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1. Broadband Multi-wavelength Properties of M87 during the 2018 EHT Campaign including a Very High Energy Flaring Episode

Author: Algaba, J. C., Balokovic, M., Chandra, S., Cheong, W. Y., Cui, Y. Z., D'Ammando, F., Falcone, A. D., Ford, N. M., Giroletti, M., Goddi, C., Gurwell, M. A., Hada, K., Haggard, D., Jorstad, S., Kaur, A., Kawashima, T., Kerby, S., Kim, J. Y., Kino, M., Kravchenko, E. V., Lee, S. S., Lu, R. S., Markoff, S., Michail, J., Neilsen, J., Nowak, M. A., Principe, G., Ramakrishnan, V., Ripperda, B., Sasada, M., Savchenko, S. S., Sheridan, C., Akiyama, K., Alberdi, A., Alef, W., Anantua, R., Asada, K., Azulay, R., Bach, U., Baczko, A. -K., Ball, D., Bandyopadhyay, B., Barrett, J., Bauböck, M., Benson, B. A., Bintley, D., Blackburn, L., Blundell, R., Bouman, K. L., Bower, G. C., Boyce, H., Bremer, M., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Bustamante, S., Carlstrom, J. E., Chael, A., Chan, C. -K., Chang, D. O., Chatterjee, K., Chatterjee, S., Chen, M. -T., Chen, Y., Cheng, X., Cho, I., Christian, P., Conroy, N. S., Conway, J. E., Crawford, T. M., Crew, G. B., Cruz-Osorio, A., Dahale, R., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Dhruv, V., Dihingia, I. K., Doeleman, S. S., Dzib, S. A., Eatough, R. P., Emami, R., Falcke, H., Farah, J., Fish, V. L., Fomalont, E., Ford, H. A., Foschi, M., Fraga-Encinas, R., Freeman, W. T., Friberg, P., Fromm, C. M., Fuentes, A., Galison, P., Gammie, C. F., García, R., Gentaz, O., Georgiev, B., Gold, R., Gómez-Ruiz, A. I., Gómez, J. L., Gu, M., Hesper, R., Heumann, D., Ho, L. C., Ho, P., Honma, M., Huang, C. -W. L., Huang, L., Hughes, D. H., Ikeda, S., Impellizzeri, C. M. V., Inoue, M., Issaoun, S., James, D. J., Jannuzi, B. T., Janssen, M., Jeter, B., Jiang, W., Jiménez-Rosales, A., Johnson, M. D., Jones, A. C., Joshi, A. V., Jung, T., Karuppusamy, R., Keating, G. K., Kettenis, M., Kim, D. -J., Kim, J., Koay, J. Y., Kocherlakota, P., Kofuji, Y., Koch, P. M., Koyama, S., Kramer, C., Kramer, J. A., Kramer, M., Krichbaum, T. P., Kuo, C. -Y., La Bella, N., Levis, A., Li, Z., Lico, R., Lindahl, G., Lindqvist, M., Lisakov, M., Liu, J., Liu, K., Liuzzo, E., Lo, W. -P., Lobanov, A. P., Loinard, L., Lonsdale, C. J., Lowitz, A. E., MacDonald, N. R., Mao, J., Marchili, N., Marrone, D. P., Marscher, A. P., Martí-Vidal, I., Matsushita, S., Matthews, L. D., Medeiros, L., Menten, K. M., Mizuno, I., Mizuno, Y., Montgomery, J., Moran, J. M., Moriyama, K., Moscibrodzka, M., Mulaudzi, W., Müller, C., Müller, H., Mus, A., Musoke, G., Myserlis, I., Nagai, H., Nagar, N. M., Nair, D. G., Nakamura, M., Narayanan, G., Natarajan, I., Nathanail, A., Fuentes, S. Navarro, Ni, C., Oh, J., Okino, H., Olivares, H., Oyama, T., Özel, F., Palumbo, D. C. M., Paraschos, G. Filippos, Park, J., Parsons, H., Patel, N., Pen, U. -L., Pesce, D. W., Piétu, V., PopStefanija, A., Porth, O., Prather, B., Psaltis, D., Pu, H. -Y., Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ricarte, A., Roelofs, F., Romero-Cañizales, C., Ros, E., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruiz, I., Ruszczyk, C., Rygl, K. L. J., Sánchez, S., Sánchez-Argüelles, D., Sánchez-Portal, M., Satapathy, K., Savolainen, T., Schloerb, F. P., Schonfeld, J., Schuster, K. -F., Shao, L., Shen, Z., Small, D., Sohn, B. W., SooHoo, J., Salas, L. D. Sosapanta, Souccar, K., Stanway, J. S., Sun, H., Tazaki, F., Tetarenko, A. J., Tiede, P., Tilanus, R. P. J., Titus, M., Toma, K., Torne, P., Toscano, T., Traianou, E., Trent, T., Trippe, S., Turk, M., van Bemmel, I., van Langevelde, H. J., van