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1. The age-mass relation for chromospherically active binaries .2. Lithium depletion in dwarf components

Author

Barrado Navascués, David, Fernández Figueroa, María José, García López, R. J., Castro Rubio, Elisa de, Cornide Castro-Piñeiro, Manuel, Barrado Navascués, David, Fernández Figueroa, María José, García López, R. J., Castro Rubio, Elisa de, and Cornide Castro-Piñeiro, Manuel

Abstract

© 1997 EDP Sciencies. This research has made use of the Simbad database, operated at CDS, Strasbourg, France. We greatly appreciate the comments and suggestion on this paper by the referee, R. Gratton. DBN acknowledges the support by the Universidad Complutense with a grant and by the Real Colegio Complutense at Harvard University. This work has been partially supported by the Spanish Dirección General de Investigación Científica y Técnica (DGICYT) under projects PB92-0434-c02-01 and PB94-0203., We present an extensive study of lithium abundances in dwarf components of chromospherically active binary stars (CABS). Since most of these binaries have known radii, masses and ages, this kind of data is especially useful for comparisons with theoretical models which try to explain the Li depletion phenomenon. We show that a significant part of these stars have clear Li overabundances with respect to the typical values for stars of the same mass and evolutionary stage. These excesses are evident when comparing our sample of CABS with binary and single stars belonging to open clusters of different ages, namely Pleiades, Hyades, NGC752, M67 and NGC188, which have ages ranging from 7x10^7 to 10^10 yr. The Li excesses are more conspicuous for masses in the range 0.75-0.95 M_⊙., indicating that the rate of Li depletion has been less pronounced in CABS than in single stars. This phenomenon is interpreted in the context of transport of angular momentum from the orbit to the stellar rotation due to tidal effects. This angular momentum transfer would avoid the radial differential rotation and the associated turbulent mixing of material in the stellar interior. Other explanations, however, can not be ruled out. This is the case of transport of material induced by internal gravity waves, which could be inhibited due to the presence of strong magnetic fields associated with the effective dynamo in CABS. The confirmed existence of a relation between Li abundances and the fluxes in Ca II H&K lines can also be accommodated within both scenarios., Universidad Complutense de Madrid (UCM), Real Colegio Complutense at Harvard University, Dirección General de Investigación Científica y Técnica (DGICYT), España, Ministerio de Economía y Competitividad (MINECO), España, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

Published
2023

2. The age-mass relation for chromospherically active binaries - III. Lithium depletion in giant components

Author

Barrado y Navascués, D., Castro Rubio, Elisa de, Fernández Figueroa, María José, Cornide Castro-Piñeiro, Manuel, García López, R. J., Barrado y Navascués, D., Castro Rubio, Elisa de, Fernández Figueroa, María José, Cornide Castro-Piñeiro, Manuel, and García López, R. J.

Abstract

© 1998 EDP Sciencies. This research has made use of the Simbad database, operated at CDS, Strasbourg, France. We greatly appreciate the comments and suggestions on this paper by the referee, Dr. Sofia Randich, which helped to improve the presentation and discussion of the results. DBN acknowledges the support by the Universidad Complutense, the Real Colegio Complutense at Harvard University, and the MEC/Fulbright commission. This work has been partially supported by the Spanish Dirección General de Educación Superior (DGES) under projects PB92-0434-C02-01, PB94-0203, and PB95-1132-C02-01., We present a study of the lithium abundances of a sample of evolved components of Chromospherically Active Binary Systems. We show that a significant part of them have lithium excesses, independently of their mass and evolutionary stage. Therefore, it can be concluded that Li abundance does not depend on age for giant components of CABS. These overabundances appear to be closely related to the stellar rotation, and we interpret them as a consequence of the transfer of angular momentum from the orbit to the rotation as the stars evolve: in and off the Main Sequence, in a similar way as it happens in the dwarf components of the same systems and in the Tidally Locked Binaries belonging to the Hyades and M67., Universidad Complutense de Madrid (UCM), Real Colegio Complutense at Harvard University, Ministerio de Educación y Ciencia (MEC), España, Spanish Dirección General de Educación Superior (DGES), Comisión Fulbright, España, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

