Delgado, Prester, D. Domini, Dorner, D., Doro, M., Einecke, S., Eisenacher, D., Elsaesser, D., Fonseca, M. V., Font, L., Frantzen, K., Fruck, C., Galindo, D., López, R. J. García, Garczarczyk, M., Terrats, D. Garrido, Gaug, M., Godinoviæ, N., Muñoz, A. González, Gozzini, S. R., Hadasch, D., Hanabata, Y., Hayashida, M., Herrera, J., Hildebr, D., Hose, J., Hrupec, D., Idec, W., Kadenius, V., Kellermann, H., Kodani, K., Konno, Y., Krause, J., Kubo, H., Kushida, J., Barbera, A. La, Lelas, D., Lewowska, N., Lindfors, E., Lombardi, S., Longo, Francesco, López, M., López Coto, R., López Oramas, A., Lorenz, E., Lozano, I., Makariev, M., Mallot, K., Maneva, G., Mankuzhiyil, N., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Mira, J. M., Mirzoyan, R., Moralejo, A., Munar Adrover, P., Nakajima, D., Niedzwiecki, A., Nilsson, K., Nishijima, K., Noda, K., Orito, R., Overkemping, A., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Paredes Fortuny, X., Persic, M., Poutanen, J., Moroni, P. G. Prada, Prini, E., Puljak, I., Reinthal, R., Rhode, W., Ribó, M., Rico, J., Garcia, J. Rodriguez, Rügamer, S., Saito, T., Saito, K., Satalecka, K., Scalzotto, V., Scapin, V., Schultz, C., Schweizer, T., Shore, S. N., Sillanpää, A., Sitarek, J., Snidaric, I., Sobczynska, D., Spanier, F., Stamatescu, V., Stamerra, A., Steinbring, T., Storz, J., Strzys, M., Takalo, L., Takami, H., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Thaele, J., Tibolla, O., Torres, D. F., Toyama, T., Treves, A., Uellenbeck, M., Vogler, P., Zanin, R., Kadler, M., Schulz, R., Ros, E., Bach, U., Krauß, F., and Wilms, J.
Subjects: Black Holes, Radio galaxy, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Very High Energy Gamma Astronomy, Black Holes, Very High Energy Gamma Astronomy, Active Galactic Nuclei, X-shaped radio galaxy, supermassive black hole, jet formation, IC 310, MAGIC telescopes, Astrophysics::Galaxy Astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), astro-ph.HE, Supermassive black hole, ta115, Multidisciplinary, Active Galactic Nuclei, Astronomy and Astrophysics, Galaxy, Intermediate-mass black hole, Stellar black hole, Electrónica, Física nuclear, ddc:500, Spin-flip, Electricidad, Astrophysics - High Energy Astrophysical Phenomena, Schwarzschild radius
Abstract: Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet formation using radio interferometry, but still suffer from insufficient angular resolution. An alternative method to resolve small structures is to measure the time variability of their emission. Here, we report on gamma-ray observations of the radio galaxy IC 310 obtained with the MAGIC telescopes revealing variability with doubling time scales faster than 4.8 min. Causality constrains the size of the emission region to be smaller than 20\% of the gravitational radius of its central black hole. We suggest that the emission is associated with pulsar-like particle acceleration by the electric field across a magnetospheric gap at the base of the radio jet., 19 pages, 10 figures, includes Supplementary Materials
Published: 2014

4. Unprecedented study of the broadband emission of Mrk 421 during flaring activity in March 2010

Author: E. Pueschel, J. Hose, Svetlana G. Jorstad, M. F. Aller, David A. Williams, G. H. Sembroski, D. Nakajima, M. Strzys, R. Welsing, A. Archer, E. Colombo, B. Biasuzzi, F. Borracci, Stefano Ansoldi, Riccardo Paoletti, I. Telezhinsky, Jamie Holder, D. Elsaesser, D. Staszak, Dario Hrupec, L. Ciupik, L. C. Reyes, G. Bonnoli, K. Ragan, M. A. Lopez, N. Galante, Hajime Takami, J. M. Paredes, P. T. Reynolds, Natalia Lewandowska, Hugh D. Aller, L. O. Takalo, G. H. Gillanders, T. Schweizer, Mosè Mariotti, Wystan Benbow, A.-K. Overkemping, D. Hadasch, Victor Stamatescu, J. Biteau, Paul S. Smith, Gordon T. Richards, Wei Cui, A. La Barbera, Sinéad M. Griffin, E. Roache, A. López-Oramas, S. Rügamer, Juan Abel Barrio, J. A. Ros, O. M. Kurtanidze, Alessandro Carosi, Ruben Lopez-Coto, X. Paredes-Fortuny, Mark Gurwell, U. Menzel, Saverio Lombardi, Calvin A. Johnson, P. Kar, M. Villata, K. Mallot, R. J. García López, Felix Spanier, M. Kertzman, A. C. S. Readhead, E. Prandini, D. Galindo, Merja Tornikoski, Yusuke Konno, Diego F. Torres, M. G. Nikolashvili, D. Eisenacher, Antonio Stamerra, K. Kodani, Givi N. Kimeridze, Julian Sitarek, Lorand A. Sigua, K. Nishijima, J. V. Tucci, A. Cesarini, M. Perri, P. Kaaret, J. Storz, D. Dominis Prester, Martin Pohl, C. M. Raiteri, Markus Garczarczyk, C. Fruck, A. Sillanpää, N. Håkansson, M. Makariev, T. Toyama, L. Maraschi, A. Pichel, Jose Miguel Miranda, Matteo Cerruti, Konstancja Satalecka, J. Becerra González, P. Antoranz, Amy Furniss, S. P. Wakely, B. Jordan, Elena G. Larionova, Xuhui Chen, H. C. Lin, Geza Gyuk, Louis Antonelli, Michele Doro, Abelardo Moralejo, Jelena Aleksić, S. McArthur, M. L. Knoetig, P. G. Prada Moroni, P. Munar-Adrover, Ivica Puljak, E. Collins-Hughes, K. Meagher, Nikola Godinovic, Benito Marcote, T. Steinbring, W. Idec, M. V. Fonseca, Pierre Colin, P. Temnikov, M. Hayashida, Patrick Vogler, J. Tyler, A. Niedzwiecki, C. Schultz, V. Scapin, J. H. Buckley, P. Moriarty, Tomislav Terzić, K. Berger, T. Sakamoto, C. Delgado Mendez, S. R. Gozzini, B. McBreen, O. Tibolla, Shan Sun, E. de Oña Wilhelmi, Ivan S. Troitsky, David Paneque, I. Snidaric, Marc Ribó, P. Da Vela, D. Hildebrand, B. Steinke, Steven N. Shore, Q. Feng, K. Frantzen, Massimo Persic, Hidetoshi Kubo, A. Boller, D. A. Morozova, A. Wilhelm, R. Reinthal, Thomas Bretz, Sofia O. Kurtanidze, Kari Nilsson, Elina Lindfors, Justin D. Finke, J. Krause, B. De Lotto, Walter Max-Moerbeck, K. Saito, Razmik Mirzoyan, U. Barres de Almeida, A. González Muñoz, V. Kadenius, Damir Lelas, N. Mankuzhiyil, J. P. Finley, J. S. Perkins, Wen Ping Chen, S. Paiano, E. Lorenz, Karl Mannheim, H. Prokoph, Hanna Kellermann, Daniel Mazin, I. Lozano, Dorota Sobczyńska, J. D. Eisch, Wolfgang Rhode, Daniela Dorner, M. Palatiello, Joseph Moody, Lucy Fortson, M. I. Martínez, M. Gaug, P. Bangale, G. De Caneva, J. Herrera, Matthias Beilicke, Koji Noda, J. Millis, Abraham D. Falcone, Francesco Dazzi, Karlen Shahinyan, Elisa Bernardini, S. Bonnefoy, Sabrina Einecke, J. Rodriguez Garcia, W. Bednarek, Fabrizio Tavecchio, Ll. Font, A. C. Sadun, Anne Lähteenmäki, Stefano Covino, M. J. Lang, A. Varlotta, Masahiro Teshima, A. McCann, Ekaterina Koptelova, A. C. Rovero, J. Kushida, D. Tescaro, Jose Luis Contreras, G. Hughes, M. Uellenbeck, Takashi Saito, Y. Hanabata, A. Popkow, Juan Cortina, V. Bugaev, David Kieda, Reiko Orito, S. Buson, J. L. Richards, Ann E. Wehrle, D. Garrido Terrats, P. Fortin, Oscar Blanch, Ralph Bird, S. Archambault, Valeri M. Larionov, V. Scalzotto, Ana Babić, Julia Thaele, E. Carmona, A. De Angelis, A. Treves, R. A. Ong, G. Maneva, R. Zanin, A. N. Otte, Adrian Biland, J. Rico, Alan P. Marscher, Universitat de Barcelona, Department of Radio Science and Engineering, Aalto-yliopisto, Aalto University, and ~
Subjects: extragalactic background light, Ciencias Físicas, spectral energy-distribution, Flux, Non-thermal / galaxies, Astrophysics, law.invention, Relativistic particle, purl.org/becyt/ford/1 [https], atmospheric cherenkov telescopes, Raigs gamma, bl lacertae objects, law, MAGIC (telescope), Active / BL Lacertae objects, astro-ph.HE, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, individual: Mrk 421 [BL Lacertae objects], education.field_of_study, gamma-ray outburst, non-thermal [radiation mechanisms], BL Lacertae objects: individual: Mrk 421, Galaxies: active, Gamma rays: galaxies, Radiation mechanisms: non-thermal, Astronomy and Astrophysics, Space and Planetary Science, Particle acceleration, NON THERMAL RADIATION, large-area telescope, active [galaxies], galaxies [gamma rays], BL LACERTAE OBJECTS, Electrónica, self-compton model, Electricidad, Astrophysics - High Energy Astrophysical Phenomena, CIENCIAS NATURALES Y EXACTAS, Flare, Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, Population, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Radio telescope, radiation mechanisms: non-thermal, gamma rays: galaxies, Radiation mechanisms, BL Lacertae objects: individual, simultaneous multiwavelength observations, AGN, education, Blazar, Individual: Mrk 421 / gamma rays, tev blazars, Gamma rays, Institut für Physik und Astronomie, purl.org/becyt/ford/1.3 [https], Galaxies, Astronomía, x-ray, Galàxies actives, Active galaxies, ddc:520
Abstract: A flare from the TeV blazar Mrk 421, occurring in March 2010, was observed for 13 consecutive days from radio to very high energy (VHE, E > 100 GeV) gamma-rays with MAGIC, VERITAS, Whipple, FermiLAT, MAXI, RXTE, Swift, GASP-WEBT, and several optical and radio telescopes. We model the day-scale SEDs with one-zone and two-zone synchrotron self-Compton (SSC) models, investigate the physical parameters, and evaluate whether the observed broadband SED variability can be associated to variations in the relativistic particle population. Flux variability was remarkable in the X-ray and VHE bands while it was minor or not significant in the other bands. The one-zone SSC model can describe reasonably well the SED of each day for the 13 consecutive days. This flaring activity is also very well described by a two-zone SSC model, where one zone is responsible for the quiescent emission while the other smaller zone, which is spatially separated from the first one, contributes to the daily-variable emission occurring in X-rays and VHE gamma-rays. Both the one-zone SSC and the two-zone SSC models can describe the daily SEDs via the variation of only four or five model parameters, under the hypothesis that the variability is associated mostly to the underlying particle population. This shows that the particle acceleration and cooling mechanism producing the radiating particles could be the main one responsible for the broadband SED variations during the flaring episodes in blazars. The two-zone SSC model provides a better agreement to the observed SED at the narrow peaks of the low- and high-energy bumps during the highest activity, although the reported one-zone SSC model could be further improved by the variation of the parameters related to the emitting region itself ($\delta$, $B$ and $R$), in addition to the parameters related to the particle population., Comment: Published in A&A, 30 pages, 15 figures, 6 tables. Online-data: multi-wavelength light curves (data in Fig. 1) and broadband spectral energy distributions (the data in Figs. 6, and B1-B4) are available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/578/A22. Corresponding authors: David Paneque (dpaneque@mpp.mpg.de), Shangyu Sun (sysun@mpp.mpg.de), Hajime Takami (takami@post.kek.jp)
Published: 2014

5. First broadband characterization and redshift determination of the VHE blazar MAGIC J2001+439

Author: Robert Wagner, Konstancja Satalecka, Michele Doro, K. Nishijima, K. Mallot, R. J. García López, A. Herrero, D. Dominis Prester, M. Uellenbeck, Nina Nowak, J. M. Paredes, A. López-Oramas, J. Kushida, Antonio Stamerra, Jelena Aleksić, Nikola Godinovic, Benito Marcote, Jose Luis Contreras, A. Niedzwiecki, David Paneque, Wlodek Bednarek, Alessandro Carosi, Francisco Prada, J. L. Richards, Juan Cortina, K. Kodani, Ruben Lopez-Coto, Massimo Persic, D. Nakajima, J. Storz, D. Garrido Terrats, Talvikki Hovatta, Patrick Vogler, P. G. Prada Moroni, Valeri M. Larionov, Jose Miguel Miranda, V. Scalzotto, C. Schultz, V. Scapin, Tomislav Terzić, Yusuke Konno, Anthony C. S. Readhead, J. Krause, O. Tibolla, M. Hayashida, B. De Lotto, P. Da Vela, Ana Babić, Hanna Kellermann, L. Maraschi, Elina Lindfors, Kari Nilsson, Daniel Mazin, Marc Ribó, M. V. Fonseca, P. Bangale, Julia Thaele, Hidetoshi Kubo, Stefano Covino, U. Menzel, Emanuele Paolo Farina, A. De Angelis, D. Tescaro, M. Perri, I. Snidaric, Natalia Lewandowska, M. Palatiello, Diego F. Torres, S. Rügamer, Stefano Ansoldi, Juan Abel Barrio, M. I. Martínez, Riccardo Paoletti, Felix Spanier, T. Sakamoto, M. Garczarczyk, E. Lorenz, Hajime Takami, A. La Barbera, L. A. Antonelli, Francesco Dazzi, Sabrina Einecke, P. Antoranz, R. Reinthal, J. Rodriguez Garcia, Dominik Elsaesser, Giacomo Bonnoli, X. Paredes-Fortuny, U. Barres de Almeida, I. Lozano, Fabrizio Tavecchio, Damir Lelas, Ll. Font, Masahiro Teshima, Victor Stamatescu, S. Bonnefoy, R. D. Schwartz, Filippo D'Ammando, Dorota Sobczyńska, R. Mirzoyan, D. Eisenacher, Abelardo Moralejo, P. Temnikov, Fabio Zandanel, Shan Sun, E. Carmona, T. Steinbring, Julian Sitarek, J. Hose, Aaron Dominguez, E. Prandini, Daniela Hadasch, T. Toyama, Aldo Treves, W. Idec, Thomas Bretz, S. N. Shore, Walter Max-Moerbeck, Wolfgang Rhode, K. Frantzen, Ivica Puljak, Tihomir Surić, Pierre Colin, D. Carreto Fidalgo, T. Schweizer, C. Delgado Mendez, S. R. Gozzini, F. Borracci, V. Kadenius, S. Paiano, Karl Mannheim, J. Becerra González, Mario Meucci, F. Verrecchia, E. Colombo, Nijil Mankuzhiyil, P. Munar-Adrover, G. Maneva, Silvia Preziuso, L. O. Takalo, R. Zanin, A. Saggion, Adrian Biland, A. González Muñoz, Mosè Mariotti, A.-K. Overkemping, J. Rico, A. Sillanpää, Daniela Dorner, Takashi Saito, Saverio Lombardi, M. Gaug, Reiko Orito, J. Herrera, Koji Noda, Elisa Bernardini, Christian Fruck, K. Saito, D. Hildebrand, Daniel Ferenc, G. De Caneva, S. Partini, Marcel Strzys, L. C. Reyes, Martin Makariev, Oscar Blanch, M. Doert, Dario Hrupec, M. A. Lopez, Aleksic J, Ansoldi S, Antonelli LA, Antoranz P, Babic A, Bangale P, de Almeida UB, Barrio JA, Gonzalez JB, Bednarek W, Bernardini E, Biland A, Blanch O, Bonnefoy S, Bonnoli G, Borracci F, Bretz T, Carmona E, Carosi A, Fidalgo DC, Colin P, Colombo E, Contreras JL, Cortina J, Covino S, Da Vela P, Dazzi F, De Angelis A, De Caneva G, De Lotto B, Mendez CD, Doert M, Dominguez A, Prester DD, Dorner D, Doro M, Einecke S, Eisenacher D, Elsaesser D, Farina E, Ferenc D, Fonseca MV, Font L, Frantzen K, Fruck C, Lopez RJG, Garczarczyk M, Terrats DG, Gaug M, Godinovic N, Munoz AG, Gozzini SR, Hadasch D, Hayashida M, Herrera J, Herrero A, Hildebrand D, Hose J, Hrupec D, Idec W, Kadenius V, Kellermann H, Kodani K, Konno Y, Krause J, Kubo H, Kushida J, La Barbera A, Lelas D, Lewandowska N, Lindfors E, Lombardi S, Lopez M, Lopez-Coto R, Lopez-Oramas A, Lorenz E, Lozano I, Makariev M, Mallot K, Maneva G, Mankuzhiyil N, Mannheim K, Maraschi L, Marcote B, Mariotti M, Martinez M, Mazin D, Menzel U, Meucci M, Miranda JM, Mirzoyan R, Moralejo A, Munar-Adrover P, Nakajima D, Niedzwiecki A, Nilsson K, Nishijima K, Noda K, Nowak N, Orito R, Overkemping A, Paiano S, Palatiello M, Paneque D, Paoletti R, Paredes JM, Paredes-Fortuny X, Partini S, Persic M, Prada F, Moroni PGP, Prandini E, Preziuso S, Puljak I, Reinthal R, Rhode W, Riboo M, Rico J, Garcia JR, Rugamer S, Saggion A, Saito T, Saito K, Satalecka K, Scalzotto V, Scapin V, Schultz C, Schweizer T, Shore SN, Sillanpaa A, Sitarek J, Snidaric I, Sobczynska D, Spanier F, Stamatescu V, Stamerra A, Steinbring T, Storz J, Strzys M, Sun S, Suric T, Takalo L, Takami H, Tavecchio F, Temnikov P, Terzic T, Tescaro D, Teshima M, Thaele J, Tibolla O, Torres DF, Toyama T, Treves A, Uellenbeck M, Vogler P, Wagner RM, Zandanel F, Zanin R, DAmmando F, Hovatta T, Larionov VM, Max-Moerbeck W, Perri M, Readhead ACS, Richards JL, Sakamoto T, Schwartz RD, Verrecchia F, and Reyes LC
Subjects: ACTIVE GALACTIC NUCLEI, BL Lacertae objects: individual: MAGIC J2001+439, Galaxies: active, BL Lac objects: individual (MAGIC J2001+435), gamma rays: observations, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, LARGE-AREA TELESCOPE, Nordic Optical Telescope, Spectral line, BL Lacertae objects: individual: MAGIC J2001+435, Gamma rays: galaxies, 0103 physical sciences, GAMMA-RAY SPECTRUM, MAGIC (telescope), 010306 general physics, Blazar, 010303 astronomy & astrophysics, Physics, astro-ph.HE, High Energy Astrophysical Phenomena (astro-ph.HE), galaxies: active – BL Lacertae objects: individual: MAGIC J2001+435 – BL Lacertae objects: individual: MAGIC J2001+439 – gamma rays: galaxies, FERMI ERA, Astronomy and Astrophysics, PKS 1424+240, BL-LACERTAE OBJECTS, Galaxy, Redshift, EXTRAGALACTIC BACKGROUND LIGHT, LAC OBJECTS, SKY SURVEY, RADIATION, Amplitude, Space and Planetary Science, ddc:520, Electrónica, Física nuclear, Electricidad, Astrophysics - High Energy Astrophysical Phenomena, BL Lac object
Abstract: We aim to characterize the broadband emission from 2FGL J2001.1+4352, which has been associated with the unknown-redshift blazar MG4 J200112+4352. Based on its gamma-ray spectral properties, it was identified as a potential very high energy (VHE; E > 100 GeV) gamma-ray emitter. The source was observed with MAGIC first in 2009 and later in 2010 within a multi-instrument observation campaign. The MAGIC observations yielded 14.8 hours of good quality stereoscopic data. The object was monitored at radio, optical and gamma-ray energies during the years 2010 and 2011. The source, named MAGIC J2001+439, is detected for the first time at VHE with MAGIC at a statistical significance of 6.3 {\sigma} (E > 70 GeV) during a 1.3-hour long observation on 2010 July 16. The multi-instrument observations show variability in all energy bands with the highest amplitude of variability in the X-ray and VHE bands. We also organized deep imaging optical observations with the Nordic Optical Telescope in 2013 to determine the source redshift. We determine for the first time the redshift of this BL Lac object through the measurement of its host galaxy during low blazar activity. Using the observational evidence that the luminosities of BL Lac host galaxies are confined to a relatively narrow range, we obtain z = 0.18 +/- 0.04. Additionally, we use the Fermi-LAT and MAGIC gamma-ray spectra to provide an independent redshift estimation, z = 0.17 +/- 0.10. Using the former (more accurate) redshift value, we adequately describe the broadband emission with a one-zone SSC model for different activity states and interpret the few-day timescale variability as produced by changes in the high-energy component of the electron energy distribution., Comment: 17 pages, 15 figures, Accepted for publication in A&A
Published: 2014