Rossum, D. R., Vos, J., Wagner, J., Ward-Thompson, D., Wardle, J., Washington, J. E., Weintroub, J., Wharton, R., Wielgus, M., Wiik, K., Witzel, G., Wondrak, M. F., Wong, G. N., Wu, Q., Yadlapalli, N., Yamaguchi, P., Yfantis, A., Yoon, D., Young, A., Younsi, Z., Yu, W., Yuan, F., Yuan, Y. -F., Zensus, J. A., Zhang, S., Zhao, G. -Y., Zhao, S. -S., Bellazzini, R., Berenji, B., Bissaldi, E., Blandford, R. D., Bonino, R., Bruel, P., Cameron, R. A., Caraveo, P. A., Cavazzuti, E., Cheung, C. C., Ciprini, S., Orestano, P. Cristarella, Cutini, S., Di Lalla, N., Dinesh, A., Di Venere, L., Domínguez, A., Fegan, S. J., Franckowiak, A., Fukazawa, Y., Fusco, P., Gargano, F., Gasbarra, C., Germani, S., Giliberti, M., Grenier, I. A., Hays, E., Horan, D., Kuss, M., Larsson, S., Liodakis, I., Longo, F., Loparco, F., Lovellette, M. N., Maldera, S., Mazziotta, M. N., Mereu, I., Michelson, P. F., Mirabal, N., Mizuno, T., Monzani, M. E., Morselli, A., Negro, M., Omodei, N., Orlando, E., Persic, M., Rainò, S., Rani, B., Reimer, A., Reimer, O., Sánchez-Conde, M., Parkinson, P. M. Saz, Sgrò, C., Siskind, E. J., Spinelli, P., Suson, D. J., Tajima, H., Torres, D. F., Zaharijas, G., Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bouyahiaoui, M., Bradascio, F., Brose, R., Brown, A., Bruno, B., Bulik, T., Burger-Scheidlin, C., Casanova, S., Cecil, R., Celic, J., Cerruti, M., Chand, T., Chen, A., Chibueze, J., Chibueze, O., Czerny, T., Dainotti, M., Dubus, F., Dumm, J., D'Urso, G., Drouhin, A., Durouchoux, P., Fabbian, D., Franczak, D., Funk, M., Gabanyi, J., Gaggero, G., Garcia, N., Geiger, A., Giorgi, M. G., Gleeson, S., Gonzalez, S., Gauthier, G. T., Grasso, P., Hovatta, T., Hyman, J., Kaaret, C., Kirk, D., Lal, S., Lesch, T. M., Lohmann, K., Massaro, C., Mayer, M., Meintjes, P. J., Miral, E., Mirra, A., Neronov, J., Padovani, E., Paccagnella, F., Parisi, E., Piotrowska, A., Pohl, S., Puga, G., Ramirez, L. R., Reville, S., Rowell, D. S., Rudge, M., Rybka, G., Schlenstedt, M. S., Seo, E. S., Svirski, J., Taylor, J. R., Torres, F., Tsujimoto, K., Tosti, F., Volpi, S., Walraven, N. A., Welker, L., Zietkiewicz, M., Abdalla, G., Aleva, C., Benkhali, H. A. Ait, Aldous, M., Amin, M., Aschieri, M. A., de Deus, E., Santos, J. de Los, Fontanot, D., Jorfi, S., Levens, P., Zwart, A. E. E., Oliviero, S., Puglisi, D., Thiel, M., Zaharijas, C., Amaral, F., Boella, L., Holincheck, L., Queiroz, R., Sofue, H., Tellis, G., Wagner, G., Wierzcholska, A., Zacharias, M., Zdziarski, A. A., Zech, A., Zywucka, N., Abe, S., Abhir, J., Abhishek, A., Acciari, V. A., Aguasca-Cabot, A., Agudo, I., Aniello, T., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Arcaro, C., Artero, M., Asano, K., Babic, A., de Almeida, U. Barres, Barrio, J. A., Batkovic, I., Bautista, A., Baxter, J., González, J. Becerra, Bednarek, W., Bernardini, E., Bernete, J., Berti, A., Besenrieder, J., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bosnjak, Z., Bronzini, E., Burelli, I., Busetto, G., Campoy-Ordaz, A., Carosi, A., Carosi, R., Carretero-Castrillo, M., Castro-Tirado, A. J., Cerasole, D., Ceribella, G., Chai, Y., Cifuentes, A., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Amico, G., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., de Menezes, R., Delfino, M., Delgado, J., Mendez, C. Delgado, Di Pierro, F., Di Tria, R., Prester, D. Dominis, Donini, A., Dorner, D., Doro, M., Elsaesser, D., Escudero, J., Fariña, L., Fattorini, A., Foffano, L., Font, L., Fröse, S., Fukami, S., López, R. J. García, Garczarczyk, M., Gasparyan, S., Gaug, M., Paiva, J. G. Giesbrecht, Giglietto, N., Giordano, F., Gliwny, P., Godinovic, N., Gradetzke, T., Grau, R., Green, D., Green, J. G., Günther, P., Hadasch, D., Hahn, A., Hassan, T., Heckmann, L., Llorente, J. Herrera, Hrupec, D., Imazawa, R., Ishio, K., Martínez, I. Jiménez, Jormanainen, J., Kayanoki, T., Kerszberg, D., Kluge, G. W., Kobayashi, Y., Kouch, P. M., Kubo, H., Kushida, J., Laínez, M., Lamastra, A., Leone, F., Lindfors, E., Lombardi, S., López-Coto, R., López-Moya, M., López-Oramas, A., Loporchio, S., Lorini, A., Lyard, E., Fraga, B. Machado