Published
2023

3. A fast, very-high-energy gamma-ray flare from BL Lacertae during a period of multi-wavelength activity in June 2015

Author

MAGIC Collaboration, Acciari, V. A., Ansoldi, S., ANTONELLI, Lucio Angelo, Arbet Engels, A., Baack, D., Babić, A., Banerjee, B., Bangale, P., Barres de Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., BIGONGIARI, Ciro, Biland, A., Blanch, O., Bonnoli, G., Carosi, R., Ceribella, G., Cikota, S., Colak, S. M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., COVINO, Stefano, D'Elia, V., da Vela, P., Dazzi, F., de Angelis, A., de Lotto, B., Delfino, M., Delgado, J., di Pierro, F., Do Souto Espiñera, E., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Fernández-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., GALLOZZI, Stefano, García López, R. J., Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Herrera, J., Hoang, J., Hrupec, D., Inoue, S., Ishio, K., Iwamura, Y., Kubo, H., Kushida, J., Kuveždić, D., LAMASTRA, Alessandra, Lelas, D., LEONE, FRANCESCO, Lindfors, E., LOMBARDI, Saverio, Longo, F., López, M., López-Oramas, A., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Masuda, S., Mazin, D., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Nöthe, M., PAIANO, Simona, Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, G., Peñil, P., Peresano, M., PERSIC, Massimo, Prada Moroni, P. G., PRANDINI, ELISA, Puljak, I., Garcia, J. R., Rhode, W., Ribó, M., Rico, J., Righi, Chiara, Rugliancich, A., Saha, L., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Somero, A., STAMERRA, Antonio, Strzys, M., Surić, T., TAVECCHIO, Fabrizio, Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tsujimoto, S., van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Vovk, I., Will, M., Zarić, D., D'AMMANDO, FILIPPO, Hada, K., Jorstad, S., Marscher, A. P., Mobeen, M. Z., Hovatta, T., Larionov, V. M., Borman, G. A., Grishina, T. S., Kopatskaya, E. N., Morozova, D. A., Nikiforova, A. A., Lähteenmäki, A., Tornikoski, M., Agudo, I., ITA, Acciari, V. A., Ansoldi, S., Antonelli, L. A., Arbet Engels, A., Baack, D., Babic, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra Gonzalez, J., Bednarek, W., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Carosi, R., Ceribella, G., Cikota, S., Colak, S. M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Di Pierro, F., Do Souto Espinera, E., Dominguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Fernandez-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., Gallozzi, S., Garcia Lopez, R. J., Garczarczyk, M., Gaug, M., Giammaria, P., Godinovic, N., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Herrera, J., Hoang, J., Hrupec, D., Inoue, S., Ishio, K., Iwamura, Y., Kubo, H., Kushida, J., Kuvezdic, D., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., Lopez, M., Lopez-Oramas, A., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martinez, M., Masuda, S., Mazin, D., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogues, L., Nothe, M., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, G., Penil, P., Peresano, M., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Rhode, W., Ribo, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., Snidaric, I., Sobczynska, D., Somero, A., Stamerra, A., Strzys, M., Suric, T., Tavecchio, F., Temnikov, P., Terzic, T., Teshima, M., Torres-Alba, N., Tsujimoto, S., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Vovk, I., Will, M., Zaric, D., D'Ammando, F., Hada, K., Jorstad, S., Marscher, A. P., Mobeen, M. Z., Hovatta, T., Larionov, V. M., Borman, G. A., Grishina, T. S., Kopatskaya, E. N., Morozova, D. A., Nikiforova, A. A., Lahteenmaki, A., Tornikoski, M., Agudo, I., Istituto Nazionale di Fisica Nucleare, Department of Atomic Energy (India), Japanese Government, Croatian Science Foundation, University of Rijeka, German Research Foundation, Polish Academy of Sciences, Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil), Ministry of Science and Technology (South Korea), Junta de Andalucía, Russian Science Foundation, National Science Foundation (US), National Aeronautics and Space Administration (US), Istituto Nazionale di Astrofisica, Swiss National Science Foundation, Ministerio de Economía y Competitividad (España), Federal Ministry of Education and Research (Germany), Department of Electronics and Nanoengineering, Aalto-yliopisto, and Aalto University