6. Discovery of very high energy gamma-ray emission from the blazar 1ES 0033+595 by the MAGIC telescopes

Author: T. Steinbring, A. González Muñoz, Natalia Lewandowska, D. Hildebrand, A. La Barbera, Daniela Dorner, X. Paredes-Fortuny, A. De Angelis, F. Borracci, M. Uellenbeck, Konstancja Satalecka, Michele Doro, S. Partini, S. Buson, Aaron Dominguez, Dario Hrupec, M. A. Lopez, K. Saito, U. Menzel, M. Gaug, J. Becerra González, Mario Meucci, Jelena Aleksić, R. López-Coto, Julian Sitarek, J. Hose, Daniela Hadasch, K. Nishijima, Takashi Saito, A. Niedzwiecki, J. Herrera, T. Toyama, Koji Noda, Giacomo Bonnoli, D. Dominis Prester, Reiko Orito, Diego F. Torres, Thomas Bretz, K. Frantzen, David Paneque, Elisa Bernardini, S. N. Shore, D. Nakajima, G. Maneva, Nikola Godinovic, Benito Marcote, R. Zanin, A. Saggion, P. G. Prada Moroni, M. Garczarczyk, Tihomir Surić, D. Carreto Fidalgo, Martin Makariev, M. I. Martínez, A. Borghese, E. Prandini, Oscar Blanch, O. Tibolla, V. Kadenius, P. Temnikov, Adrian Biland, Francisco Prada, S. Paiano, Lluis Font, Karl Mannheim, M. Hayashida, Victor Stamatescu, J. Krause, A. Herrero, B. De Lotto, J. Rico, Alicia López-Oramas, Stefano Covino, A. Sillanpää, K. Berger, M. Doert, C. Delgado Mendez, V. Tronconi, Hajime Takami, I. Lozano, Nijil Mankuzhiyil, G. De Caneva, S. Bonnefoy, Wolfgang Rhode, Aldo Treves, Sabrina Einecke, S. R. Gozzini, Robert Wagner, J. Rodriguez Garcia, Felix Spanier, W. Idec, P. Munar-Adrover, M. Palatiello, Francesco Dazzi, Masahiro Teshima, S. Sun, Christian Fruck, Daniel Ferenc, D. Tescaro, Yusuke Konno, Silvia Preziuso, Mosè Mariotti, A.-K. Overkemping, P. Da Vela, C. Schultz, V. Scapin, Ivica Puljak, Pierre Colin, Saverio Lombardi, Wlodek Bednarek, Alessandro Carosi, L. Maraschi, Elina Lindfors, E. Colombo, Julia Thaele, Daniel Mazin, Fabio Zandanel, Marc Ribó, L. O. Takalo, P. Bangale, Jose Miguel Miranda, R. Reinthal, Dominik Elsaesser, Hidetoshi Kubo, U. Barres de Almeida, Damir Lelas, R. Mirzoyan, M. V. Fonseca, P. Antoranz, Dorota Sobczyńska, D. Eisenacher, L. A. Antonelli, J. A. Barrio, E. Carmona, Fabrizio Tavecchio, Emanuele Paolo Farina, Nina Nowak, T. Schweizer, S. Rügamer, Tomislav Terzić, Patrick Vogler, I. Snidaric, Hanna Kellermann, K. Mallot, R. J. García López, E. Lorenz, Massimo Persic, J. M. Paredes, Antonio Stamerra, K. Kodani, J. Storz, Stefano Ansoldi, Riccardo Paoletti, J. Kushida, Jose Luis Contreras, Juan Cortina, D. Garrido Terrats, V. Scalzotto, Ana Babić, Kari Nilsson, and Abelardo Moralejo
Subjects: BL Lacertae objects: individual: (1ES 0033+595), Gamma-rays: galaxies, Astronomy and Astrophysics, Space and Planetary Science, Cosmology and Nongalactic Astrophysics (astro-ph.CO), astro-ph.HE, astro-ph.CO, astro-ph.GA, Astrophysics::High Energy Astrophysical Phenomena, Population, FOS: Physical sciences, individual: (1ES 0033 595), gamma-rays: galaxies [BL Lacertae objects], Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, BL Lacertae objects: individual: (1ES 0033 595), 01 natural sciences, Luminosity, 0103 physical sciences, MAGIC (telescope), education, Blazar, 010303 astronomy & astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), education.field_of_study, ta115, 010308 nuclear & particles physics, galaxies: BL Lacertae objects: individual (1ES 0033+595), gamma rays: galaxies, Compton scattering, Astronomy, Astrophysics - Astrophysics of Galaxies, Extragalactic background light, Astrophysics of Galaxies (astro-ph.GA), ddc:520, Spectral energy distribution, Astrophysics - High Energy Astrophysical Phenomena, Fermi Gamma-ray Space Telescope, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: Monthly Notices of the Royal Astronomical Society, 446 (1), ISSN:0035-8711, ISSN:1365-2966, ISSN:1365-8711
Published: 2014

7. Energy Sources and Light Curves of Macronovae

Author: Kunihito Ioka, Hajime Takami, and Shota Kisaka
Subjects: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Gravitational wave, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Kilonova, Black hole, Neutron star, Space and Planetary Science, r-process, Astrophysics::Solar and Stellar Astrophysics, Ejecta, Gamma-ray burst, Energy source, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics
Abstract: A macronova (kilonova) was discovered with a short gamma-ray burst, GRB 130603B, which is widely believed to be powered by the radioactivity of $r$-process elements synthesized in the ejecta of a neutron star binary merger. As an alternative, we propose that macronovae are energized by the central engine, i.e., a black hole or neutron star, and the injected energy is emitted after the adiabatic expansion of ejecta. This engine model is motivated by extended emission of short GRBs. In order to compare the theoretical models with observations, we develop analytical formulae for the light curves of macronovae. The engine model allows a wider parameter range, especially smaller ejecta mass, and better fit to observations than the $r$-process model. Future observations of electromagnetic counterparts of gravitational waves should distinguish energy sources and constrain the activity of central engine and the $r$-process nucleosynthesis., 19 pages, 7 figures, 1 table; accepted to ApJ
Published: 2014

8. Bounds on the origin of extragalactic ultrahigh energy cosmic rays from the IceCube neutrino observations

Author: S. Yoshida and Hajime Takami
Subjects: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Nuclear and High Energy Physics, media_common.quotation_subject, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, FOS: Physical sciences, Cosmic ray, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Redshift, Universe, Neutrino detector, Optical depth (astrophysics), Production (computer science), Neutrino, Astrophysics - High Energy Astrophysical Phenomena, Energy (signal processing), media_common
Abstract: We study general implications of the IceCube observations in the energy range from $10^{6}$ GeV to $10^{10}$ GeV for the origin of extragalactic ultrahigh energy cosmic rays assuming that high energy neutrinos are generated by the photomeson production of protons in the extragalactic universe. The PeV-energy neutrino flux observed by IceCube gives strong bounds on the photomeson-production optical depth of protons in their sources and the intensity of the proton component of extragalactic cosmic rays. The neutrino flux implies that extragalactic cosmic-ray sources should have the optical depth greater than $\sim 0.01$ and contribute to more than a few percent of the observed bulk of cosmic rays at 10 PeV. If the spectrum of cosmic rays from these extragalactic sources extends well beyond 1 EeV, the neutrino flux indicates that extragalactic cosmic rays are dominant in the observed total cosmic-ray flux at 1 EeV and above, favoring the dip transition model of cosmic rays. The cosmic-ray sources are also required to be efficient neutrino emitters with the optical depth close to unity in this case. The highest energy cosmic-ray ($\sim 10^{11}$ GeV) sources should not be strongly evolved with redshift to account for the IceCube observations, suggesting that any cosmic-ray radiation scenarios involving distant powerful astronomical objects with strong cosmological evolution are strongly disfavored. These considerations conclude that none of the known extragalactic astronomical objects can be simultaneously a source of both PeV and trans-EeV energy cosmic rays. We also discuss a possible effect of cosmic-ray propagation in magnetized intergalactic space to the connection between the observed total cosmic-ray flux and neutrino flux., 14 pages, 6 figures, to appear in Physical Review D
Published: 2014

9. MAGIC search for vhe γ-ray emission from ae aquarii in a multiwavelength context

Author: D. Nakajima, P. G. Prada Moroni, Laura Maraschi, Yusuke Konno, A. López-Oramas, Alessandro Carosi, Ruben Lopez-Coto, Victor Stamatescu, B. Biasuzzi, Konstancja Satalecka, Michele Doro, D. Dorner, I. Snidaric, Jose Miguel Miranda, M. Bogosavljevic, E. Lorenz, Fabrizio Tavecchio, Hajime Takami, Z. Ioannou, Tomislav Terzić, Ll. Font, A.-K. Overkemping, Elina Lindfors, M. López, Julia Thaele, E. Carmona, Daniel Mazin, A. Treves, K. Nishijima, M. V. Fonseca, Abelardo Moralejo, Patrick Vogler, M. Mariotti, Thomas Bretz, S. Rügamer, Julian Sitarek, Saverio Lombardi, T. Steinbring, Louis Antonelli, Morihiro Hayashida, P. Da Vela, Pierre Colin, K. Nilsson, J. Kushida, D. Hadasch, Dorothee Hildebrand, P. Antoranz, Robert Wagner, G. De Caneva, J. Becerra González, S. Bonnefoy, C. Schultz, X. Paredes-Fortuny, T. Toyama, Dario Hrupec, R. Paoletti, P. Munar-Adrover, Razmik Mirzoyan, M. Palatiello, I. Lozano, M. Strzys, Jose Luis Contreras, Jelena Aleksić, Silvia Preziuso, Damir Lelas, D. Galindo, D. Dominis Prester, R. Zanin, A. Niedzwiecki, A. Saggion, A. De Angelis, A. Sillanpää, Stefano Covino, Dorota Sobczyńska, V. Scapin, Juan Cortina, K. Frantzen, David Paneque, A. Biland, Diego F. Torres, Masahiro Teshima, Christopher W. Mauche, Takashi Saito, E. de Ona Wilhelmi, Y. Hanabata, D. Tescaro, W. Idec, J. M. Paredes, Nikola Godinovic, Benito Marcote, D. Garrido Terrats, R. Reinthal, M. Uellenbeck, Natalia Lewandowska, Reiko Orito, Francesco Dazzi, V. Scalzotto, A. La Barbera, T. Schweizer, Ana Babić, E. V. Palaiologou, Leo O. Takalo, R. J. García López, Antonio Stamerra, Oscar Blanch, Petar Temnikov, Koji Noda, J. Herrera, Elisa Bernardini, H. Kellermann, G. Bonnoli, N. Mankuzhiyil, W. Rhode, Felix Spanier, K. Kodani, C. Delgado Mendez, O. Tibolla, G. Maneva, A. González Muñoz, Christian Fruck, J. Storz, Juan Abel Barrio, I. Puljak, Stefano Ansoldi, D. Eisenacher, Markus Gaug, Markus Garczarczyk, Nina Nowak, D. Elsaesser, J. Hose, B. De Lotto, Elisa Prandini, M. Makariev, W. Bednarek, J. Rico, S. Paiano, U. Menzel, Miguel A. Pérez-Torres, M. I. Martínez, E. Colombo, P. Bangale, V. Kadenius, M. Doert, Sabrina Einecke, S. R. Gozzini, J. Rodriguez Garcia, K. Saito, Marc Ribó, Hidetoshi Kubo, F. Borracci, K. Mallot, T. Tuominen, Massimo Persic, K. Mannheim, J. Krause, and Universitat de Barcelona
Subjects: accretion: accretion disks, Radiation mechanisms: non-thermal, Novae: cataclysmic variables, Gamma rays: stars, Astrofísica, Accretion, Photon, Astrophysics::High Energy Astrophysical Phenomena, Signal region, Cataclysmic variable star, Astrophysics, Noves (Estels), Raigs gamma, Coincident, Accretion, accretion disks, Novae, cataclysmic variables, Astronomy and Astrophysics, Space and Planetary Science, New stars, Novae, Astrophysics::Galaxy Astrophysics, Physics, astro-ph.HE, cataclysmic variables, Spectral index, accretion disks, Gamma rays, Gamma ray, Stars, Estels, Wavelength, 13. Climate action, ddc:520, Electrónica, Física nuclear, Rayleigh test, Electricidad, Astrophysics - High Energy Astrophysical Phenomena
Abstract: It has been claimed that the nova-like cataclysmic variable (CV) AE Aquarii (AE Aqr) is a very-high-energy (VHE, $E>$100 GeV) source both on observational and theoretical grounds. We aim to search for VHE gamma-ray emission from AE Aqr during different states of the source at several wavelengths to confirm or rule out previous claims of detection of gamma-ray emission from this object. We report on observations of AE Aqr performed by MAGIC. The source was observed during 12 hours as part of a multiwavelength campaign carried out between May and June 2012 covering the optical, X-ray, and gamma-ray ranges. Besides MAGIC, the other facilities involved were the KVA, Skinakas, and Vidojevica telescopes in the optical and Swift in X-rays. We calculated integral upper limits coincident with different states of the source in the optical. We computed upper limits to the pulsed emission limiting the signal region to 30% of the phaseogram and we also searched for pulsed emission at different frequencies applying the Rayleigh test. AE Aqr was not detected at VHE energies during the multiwavelength campaign. We establish integral upper limits at the 95\% confidence level for the steady emission assuming the differential flux proportional to a power-law function d\phi/dE \propto E^{-Gamma}, with a Crab-like photon spectral index of Gamma=2.6. The upper limit above 200 GeV is 6.4\times10^{-12} cm^{-2}s^{-1} and above 1 TeV is 7.4\times10^{-13} cm^{-2}s^{-1}. We obtained an upper limit for the pulsed emission of 2.6\times10^{-12} cm^{-2}s^{-1} for energies above 200 GeV. Applying the Rayleigh test for pulsed emission at different frequencies we did not find any significant signal. Our results indicate that AE Aqr is not a VHE gamma-ray emitter at the level of emission previously claimed. We have established the most constraining upper limits for the VHE gamma-ray emission of AE Aqr., Comment: 9 pages, 5 figures. Accepted for publication in A&A
Published: 2014

10. Dust formation in macronovae

Author: Takaya Nozawa, Hajime Takami, and Kunihito Ioka
Subjects: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Opacity, Astrophysics::High Energy Astrophysical Phenomena, Extinction (astronomy), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Neutron star, Space and Planetary Science, Nucleosynthesis, r-process, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Gamma-ray burst, Ejecta, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics, Cosmic dust
Abstract: We examine dust formation in macronovae (as known as kilonovae), which are the bright ejecta of neutron star binary mergers and one of the leading sites of r-process nucleosynthesis. We find that dust grains of r-process elements are difficult to form because of the low number density of the r-process atoms, while carbon or elements lighter than irons can condense into dust if they are abundant, in light of the first macronova candidate associated with GRB 130603B. Dust grains absorb emission from ejecta with opacity even greater than that of the r-process elements, and re-emit photons at infrared wavelengths. Such dust emission can potentially account for the macronova without r-process nucleosynthesis as an alternative model. This dust scenario predicts a more featureless spectrum than the r-process model and day-scale optical-to-ultraviolet emission., 5 pages, 4 figures, 1 table, accepted for publication in ApJ Letters
Published: 2014