Subjects
galaxies [Gamma rays], Photon, model [emission], VHE [gamma ray], Inverse, Astrophysics, 4/3, BL Lacertae objects: individual: BL Lacertae, 01 natural sciences, 7. Clean energy, rotation, law.invention, star, law, jet, Gamma rays: galaxies, 010303 astronomy & astrophysics, Physics, astro-ph.HE, radio wave, model [interaction], photon, Gamma ray, Optical polarization, tension, 3. Good health, optical [polarization], Spectral energy distribution, high [energy], Física nuclear, Astrophysics - High Energy Astrophysical Phenomena, Flare, Active galactic nucleus, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics, gamma rays: galaxies, X-ray, 0103 physical sciences, AGN, individual: BL Lacertae [BL Lacertae objects], 010308 nuclear & particles physics, Astronomy and Astrophysics, Light curve, MAGIC, flux, Space and Planetary Science, ddc:520, spectral
Abstract

The mechanisms producing fast variability of the γ-ray emission in active galactic nuclei (AGNs) are under debate. The MAGIC telescopes detected a fast, very-high-energy (VHE, E > 100 GeV) γ-ray flare from BL Lacertae on 2015 June 15. The flare had a maximum flux of (1.5 ± 0.3) × 10-10 photons cm-2 s-1 and halving time of 26 ± 8 min. The MAGIC observations were triggered by a high state in the optical and high-energy (HE, E > 100 MeV) γ-ray bands. In this paper we present the MAGIC VHE γ-ray data together with multi-wavelength data from radio, optical, X-rays, and HE γ rays from 2015 May 1 to July 31. Well-sampled multi-wavelength data allow us to study the variability in detail and compare it to the other epochs when fast, VHE γ-ray flares have been detected from this source. Interestingly, we find that the behaviour in radio, optical, X-rays, and HE γ-rays is very similar to two other observed VHE γ-ray flares. In particular, also during this flare there was an indication of rotation of the optical polarization angle and of activity at the 43 GHz core. These repeating patterns indicate a connection between the three events. We also test modelling of the spectral energy distribution based on constraints from the light curves and VLBA observations, with two different geometrical setups of two-zone inverse Compton models. In addition we model the γ-ray data with the star-jet interaction model. We find that all of the tested emission models are compatible with the fast VHE γ-ray flare, but all have some tension with the multi-wavelength observations. © ESO 2019., The financial support of the German BMBF and MPG, the Italian INFN and INAF, the Swiss National Fund SNF, the ERDF under the Spanish MINECO (FPA2015-69818-P, FPA2012-36668, FPA 2015-68378-P, FPA2015-69210-C6-2-R, FPA2015-69210-C6-4-R, FPA201569210-C6-6-R, AYA2015-71042-P, AYA2016-76012-C3-1-P, ESP2015-71662C2-2-P, FPA201790566REDC), the Indian Department of Atomic Energy and the Japanese JSPS and MEXT is gratefully acknowledged. This work was also supported by the Spanish Centro de Excelencia >Severo Ochoa> SEV-2016-0588 and SEV-2015-0548, and Unidad de Excelencia >Maria de Maeztu> MDM-20140369, by the Croatian Science Foundation (HrZZ) Project IP-2016-06-9782 and the University of Rijeka Project 13.12.1.3.02, by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, the Polish National Research Centre grant UMO-2016/22/M/ST9/00382 and by the Brazilian MCTIC, CNPq and FAPERJ. The work of the author M. Vazquez Acosta is financed with grant RYC-2013-14660 of MINECO. F. D'Ammando is grateful for support from the National Research Council of Science and Technology, Korea (EU16-001). The Fermi-LAT Collaboration acknowledges generous ongoing support from a number of agencies and institutes that have supported both the development and the operation of the LAT as well as scientific data analysis. These include the National Aeronautics and Space Administration and the Department of Energy in the United States, the Commissariat a l'Energie Atomique and the Centre National de la Recherche Scientifique/Institut National de Physique Nucleaire et de Physique des Particules in France, the Agenzia Spaziale Italiana and the Istituto Nazionale di Fisica Nucleare in Italy, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), High Energy Accelerator Research Organization (KEK) and Japan Aerospace Exploration Agency (JAXA) in Japan, and the K. A. Wallenberg Foundation, the Swedish Research Council and the Swedish National Space Board in Sweden. Additional support for science analysis during the operations phase is gratefully acknowledged from the Istituto Nazionale di Astrofisica in Italy and the Centre National d'Etudes Spatiales in France. This work performed in part under DOE Contract DE-AC02-76SF00515. Based on observations made with the Nordic Optical Telescope, operated by the Nordic Optical Telescope Scientific Association at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofisica de Canarias., Acquisition and reduction of the MAPCAT data was supported in part by MINECO through grants AYA201014844, AYA2013-40825-P, and AYA2016-80889-P, and by the Regional Government of Andalucia through grant P09-FQM-4784. The MAPCAT observations were carried out at the German-Spanish Calar Alto Observatory, which is jointly operated by the Max-Plank-Institut fur Astronomie and the Instituto de Astrofisica de Andalucia-CSIC. The St. Petersburg University team acknowledges support from Russian Science Foundation grant 17-12-01029. This publication makes use of data obtained at the Metsahovi Radio Observatory, operated by Aalto University, Finland. This study makes use of 43-GHz VLBA data from the VLBA-BU Blazar Monitoring Program (VLBA-BUBLAZAR; http://www.bu.edu/blazars/VLBAproject.html), funded by NASA through the Fermi Guest Investigator Program. The VLBA is an instrument of the National Radio Astronomy Observatory. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated by Associated Universities, Inc. The BU group acknowledges support from NASA Fermi GI program grant 80NSSC17K0694 and US National Science Foundation grant AST-1615796. The OVRO 40-m monitoring program is supported in part by NASA grants NNX08AW31G, NNX11A043G and NNX14AQ89G, and NSF grants AST-0808050 and AST-1109911.

Published
2019

4. The age-mass relation for chromospherically active binaries .2. Lithium depletion in dwarf components

Author

Barrado Navascués, David, Fernández Figueroa, María José, García López, R. J., Castro Rubio, Elisa de, and Cornide Castro-Piñeiro, Manuel

Subjects
Astrofísica, Astronomía, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We present an extensive study of lithium abundances in dwarf components of chromospherically active binary stars (CABS). Since most of these binaries have known radii, masses and ages, this kind of data is especially useful for comparisons with theoretical models which try to explain the Li depletion phenomenon. We show that a significant part of these stars have clear Li overabundances with respect to the typical values for stars of the same mass and evolutionary stage. These excesses are evident when comparing our sample of CABS with binary and single stars belonging to open clusters of different ages, namely Pleiades, Hyades, NGC752, M67 and NGC188, which have ages ranging from 7x10^7 to 10^10 yr. The Li excesses are more conspicuous for masses in the range 0.75-0.95 M_⊙., indicating that the rate of Li depletion has been less pronounced in CABS than in single stars. This phenomenon is interpreted in the context of transport of angular momentum from the orbit to the stellar rotation due to tidal effects. This angular momentum transfer would avoid the radial differential rotation and the associated turbulent mixing of material in the stellar interior. Other explanations, however, can not be ruled out. This is the case of transport of material induced by internal gravity waves, which could be inhibited due to the presence of strong magnetic fields associated with the effective dynamo in CABS. The confirmed existence of a relation between Li abundances and the fluxes in Ca II H&K lines can also be accommodated within both scenarios.