11. Discovery of very high energy gamma-ray emission from the blazar 1ES 1727+502 with the MAGIC Telescopes

Author: Nina Nowak, Abelardo Moralejo, D. Häfner, L. A. Antonelli, W. Idec, J. Masbou, M. I. Martínez, J. M. Paredes, Antonio Stamerra, M. Salvati, Dario Hrupec, Thomas Bretz, V. Kadenius, S. Rügamer, Mosè Mariotti, Marc Ribó, M. A. Lopez, Fabrizio Tavecchio, S. N. Shore, Juan Abel Barrio, D. Borla Tridon, Dominik Elsaesser, U. Barres de Almeida, S. Bonnefoy, K. Berger, Ll. Font, A. Hadamek, M. Doert, Emanuele Paolo Farina, Aaron Dominguez, J. Storz, G. De Caneva, Damir Lelas, R. Mirzoyan, Michael Backes, A. De Angelis, Christian Fruck, D. Eisenacher, J. Becerra González, Saverio Lombardi, T. Krähenbühl, M. L. Knoetig, Ignasi Reichardt, P. G. Prada Moroni, E. Carmona, I. Snidaric, Markus Garczarczyk, Nijil Mankuzhiyil, P. Munar-Adrover, Wolfgang Rhode, O. Tibolla, Dorota Sobczyńska, Kari Nilsson, M. V. Fonseca, Mario Meucci, Felix Spanier, M. Palatiello, E. Colombo, G. Maneva, Daniel Ferenc, A. Boller, L. Cossio, R. Zanin, A. Saggion, Ralph Bock, Nikola Godinovic, Benito Marcote, K. Mallot, R. J. García López, S. Spiro, E. Lorenz, Adrian Biland, Francesco Dazzi, L. O. Takalo, B. Steinke, Riccardo Paoletti, S. Partini, D. Dominis Prester, Artemio Herrero, J. Rico, K. Saito, J. Kushida, Jose Luis Contreras, Tomislav Terzić, J. Moldón, Francisco Prada, Juan Cortina, Hajime Takami, Ivica Puljak, Massimo Persic, Pierre Colin, R. Reinthal, Giacomo Bonnoli, Patrick Vogler, J. Krause, B. De Lotto, Martin Makariev, M. Asensio, Oscar Blanch, D. Garrido Terrats, A. Sillanpää, V. Scalzotto, Takashi Saito, Q. Weitzel, Tihomir Surić, Reiko Orito, C. Schultz, V. Scapin, D. Carreto Fidalgo, E. Prandini, Aldo Treves, S. Klepser, S. Paiano, C. Delgado Mendez, S. R. Gozzini, Karl Mannheim, Gianluca Giavitto, A. González Muñoz, Daniela Dorner, M. Gaug, Diego F. Torres, Elisa Bernardini, Natalia Lewandowska, F. Jankowski, F. Borracci, A. La Barbera, A. López-Oramas, Wlodek Bednarek, Alessandro Carosi, Ruben Lopez-Coto, D. Nakajima, Jose Miguel Miranda, P. Antoranz, L. Maraschi, M. Uellenbeck, Elina Lindfors, Konstancja Satalecka, Daniel Mazin, Michele Doro, P. Temnikov, Fabio Zandanel, Shan Sun, Jelena Aleksić, I. Lozano, D. Hadasch, Masahiro Teshima, A. Niedzwiecki, T. Schweizer, Stefano Covino, David Paneque, D. Tescaro, Robert Wagner, Victor Stamatescu, Julian Sitarek, J. Hose, T. Toyama, P. Da Vela, and Universitat de Barcelona
Subjects: Astrofísica, Swift Gamma-Ray Burst Mission, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, 7. Clean energy, law.invention, Telescope, Raigs gamma, law, 0103 physical sciences, MAGIC (telescope), Nucli galàctic actiu, Blazar, 010303 astronomy & astrophysics, BL Lac objects: individual(1ES 1727+502), galaxies: active, gamma rays, Astrophysics::Galaxy Astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), astro-ph.HE, Active galactic nuclei, Telescopis, 010308 nuclear & particles physics, Gamma rays, Gamma ray, Astronomy and Astrophysics, Galaxies: active, Space and Planetary Science, Galaxies, Galàxies, Crab Nebula, 13. Climate action, ddc:520, Spectral energy distribution, Electrónica, Física nuclear, Electricidad, Astrophysics - High Energy Astrophysical Phenomena, BL Lac object, Telescopes
Abstract: Motivated by the Costamante & Ghisellini (2002) predictions we investigated if the blazar 1ES 1727+502 (z=0.055) is emitting very high energy (VHE, E>100 GeV) gamma rays. We observed the BL Lac object 1ES 1727+502 in stereoscopic mode with the two MAGIC telescopes during 14 nights between May 6th and June 10th 2011, for a total effective observing time of 12.6 hours. For the study of the multiwavelength spectral energy distribution (SED) we use simultaneous optical R-band data from the KVA telescope, archival UV/optical and X-ray observations by instruments UVOT and XRT on board of the Swift satellite and high energy (HE, 0.1 GeV - 100 GeV) gamma-ray data from the Fermi-LAT instrument. We detect, for the first time, VHE gamma-ray emission from 1ES 1727+502 at a statistical significance of 5.5 sigma. The integral flux above 150 GeV is estimated to be (2.1\pm0.4)% of the Crab Nebula flux and the de-absorbed VHE spectrum has a photon index of (2.7\pm0.5). No significant short-term variability was found in any of the wavebands presented here. We model the SED using a one-zone synchrotron self-Compton model obtaining parameters typical for this class of sources., 7 pages, 5 figures, 2 tables, submitted to A&A
Published: 2014

12. Optimized dark matter searches in deep observations of Segue 1 with MAGIC

Author: M. V. Fonseca, L. Maraschi, M. Palatiello, Daniel Ferenc, Antonio Stamerra, Christian Fruck, Juan Abel Barrio, I. Puljak, J. Kushida, K. Kodani, Mosè Mariotti, Abelardo Moralejo, A.-K. Overkemping, Stefano Covino, Jose Luis Contreras, Oscar Blanch, Tomislav Terzić, Francesco Dazzi, Daniela Dorner, Juan Cortina, T. Steinbring, J. Storz, R. J. García López, Fabio Zandanel, G. Bonnoli, Shan Sun, Nikola Godinovic, Benito Marcote, R. Zanin, P. Da Vela, Robert Wagner, D. Hadasch, A. Saggion, Tihomir Surić, D. Carreto Fidalgo, Jelena Aleksić, D. Tescaro, A. Niedzwiecki, Adrian Biland, David Paneque, B. De Lotto, Saverio Lombardi, D. Garrido Terrats, K. Frantzen, Nijil Mankuzhiyil, X. Paredes-Fortuny, D. Dominis Prester, Damir Lelas, D. Nakajima, Louis Antonelli, Elina Lindfors, Karl Mannheim, P. Munar-Adrover, P. G. Prada Moroni, Daniel Mazin, A. De Angelis, V. Scalzotto, Stefano Ansoldi, Konstancja Satalecka, Silvia Preziuso, Riccardo Paoletti, Markus Gaug, S. Rügamer, Michele Doro, C. Schultz, V. Scapin, Dario Hrupec, Aaron Dominguez, Marc Ribó, A. López-Oramas, M. Uellenbeck, Dorothee Hildebrand, Ana Babić, G. De Caneva, R. Reinthal, Alessandro Carosi, P. Antoranz, Hidetoshi Kubo, S. Bonnefoy, Ruben Lopez-Coto, J. Becerra González, Petar Temnikov, J. M. Paredes, J. Hose, Diego F. Torres, Jose Miguel Miranda, Kari Nilsson, M. López, Dorota Sobczyńska, Elisa Bernardini, D. Elsaesser, T. Schweizer, H. Kellermann, Yusuke Konno, O. Tibolla, U. Barres de Almeida, Mario Meucci, K. Berger, I. Lozano, M. Salvati, F. Borracci, W. Idec, R. K. Bock, Emanuele Paolo Farina, A. Sillanpää, M. Doert, Takashi Saito, Masahiro Teshima, Alejandro Ibarra, E. Colombo, Hajime Takami, Reiko Orito, G. Maneva, C. Delgado Mendez, Felix Spanier, Natalia Lewandowska, K. Saito, Julian Sitarek, Pierre Colin, Julia Thaele, Aldo Treves, L. O. Takalo, A. La Barbera, E. Carmona, M. I. Martínez, Kazuyoshi Nishijima, M. Hayashida, P. Bangale, Gianluca Giavitto, A. González Muñoz, V. Kadenius, Sabrina Einecke, S. R. Gozzini, Francisco Prada, J. Rodriguez Garcia, M. Makariev, J. Rico, Victor Stamatescu, U. Menzel, Simona Paiano, Thomas Bretz, R. Mirzoyan, Wolfgang Rhode, J. Krause, K. Mallot, Massimo Persic, Takeshi Toyama, I. Snidaric, D. Eisenacher, Markus Garczarczyk, Nina Nowak, E. Lorenz, W. Bednarek, Fabrizio Tavecchio, Ll. Font, Elisa Prandini, Patrick Vogler, A. Herrero, S. Partini, Universitat de Barcelona, and SCOAP
Subjects: Astrofísica, Particle physics, Electromagnetic spectrum, Astrophysics::High Energy Astrophysical Phenomena, Dark matter, dark matter, indirect searches, gamma-ray experiments, Imaging Air Cherenkov Telescopes, dwarf spheroidal galaxies, Segue 1, Gamma ray experiments, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, Gamma ray astronomy, Satellite galaxy, Astronomia de raigs gamma, ddc:530, 010306 general physics, Dwarf galaxies, Dwarf galaxy, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Annihilation, Telescopis, 010308 nuclear & particles physics, Bremsstrahlung, Astronomy and Astrophysics, Segue, Galaxies, dwarfs galaxies, Galàxies, High Energy Physics - Phenomenology, Dark matter experiments, Dark matter (Astronomy), dark matter experiments, gamma ray experiments, Monochromatic color, Matèria fosca (Astronomia), Astrophysics - High Energy Astrophysical Phenomena, Telescopes
Abstract: Aleksic, J. et al., We present the results of stereoscopic observations of the satellite galaxy Segue 1 with the MAGIC Telescopes, carried out between 2011 and 2013. With almost 160 hours of good-quality data, this is the deepest observational campaign on any dwarf galaxy performed so far in the very high energy range of the electromagnetic spectrum. We search this large data sample for signals of dark matter particles in the mass range between 100 GeV and 20 TeV. For this we use the full likelihood analysis method, which provides optimal sensitivity to characteristic gamma-ray spectral features, like those expected from dark matter annihilation or decay. In particular, we focus our search on gamma-rays produced from different final state Standard Model particles, annihilation with internal bremsstrahlung, monochromatic lines and box-shaped signals. Our results represent the most stringent constraints to the annihilation cross-section or decay lifetime obtained from observations of satellite galaxies, for masses above few hundred GeV. In particular, our strongest limit (95% confidence level) corresponds to a ~ 500 GeV dark matter particle annihilating into τ+τ−, and is of order langleσannvrangle simeq 1.2 × 10−24 cm3 s−1 — a factor ~ 40 above the langleσannvrangle simeq thermal value., The support of the German BMBF and MPG, the Italian INFN, the Swiss National Fund SNF, and the Spanish MICINN is gratefully acknowledged. This work was also supported by the CPAN CSD2007-00042 and MultiDark CSD2009-00064 projects of the Spanish Consolider- Ingenio 2010 programme, by grant 127740 of the Academy of Finland, by the DFG Cluster of Excellence “Origin and Structure of the Universe”, by the Croatian Science Foundation Project 09/176, by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, and by the Polish MNiSzW grant 745/N-HESS-MAGIC/2010/0.
Published: 2014

13. MAGIC long-term study of the distant TeV blazar PKS 1424+240 in a multiwavelength context

Author: Aaron Dominguez, Mosè Mariotti, A.-K. Overkemping, P. G. Prada Moroni, C. Schultz, V. Scapin, Anthony C. S. Readhead, A. González Muñoz, Hajime Takami, O. Tibolla, A. De Angelis, A. Treves, Saverio Lombardi, Daniela Dorner, Daniel Ferenc, S. Rügamer, Juan Abel Barrio, M. Gaug, J. Herrera, Koji Noda, Hanna Kellermann, Elisa Bernardini, G. Maneva, R. Zanin, A. Saggion, S. Partini, Antonio Stamerra, S. N. Shore, K. Kodani, Adrian Biland, Victor Stamatescu, C. Delgado Mendez, J. Rico, P. Temnikov, Stefano Covino, J. Storz, Nina Nowak, Fabio Zandanel, Nikola Godinovic, Benito Marcote, S. Sun, Jari Kotilainen, Julian Sitarek, S. Bonnefoy, D. Tescaro, C. Fruck, T. Toyama, M. Palatiello, Dario Gasparrini, D. Eisenacher, T. Schweizer, Stefano Ansoldi, M. Uellenbeck, Francesco Dazzi, Riccardo Paoletti, E. Carmona, Markus Garczarczyk, A. K. Furniss, Oscar Blanch, J. L. Richards, Elina Lindfors, K. Mallot, Daniel Mazin, R. J. García López, Matthew L. Lister, Konstancja Satalecka, E. Prandini, Michele Doro, Talvikki Hovatta, G. De Caneva, G. Bonnoli, M. Doert, Massimo Persic, P. Da Vela, Ivica Puljak, Pierre Colin, M. Makariev, D. Nakajima, Robert Wagner, R. Reinthal, Razmik Mirzoyan, U. Barres de Almeida, U. Menzel, Jelena Aleksić, Damir Lelas, I. Lozano, D. Hildebrand, W. Idec, M. V. Fonseca, A. Niedzwiecki, Vasiliki Pavlidou, Dorota Sobczyńska, David Paneque, Anne Lähteenmäki, A. Sillanpää, Masahiro Teshima, K. Nishijima, K. Saito, Tuomas Kangas, Takashi Saito, Dario Hrupec, D. Dominis Prester, D. Hadasch, M. I. Martínez, P. Bangale, Francisco Prada, Reiko Orito, Sabrina Einecke, S. R. Gozzini, J. Rodriguez Garcia, E. Colombo, Louis Antonelli, Felix Spanier, L. O. Takalo, Nijil Mankuzhiyil, X. Paredes-Fortuny, P. Munar-Adrover, Silvia Preziuso, M. A. Lopez, P. Antoranz, Natalia Lewandowska, A. La Barbera, Yusuke Konno, Julia Thaele, J. Becerra González, Mario Meucci, K. Frantzen, Tihomir Surić, D. Carreto Fidalgo, J. M. Paredes, V. Kadenius, S. Paiano, Karl Mannheim, M. Hayashida, Alicia López-Oramas, J. Krause, B. De Lotto, Marc Ribó, Diego F. Torres, Hidetoshi Kubo, Abelardo Moralejo, J. Hose, T. Steinbring, D. Elsaesser, A. Herrero, Emanuele Paolo Farina, S. Cutini, Kari Nilsson, Thomas Bretz, J. Kushida, Jose Luis Contreras, Juan Cortina, F. Borracci, D. Garrido Terrats, V. Scalzotto, Ana Babić, Walter Max-Moerbeck, Wolfgang Rhode, Alessandro Carosi, Ruben Lopez-Coto, Jose Miguel Miranda, W. Bednarek, Fabrizio Tavecchio, Ll. Font, I. Snidaric, E. Lorenz, Patrick Vogler, Erkki Kankare, L. Maraschi, Tomislav Terzić, Universitat de Barcelona, Metsähovi Radio Observatory, Department of Radio Science and Engineering, Aalto-yliopisto, Aalto University, and Anne Lähteenmäki Group
Subjects: Astrofísica, PARTICLE-ACCELERATION, Astrophysics, 7. Clean energy, LARGE-AREA TELESCOPE, Spectral line, Raigs gamma, Gamma rays: galaxies, Astronomy and Astrophysics, Space and Planetary Science, MAGIC (telescope), High Energy Astrophysical Phenomena (astro-ph.HE), Physics, astro-ph.HE, 213 Electronic, automation and communications engineering, electronics, BL-LACERTAE OBJECTS, EXTRAGALACTIC BACKGROUND LIGHT, GAMMA-RAY EMISSION, SPECTRAL ENERGY-DISTRIBUTION, ACTIVE GALACTIC NUCLEI, LAC OBJECTS, X-RAY, FERMI OBSERVATIONS, Gamma ray, Extragalactic background light, galaxies [gamma rays], astro-ph.CO, Spectral energy distribution, Electrónica, Física nuclear, Electricidad, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics, 1171 Geosciences, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::High Energy Astrophysical Phenomena, education, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, gamma rays: observations, blazar, BL Lac: AGNs: individual (PKS 1424+240), 114 Physical sciences, Nucli galàctic actiu, Blazar, Active galactic nuclei, Telescopis, 221 Nanotechnology, Gamma rays, Light curve, Redshift, individual: PKS 1424+240 [BL Lacertae objects], 115 Astronomy and space science, 216 Materials engineering, ddc:520, Telescopes
Abstract: We present a study of the very high energy (VHE; E > 100 GeV) gamma-ray emission of the blazar PKS 1424+240 observed with the MAGIC telescopes. The primary aim of this paper is the multiwavelength spectral characterization and modeling of this blazar, which is made particularly interesting by the recent discovery of a lower limit of its redshift of z > 0.6 and makes it a promising candidate to be the most distant VHE source. The source has been observed with the MAGIC telescopes in VHE gamma rays for a total observation time of ~33.6 h from 2009 to 2011. The source was marginally detected in VHE gamma rays during 2009 and 2010, and later, the detection was confirmed during an optical outburst in 2011. The combined significance of the stacked sample is ~7.2 sigma. The differential spectra measured during the different campaigns can be described by steep power laws with the indices ranging from 3.5 +/- 1.2 to 5.0 +/- 1.7. The MAGIC spectra corrected for the absorption due to the extragalactic background light connect smoothly, within systematic errors, with the mean spectrum in 2009-2011 observed at lower energies by the Fermi-LAT. The absorption-corrected MAGIC spectrum is flat with no apparent turn down up to 400 GeV. The multiwavelength light curve shows increasing flux in radio and optical bands that could point to a common origin from the same region of the jet. The large separation between the two peaks of the constructed non-simultaneous spectral energy distribution also requires an extremely high Doppler factor if an one zone synchrotron self-Compton model is applied. We find that a two-component synchrotron self-Compton model describes the spectral energy distribution of the source well, if the source is located at z~0.6., 15 pages, 8 figures. A&A accepted for publication
Published: 2014

14. Detection of bridge emission above 50 GeV from the Crab pulsar with the MAGIC telescopes

Author: P. G. Prada Moroni, W. Bednarek, Pierre Colin, Diego F. Torres, D. Nakajima, Fabrizio Tavecchio, Stefano Covino, Ll. Font, Konstancja Satalecka, Michele Doro, Kouichi Hirotani, Nijil Mankuzhiyil, X. Paredes-Fortuny, Dario Hrupec, R. Zanin, A. Saggion, Adrian Biland, Kazuo Saito, P. Munar-Adrover, A. Treves, R. Reinthal, Shan Sun, A. Sillanpää, Antonio Stamerra, Silvia Preziuso, M. A. Lopez, Marc Ribó, Thomas Bretz, S. N. Shore, G. Maneva, Jelena Aleksić, Takashi Saito, A. Niedzwiecki, Abelardo Moralejo, J. Kushida, Jose Luis Contreras, J. M. Paredes, Hidetoshi Kubo, Reiko Orito, Natalia Lewandowska, U. Barres de Almeida, T. Steinbring, M. Makariev, A. Herrero, I. Puljak, M. V. Fonseca, E. Lorenz, M. Uellenbeck, D. Hadasch, J. Storz, Juan Cortina, D. Paneque, G. De Caneva, A. La Barbera, J. Rico, Christian Fruck, Elina Lindfors, S. Partini, Yusuke Konno, Emanuele Paolo Farina, U. Menzel, S. Bonnefoy, M. Doert, Daniel Mazin, Simona Paiano, B. Biasuzzi, Patrick Vogler, Daniel Ferenc, Elisa Prandini, P. Da Vela, T. Schweizer, Razmik Mirzoyan, S. Rügamer, B. De Lotto, L. Maraschi, Robert Wagner, J. Krause, I. Lozano, J. Becerra González, S. Ansoldi, Damir Lelas, M. I. Martínez, P. Bangale, V. Kadenius, Tomislav Terzić, D. Tescaro, G. Bonnoli, Hajime Takami, C. Delgado Mendez, Dorota Sobczyńska, Sabrina Einecke, Oscar Blanch, M. Hayashida, S. R. Gozzini, R. J. García López, N. Nowak, Kari Nilsson, Masahiro Teshima, Juan Abel Barrio, J. Rodriguez Garcia, Riccardo Paoletti, Markus Gaug, Nikola Godinovic, Benito Marcote, J. Hose, D. Garrido Terrats, Daniela Dorner, Takeshi Toyama, K. Mallot, W. Rhode, V. Scalzotto, D. Eisenacher, I. Šnidarić, K. Frantzen, M. Palatiello, Markus Garczarczyk, D. Elsaesser, Massimo Persic, Ana Babić, Petar Temnikov, Koji Noda, Elisa Bernardini, H. Kellermann, A. González Muñoz, C. Schultz, V. Scapin, Jose Carlos Herrera, Francesco Dazzi, A. López-Oramas, Karl Mannheim, Alessandro Carosi, Ruben Lopez-Coto, Jose Miguel Miranda, F. Borracci, T. Surić, Julia Thaele, E. Carmona, D. Fidalgo, Dorothee Hildebrand, P. Antoranz, M. Strzys, Julian Sitarek, Victor Stamatescu, Felix Spanier, K. Nishijima, D. Dominis Prester, Omar Tibolla, Louis Antonelli, A. De Angelis, K. Kodani, W. Idec, Mosè Mariotti, A.-K. Overkemping, Saverio Lombardi, E. Colombo, L. O. Takalo, and Universitat de Barcelona
Subjects: Astrofísica, Spectral shape analysis, Astrophysics::High Energy Astrophysical Phenomena, Theoretical models, FOS: Physical sciences, Gamma rays: stars, Pulsars: individual: Crab pulsar, Stars: neutron, Astronomy and Astrophysics, Space and Planetary Science, Astrophysics, Spectral line, Raigs gamma, MAGIC (telescope), Connection (algebraic framework), pulsars: individual: Crab pulsar, gamma rays: stars, Pulsars, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Telescopis, Crab Pulsar, Gamma rays, Light curve, Stars, Púlsars, Estels, ddc:520, Electrónica, Física nuclear, Electricidad, Astrophysics - High Energy Astrophysical Phenomena, Telescopes, Fermi Gamma-ray Space Telescope
Abstract: The Crab pulsar is the only astronomical pulsed source detected at very high energy (VHE, E>100GeV) gamma-rays. The emission mechanism of VHE pulsation is not yet fully understood, although several theoretical models have been proposed. In order to test the new models, we measured the light curve and the spectra of the Crab pulsar with high precision by means of deep observations. We analyzed 135 hours of selected MAGIC data taken between 2009 and 2013 in stereoscopic mode. In order to discuss the spectral shape in connection with lower energies, 4.6 years of {\it Fermi}-LAT data were also analyzed. The known two pulses per period were detected with a significance of $8.0 \sigma$ and $12.6 \sigma$. In addition, significant emission was found between the two pulses with $6.2 \sigma$. We discovered the bridge emission above 50 GeV between the two main pulses. This emission can not be explained with the existing theories. These data can be used for testing new theoretical models., Comment: 5 pages, 4 figures
Published: 2014