Published
1997

5. Very high-energy gamma-ray observations of novae and dwarf novae with the MAGIC telescopes

Author

J. Kushida, Jose Luis Contreras, Juan Cortina, Tomislav Terzić, A. De Angelis, A. Treves, Vitaly Neustroev, M. Hayashida, Marc Ribó, Marina Manganaro, P. Bangale, D. Galindo, Hidetoshi Kubo, B. Biasuzzi, Abelardo Moralejo, H. Takami, Vassil Verguilov, G. Maneva, D. Nakajima, Konstancja Satalecka, Michele Doro, Giacomo Bonnoli, Julia Thaele, M. I. Martínez, R. Zanin, Adrian Biland, Arka Chatterjee, P. G. Prada Moroni, T. Steinbring, D. Fidalgo, K. Mallot, R. J. García López, J. Rico, M. Palatiello, Kyoshi Nishijima, Yusuke Konno, Sabrina Einecke, Pratik Majumdar, R. Reinthal, Francesco Dazzi, Gareth Hughes, M. V. Fonseca, K. Kodani, C. Schultz, V. Scapin, J. Rodriguez Garcia, Dominik Elsaesser, U. Barres de Almeida, R. Desiante, Stefano Covino, R. López-Coto, B. Banerjee, Max Ludwig Ahnen, Stefano Ansoldi, A. Niedzwiecki, Riccardo Paoletti, G. De Caneva, Damir Lelas, Massimo Persic, D. Tescaro, David Paneque, K. Saito, J. Palacio, Ievgen Vovk, D. Guberman, Dorota Sobczyńska, Julian Sitarek, J. M. Paredes, Antonio Stamerra, P. Giammaria, L. Maraschi, Nikola Godinovic, Benito Marcote, E. Hays, Elina Lindfors, J. Hose, Daniel Mazin, T. Toyama, Hanna Kellermann, B. De Lotto, T. Schweizer, D. Dominis Prester, Ivica Puljak, S. Bonnefoy, R. Clavero, P. Temnikov, Pierre Colin, L. A. Antonelli, Kari Nilsson, M. Will, K. Frantzen, Thomas Bretz, F. Di Pierro, R. Mirzoyan, Juri Poutanen, D. Garrido Terrats, P. Da Vela, Wlodek Bednarek, Alessandro Carosi, E. de Oña Wilhelmi, Y. Hanabata, J. A. Barrio, P. Antoranz, E. Carmona, Masahiro Teshima, S. Paiano, Wolfgang Rhode, Karl Mannheim, Jose Miguel Miranda, Fabrizio Tavecchio, Alicia López-Oramas, Ana Babić, F. Borracci, I. Snidaric, Natalia Lewandowska, A. La Barbera, D. Eisenacher Glawion, X. Paredes-Fortuny, M. Nievas Rosillo, E. Lorenz, J. Becerra González, Takashi Saito, Reiko Orito, E. Prandini, U. Menzel, Daniela Dorner, Diego F. Torres, M. Garczarczyk, A. Sillanpää, E. Colombo, M. Gaug, J. Herrera, L. O. Takalo, Francesco Longo, Koji Noda, Elisa Bernardini, Lluis Font, Marcel Strzys, Martin Makariev, Oscar Blanch, Alba Fernández-Barral, W. Idec, Christian Fruck, Mosè Mariotti, A.-K. Overkemping, Dario Hrupec, M. A. Lopez, A. González Muñoz, Saverio Lombardi, C. Delgado Mendez, Ahnen, M. L, Ansoldi, S., Antonelli, L. A., Antoranz, P., Babic, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carmona, E., Carosi, A., Chatterjee, A., Clavero, R., 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., Delgado Mendez, C., Di Pierro, F., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Eisenacher Glawion, D., Elsaesser, D., Fernández Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Frantzen, K., Fruck, C., Galindo, D., García López, R. J., Garczarczyk, M., Garrido Terrats, D., Gaug, M., Giammaria, P., Godinović, N., González Muñoz, A., Guberman, D., Hanabata, Y., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Idec, W., Kellermann, H., Kodani, K., Konno, Y., Kubo, H., Kushida, J., La Barbera, A., Lelas, D., Lewandowska, N., Lindfors, E., Lombardi, S., Longo, Francesco, López, M., López Coto, R., López Oramas, A., Lorenz, E., Majumdar, P., Makariev, M., Mallot, K., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Miranda, J. M., Mirzoyan, R., Moralejo, A., Nakajima, D., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nilsson, K., Nishijima, K., Noda, K., Orito, R., Overkemping, A., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Paredes Fortuny, X., Persic, M., Poutanen, J., Prada Moroni, P. G., Prandini, E., Puljak, I., Reinthal, R., Rhode, W., Ribó, M., Rico, J., Rodriguez Garcia, J., Saito, T., Saito, K., Satalecka, K., Scapin, V., Schultz, C., Schweizer, T., Sillanpää, A., Sitarek, J., Snidaric, I., Sobczynska, D., Stamerra, A., Steinbring, T., Strzys, M., Takalo, L., Takami, H., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Thaele, J., Torres, D. F., Toyama, T., Treves, A., Verguilov, V., Vovk, I., Will, M., Zanin, R., Desiante, R., Hays, E., and Universitat de Barcelona