15. Lower Bounds on Magnetic Fields in Intergalactic Voids from Long-Term GeV-TeV Light Curves of the Blazar Mrk 421

Author: Susumu Inoue, Kiyotomo Ichiki, Keitaro Takahashi, Hajime Takami, and Masaki Mori
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Sigma, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Light curve, Galaxy, Amplitude, Space and Planetary Science, Cosmic infrared background, Intergalactic travel, Blazar, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics, Fermi Gamma-ray Space Telescope, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: Lower bounds are derived on the amplitude B of intergalactic magnetic fields (IGMFs) in the region between Galaxy and the blazar Mrk 421, from constraints on the delayed GeV pair-echo flux that are emitted by secondary e^-e^+ produced in \gamma\gamma interactions between primary TeV gamma-rays and the cosmic infrared background. The distribution of galaxies mapped by the Sloan Digital Sky Survey shows that this region is dominated by a large intergalactic void. We utilize data from long-term, simultaneous GeV-TeV observations by the Fermi Large Area Telescope and the ARGO-YBJ experiment extending over 850 days. For an assumed value of B, we evaluate the daily GeV pair-echo flux expected from the TeV data, select the dates where this exceeds the Fermi 2-\sigma sensitivity, compute the probability that this flux is excluded by the Fermi data for each date, and then combine the probabilities using the inverse normal method. Consequently, we exclude B < 10^{-20.5} G for a field coherence length of 1 kpc at 4- \sigma level, as long as plasma instabilities are unimportant for cooling of the pair beam. This is much more significant than the 2-\sigma bounds we obtained previously from observations of Mrk 501, by virtue of more extensive data from the ARGO-YBJ, as well as improved statistical analysis. Compared with most other studies of IGMF bounds, the evidence we present here for a non-zero IGMF is more robust as it does not rely on unproven assumptions on the primary TeV emission during unobserved periods., Comment: 7 pages, 5 figures. to be published in ApJL
Published: 2013

16. Rapid and multi-band variability of the TeV-bright active nucleus of the galaxy IC 310

Author: Dario Hrupec, M. A. Lopez, I. Lozano, D. Dominis Prester, Takashi Saito, S. Rügamer, Juan Abel Barrio, R. Zanin, D. Borla Tridon, A. Saggion, Adrian Biland, J. Becerra González, Francisco Prada, Reiko Orito, M. Salvati, A. Sillanpää, J. Rico, I. Snidaric, Mario Meucci, Masahiro Teshima, Daniela Dorner, Stefano Covino, Christian Fruck, M. L. Knoetig, T. Krähenbühl, Nikola Godinovic, Benito Marcote, S. Wilbert, Kari Nilsson, Daniel Ferenc, Abelardo Moralejo, M. V. Fonseca, Tomislav Terzić, A. De Angelis, K. Berger, S. Spiro, E. Lorenz, D. Tescaro, Mosè Mariotti, A.-K. Overkemping, Nijil Mankuzhiyil, E. Prandini, P. Munar-Adrover, Silvia Preziuso, J. Moldón, A. Boller, L. Cossio, M. Gaug, Ignasi Reichardt, Giacomo Bonnoli, M. Palatiello, J. Kushida, Q. Weitzel, Tihomir Surić, Aldo Treves, Artemio Herrero, M. Doert, Jose Luis Contreras, D. Carreto Fidalgo, Juan Cortina, P. Temnikov, Marc Ribó, Patrick Vogler, K. Saito, B. Steinke, G. Maneva, Elisa Bernardini, Riccardo Paoletti, L. Font, V. Kadenius, Fabio Zandanel, Shan Sun, S. Paiano, L. Maraschi, Karl Mannheim, Felix Spanier, G. De Caneva, Ivica Puljak, Gianluca Giavitto, L. A. Antonelli, Elina Lindfors, Daniel Mazin, D. Garrido Terrats, Natalia Lewandowska, J. Masbou, Pierre Colin, Jörn Wilms, P. Fortin, Thomas Bretz, S. N. Shore, M. I. Martínez, Francesco Dazzi, A. González Muñoz, Saverio Lombardi, S. Bonnefoy, A. La Barbera, Konstancja Satalecka, J. M. Paredes, Antonio Stamerra, Hajime Takami, V. Scalzotto, Michele Doro, Diego F. Torres, Julia Thaele, M. Uellenbeck, Fabrizio Tavecchio, D. Häfner, R. Mirzoyan, R. Reinthal, Dominik Elsaesser, S. Partini, Wolfgang Rhode, D. Eisenacher, U. Barres de Almeida, Damir Lelas, J. Krause, Ana Babić, Emanuele Paolo Farina, B. De Lotto, Aaron Dominguez, C. Delgado Mendez, S. R. Gozzini, Dorota Sobczyńska, T. Dauser, A. Hadamek, Matthias Kadler, W. Idec, J. Storz, E. Carmona, Markus Garczarczyk, Martin Makariev, Nina Nowak, F. Krauß, E. Colombo, P. Antoranz, Oscar Blanch, P. G. Prada Moroni, Ralph Bock, L. O. Takalo, O. Tibolla, Robert Wagner, C. Schultz, V. Scapin, T. Schweizer, Jelena Aleksić, A. López-Oramas, Wlodek Bednarek, Alessandro Carosi, Ruben Lopez-Coto, D. Nakajima, A. Niedzwiecki, Jose Miguel Miranda, F. Borracci, David Paneque, K. Mallot, R. J. García López, Massimo Persic, Julian Sitarek, J. Hose, Daniela Hadasch, T. Toyama, P. Da Vela, Victor Stamatescu, Institut de Física d’Altes Energies [Barcelone] (IFAE), Universitat Autònoma de Barcelona (UAB), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Instituto de Fisica Corpuscular (IFIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Universitat de València (UV), Politecnico di Milano [Milan] (POLIMI), Universitá degli Studi dell’Insubria, Technische Universität Dortmund [Dortmund] (TU), IEEC-CSIC, Departamento de Ecología e Hidrología, Universidad de Murcia, Laboratoire d'études dynamiques et structurales de la sélectivité (LEDSS), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Département de Physique des Particules (ex SPP) (DPP), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Departament d'Astronomia i Meteorologia [Barcelona] (DAM), Universitat de Barcelona (UB), Universita degli Studi di Padova, Universidad de Cantabria [Santander], Istituto Nazionale di Fisica Nucleare, Sezione di Padova (INFN, Sezione di Padova), Istituto Nazionale di Fisica Nucleare (INFN), Max-Planck-Institut für Physik (Werner-Heisenberg-Institut) (MPI-P), Instituto de Biotecnología, Departamento de Biología Molecular de Plantas, UNAM, Institute for Physical Research (IPR), National Academy of Sciences of the Republic of Armenia [Yerevan] (NAS RA), Netherlands Institute for Radio Astronomy (ASTRON), INAF - Osservatorio Astronomico di Trieste (OAT), Istituto Nazionale di Astrofisica (INAF), Instituto de Física Teórica UAM/CSIC (IFT), Universidad Autonoma de Madrid (UAM)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Dept. of Physics, Institut de Ciencies del Cosmos (ICCUB), Kao Group, Centre de Recherches sur les Macromolécules Végétales (CERMAV), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Optoelectronic Research Centre, University of Southampton, Department of Chemistry, Oulu, INAF - Osservatorio Astronomico di Brera (OAB), Max-Planck-Institut für Kernphysik (MPIK), Max-Planck-Gesellschaft, Universität Erlangen-Nürnberg - Erlangen, German Aerospace Center (DLR), Erlangen Centre for Astroparticle Physics (ECAP), Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Universitá degli Studi dell’Insubria = University of Insubria [Varese] (Uninsubria), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Département de Physique des Particules (ex SPP) (DPhP), Università degli Studi di Padova = University of Padua (Unipd), Universidad Autónoma de Madrid (UAM)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Universitat de Barcelona
Subjects: Astrofísica, [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Photon, Spectral shape analysis, [PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Radio galaxy, Raigs còsmics, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], X-ray astronomy, Galaxies: individual: IC 310, galaxies active, galaxies individual, IC 310, gamma rays galaxies, X-rays galaxies, Gamma ray astronomy, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Galaxies: active, Gamma rays: galaxies, X-rays: galaxies, Astronomy and Astrophysics, Space and Planetary Science, Astronomia de raigs gamma, Blazar, Cosmic rays, ComputingMilieux_MISCELLANEOUS, Physics, astro-ph.HE, High Energy Astrophysical Phenomena (astro-ph.HE), Light curve, Galaxy, Astronomia de raigs X, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Galàxies actives, Active galaxies, ddc:520, Astrophysics - High Energy Astrophysical Phenomena, Schwarzschild radius, Order of magnitude
Abstract: Context. The radio galaxy IC 310 has recently been identified as a gamma-ray emitter based on observations at GeV energies with Fermi-LAT and at very high energies (VHE, E>100GeV) with the MAGIC telescopes. Originally classified as a head-tail radio galaxy, the nature of this object is subject of controversy since its nucleus shows blazar-like behavior. Aims. In order to understand the nature of IC 310 and the origin of the VHE emission we studied the spectral and flux variability of IC 310 from the X-ray band to the VHE gamma-ray regime. Methods. The light curve of IC 310 above 300GeV has been measured with the MAGIC telescopes from Oct. 2009 to Feb. 2010. Fermi-LAT data (2008-2011) in the 10-500GeV energy range were also analyzed. In X-ray, archival observations from 2003 to 2007 with XMM, Chandra, and Swift-XRT in the 0.5-10keV band were studied. Results. The VHE light curve reveals several high-amplitude and short-duration flares. Day-to-day flux variability is clearly present. The photon index between 120GeV and 8TeV remains at the value $\Gamma\sim2.0$ during both low and high flux states. The VHE spectral shape does not show significant variability, whereas the flux at 1TeV changes by a factor of $\sim7$. Fermi-LAT detected only eight gamma-ray events in the energy range 10GeV-500GeV in three years of observation. The measured photon index of $\Gamma=1.3\pm0.5$ in the Fermi-LAT range is very hard. The X-ray measurements show strong variability in flux and photon index. The latter varied from $1.76\pm0.07$ to $2.55\pm0.07$. Conclusion. The rapid variability measured confirms the blazar-like behavior of IC 310. The TeV emission seems to originate from scales of less than 80 Schwarzschild radii within the compact core of its FRI radio jet with orientation angle 10deg-38deg. The SED resembles that of an extreme blazar, albeit the luminosity is more than two orders of magnitude lower., Comment: 9 pages, 5 figures, 4 tables. Accepted for publication in A&A
Published: 2013
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17. Observations of the magnetars 4U 0142+61 and 1E 2259+586 with the MAGIC telescopes

Author: K. Berger, E. Prandini, Aldo Treves, Felix Spanier, J. Moldón, Daniel Ferenc, R. Zanin, A. Saggion, Adrian Biland, D. Dominis Prester, A. Boller, S. Partini, E. Colombo, Ivica Puljak, Francisco Prada, L. Cossio, Pierre Colin, Dario Hrupec, M. A. Lopez, Ralph Bock, L. O. Takalo, Mario Meucci, V. Scapin, S. Bonnefoy, R. Reinthal, Dominik Elsaesser, Daniela Dorner, Nijil Mankuzhiyil, J. M. Paredes, P. Munar-Adrover, P. G. Prada Moroni, U. Barres de Almeida, Damir Lelas, Nikola Godinovic, Benito Marcote, Konstancja Satalecka, P. Temnikov, Michele Doro, Antonio Stamerra, Artemio Herrero, Dorota Sobczyńska, Q. Weitzel, Tihomir Surić, D. Carreto Fidalgo, Thomas Bretz, S. N. Shore, Fabio Zandanel, M. Pilia, Aaron Dominguez, Shan Sun, Takashi Saito, Ignasi Reichardt, M. Gaug, Jelena Aleksić, Stefano Covino, Giacomo Bonnoli, Marc Ribó, Martin Makariev, Oscar Blanch, Reiko Orito, T. Schweizer, O. Tibolla, R. Mirzoyan, V. Kadenius, S. Paiano, Karl Mannheim, Julian Sitarek, Nanda Rea, S. Rügamer, A. López-Oramas, K. Saito, D. Eisenacher, A. Niedzwiecki, Wlodek Bednarek, Alessandro Carosi, Natalia Lewandowska, Juan Abel Barrio, M. Asensio, J. Hose, M. Doert, Elisa Bernardini, D. Borla Tridon, F. Jankowski, A. La Barbera, Ruben Lopez-Coto, M. Uellenbeck, A. Hadamek, G. Maneva, D. Tescaro, D. Nakajima, Daniel Nieto, T. Toyama, J. Storz, Mosè Mariotti, G. De Caneva, E. Carmona, Markus Garczarczyk, David Paneque, M. Palatiello, Jose Miguel Miranda, Nina Nowak, M. L. Knoetig, D. Garrido Terrats, P. Antoranz, C. Delgado Mendez, S. R. Gozzini, K. Mallot, Wolfgang Rhode, A. De Angelis, J. Rico, L. Maraschi, M. V. Fonseca, Francesco Dazzi, Tomislav Terzić, Saverio Lombardi, R. J. García López, V. Scalzotto, Elina Lindfors, Christian Fruck, M. Salvati, E. Leonardo, Daniel Mazin, A. Sillanpää, Gianluca Giavitto, P. Da Vela, B. Steinke, A. González Muñoz, Riccardo Paoletti, Victor Stamatescu, J. Masbou, I. Lozano, D. Hadasch, M. I. Martínez, Robert Wagner, Massimo Persic, T. Krähenbühl, C. Schultz, Masahiro Teshima, J. Kushida, Jose Luis Contreras, L. Font, Hajime Takami, Juan Cortina, Kari Nilsson, Patrick Vogler, L. A. Antonelli, Fabrizio Tavecchio, I. Snidaric, S. Spiro, E. Lorenz, Diego F. Torres, Abelardo Moralejo, J. Krause, B. De Lotto, S. Klepser, Universitat de Barcelona, Istituto Nazionale di Fisica Nucleare, Sezione di Padova (INFN, Sezione di Padova), Istituto Nazionale di Fisica Nucleare (INFN), Institut de Física d’Altes Energies [Barcelone] (IFAE), Universitat Autònoma de Barcelona (UAB), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Instituto de Fisica Corpuscular (IFIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Universitat de València (UV), Politecnico di Milano [Milan] (POLIMI), Universitá degli Studi dell’Insubria, Technische Universität Dortmund [Dortmund] (TU), IEEC-CSIC, Departamento de Ecología e Hidrología, Universidad de Murcia, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Friedrich-Alexander-Universität, Deutsches Elektronen-Synchrotron [Zeuthen] (DESY), Helmholtz-Gemeinschaft = Helmholtz Association, Laboratoire d'études dynamiques et structurales de la sélectivité (LEDSS), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Département de Physique des Particules (ex SPP) (DPP), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Departament d'Astronomia i Meteorologia [Barcelona] (DAM), Universitat de Barcelona (UB), Universita degli Studi di Padova, Universidad de Cantabria [Santander], Max-Planck-Institut für Physik (Werner-Heisenberg-Institut) (MPI-P), Instituto de Biotecnología, Departamento de Biología Molecular de Plantas, UNAM, Institute for Physical Research (IPR), National Academy of Sciences of the Republic of Armenia [Yerevan] (NAS RA), Netherlands Institute for Radio Astronomy (ASTRON), INAF - Osservatorio Astronomico di Trieste (OAT), Istituto Nazionale di Astrofisica (INAF), INAF-Cagliari Astronomical Observatory, Instituto de Física Teórica UAM/CSIC (IFT), Universidad Autonoma de Madrid (UAM)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Dept. of Physics, Institut de Ciencies del Cosmos (ICCUB), Kao Group, Centre de Recherches sur les Macromolécules Végétales (CERMAV), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Optoelectronic Research Centre, University of Southampton, Department of Chemistry, Oulu, INAF - Osservatorio Astronomico di Brera (OAB), Max-Planck-Institut für Kernphysik (MPIK), Max-Planck-Gesellschaft, Institut de Ciencies de l'Espai [Barcelona] (ICE-CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Universitá degli Studi dell’Insubria = University of Insubria [Varese] (Uninsubria), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Département de Physique des Particules (ex SPP) (DPhP), Università degli Studi di Padova = University of Padua (Unipd), Universidad Autónoma de Madrid (UAM)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], High energy, [PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], astro-ph.GA, Astronomy, FOS: Physical sciences, Astrophysics, Magnetar, 01 natural sciences, Neutron stars, law.invention, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Telescope, law, Gamma ray astronomy, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Astronomia de raigs gamma, Analysis software, 010306 general physics, 010303 astronomy & astrophysics, Cherenkov radiation, Estels de neutrons, astro-ph.HE, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Telescopis, Magic (programming), Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, radiation mechanisms: non-thermal, stars: magnetars, gamma rays: stars, stars: individual: 4U 0142+61, 1E 2259+586, Neutron star, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astronomia, ddc:520, Astrophysics - High Energy Astrophysical Phenomena, High magnetic field, Telescopes
Abstract: Astronomy and astrophysics 549(A23), 1-4 (2013). doi:10.1051/0004-6361/201220275, Magnetars are an extreme, highly magnetized class of isolated neutron stars whose large X-ray luminosity is believed to be driven by their high magnetic field. In this work we study for the first time the possible very high energy gamma-ray emission above 100 GeV from magnetars, observing the sources 4U 0142+61 and 1E 2259+586. We observed the two sources with atmospheric Cherenkov telescopes in the very high energy range (E > 100 GeV). 4U 0142+61 was observed with the MAGIC I telescope in 2008 for ~25 h and 1E 2259+586 was observed with the MAGIC stereoscopic system in 2010 for ~14 h. The data were analyzed with the standard MAGIC analysis software. Neither magnetar was detected. Upper limits to the differential and integral flux above 200 GeV were computed using the Rolke algorithm. We obtain integral upper limits to the flux of 1.52*10^-12cm^-2 s^-1 and 2.7*10^-12cm^-2 s^-1 with a confidence level of 95% for 4U 0142+61 and 1E 2259+586, respectively. The resulting differential upper limits are presented together with X-ray data and upper limits in the GeV energy range., Published by EDP Sciences, Les Ulis
Published: 2012

18. ISOTROPY CONSTRAINTS ON POWERFUL SOURCES OF ULTRAHIGH-ENERGY COSMIC RAYS AT 1019eV

Author: Hajime Takami, Kohta Murase, and Charles D. Dermer
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Pierre Auger Observatory, Physics, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astronomy and Astrophysics, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Universe, Redshift, Galaxy, Luminosity, Space and Planetary Science, 0103 physical sciences, Intergalactic travel, Astrophysics - High Energy Astrophysical Phenomena, Anisotropy, 010303 astronomy & astrophysics, media_common
Abstract: Anisotropy in the arrival direction distribution of ultrahigh-energy cosmic rays (UHECRs) produced by powerful sources is numerically evaluated. We show that, taking account of the Galactic magnetic field, nondetection of significant anisotropy at $\approx 10^{19}$ eV at present and in future experiments imposes general upper limits on UHECR proton luminosity of steady sources as a function of source redshifts. The upper limits constrain the existence of typical steady sources in the local universe and limit the local density of $10^{19}$ eV UHECR sources to be $\gtrsim 10^{-3}$ Mpc$^{-3},$ assuming average intergalactic magnetic fields less than $10^{-9}$ G. This isotropy, which is stronger than measured at the highest energies, may indicate the transient generation of UHECRs. Our anisotropy calculations are applied for extreme high-frequency-peaked BL Lac objects 1ES 0229+200, 1ES 1101-232, and 1ES 0347-121, to test the UHECR-induced cascade model, in which beamed UHECR protons generate TeV radiation in transit from sources. While the magnetic-field structure surrounding the sources affects the required absolute cosmic-ray luminosity of the blazars, the magnetic-field structure surrounding the Milky Way directly affects the observed anisotropy. If both of the magnetic fields are weak enough, significant UHECR anisotropy from these blazars should be detectable by the Pierre Auger Observatory unless the maximum energy of UHECR protons is well below $10^{19}$ eV. Furthermore, if these are the sources of UHECRs above $10^{19}$ eV, a local magnetic structure surrounding the Milky Way is needed to explain the observed isotropy at $\sim 10^{19}$ eV, which may be incompatible with large magnetic structures around all galaxies for the UHECR-induced cascade model to work with reasonable jet powers., Comment: 15 pages, 10 figures, accepted for publication in The Astrophysical Journal
Published: 2016

19. PG 1553+113: five years of observations with MAGIC

Author: R. Reinthal, Dominik Elsaesser, Damir Lelas, S. Spiro, E. Lorenz, Dorota Sobczyńska, F. D'Ammando, M. I. Martínez, Michael Backes, T. Krähenbühl, S. Klepser, Kari Nilsson, D. Tescaro, N. Strah, P. G. Prada Moroni, Denis Bastieri, Q. Weitzel, Tihomir Surić, J. Moldón, M. Pilia, Andrei Berdyugin, M. Salvati, Gianluca Giavitto, D. Dominis Prester, Karl Mannheim, A. Boller, L. Cossio, E. Colombo, O. Tibolla, E. Prandini, Jose Luis Contreras, Francisco Prada, Artemio Herrero, Juan Cortina, Aldo Treves, Daniel Ferenc, K. Saito, Hiroko Miyamoto, A. La Barbera, Daniela Dorner, C. Schultz, V. Scapin, Silvia Pardo, P. Temnikov, H. Vankov, Ilana M. Braun, Fabio Zandanel, K. Berger, J. Krause, A. Cañellas, Ivica Puljak, Pierre Colin, B. De Lotto, Victor Stamatescu, S. Partini, D. Höhne-Mönch, Jelena Aleksić, M. Shayduk, Aaron Dominguez, Tomislav Terzić, A. López-Oramas, Abelardo Moralejo, Dario Hrupec, Stefano Covino, Wlodek Bednarek, Alessandro Carosi, Patrick Vogler, J. Becerra González, Elisa Bernardini, Nijil Mankuzhiyil, D. Horan, H. Kellermann, P. Munar-Adrover, M. A. Lopez, V. Scalzotto, Felix Spanier, Riccardo Paoletti, Masahiro Teshima, Mario Meucci, Felicitas Pauss, Victor Zabalza, D. Garrido, Thomas Bretz, Julian Sitarek, D. Hildebrand, L. Peruzzo, Ralph Bock, S. N. Shore, J. Hose, Marc Ribó, M. Uellenbeck, Jose Miguel Miranda, J. M. Paredes, Martin Makariev, G. De Caneva, Daniela Hadasch, Antonio Stamerra, S. Buson, Oscar Blanch, T. Jogler, E. A. Alvarez, L. O. Takalo, J. Storz, Wolfgang Rhode, Nikola Godinovic, B. Huber, E. Carmona, Giacomo Bonnoli, E. De Cea del Pozo, Francesco Dazzi, Diego F. Torres, M. Pasanen, Hajime Takami, R. J. García López, Ignasi Reichardt, David Paneque, E. Leonardo, T. Schweizer, L. Maraschi, Elina Lindfors, Daniel Mazin, P. Antoranz, M. Doert, S. Larsson, Massimo Persic, M. Asensio, Daniel Nieto, G. Maneva, Konstancja Satalecka, Michele Doro, A. Saggion, A. Diago Ortega, Robert Wagner, Adrian Biland, Mosè Mariotti, J. Rico, A. De Angelis, Saverio Lombardi, J. Pochon, D. Häfner, R. Mirzoyan, Markus Garczarczyk, Takashi Saito, L. A. Antonelli, R. Zanin, Igor Oya, Fabrizio Tavecchio, Ll. Font, Reiko Orito, M. A. Perez-Torres, A. Sillanpää, M. V. Fonseca, Christian Fruck, B. Steinke, S. Rügamer, Juan Abel Barrio, D. Borla Tridon, C. Delgado Mendez, Aleksic J, Alvarez EA, Antonelli LA, Antoranz P, Asensio M, Backes M, Barrio JA, Bastieri D, Gonzalez JB, Bednarek W, Berdyugin A, Berger K, Bernardini E, Biland A, Blanch O, Bock RK, Boller A, Bonnoli G, Tridon DB, Braun I, Bretz T, Canellas A, Carmona E, Carosi A, Colin P, Colombo E, Contreras JL, Cortina J, Cossio L, Covino S, Dazzi F, De Angelis A, De Caneva G, del Pozo ED, De Lotto B, Mendez CD, Ortega AD, Doert M, Dominguez A, Prester DD, Dorner D, Doro M, Elsaesser D, Ferenc D, Fonseca MV, Font L, Fruck C, Lopez RJG, Garczarczyk M, Garrido D, Giavitto G, Godinovic N, Hadasch D, Hafner D, Herrero A, Hildebrand D, Ohne-Monch DH, Hose J, Hrupec D, Huber B, Jogler T, Kellermann H, Klepser S, Krahenbuhl T, Krause J, La Barbera A, Lelas D, Leonardo E, Lindfors E, Lombardi S, Lopez M, Lopez-Oramas A, Lorenz E, Makariev M, Maneva G, Mankuzhiyil N, Mannheim K, Maraschi L, Mariotti M, Martinez M, Mazin D, Meucci M, Miranda JM, Mirzoyan R, Miyamoto H, Moldon J, Moralejo A, Munar-Adrover P, Nieto D, Nilsson K, Orito R, Oya I, Paneque D, Paoletti R, Pardo S, Paredes JM, Partini S, Pasanen M, Pauss F, Perez-Torres MA, Persic M, Peruzzo L, Pilia M, Pochon J, Prada F, Moroni PGP, Prandini E, Puljak I, Reichardt I, Reinthal R, Rhode W, Ribo M, Rico J, Rugamer S, Saggion A, Saito K, Saito TY, Salvati M, Satalecka K, Scalzotto V, Scapin V, Schultz C, Schweizer T, Shayduk M, Shore SN, Sillanpaa A, Sitarek J, Sobczynska D, Spanier F, Spiro S, Stamatescu V, Stamerra A, Steinke B, Storz J, Strah N, Suric T, Takalo L, Takami H, Tavecchio F, Temnikov P, Terzic T, Tescaro D, Teshima M, Tibolla O, Torres DF, Treves A, Uellenbeck M, Vankov H, Vogler P, Wagner RM, Weitzel Q, Zabalza V, Zandanel F, Zanin R, Buson S, Horan D, Larsson S, and DAmmando F
Subjects: Flux, Astrophysics, 01 natural sciences, Raigs gamma, MAGIC (telescope), 010303 astronomy & astrophysics, astro-ph.HE, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), TEV BLAZARS, Gamma ray, radiation mechanisms: non-thermal, gamma-rays: observations, BL Lacertae objects: individual (PG 1553+113), astro-ph.CO, BL LACERTAE OBJECTS, Spectral energy distribution, Electrónica, Física nuclear, Electricidad, Astrophysics - High Energy Astrophysical Phenomena, BL Lac object, Astrophysics - Cosmology and Nongalactic Astrophysics, ACTIVE GALACTIC NUCLEI, Cosmology and Nongalactic Astrophysics (astro-ph.CO), TELESCOPE, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, gamma ray astronomy, Cosmic rays, IMAGING CHERENKOV DETECTOR, FERMI, 0103 physical sciences, Blazar, MULTIWAVELENGTH OBSERVATIONS, BL Lacertae objects: individual (PG 1553+113) – gamma rays: galaxies – radiation mechanisms: non-thermal, 010308 nuclear & particles physics, Gamma rays, Astronomy and Astrophysics, Galaxies, Galàxies, EXTRAGALACTIC BACKGROUND LIGHT, Crab Nebula, Space and Planetary Science, LAC OBJECTS, ddc:520, SKY SURVEY, GAMMA-RAY EMISSION, Fermi Gamma-ray Space Telescope
Abstract: We present the results of five years (2005-2009) of MAGIC observations of the BL Lac object PG 1553+113 at very high energies (VHEs, E > 100 GeV). Power law fits of the individual years are compatible with a steady mean photon index ��= 4.27 $\pm$ 0.14. In the last three years of data, the flux level above 150 GeV shows a clear variability (probability of constant flux < 0.001%). The flux variations are modest, lying in the range from 4% to 11% of the Crab Nebula flux. Simultaneous optical data also show only modest variability that seems to be correlated with VHE gamma ray variability. We also performed a temporal analysis of (all available) simultaneous Fermi/LAT data of PG 1553+113 above 1 GeV, which reveals hints of variability in the 2008-2009 sample. Finally, we present a combination of the mean spectrum measured at very high energies with archival data available for other wavelengths. The mean spectral energy distribution can be modeled with a one-zone Synchrotron Self Compton (SSC) model, which gives the main physical parameters governing the VHE emission in the blazar jet., 11 pages, 6 figures, accepted for publication in ApJ
Published: 2012

20. Discovery of VHE gamma-rays from the blazar 1ES 1215+303 with the MAGIC Telescopes and simultaneous multi-wavelength observations

Author: I. Snidaric, Aaron Dominguez, M. Makariev, Victor Zabalza, S. Spiro, E. Lorenz, Daniela Dorner, R. J. García López, I. Puerto Gimenez, Natalia Lewandowska, S. Larsson, Massimo Persic, Elisa Bernardini, D. Hildebrand, F. Jankowski, A. La Barbera, Abelardo Moralejo, W. Bednarek, Fabrizio Tavecchio, K. Berger, M. I. Martínez, Gianluca Giavitto, E. A. Alvarez, A. González Muñoz, K. Saito, Patrick Vogler, Silvia Pardo, Dario Hrupec, Joni Tammi, B. Huber, P. G. Prada Moroni, S. Partini, A. De Angelis, J. Becerra González, M. A. Lopez, S. Rügamer, E. De Cea del Pozo, A. Boller, Ignasi Reichardt, Juan Abel Barrio, L. Cossio, A. Diago Ortega, Robert Wagner, T. Krähenbühl, D. Eisenacher, O. Tibolla, Mario Meucci, V. Scapin, Artemio Herrero, L. Maraschi, D. Borla Tridon, G. Maneva, Stefano Ansoldi, E. Carmona, Jelena Aleksić, N. Strah, Nikola Godinovic, Markus Garczarczyk, Riccardo Paoletti, Andrei Berdyugin, Tomislav Terzić, T. Jogler, R. Zanin, A. Saggion, A. Niedzwiecki, Adrian Biland, Emilia Järvelä, Nina Nowak, Daniel Ferenc, M. Asensio, Denis Bastieri, Q. Weitzel, J. M. Paredes, C. Schultz, J. Rico, Diego F. Torres, David Paneque, Tihomir Surić, Antonio Stamerra, Oscar Blanch, Marc Ribó, Louis Antonelli, M. Salvati, V. Kadenius, S. Paiano, C. Delgado Mendez, S. R. Gozzini, M. Doert, Michael Backes, J. Hose, A. Sillanpää, M. A. Perez-Torres, Karl Mannheim, Felix Spanier, L. Font, Francesco Dazzi, M. V. Fonseca, E. Colombo, J. Krause, D. Elsaesser, J. Storz, G. Bonnoli, E. Leonardo, P. Antoranz, B. De Lotto, Nijil Mankuzhiyil, Christian Fruck, Hajime Takami, P. Munar-Adrover, Kari Nilsson, Daniel Nieto, Thomas Bretz, Konstancja Satalecka, Michele Doro, S. N. Shore, D. Dominis Prester, S. Klepser, B. Steinke, G. De Caneva, Hanna Kellermann, M. Pilia, Francisco Prada, A. López-Oramas, Alessandro Carosi, D. Garrido Terrats, A. Cañellas, Ruben Lopez-Coto, Ralph Bock, V. Scalzotto, L. O. Takalo, Wolfgang Rhode, Jose Miguel Miranda, J. Moldón, D. Häfner, S. Buson, T. Schweizer, Jose Luis Contreras, Juan Cortina, Mosè Mariotti, Ivica Puljak, Pierre Colin, Saverio Lombardi, J. Pochon, R. Reinthal, Razmik Mirzoyan, U. Barres de Almeida, Damir Lelas, Elina Lindfors, Daniel Mazin, Dorota Sobczyńska, Stefano Covino, D. Tescaro, E. Prandini, Takashi Saito, Aldo Treves, Reiko Orito, P. Da Vela, Julian Sitarek, Victor Stamatescu, P. Temnikov, Fabio Zandanel, Shan Sun, D. Hadasch, Anne Lähteenmäki, Masahiro Teshima, M. Uellenbeck, Department of Radio Science and Engineering, School services, ELEC, Aalto-yliopisto, Aalto University, and Anne Lähteenmäki Group
Subjects: gamma-rays: galaxies, Astrophysics::High Energy Astrophysical Phenomena, education, FOS: Physical sciences, Astrophysics, gamma ray astronomy, Cosmic rays, IMAGING CHERENKOV DETECTOR, 01 natural sciences, law.invention, Telescope, Radio telescope, law, BL Lacertae objects: individual: 1ES 1215+303, Target of opportunity, 0103 physical sciences, Gamma ray astronomy, Astronomia de raigs gamma, Blazar, 010303 astronomy & astrophysics, individual: 1ES 1215+303 [BL Lacertae objects], Physics, High Energy Astrophysical Phenomena (astro-ph.HE), astro-ph.HE, 010308 nuclear & particles physics, 213 Electronic, automation and communications engineering, electronics, Optical polarization, Astronomy and Astrophysics, Galaxies, Galàxies, galaxies [gamma-rays], Space and Planetary Science, 115 Astronomy and space science, Spectral energy distribution, ddc:520, Electrónica, Física nuclear, Electricidad, Astrophysics - High Energy Astrophysical Phenomena, Fermi Gamma-ray Space Telescope, BL Lac object
Abstract: Context. We present the discovery of very high energy (VHE, E > 100GeV) gamma-ray emission from the BL Lac object 1ES 1215+303 by the MAGIC telescopes and simultaneous multi-wavelength data in a broad energy range from radio to gamma-rays. Aims. We study the VHE gamma-ray emission from 1ES 1215+303 and its relation to the emissions in other wavelengths. Methods. Triggered by an optical outburst, MAGIC observed the source in January-February 2011 for 20.3 hrs. The target was monitored in the optical R-band by the KVA telescope that also performed optical polarization measurements. We triggered target of opportunity observations with the Swift satellite and obtained simultaneous and quasi-simultaneous data from the Fermi Large Area Telescope and from the Mets��hovi radio telescope. We also present the analysis of older MAGIC data taken in 2010. Results. The MAGIC observations of 1ES 1215+303 carried out in January-February 2011 resulted in the first detection of the source at VHE with a statistical significance of 9.4 sigma. Simultaneously, the source was observed in a high optical and X-ray state. In 2010 the source was observed in a lower state in optical, X-ray, and VHE, while the GeV gamma-ray flux and the radio flux were comparable in 2010 and 2011. The spectral energy distribution obtained with the 2011 data can be modeled with a simple one zone SSC model, but it requires extreme values for the Doppler factor or the electron energy distribution., 10 pages, 8 figures, accepted to A&A
Published: 2012

21. Phase-resolved energy spectra of the Crab pulsar in the range of 50-400 GeV measured with the MAGIC telescopes

Author: Adrian Biland, Aaron Dominguez, K. Berger, L. Maraschi, Elina Lindfors, Daniel Mazin, Fabio Zandanel, E. Colombo, S. Partini, D. Höhne-Mönch, Felix Spanier, Abelardo Moralejo, K. Saito, J. M. Paredes, Ralph Bock, L. O. Takalo, Victor Stamatescu, Stefano Covino, Antonio Stamerra, M. V. Fonseca, M. Uellenbeck, M. Shayduk, R. Reinthal, D. Eisenacher, V. Scalzotto, P. Antoranz, Oscar Blanch, Victor Zabalza, Christian Fruck, Patrick Vogler, Dominik Elsaesser, J. Moldón, Ignasi Reichardt, D. Dominis Prester, P. G. Prada Moroni, E. Carmona, Markus Garczarczyk, Silvia Pardo, T. Schweizer, Damir Lelas, J. Storz, D. Häfner, M. Doert, Michael Backes, T. Jogler, J. Krause, B. De Lotto, O. Tibolla, B. Steinke, C. Delgado Mendez, Nina Nowak, L. A. Antonelli, Nijil Mankuzhiyil, P. Munar-Adrover, Francisco Prada, Dorota Sobczyńska, G. Maneva, Konstancja Satalecka, Michele Doro, S. Klepser, Mosè Mariotti, Daniel Ferenc, Jelena Aleksić, Francesco Dazzi, Daniela Dorner, Elisa Prandini, M. A. Perez-Torres, H. Vankov, A. Niedzwiecki, W. Bednarek, S. Rügamer, Diego F. Torres, Ilana M. Braun, M. Pilia, E. Leonardo, Juan Abel Barrio, Kari Nilsson, David Paneque, Fabrizio Tavecchio, M. Asensio, Aldo Treves, D. Borla Tridon, A. Sillanpää, I. Puljak, Masahiro Teshima, Petar Temnikov, Julian Sitarek, Ll. Font, Elisa Bernardini, H. Kellermann, A. Cañellas, E. De Cea del Pozo, Saverio Lombardi, Takashi Saito, Gianluca Giavitto, G. Bonnoli, Pierre Colin, R. J. García López, J. Pochon, Jose Luis Contreras, A. Diago Ortega, Robert Wagner, Riccardo Paoletti, Dario Hrupec, Reiko Orito, J. Hose, Daniela Hadasch, Juan Cortina, M. A. Lopez, I. Snidaric, A. De Angelis, M. Salvati, Tomislav Terzić, J. Kushida, Thomas Bretz, S. N. Shore, R. Mirzoyan, S. Spiro, E. Lorenz, Wolfgang Rhode, Daniel Nieto, Marc Ribó, A. Boller, L. Cossio, Artemio Herrero, M. Makariev, J. Rico, I. Puerto Gimenez, Roberta Zanin, D. Hildebrand, L. Peruzzo, M. I. Martínez, D. Tescaro, T. Krähenbühl, N. Strah, A. López-Oramas, Alessandro Carosi, D. Garrido, Jose Miguel Miranda, Kouichi Hirotani, Hajime Takami, Andrei Berdyugin, G. De Caneva, C. Schultz, Massimo Persic, V. Scapin, E. A. Alvarez, Nikola Godinovic, Denis Bastieri, Q. Weitzel, Tihomir Surić, Karl Mannheim, Natalia Lewandowska, A. La Barbera, J. Becerra González, Mario Meucci, and A. Saggion
Subjects: Photon, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Flux, Astrophysics, ACCELERATION, 01 natural sciences, Spectral line, gamma rays: stars, pulsars: individual: Crab Pulsar, Raigs gamma, SLOT GAPS, Pulsar, NEBULA, OUTER MAGNETOSPHERE, 0103 physical sciences, MAGIC (telescope), 010306 general physics, 010303 astronomy & astrophysics, Cosmic rays, Pulsars, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, astro-ph.HE, Crab Pulsar, gamma ray astronomy, IMAGING CHERENKOV DETECTOR, Gamma rays, Compton scattering, Astronomy and Astrophysics, GAMMA-RAY EMISSION, RADIATION, WIND, Stars, Estels, Púlsars, Crab Nebula, Space and Planetary Science, ddc:520, Electrónica, Física nuclear, Electricidad, Astrophysics - High Energy Astrophysical Phenomena
Abstract: We use 73 h of stereoscopic data taken with the MAGIC telescopes to investigate the very high-energy (VHE) gamma-ray emission of the Crab pulsar. Our data show a highly significant pulsed signal in the energy range from 50 to 400 GeV in both the main pulse (P1) and the interpulse (P2) phase regions. We provide the widest spectra to date of the VHE components of both peaks, and these spectra extend to the energy range of satellite-borne observatories. The good resolution and background rejection of the stereoscopic MAGIC system allows us to cross-check the correctness of each spectral point of the pulsar by comparison with the corresponding (strong and well-known) Crab nebula flux. The spectra of both P1 and P2 are compatible with power laws with photon indices of 4.0 \pm 0.8 (P1) and 3.42 \pm 0.26 (P2), respectively, and the ratio P1/P2 between the photon counts of the two pulses is 0.54 \pm 0.12. The VHE emission can be understood as an additional component produced by the inverse Compton scattering of secondary and tertiary e\pm pairs on IR-UV photons., 6 pages, 4 figures. Accepted for publication in A&A on 16 February 2012
Published: 2012