Subjects
Proton, Hadron, Astrophysics, 01 natural sciences, 7. Clean energy, law.invention, Raigs gamma, law, Astrophysics::Solar and Stellar Astrophysics, novae, cataclysmic variables, gamma rays: stars, binaries: general, stars: activity, 010303 astronomy & astrophysics, Dwarf nova, Novae, Estels binaris de raigs X, astro-ph.HE, Physics, Novae, cataclysmic variable, cataclysmic variables, Binaries: general, Gamma rays: stars, Novae, cataclysmic variables, Stars: activity, Astronomy and Astrophysics, Space and Planetary Science, Gamma-rays, stars, Binaries, general, Stars, activity, Gamma ray, X-ray binaries, Electrónica, Física nuclear, Electricidad, Astrophysics - High Energy Astrophysical Phenomena, activity [Stars], Astrophysics::High Energy Astrophysical Phenomena, Noves (Estels), Telescope, star [Gamma rays], 0103 physical sciences, New stars, general [Binaries], 010308 nuclear & particles physics, Gamma rays, Astronomy and Astrophysic, 13. Climate action, ddc:520, High Energy Physics::Experiment, Fermi Gamma-ray Space Telescope, Lepton
Abstract

Context. In the last five years the Fermi Large Area Telescope (LAT) instrument detected GeV {\gamma}-ray emission from five novae. The GeV emission can be interpreted in terms of an inverse Compton process of electrons accelerated in a shock. In this case it is expected that protons in the same conditions can be accelerated to much higher energies. Consequently they may produce a second component in the {\gamma}-ray spectrum at TeV energies. Aims. We aim to explore the very-high-energy domain to search for {\gamma}-ray emission above 50 GeV and to shed light on the acceleration process of leptons and hadrons in nova explosions. Methods. We have performed observations with the MAGIC telescopes of the classical nova V339 Del shortly after the 2013 outburst, triggered by optical and subsequent GeV {\gamma}-ray detec- tions. We also briefly report on VHE observations of the symbiotic nova YY Her and the dwarf nova ASASSN-13ax. We complement the TeV MAGIC observations with the analysis of con- temporaneous Fermi-LAT data of the sources. The TeV and GeV observations are compared in order to evaluate the acceleration parameters for leptons and hadrons. Results. No significant TeV emission was found from the studied sources. We computed upper limits on the spectrum and night-by-night flux. The combined GeV and TeV observations of V339 Del limit the ratio of proton to electron luminosities to Lp, Comment: 7 pages, 2 figures, accepted for publication in A&A

Published
2015

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