22. Morphological and spectral properties of the W51 region measured with the MAGIC telescopes

Author: R. Zanin, A. Saggion, Nikola Godinovic, Daniel Nieto, Adrian Biland, Gianluca Giavitto, A. González Muñoz, Hanna Kellermann, Takashi Saito, J. M. Paredes, Antonio Stamerra, D. Dominis Prester, P. G. Prada Moroni, D. Häfner, O. Tibolla, T. Jogler, R. Reinthal, Nina Nowak, L. Maraschi, Elina Lindfors, R. J. García López, J. Rico, Dominik Elsaesser, Francesco Dazzi, M. V. Fonseca, Reiko Orito, U. Barres de Almeida, Aaron Dominguez, Daniel Mazin, E. Leonardo, Silvia Pardo, J. Storz, Nijil Mankuzhiyil, Giacomo Bonnoli, Christian Fruck, Damir Lelas, P. Munar-Adrover, M. A. Perez-Torres, Victor Stamatescu, Francisco Prada, M. I. Martínez, M. Asensio, A. Cañellas, J. Krause, A. Diago Ortega, Robert Wagner, Massimo Persic, B. De Lotto, Dorota Sobczyńska, G. De Caneva, Louis Antonelli, B. Steinke, Victor Zabalza, Denis Bastieri, Q. Weitzel, C. Delgado Mendez, S. R. Gozzini, Stefano Covino, T. Krähenbühl, Tihomir Surić, Tomislav Terzić, R. Mirzoyan, Riccardo Paoletti, D. Eisenacher, Daniela Dorner, S. Rügamer, N. Strah, E. Colombo, Ralph Bock, E. Carmona, Markus Garczarczyk, Konstancja Satalecka, Michele Doro, E. Prandini, K. Berger, S. Klepser, Juan Abel Barrio, Dario Hrupec, M. A. Lopez, L. O. Takalo, Jelena Aleksić, D. Tescaro, Masahiro Teshima, A. Boller, L. Cossio, A. Niedzwiecki, D. Borla Tridon, Aldo Treves, M. Salvati, Mosè Mariotti, Julian Sitarek, Marc Ribó, Elisa Bernardini, David Paneque, M. Uellenbeck, A. Sillanpää, Diego F. Torres, J. Hose, Daniela Hadasch, B. Huber, Artemio Herrero, V. Kadenius, Felix Spanier, A. De Angelis, Abelardo Moralejo, S. Paiano, Ignasi Reichardt, Saverio Lombardi, Ivica Puljak, Pierre Colin, P. Temnikov, Hajime Takami, Daniel Ferenc, Karl Mannheim, Fabio Zandanel, P. Da Vela, Shan Sun, J. Pochon, G. Maneva, Natalia Lewandowska, F. Jankowski, I. Puerto Gimenez, A. La Barbera, T. Schweizer, C. Schultz, V. Scapin, D. Hildebrand, J. Becerra González, Mario Meucci, P. Antoranz, S. Partini, Martin Makariev, Oscar Blanch, M. Doert, Michael Backes, A. López-Oramas, Wlodek Bednarek, Alessandro Carosi, Ruben Lopez-Coto, Thomas Bretz, D. Garrido, S. N. Shore, M. Pilia, Jose Miguel Miranda, Wolfgang Rhode, E. De Cea del Pozo, V. Scalzotto, J. Moldón, Fabrizio Tavecchio, Kari Nilsson, Ll. Font, I. Snidaric, S. Spiro, E. Lorenz, Jose Luis Contreras, K. Saito, Juan Cortina, Patrick Vogler, and E. A. Alvarez
Subjects: Hadron, Astrophysics, MOLECULAR CLOUD, 01 natural sciences, Pulsar wind nebula, SUPERNOVA REMNANT W51C, Raigs gamma, MHZ, Supernova remnant, 010303 astronomy & astrophysics, Physics, astro-ph.HE, High Energy Astrophysical Phenomena (astro-ph.HE), Supernoves, Acceleradors de partícules, gamma ray astronomy, IMAGING CHERENKOV DETECTOR, Cosmic rays, Gamma ray, NONTHERMAL EMISSION, GAMMA-RAY EMISSION, GALACTIC COSMIC-RAYS, ACCELERATION, DISCOVERY, RADIATION, Supernovae, Spectral energy distribution, Electrónica, Física nuclear, Electricidad, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, acceleration of particles, gamma rays: general, ISM: supernova remnants, ISM: clouds, gamma rays: ISM, 0103 physical sciences, 010306 general physics, Astrophysics::Galaxy Astrophysics, Molecular cloud, Gamma rays, Astronomy and Astrophysics, Particle accelerators, 13. Climate action, Space and Planetary Science, ddc:520, Fermi Gamma-ray Space Telescope
Abstract: The W51 complex hosts the supernova remnant W51C which is known to interact with the molecular clouds in the star forming region W51B. In addition, a possible pulsar wind nebula CXO J192318.5+140305 was found likely associated with the supernova remnant. Gamma-ray emission from this region was discovered by Fermi/LAT (between 0.2 and 50 GeV) and H.E.S.S. (>1 TeV). The spatial distribution of the events could not be used to pinpoint the location of the emission among the pulsar wind nebula, the supernova remnant shell and/or the molecular cloud. However, the modeling of the spectral energy distribution presented by the Fermi/LAT collaboration suggests a hadronic emission mechanism. We performed observations of the W51 complex with the MAGIC telescopes for more than 50 hours. The good angular resolution in the medium (few hundred GeV) to high (above 1 TeV) energies allow us to perform morphological studies. We detect an extended emission of very-high-energy gamma rays, with a significance of 11 standard deviations. We extend the spectrum from the highest Fermi/LAT energies to \sim 5 TeV and find that it follows a single power law with an index of 2.58 \pm 0.07stat \pm 0.22syst . The main part of the emission coincides with the shocked cloud region, while we find a feature extending towards the pulsar wind nebula. The possible contribution of the pulsar wind nebula, assuming a point-like source, shows no dependence on energy and it is about 20% of the overall emission. The broad band spectral energy distribution can be explained with a hadronic model that implies proton acceleration above 100 TeV. This result, together with the morphology of the source, tentatively suggests that we observe ongoing acceleration of ions in the interaction zone between supernova remnant and cloud. These results shed light on the long-standing problem of the origin of galactic cosmic rays., 11 pages, 7 figures, accepted by A&A, corresponding authors: J. Krause, I Reichardt, E. Carmona
Published: 2012
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23. Blazars as Ultra-high-energy Cosmic-ray Sources: Implications for TeV Gamma-Ray Observations

Author: G. Migliori, Kohta Murase, Charles D. Dermer, Hajime Takami, and Murase, K. and Dermer, C.~D. and Takami, H. and Migliori, G.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Active galactic nucleus, Radio galaxy, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astronomy and Astrophysics, Cosmic ray, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Cherenkov Telescope Array, Luminosity, symbols.namesake, cosmic rays, galaxies: active, gamma rays: galaxies, Space and Planetary Science, Eddington luminosity, symbols, Ultra-high-energy cosmic ray, Astrophysics - High Energy Astrophysical Phenomena, Blazar, Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: The spectra of BL Lac objects and Fanaroff-Riley I radio galaxies are commonly explained by the one-zone leptonic synchrotron self-Compton (SSC) model. Spectral modeling of correlated multiwavelength data gives the comoving magnetic field strength, the bulk outflow Lorentz factor and the emission region size. Assuming the validity of the SSC model, the Hillas condition shows that only in rare cases can such sources accelerate protons to much above 10^19 eV, so > 10^20 eV ultra-high-energy cosmic rays (UHECRs) are likely to be heavy ions if powered by this type of radio-loud active galactic nuclei (AGN). Survival of nuclei is shown to be possible in TeV BL Lacs and misaligned counterparts with weak photohadronic emissions. Another signature of hadronic production is intergalactic UHECR-induced cascade emission, which is an alternative explanation of the TeV spectra of some extreme non-variable blazars such as 1ES 0229+200 or 1ES 1101-232. We study this kind of cascade signal, taking into account effects of the structured extragalactic magnetic fields in which the sources should be embedded. We demonstrate the importance of cosmic-ray deflections on the gamma-ray flux, and show that required absolute cosmic-ray luminosities are larger than the average UHECR luminosity inferred from UHECR observations and can even be comparable to the Eddington luminosity of supermassive black holes. Future TeV gamma-ray observations using the Cherenkov Telescope Array and the High Altitude Water Cherenkov detector array can test for UHECR acceleration by observing >25 TeV photons from relatively low-redshift sources such as 1ES 0229+200, and > TeV photons from more distant radio-loud AGN., 14 pages, 9 figures, 2 tables, accepted for publication in ApJ, references and discussions added
Published: 2012

24. MAGIC observations of the giant radio galaxy M 87 in a low-emission state between 2005 and 2007

Author: Jose Luis Contreras, T. Schweizer, M. A. Perez-Torres, Juan Cortina, L. Maraschi, Elina Lindfors, P. Antoranz, Daniel Nieto, K. Saito, Daniel Mazin, D. Dominis Prester, Hanna Kellermann, A. Cañellas, D. Hadasch, Daniela Dorner, Stefano Covino, Abelardo Moralejo, Thomas Bretz, S. N. Shore, M. Pilia, Patrick Vogler, Francisco Prada, E. A. Alvarez, A. López-Oramas, Takashi Saito, Masahiro Teshima, M. Doert, Michael Backes, R. Mirzoyan, Giacomo Bonnoli, Wlodek Bednarek, Alessandro Carosi, L. A. Antonelli, K. Berger, Tomislav Terzić, M. Gaug, Reiko Orito, A. La Barbera, Mosè Mariotti, A. Sillanpää, M. V. Fonseca, E. Carmona, Markus Garczarczyk, M. Asensio, P. Temnikov, D. Hildebrand, L. Peruzzo, Aaron Dominguez, A. Boller, L. Cossio, Felicitas Pauss, Wolfgang Rhode, Elisa Bernardini, Dario Hrupec, Felix Spanier, Igor Oya, Fabrizio Tavecchio, Christian Fruck, Artemio Herrero, D. Garrido, Ll. Font, Julian Sitarek, Nikola Godinovic, J. Moldón, Jose Miguel Miranda, Victor Zabalza, B. Huber, Ivica Puljak, M. Uellenbeck, Pierre Colin, Denis Bastieri, Q. Weitzel, Tihomir Surić, I. Snidaric, Saverio Lombardi, J. Pochon, B. Steinke, M. A. Lopez, J. Hose, M. I. Martínez, R. J. García López, S. Partini, D. Höhne-Mönch, C. Delgado Mendez, J. Krause, B. De Lotto, Riccardo Paoletti, E. Colombo, S. Spiro, E. Lorenz, E. De Cea del Pozo, Karl Mannheim, S. Rügamer, D. Tescaro, Juan Abel Barrio, Fabio Zandanel, Ralph Bock, J. M. Paredes, M. Salvati, S. Klepser, Antonio Stamerra, Andrei Berdyugin, L. O. Takalo, A. Diago Ortega, Robert Wagner, D. Borla Tridon, Victor Stamatescu, Gianluca Giavitto, M. Shayduk, Diego F. Torres, C. Schultz, D. Häfner, M. Pasanen, Martin Makariev, A. De Angelis, J. Becerra González, J. Storz, Nijil Mankuzhiyil, Oscar Blanch, P. Munar-Adrover, T. Jogler, Mario Meucci, Ignasi Reichardt, V. Scapin, Hajime Takami, Gabriele Ghisellini, Daniel Ferenc, H. Vankov, Francesco Dazzi, Ilana M. Braun, Silvia Pardo, Marc Ribó, Konstancja Satalecka, E. Leonardo, Michele Doro, Hiroko Miyamoto, Jelena Aleksić, G. Maneva, A. Saggion, David Paneque, Adrian Biland, Roberta Zanin, J. Rico, Kari Nilsson, V. Scalzotto, P. G. Prada Moroni, Massimo Persic, T. Krähenbühl, O. Tibolla, N. Strah, G. De Caneva, E. Prandini, Aldo Treves, R. Reinthal, Dominik Elsaesser, Damir Lelas, and Dorota Sobczyńska
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), Radio galaxy, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Context (language use), Astrophysics, gamma ray astronomy, Cosmic rays, IMAGING CHERENKOV DETECTOR, 01 natural sciences, law.invention, galaxies: individual: M 87, Telescope, law, Observacions astronòmiques, Gamma ray astronomy, 0103 physical sciences, gamma rays: galaxies, Astronomia de raigs gamma, MAGIC (telescope), 010303 astronomy & astrophysics, Cherenkov radiation, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, astro-ph.HE, Spectral index, 010308 nuclear & particles physics, Spectral density, Astronomy and Astrophysics, Gamma-ray astronomy, Space and Planetary Science, astro-ph.CO, ddc:520, Electrónica, Física nuclear, Electricidad, Astrophysics - High Energy Astrophysical Phenomena, Astronomical observations, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We present the results of a long M87 monitoring campaign in very high energy $\gamma$-rays with the MAGIC-I Cherenkov telescope. We aim to model the persistent non-thermal jet emission by monitoring and characterizing the very high energy $\gamma$-ray emission of M87 during a low state. A total of 150\,h of data were taken between 2005 and 2007 with the single MAGIC-I telescope, out of which 128.6\,h survived the data quality selection. We also collected data in the X-ray and \textit{Fermi}--LAT bands from the literature (partially contemporaneous). No flaring activity was found during the campaign. The source was found to be in a persistent low-emission state, which was at a confidence level of $7\sigma$. We present the spectrum between 100\,GeV and 2\,TeV, which is consistent with a simple power law with a photon index $\Gamma=2.21\pm0.21$ and a flux normalization at 300\,GeV of $(7.7\pm1.3) \times 10^{-8}$ TeV$^{-1}$ s$^{-1}$ m$^{-2}$. The extrapolation of the MAGIC spectrum into the GeV energy range matches the previously published \textit{Fermi}--LAT spectrum well, covering a combined energy range of four orders of magnitude with the same spectral index. We model the broad band energy spectrum with a spine layer model, which can satisfactorily describe our data., Comment: 8 pages, 5 figures, 2 tables; A&A Journal version, fixed typo in the author list
Published: 2012

25. Detection of very-high energy gamma-ray emission from NGC 1275 by the MAGIC telescopes

Author: H. Vankov, Ilana M. Braun, E. De Cea del Pozo, A. López-Oramas, Wlodek Bednarek, Alessandro Carosi, Ruben Lopez-Coto, D. Garrido, Jose Miguel Miranda, Thomas Bretz, S. N. Shore, T. Jogler, Abelardo Moralejo, Wolfgang Rhode, A. Diago Ortega, Robert Wagner, Dario Hrupec, M. A. Lopez, J. Moldón, K. Saito, M. V. Fonseca, A. De Angelis, Nijil Mankuzhiyil, D. Dominis Prester, T. Krähenbühl, P. Munar-Adrover, Patrick Vogler, Francesco Dazzi, R. Reinthal, A. Cañellas, Ignasi Reichardt, Stefano Covino, L. A. Antonelli, M. Doert, Michael Backes, Victor Stamatescu, E. Leonardo, B. Steinke, Konstancja Satalecka, Dominik Elsaesser, N. Strah, Michele Doro, U. Barres de Almeida, G. Maneva, R. Zanin, Jelena Aleksić, Francisco Prada, C. Delgado Mendez, S. R. Gozzini, A. Saggion, A. Niedzwiecki, Damir Lelas, Fabrizio Tavecchio, P. Temnikov, Adrian Biland, David Paneque, Fabio Zandanel, Shan Sun, I. Snidaric, Silvia Pardo, J. Rico, S. Rügamer, Daniel Nieto, Kari Nilsson, R. J. García López, Juan Abel Barrio, Dorota Sobczyńska, S. Spiro, E. Lorenz, D. Borla Tridon, Riccardo Paoletti, Daniela Dorner, K. Berger, M. Uellenbeck, L. Maraschi, Elina Lindfors, G. De Caneva, J. M. Paredes, Antonio Stamerra, Daniel Mazin, Massimo Persic, Diego F. Torres, E. A. Alvarez, M. Pilia, P. G. Prada Moroni, T. Schweizer, E. Prandini, V. Scalzotto, S. Partini, D. Höhne-Mönch, O. Tibolla, Felix Spanier, Christoph Pfrommer, M. Shayduk, J. Storz, Elisa Bernardini, Nikola Godinovic, Aldo Treves, H. Kellermann, J. Krause, B. De Lotto, P. Antoranz, Masahiro Teshima, Takashi Saito, Marc Ribó, Gianluca Giavitto, Jose Luis Contreras, Ivica Puljak, Pierre Colin, M. Salvati, S. Klepser, Reiko Orito, Juan Cortina, Martin Makariev, A. Sillanpää, Julian Sitarek, Oscar Blanch, J. Hose, Daniela Hadasch, C. Fruck, J. Kushida, Anders Pinzke, Andrei Berdyugin, C. Schultz, V. Scapin, Tomislav Terzić, Aaron Dominguez, Victor Zabalza, Giacomo Bonnoli, M. Asensio, L. Font, Hajime Takami, I. Puerto Gimenez, E. Colombo, D. Hildebrand, L. Peruzzo, Ralph Bock, A. Boller, L. Cossio, L. O. Takalo, Mosè Mariotti, Artemio Herrero, Saverio Lombardi, J. Pochon, D. Häfner, M. I. Martínez, D. Tescaro, R. Mirzoyan, D. Eisenacher, Natalia Lewandowska, E. Carmona, Markus Garczarczyk, Nina Nowak, A. La Barbera, M. A. Perez-Torres, J. Becerra González, Mario Meucci, Denis Bastieri, Q. Weitzel, Tihomir Surić, S. Paiano, Karl Mannheim, and Daniel Ferenc
Subjects: POLARIZATION, Radio galaxy, Astrophysics::High Energy Astrophysical Phenomena, NGC-1275, Flux, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, gamma ray astronomy, Cosmic rays, IMAGING CHERENKOV DETECTOR, 01 natural sciences, Power law, Raigs gamma, 0103 physical sciences, MAGIC (telescope), galaxies: active, galaxies: jets, galaxies: individual (NGC 1275), galaxies: individual (IC 310), gamma rays: galaxies, Nuclear Experiment, 010303 astronomy & astrophysics, CRAB-NEBULA, GALAXY M87, IC 310, PERFORMANCE, DISCOVERY, EVOLUTION, VERITAS, astro-ph.HE, Physics, Spectral index, 010308 nuclear & particles physics, Gamma rays, Gamma ray, Astronomy and Astrophysics, Galaxies, Light curve, Galaxy, Galàxies, Space and Planetary Science, ddc:520, High Energy Physics::Experiment, Electrónica, Física nuclear, Electricidad, Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report on the detection of very-high energy (VHE, E>100 GeV) gamma-ray emission from NGC 1275, the central radio galaxy of the Perseus cluster of galaxies. The source has been detected by the MAGIC telescopes with a statistical significance of 6.6 sigma above 100 GeV in 46 hr of stereo observations carried out between August 2010 and February 2011. The measured differential energy spectrum between 70 GeV and 500 GeV can be described by a power law with a steep spectral index of \Gamma=-4.1+/-0.7stat+/-0.3syst, and the average flux above 100 GeV is F_{gamma}=(1.3+/-0.2stat+/-0.3syst) x 10^-11 cm^-2 s^-1. These results, combined with the power-law spectrum measured in the first two years of observations by the Fermi-LAT above 100 MeV, with a spectral index of Gamma ~ -2.1, strongly suggest the presence of a break or cut-off around tens of GeV in the NGC 1275 spectrum. The light curve of the source above 100 GeV does not show hints of variability on a month time scale. Finally, we report on the nondetection in the present data of the radio galaxy IC 310, previously discovered by the Fermi-LAT and MAGIC. The derived flux upper limit F^{U.L.}_{gamma} (>300 GeV)=1.2 x 10^-12 cm^-2 s^-1 is a factor ~ 3 lower than the mean flux measured by MAGIC between October 2009 and February 2010, thus confirming the year time-scale variability of the source at VHE., Comment: Corresponding authors are S. Lombardi, P. Colin, D. Hildebrand, and F. Zandanel. Published in A&A; 4 pages, 4 figures
Published: 2012

26. Variable Gamma-ray Emission Induced by Ultra-High Energy Neutral Beams: Application to 4C +21.35

Author: Charles D. Dermer, Kohta Murase, and Hajime Takami
Subjects: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, FOS: Physical sciences, Astronomy and Astrophysics, Quasar, Cosmic ray, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Radiation, Spectral line, Space and Planetary Science, Neutrino, Blazar, Astrophysics - High Energy Astrophysical Phenomena, Fermi Gamma-ray Space Telescope
Abstract: The flat spectrum radio quasar (FSRQ) 4C +21.35 (PKS 1222+216) displays prominent nuclear infrared emission from ~1200 K dust. A 70 -- 400 GeV flare with ~10 min variations during half an hour of observations was found by the MAGIC telescopes, and GeV variability was observed on sub-day timescales with the Large Area Telescope on Fermi. We examine 4C +21.35, assuming that it is a source of ultra-high energy cosmic rays (UHECRs). UHECR proton acceleration in the inner jet powers a neutral beam of neutrinos, neutrons and gamma rays from photopion production. The radiative efficiency and production spectra of neutrals formed through photohadronic processes with isotropic external target photons of the broad line region and torus are calculated. Secondary radiations made by this process have a beaming factor ~\delta^5, where \delta is the Doppler factor. The pair-production optical depth for gamma rays and the photopion efficiency for UHECR neutrons as they pass through external isotropic radiation fields are calculated. If target photons come from the broad line region and dust torus, large Doppler factors, \delta >~100 are required to produce rapidly variable secondary radiation with isotropic luminosity >~1e47 erg/s at the pc scale. The \gamma-ray spectra from leptonic secondaries are calculated from cascades initiated by the UHECR neutron beam at the pc-scale region and fit to the flaring spectrum of 4C +21.35. Detection of >~100 TeV neutrinos from 4C +21.35 or other VHE blazars with IceCube or KM3NeT would confirm this scenario., Comment: 21 pages, 13 figures; replaced 4 figures to show neutron and neutrino production from combined infrared and broad-line region radiation fields; added references and improvements; ApJ, in press
Published: 2012
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27. Constraining cosmic rays and magnetic fields in the Perseus galaxy cluster with TeV observations by the MAGIC telescopes

Author: S. Partini, D. Höhne-Mönch, V. Scalzotto, Silvia Pardo, G. De Caneva, Ivica Puljak, Pierre Colin, D. Dominis Prester, Martin Makariev, Oscar Blanch, Francisco Prada, Thomas Bretz, S. N. Shore, Marc Ribó, J. Krause, J. M. Paredes, Antonio Stamerra, A. Sillanpää, M. V. Fonseca, J. Storz, Kari Nilsson, B. De Lotto, Riccardo Paoletti, M. Doert, Michael Backes, P. Temnikov, Fabio Zandanel, Shan Sun, J. Kushida, E. Prandini, Aldo Treves, Christian Fruck, E. A. Alvarez, L. A. Antonelli, K. Berger, Nijil Mankuzhiyil, P. Munar-Adrover, P. Antoranz, B. Steinke, Jose Luis Contreras, Stefano Covino, Julian Sitarek, J. Hose, T. Jogler, Daniela Hadasch, Anders Pinzke, S. Klepser, Juan Cortina, R. Reinthal, Nikola Godinovic, M. Pilia, Wolfgang Rhode, Dominik Elsaesser, Abelardo Moralejo, E. Colombo, U. Barres de Almeida, Damir Lelas, Felix Spanier, Daniel Ferenc, Daniel Nieto, Konstancja Satalecka, Michele Doro, Masahiro Teshima, Dorota Sobczyńska, J. Moldón, S. Rügamer, Juan Abel Barrio, H. Vankov, Ralph Bock, Christoph Pfrommer, L. O. Takalo, M. Uellenbeck, D. Borla Tridon, R. Mirzoyan, Ilana M. Braun, T. Schweizer, Tomislav Terzić, D. Eisenacher, Fabrizio Tavecchio, Ll. Font, A. Cañellas, D. Häfner, M. Salvati, I. Snidaric, A. Diago Ortega, Robert Wagner, Giacomo Bonnoli, Mosè Mariotti, E. De Cea del Pozo, E. Carmona, Markus Garczarczyk, M. Asensio, Victor Stamatescu, Dario Hrupec, Saverio Lombardi, L. Maraschi, Elina Lindfors, Jelena Aleksić, S. Spiro, E. Lorenz, J. Pochon, M. A. Lopez, K. Saito, Daniel Mazin, A. Niedzwiecki, Patrick Vogler, Diego F. Torres, David Paneque, Nina Nowak, Takashi Saito, M. A. Perez-Torres, Reiko Orito, I. Puerto Gimenez, D. Hildebrand, L. Peruzzo, M. I. Martínez, D. Tescaro, A. Boller, L. Cossio, Artemio Herrero, Natalia Lewandowska, Daniela Dorner, A. La Barbera, J. Becerra González, Mario Meucci, Elisa Bernardini, Denis Bastieri, Q. Weitzel, Tihomir Surić, H. Kellermann, S. Paiano, Karl Mannheim, C. Delgado Mendez, S. R. Gozzini, Gianluca Giavitto, A. De Angelis, P. G. Prada Moroni, Ignasi Reichardt, O. Tibolla, M. Shayduk, Francesco Dazzi, G. Maneva, R. J. García López, E. Leonardo, R. Zanin, A. Saggion, Massimo Persic, Adrian Biland, T. Krähenbühl, N. Strah, J. Rico, Andrei Berdyugin, A. López-Oramas, Wlodek Bednarek, Alessandro Carosi, C. Schultz, Ruben Lopez-Coto, V. Scapin, D. Garrido, Aaron Dominguez, Jose Miguel Miranda, Victor Zabalza, and Hajime Takami
Subjects: Radio galaxy, gamma rays: galaxies: clusters, acceleration of particles, galaxies: clusters: individual: Perseus, Astrophysics, SCALING RELATIONS, 01 natural sciences, 7. Clean energy, Raigs gamma, DIFFUSE RADIO-EMISSION, HADRONIC MODELS, 010303 astronomy & astrophysics, PARTICLE HYDRODYNAMICS SIMULATIONS, GAMMA-RAY, X-RAY, COMA CLUSTER, DARK-MATTER, INTRACLUSTER MEDIUM, HESS OBSERVATIONS, Physics, astro-ph.HE, High Energy Astrophysical Phenomena (astro-ph.HE), Clusters of galaxies, Cosmic rays, gamma ray astronomy, IMAGING CHERENKOV DETECTOR, 16. Peace & justice, Magnetic field, astro-ph.CO, Electrónica, Física nuclear, Electricidad, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics, Cúmuls de galàxies, Structure formation, Active galactic nucleus, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, 0103 physical sciences, Cluster (physics), Cherenkov radiation, Galaxy cluster, Astrophysics::Galaxy Astrophysics, 010308 nuclear & particles physics, Gamma rays, Astronomy and Astrophysics, Galaxies, Galàxies, 13. Climate action, Space and Planetary Science, ddc:520
Abstract: Galaxy clusters are being assembled today in the most energetic phase of hierarchical structure formation which manifests itself in powerful shocks that contribute to a substantial energy density of cosmic rays (CRs). Hence, clusters are expected to be luminous gamma-ray emitters since they also act as energy reservoirs for additional CR sources, such as active galactic nuclei and supernova-driven galactic winds. To detect the gamma-ray emission from CR interactions with the ambient cluster gas, we conducted the deepest to date observational campaign targeting a galaxy cluster at very high-energy gamma-rays and observed the Perseus cluster with the MAGIC Cherenkov telescopes for a total of ~85 hr of effective observing time. This campaign resulted in the detection of the central radio galaxy NGC 1275 at energies E > 100 GeV with a very steep energy spectrum. Here, we restrict our analysis to energies E > 630 GeV and detect no significant gamma-ray excess. This constrains the average CR-to-thermal pressure ratio to be 4-9 microG, depending on the rate of decline of the magnetic field strength toward larger radii., Corresponding authors are F. Zandanel, C. Pfrommer, P. Colin, A. Pinzke and S. Lombardi. Accepted for publication in A&A on 06/03/2012
Published: 2012

28. Searches for Dark Matter annihilation signatures in the Segue 1 satellite galaxy with the MAGIC-I telescope

Author: E. Prandini, Aldo Treves, P. Antoranz, Jose Luis Contreras, Juan Cortina, Ignasi Reichardt, Ivica Puljak, S. Partini, D. Höhne-Mönch, J. Krause, B. De Lotto, V. Scalzotto, Pierre Colin, D. Dominis Prester, Silvia Pardo, Takashi Saito, G. Maneva, Masahiro Teshima, Kari Nilsson, L. Maraschi, Elina Lindfors, Dario Hrupec, R. Zanin, R. Essig, A. De Angelis, A. Saggion, Adrian Biland, T. Jogler, E. Colombo, Daniel Mazin, J. Moldón, Reiko Orito, M. A. Lopez, Francisco Prada, Ralph Bock, E. A. Alvarez, K. Saito, M. Doert, Riccardo Paoletti, Fabio Zandanel, M. Salvati, L. O. Takalo, Martin Makariev, Oscar Blanch, R. Reinthal, R. Mirzoyan, Stefano Covino, A. Sillanpää, M. Thom, M. Shayduk, Dominik Elsaesser, Diego F. Torres, Daniel Nieto, Nikola Godinovic, M. Pasanen, T. Schweizer, Julian Sitarek, Damir Lelas, A. Diago Ortega, Robert Wagner, K. Berger, J. Hose, Thomas Bretz, S. N. Shore, J. M. Paredes, Nijil Mankuzhiyil, Abelardo Moralejo, P. G. Prada Moroni, Dorota Sobczyńska, Neelima Sehgal, Michael Backes, Daniela Hadasch, C. Fruck, Antonio Stamerra, Patrick Vogler, P. Munar-Adrover, Markus Garczarczyk, A. Cañellas, D. Häfner, O. Tibolla, L. A. Antonelli, Daniel Ferenc, Louis E. Strigari, Wolfgang Rhode, J. Storz, Konstancja Satalecka, Francesco Dazzi, E. De Cea del Pozo, H. Vankov, M. Asensio, M. Pilia, E. Leonardo, Mosè Mariotti, Ilana M. Braun, Igor Oya, Fabrizio Tavecchio, Felix Spanier, Ll. Font, G. Bonnoli, Marc Ribó, E. Carmona, J. Rico, Mattia Fornasa, Saverio Lombardi, M. A. Perez-Torres, S. Spiro, E. Lorenz, J. Pochon, Hajime Takami, Tomislav Terzić, Wlodek Bednarek, Alessandro Carosi, Aaron Dominguez, Felicitas Pauss, D. Hildebrand, Victor Zabalza, L. Peruzzo, M. I. Martínez, D. Garrido, M. V. Fonseca, Jose Miguel Miranda, B. Steinke, D. Tescaro, A. Boller, L. Cossio, S. Rügamer, Juan Abel Barrio, D. Borla Tridon, Artemio Herrero, Andrei Berdyugin, C. Schultz, V. Scapin, Michele Doro, Hiroko Miyamoto, Jelena Aleksić, David Paneque, Gianluca Giavitto, Daniela Dorner, Petar Temnikov, Elisa Bernardini, C. Delgado Mendez, J. Becerra González, Mario Meucci, A. La Barbera, Denis Bastieri, Q. Weitzel, Tihomir Surić, B. Huber, S. Paiano, Karl Mannheim, T. Krähenbühl, S. Klepser, N. Strah, R. J. García López, and Massimo Persic
Subjects: SPECTROSCOPIC SURVEY, DWARF SPHEROIDAL GALAXIES, ENERGIES, Astrophysics::High Energy Astrophysical Phenomena, Dark matter, FOS: Physical sciences, gamma ray experiments, Astrophysics, Parameter space, 01 natural sciences, Spectral line, LARGE-AREA TELESCOPE, FERMI, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Positron, ddc:670, 0103 physical sciences, Satellite galaxy, Emission spectrum, GALACTIC SATELLITES, 010303 astronomy & astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), astro-ph.HE, Annihilation, 010308 nuclear & particles physics, hep-ex, dark matter experiments, CONSTRAINTS, Astronomy and Astrophysics, Segue, Estels nans, dwarfs galaxies, dwarf galaxies, Dark matter (Astronomy), Dwarf stars, MILKY-WAY HALO, Electrónica, Física nuclear, Matèria fosca (Astronomia), GAMMA-RAY EMISSION, PARTICLE, Electricidad, Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report the results of the observation of the nearby satellite galaxy Segue 1 performed by the MAGIC-I ground-based gamma-ray telescope between November 2008 and March 2009 for a total of 43.2 hours. No significant gamma-ray emission was found above the background. Differential upper limits on the gamma-ray flux are derived assuming various power-law slopes for the possible emission spectrum. Integral upper limits are also calculated for several power-law spectra and for different energy thresholds. The values are of the order of 10^{-11} ph cm^{-2}$ s^{-1} above 100 GeV and 10^{-12} ph cm^{-2} s^{-1} above 200 GeV. Segue 1 is currently considered one of the most interesting targets for indirect dark matter searches. In these terms, the upper limits have been also interpreted in the context of annihilating dark matter particles. For such purpose, we performed a grid scan over a reasonable portion of the parameter space for the minimal SuperGravity model and computed the flux upper limit for each point separately, taking fully into account the peculiar spectral features of each model. We found that in order to match the experimental upper limits with the model predictions, a minimum flux boost of 10^{3} is required, and that the upper limits are quite dependent on the shape of the gamma-ray energy spectrum predicted by each specific model. Finally we compared the upper limits with the predictions of some dark matter models able to explain the PAMELA rise in the positron ratio, finding that Segue 1 data are in tension with the dark matter explanation of the PAMELA spectrum in the case of a dark matter candidate annihilating into tau+tau-. A complete exclusion however is not possible due to the uncertainties in the Segue 1 astrophysical factor., Comment: 26 pages, 10 figures. Matched to published version
Published: 2011
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29. A search for Very High Energy gamma-ray emission from Sco X-1 with the MAGIC telescopes

Author: Daniel Ferenc, Abelardo Moralejo, H. Vankov, L. Maraschi, Elina Lindfors, Ilana M. Braun, Daniel Mazin, L. A. Antonelli, E. Prandini, Aldo Treves, Michael Backes, Hiroko Miyamoto, Wlodek Bednarek, Alessandro Carosi, Aaron Dominguez, D. Garrido, Jose Miguel Miranda, Felicitas Pauss, A. Saggion, J. Moldón, Adrian Biland, T. Jogler, Dario Hrupec, M. A. Lopez, Tomislav Terzić, Igor Oya, Jelena Aleksić, Stefano Covino, Ivica Puljak, Fabrizio Tavecchio, Silvia Pardo, Victor Zabalza, Pierre Colin, Ll. Font, Takashi Saito, Giacomo Bonnoli, M. Shayduk, Julian Sitarek, E. A. Alvarez, J. Hose, Diego F. Torres, M. Pasanen, E. Colombo, M. Pilia, Daniela Hadasch, R. Zanin, Reiko Orito, M. Asensio, S. Partini, David Paneque, J. Becerra González, R. Reinthal, Ralph Bock, D. Höhne-Mönch, T. Schweizer, Dominik Elsaesser, L. O. Takalo, Daniel Nieto, Damir Lelas, Jose Luis Contreras, A. Cañellas, Nijil Mankuzhiyil, K. Berger, Nikola Godinovic, J. Krause, B. De Lotto, Dorota Sobczyńska, Hajime Takami, P. Munar-Adrover, Mario Meucci, E. De Cea del Pozo, Fabio Zandanel, Konstancja Satalecka, Michele Doro, Juan Cortina, D. Häfner, E. Carmona, A. De Angelis, Martin Makariev, Andrei Berdyugin, Oscar Blanch, Ignasi Reichardt, Valentí Bosch-Ramon, Masahiro Teshima, Felix Spanier, C. Schultz, A. Diago Ortega, Robert Wagner, V. Scapin, Gianluca Giavitto, P. Antoranz, G. Maneva, Thomas Bretz, S. N. Shore, Mosè Mariotti, D. Dominis Prester, Kari Nilsson, M. Salvati, Saverio Lombardi, A. Sillanpää, M. V. Fonseca, M. Thom, J. Pochon, Denis Bastieri, Q. Weitzel, Wolfgang Rhode, Tihomir Surić, Francesco Dazzi, Daniela Dorner, V. Scalzotto, Francisco Prada, Christian Fruck, Pol Bordas, E. Leonardo, Karl Mannheim, Petar Temnikov, B. Steinke, Elisa Bernardini, P. G. Prada Moroni, A. La Barbera, S. Rügamer, Juan Abel Barrio, J. M. Paredes, C. Delgado Mendez, O. Tibolla, R. Mirzoyan, Antonio Stamerra, D. Borla Tridon, K. Saito, Patrick Vogler, Markus Garczarczyk, S. Spiro, E. Lorenz, J. Storz, M. A. Perez-Torres, Riccardo Paoletti, J. Rico, M. Doert, D. Hildebrand, L. Peruzzo, M. I. Martínez, D. Tescaro, A. Boller, L. Cossio, Artemio Herrero, Marc Ribó, B. Huber, T. Krähenbühl, S. Klepser, N. Strah, R. J. García López, Massimo Persic, and Universitat de Barcelona
Subjects: High energy, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, gamma rays: stars, 01 natural sciences, MICROQUASAR, X-rays: binaries, HESS, 0103 physical sciences, X-rays, FIELD, 010306 general physics, 010303 astronomy & astrophysics, acceleration of particles, Estels binaris de raigs X, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, astro-ph.HE, acceleration of particles — X-rays: binaries — Stars: individual (Sco X-1) — Gamma rays: stars, RADIO, Acceleradors de partícules, Gamma ray, Astronomy and Astrophysics, BINARY, PULSAR, Horizontal branch, EVOLUTION, Particle accelerators, X-ray binaries, stars: individual: Sco X-1, 13. Climate action, Space and Planetary Science, DISCOVERY, Power ratio, X-RAY, RADIATION, Electrónica, Física nuclear, High Energy Physics::Experiment, Raigs X, Electricidad, Astrophysics - High Energy Astrophysical Phenomena
Abstract: The acceleration of particles up to GeV or higher energies in microquasars has been the subject of considerable theoretical and observational efforts in the past few years. Sco X-1 is a microquasar from which evidence of highly energetic particles in the jet has been found when it is in the so-called Horizontal Branch (HB), a state when the radio and hard X-ray fluxes are higher and a powerful relativistic jet is present. Here we present the first very high energy gamma-ray observations of Sco X-1 obtained with the MAGIC telescopes. An analysis of the whole dataset does not yield a significant signal, with 95% CL flux upper limits above 300 GeV at the level of 2.4x10^{-12} ph/cm^2/s. Simultaneous RXTE observations were conducted to search for TeV emission during particular X-ray states of the source. A selection of the gamma-ray data obtained during the HB based on the X-ray colors did not yield a signal either, with an upper limit of 3.4x10^{-12} ph/cm^2/s. These upper limits place a constraint on the maximum TeV luminosity to non-thermal X-ray luminosity of L_{VHE}/L_{ntX}, 5 pages, 2 figures, 2 tables. Version as published in ApJL
Published: 2011

30. The Role of Structured Magnetic Fields on Constraining Properties of Transient Sources of Ultra-high-energy Cosmic Rays

Author: Kohta Murase and Hajime Takami
Subjects: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Number density, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astronomy and Astrophysics, Cosmic ray, Astrophysics, Arrival time, Galaxy, Magnetic field, Space and Planetary Science, Ultra-high-energy cosmic ray, Transient (oscillation), Astrophysics - High Energy Astrophysical Phenomena, Energy (signal processing), Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We study how the properties of transient sources of ultra-high-energy cosmic rays (UHECRs) can be accessed by exploiting UHECR experiments, taking into account the propagation of UHECRs in magnetic structures which the sources are embedded in, i.e., clusters of galaxies and filamentary structures. Adopting simplified analytical models, we demonstrate that the structured extragalactic magnetic fields (EGMFs) play crucial roles in unveiling the properties of the transient sources. These EGMFs unavoidably cause significant delay in the arrival time of UHECRs as well as the Galactic magnetic field, even if the strength of magnetic fields in voids is zero. Then, we show that, given good knowledge on the structured EGMFs, UHECR observations with high statistics above $10^{20}$ eV allow us to constrain the generation rate of transient UHECR sources and their energy input per burst, which can be compared with the rates and energy release of known astrophysical phenomena. We also demonstrate that identifying the energy dependence of the apparent number density of UHECR sources at the highest energies is crucial as a clue to such transient sources. Future UHECR experiments with extremely large exposure are required to reveal the nature of transient UHECR sources., Comment: 11 pages, 7 figures, accepted for publication in Astrophysical Journal
Published: 2011
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31. Propagation of Ultra-high-energy Cosmic Rays in Galactic Magnetic Field

Author: Hajime Takami, Hiroyuki Sagawa, Yoshiya Kawasaki, Takashi Sako, Masahiro Takeda, and Yoshiki Tsunesada
Subjects: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Computer Science::Software Engineering, FOS: Physical sciences, Cosmic ray, Quasar, Astrophysics, Magnetic field, Accretion disc, Ultra-high-energy cosmic ray, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics
Abstract: The propagation trajectories of ultra-high-energy cosmic rays (UHECRs) are inevitably affected by Galactic magnetic field (GMF). Because of the inevitability, the importance of the studies of the propagation in GMF have increased to interpret the results of recent UHECR experiments. This article reviews the effects of GMF to the propagation and arrival directions of UHECRs and introduces recent studies to constrain UHECR sources., Comment: 6 pages, 3 figures. An invited review article to appear in the Proceedings of the International Workshop on the Recent Progress of Ultra-high Energy Cosmic Ray Observation (UHECR2010), Nagoya, Japan, 2010
Published: 2011
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32. Systematic Survey of the Correlation between Northern HECR Events and SDSS Galaxies

Author: Hajime Takami, Takahiro Nishimichi, and Katsuhiko Sato
Subjects: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Spatial correlation, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Physics and Astronomy (miscellaneous), media_common.quotation_subject, FOS: Physical sciences, Cosmic ray, Scale (descriptive set theory), Astrophysics, Akeno Giant Air Shower Array, Astrophysics::Cosmology and Extragalactic Astrophysics, Galaxy, Redshift, Luminosity, Sky, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics, media_common, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We investigated the spatial correlation between the arrival directions of the highest energy cosmic rays (HECRs) detected by the Akeno Giant Air Shower Array (AGASA) with energies above $4 \times 10^{19}$ eV and the positions of galaxies observed by the Sloan Digital Sky Survey (SDSS) within $z = 0.024$. We systematically tested the dependence of the correlation on the redshift ranges and properties of the galaxies, i.e., absolute luminosity, color, and morphology, to understand where HECR sources are and what objects are HECR sources. In the systematic survey, we found potential signals of the positive correlation at small angular scale ($, 22 pages, 11 figures, accepted for publication in Progress of Theoretical Physics
Published: 2009

33. Does Galactic Magnetic Field Disturb the Correlation of the Highest Energy Cosmic Rays with their Sources?

Author: Katsuhiko Sato and Hajime Takami
Subjects: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Cosmology and Nongalactic Astrophysics (astro-ph.CO), Proton, Astrophysics::High Energy Astrophysical Phenomena, Hadron, Order (ring theory), FOS: Physical sciences, Astronomy and Astrophysics, Cosmic ray, Astrophysics, Dipole, Space and Planetary Science, Intergalactic travel, Astrophysics - High Energy Astrophysical Phenomena, Nucleon, Energy (signal processing), Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: The propagation trajectories of the highest energy cosmic rays (HECRs) are deflected by not only intergalactic magnetic field but also Galactic magnetic field (GMF). These magnetic fields can weaken the positive correlation between the arrival directions of HECRs and the positions of their sources. In order to explore the effect of GMF on the expected correlation, we simulate the arrival distribution of protons with the energy above $6 \times 10^{19}$ eV taking several GMF models into account, and then test the correlation between the protons and their sources assumed in the simulation. The dependence of the correlation signals on GMF models are also investigated. The correlation can be observed by accumulating $\sim 200$ protons in a half hemisphere. Typical angular scale at which the positive signal of the correlation is maximized depends on the spiral component of GMF models. That angular scale is $\sim 5^o$ for bisymmetric spiral (BS) GMF models and $\sim 7^o$ for axisymmetric spiral (AS) GMF models if the number density of HECR sources, $n_s$, is $\sim 10^{-4}$ Mpc$^{-3}$. An additional vertical (dipole) component of GMF affects these angular scale by $0.5^o$ - $1^o$. The difference between the correlation signal for the BS models and that for the AS models is prominent in the northern sky. Significance of the positive correlation depends on source distribution. The probability that the number of simulated HECR events correlating with sources is smaller than the number of random events correlating with the same sources by chance is much less than $10^{-3}$ ($\sim 3\sigma$) in almost all the source distributions with $n_s = 10^{-4}$ Mpc$^{-3}$ under 200 protons detection, but $\sim 10\%$ of source distributions predicts the chance probability more than $10^{-3}$ in the AS GMF model. In addition, we also briefly discuss the effect of GMF for heavy-nuclei dominated composition., Comment: 17 pages, 16 figures, accepted for publication in Astrophysical Journal
Published: 2009
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34. DISENTANGLING HADRONIC AND LEPTONIC CASCADE SCENARIOS FROM THE VERY-HIGH-ENERGY GAMMA-RAY EMISSION OF DISTANT HARD-SPECTRUM BLAZARS

Author: Charles D. Dermer, Kohta Murase, and Hajime Takami
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Gamma ray, FOS: Physical sciences, Astronomy and Astrophysics, Quasar, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Cherenkov Telescope Array, Redshift, Space and Planetary Science, Astrophysics - High Energy Astrophysical Phenomena, Blazar, Cherenkov radiation, Fermi Gamma-ray Space Telescope
Abstract: Recent data from the \emph{Fermi} Large Area Telescope have revealed about a dozen distant hard-spectrum blazars that have very-high-energy (VHE; $\gtrsim 100$ GeV) photons associated with them, but most of them have not yet been detected by imaging atmospheric Cherenkov telescopes. Most of these high-energy gamma-ray spectra, like those of other extreme high-frequency peaked BL Lac objects, can be well explained either by gamma rays emitted at the source or by cascades induced by ultra-high-energy cosmic rays, as we show specifically for KUV 00311$-$1938. We consider the prospects for detection of the VHE sources by the planned Cherenkov Telescope Array (CTA) and show how it can distinguish the two scenarios by measuring the integrated flux above $\sim 500$ GeV (depending on source redshift) for several luminous sources with $z \lesssim 1$ in the sample. Strong evidence for the origin of ultra-high-energy cosmic rays could be obtained from VHE observations with CTA. Depending on redshift, if the often quoted redshift of KUV 00311-1938 ($z = 0.61$) is believed, preliminary H.E.S.S. data favor cascades induced by ultra-high-energy cosmic rays. Accurate redshift measurements of hard-spectrum blazars are essential for this study., 5 pages, 3 figures, accepted for publication in Astrophysical Journal Letters
Published: 2013

35. MAGIC reveals a complex morphology within the unidentified gamma-ray source HESS J1857+026

Author: K. Frantzen, Tihomir Surić, P. Temnikov, Fabio Zandanel, Patrick Vogler, Daniel Ferenc, V. Kadenius, R. Zanin, S. Paiano, Karl Mannheim, Alicia López-Oramas, Natalia Lewandowska, M. V. Fonseca, A. La Barbera, A. Saggion, X. Paredes-Fortuny, M. Palatiello, Adrian Biland, Nina Nowak, I. Lozano, K. Nishijima, F. Borracci, G. De Caneva, I. Snidaric, Masahiro Teshima, Christian Fruck, Stefano Covino, J. Becerra González, E. Lorenz, U. Menzel, J. Rico, D. Dominis Prester, Francesco Dazzi, Mario Meucci, S. Sun, A. González Muñoz, Diego F. Torres, M. Uellenbeck, Dario Hrupec, Stefano Ansoldi, Riccardo Paoletti, L. A. Antonelli, D. Tescaro, A. Sillanpää, M. A. Lopez, S. Rügamer, Juan Abel Barrio, Fabrizio Tavecchio, Ll. Font, D. Garrido Terrats, M. Garczarczyk, D. Nakajima, Nikola Godinovic, Benito Marcote, J. Krause, Hajime Takami, B. De Lotto, Francisco Prada, Emanuele Paolo Farina, K. Saito, S. Klepser, Nijil Mankuzhiyil, P. Munar-Adrover, Silvia Preziuso, Wlodek Bednarek, Alessandro Carosi, J. M. Paredes, Antonio Stamerra, V. Scalzotto, L. Maraschi, Elina Lindfors, K. Kodani, Abelardo Moralejo, Daniel Mazin, T. Steinbring, Ruben Lopez-Coto, Jose Miguel Miranda, P. G. Prada Moroni, K. Mallot, Thomas Bretz, S. N. Shore, Hanna Kellermann, J. Storz, A. Herrero, R. J. García López, O. Tibolla, Ana Babić, M. I. Martínez, W. Idec, G. Maneva, A. De Angelis, C. Schultz, V. Scapin, Yusuke Konno, Felix Spanier, Aaron Dominguez, J. Kushida, R. Reinthal, S. Bonnefoy, Wolfgang Rhode, E. Colombo, Dominik Elsaesser, U. Barres de Almeida, Takashi Saito, Jose Luis Contreras, M. Hayashida, Damir Lelas, Sabrina Einecke, S. R. Gozzini, R. Mirzoyan, D. Eisenacher, L. O. Takalo, Giacomo Bonnoli, Dorota Sobczyńska, J. Rodriguez Garcia, Juan Cortina, Reiko Orito, E. Carmona, Mosè Mariotti, A.-K. Overkemping, Marc Ribó, Massimo Persic, P. Bangale, Hidetoshi Kubo, Marcel Strzys, E. Prandini, Saverio Lombardi, D. Hildebrand, Aldo Treves, Ivica Puljak, Kari Nilsson, Pierre Colin, Tomislav Terzić, E. de Oña Wilhelmi, Julia Thaele, T. Schweizer, P. Antoranz, D. Fidalgo Carreto, S. Partini, C. Delgado Mendez, Daniela Dorner, M. Gaug, J. Herrera, Koji Noda, Elisa Bernardini, Martin Makariev, Oscar Blanch, M. Doert, Victor Stamatescu, Julian Sitarek, J. Hose, Daniela Hadasch, T. Toyama, Jelena Aleksić, A. Niedzwiecki, David Paneque, P. Da Vela, Robert Wagner, Konstancja Satalecka, and Michele Doro
Subjects: Acceleration of particles - gamma rays, HII regions, PSR J1856+0245, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Individual, Astrophysics, 01 natural sciences, Power law, Pulsar wind nebula, ISM: clouds, Coincidence, Clouds - HII regions - ISM, HESS J1857+026 -pulsars, Individual objects, ISM - ISM, Astronomy and Astrophysics, Space and Planetary Science, gamma rays: ISM, Pulsar, 0103 physical sciences, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, acceleration of particles, High Energy Astrophysical Phenomena (astro-ph.HE), astro-ph.HE, Physics, 010308 nuclear & particles physics, Molecular cloud, Gamma ray, Galactic plane, pulsars: individual: PSR J1856+0245, ISM: individual objects: HESS J1857+026, gamma-rays: ISM, Hii regions, ddc:520, Spectral energy distribution, Electrónica, Física nuclear, High Energy Physics::Experiment, Electricidad, Astrophysics - High Energy Astrophysical Phenomena
Abstract: HESS J1857+026 is an extended TeV gamma-ray source that was discovered by H.E.S.S. as part of its Galactic plane survey. Given its broadband spectral energy distribution and its spatial coincidence with the young energetic pulsar PSR J1856+0245, the source has been put forward as a pulsar wind nebula (PWN) candidate. MAGIC has performed follow-up observations aimed at mapping the source down to energies approaching 100 GeV in order to better understand its complex morphology. HESS J1857+026 was observed by MAGIC in 2010, yielding 29 hours of good quality stereoscopic data that allowed us to map the source region in two separate ranges of energy. We detected very-high-energy gamma-ray emission from HESS J1857+026 with a significance of $12 \sigma$ above $150$ GeV. The differential energy spectrum between $100$ GeV and $13$ TeV is well described by a power law function $dN/dE = N_0(E/1\textrm{TeV})^{-\Gamma}$ with $N_0 = (5.37 \pm0.44_{stat} \pm1.5_{sys}) \times 10^{-12} (\textrm{TeV}^{-1} \textrm{cm}^{-2}$ $\textrm{ s}^{-1})$ and $\Gamma = 2.16\pm0.07_{stat} \pm0.15_{sys}$, which bridges the gap between the GeV emission measured by Fermi-LAT and the multi-TeV emission measured by H.E.S.S.. In addition, we present a detailed analysis of the energy-dependent morphology of this region. We couple these results with archival multi-wavelength data and outline evidence in favor of a two-source scenario, whereby one source is associated with a PWN, while the other could be linked with a molecular cloud complex containing an HII region and a possible gas cavity., Comment: 9 pages, 6 figures. Accepted for publication in A&A

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35 results on '"HAJIME TAKAMI"'

1. Propagation of ultra-high-energy cosmic ray nuclei in cosmic magnetic fields and implications for anisotropy measurements

2. The production of ultra high energy cosmic rays during the early epochs of radio-loud AGN

3. Black hole lightning due to particle acceleration at subhorizon scales

4. Unprecedented study of the broadband emission of Mrk 421 during flaring activity in March 2010

5. First broadband characterization and redshift determination of the VHE blazar MAGIC J2001+439

6. Discovery of very high energy gamma-ray emission from the blazar 1ES 0033+595 by the MAGIC telescopes

7. Energy Sources and Light Curves of Macronovae

8. Bounds on the origin of extragalactic ultrahigh energy cosmic rays from the IceCube neutrino observations

9. MAGIC search for vhe γ-ray emission from ae aquarii in a multiwavelength context

10. Dust formation in macronovae

11. Discovery of very high energy gamma-ray emission from the blazar 1ES 1727+502 with the MAGIC Telescopes

12. Optimized dark matter searches in deep observations of Segue 1 with MAGIC

13. MAGIC long-term study of the distant TeV blazar PKS 1424+240 in a multiwavelength context

14. Detection of bridge emission above 50 GeV from the Crab pulsar with the MAGIC telescopes

15. Lower Bounds on Magnetic Fields in Intergalactic Voids from Long-Term GeV-TeV Light Curves of the Blazar Mrk 421

16. Rapid and multi-band variability of the TeV-bright active nucleus of the galaxy IC 310

17. Observations of the magnetars 4U 0142+61 and 1E 2259+586 with the MAGIC telescopes

18. ISOTROPY CONSTRAINTS ON POWERFUL SOURCES OF ULTRAHIGH-ENERGY COSMIC RAYS AT 1019eV

19. PG 1553+113: five years of observations with MAGIC

20. Discovery of VHE gamma-rays from the blazar 1ES 1215+303 with the MAGIC Telescopes and simultaneous multi-wavelength observations

21. Phase-resolved energy spectra of the Crab pulsar in the range of 50-400 GeV measured with the MAGIC telescopes

22. Morphological and spectral properties of the W51 region measured with the MAGIC telescopes

23. Blazars as Ultra-high-energy Cosmic-ray Sources: Implications for TeV Gamma-Ray Observations

24. MAGIC observations of the giant radio galaxy M 87 in a low-emission state between 2005 and 2007

25. Detection of very-high energy gamma-ray emission from NGC 1275 by the MAGIC telescopes

26. Variable Gamma-ray Emission Induced by Ultra-High Energy Neutral Beams: Application to 4C +21.35

27. Constraining cosmic rays and magnetic fields in the Perseus galaxy cluster with TeV observations by the MAGIC telescopes

28. Searches for Dark Matter annihilation signatures in the Segue 1 satellite galaxy with the MAGIC-I telescope

29. A search for Very High Energy gamma-ray emission from Sco X-1 with the MAGIC telescopes

30. The Role of Structured Magnetic Fields on Constraining Properties of Transient Sources of Ultra-high-energy Cosmic Rays

31. Propagation of Ultra-high-energy Cosmic Rays in Galactic Magnetic Field

32. Systematic Survey of the Correlation between Northern HECR Events and SDSS Galaxies

33. Does Galactic Magnetic Field Disturb the Correlation of the Highest Energy Cosmic Rays with their Sources?

34. DISENTANGLING HADRONIC AND LEPTONIC CASCADE SCENARIOS FROM THE VERY-HIGH-ENERGY GAMMA-RAY EMISSION OF DISTANT HARD-SPECTRUM BLAZARS

35. MAGIC reveals a complex morphology within the unidentified gamma-ray source HESS J1857+026

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