de Oliveira, Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mangano, S., Mannheim, K., Mariotti, M., Martínez, M., Martínez-Chicharro, M., Mas-Aguilar, A., Mazin, D., Menchiari, S., Mender, S., Miceli, D., Miener, T., Miranda, J. M., Mirzoyan, R., González, M. Molero, Molina, E., Mondal, H. A., Moralejo, A., Morcuende, D., Nakamori, T., Nanci, C., Neustroev, V., Nickel, L., Rosillo, M. Nievas, Nigro, C., Nikolic, L., Nilsson, K., Nishijima, K., Ekoume, T. Njoh, Noda, K., Nozaki, S., Ohtani, Y., Okumura, A., Otero-Santos, J., Paiano, S., Paneque, D., Paoletti, R., Paredes, J. M., Peresano, M., Pihet, M., Pirola, G., Podobnik, F., Moroni, P. G. Prada, Prandini, E., Priyadarshi, C., Ribó, M., Rico, J., Righi, C., Sahakyan, N., Saito, T., Saturni, F. G., Schmidt, K., Schmuckermaier, F., Schubert, J. L., Schweizer, T., Sciaccaluga, A., Silvestri, G., Sitarek, J., Sliusar, V., Sobczynska, D., Spolon, A., Stamerra, A., Strišković, J., Strom, D., Strzys, M., Suda, Y., Suutarinen, S., Takahashi, M., Takeishi, R., Tavecchio, F., Temnikov, P., Terauchi, K., Terzic, T., Teshima, M., Truzzi, S., Tutone, A., Ubach, S., van Scherpenberg, J., Acosta, M. Vazquez, Ventura, S., Verna, G., Viale, I., Vigorito, C. F., Vitale, V., Vovk, I., Walter, R., Will, M., Wunderlich, C., Yamamoto, T., Acharyya, A., Adams, C. B., Bangale, P., Bartkoske, J. T., Benbow, W., Christiansen, J. L., Duerr, A., Errando, M., Feng, Q., Foote, G. M., Fortson, L., Furniss, A., Hanlon, W., Hervet, O., Hinrichs, C. E., Holder, J., Humensky, T. B., Jin, W., Johnson, M. N., Kaaret, P., Kertzman, M., Kieda, D., Kleiner, T. K., Korzoun, N., Krennrich, F., Kumar, S., Lang, M. J., Lundy, M., Maier, G., McGrath, C. E., Millard, M. J., Mooney, C. L., Moriarty, P., Mukherjee, R., Ning, W., O'Brien, S., Ong, R. A., Pohl, M., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Ribeiro, D., Roache, E., Ryan, J. L., Sadeh, I., Saha, L., Santander, M., Sembroski, G. H., Shang, R., Splettstoesser, M., Talluri, A. K., Tucci, J. V., Valverde, J., Vassiliev, V. V., Williams, D. A., Wong, S. L., Chen, Z., Cui, L., Hirota, T., Li, B., Li, G., Liu, Q., Liu, X., Liu, Z., Ma, J., Niinuma, K., Ro, H., Sakai, N., Sawada-Satoh, S., Wajima, K., Wang, J., Wang, N., Xia, B., Yan, H., Yonekura, Y., Zhang, H., Zhao, R., Zhong, W., group, The Event Horizon Telescope - Multi-wavelength science working, Collaboration, The Event Horizon Telescope, Collaboration, The Fermi Large Area Telescope, Collaboration, H. E. S. S., Collaboration, MAGIC, Collaboration, VERITAS, and Collaboration, EAVN
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract: The nearby elliptical galaxy M87 contains one of the only two supermassive black holes whose emission surrounding the event horizon has been imaged by the Event Horizon Telescope (EHT). In 2018, more than two dozen multi-wavelength (MWL) facilities (from radio to gamma-ray energies) took part in the second M87 EHT campaign. The goal of this extensive MWL campaign was to better understand the physics of the accreting black hole M87*, the relationship between the inflow and inner jets, and the high-energy particle acceleration. Understanding the complex astrophysics is also a necessary first step towards performing further tests of general relativity. The MWL campaign took place in April 2018, overlapping with the EHT M87* observations. We present a new, contemporaneous spectral energy distribution (SED) ranging from radio to very high energy (VHE) gamma-rays, as well as details of the individual observations and light curves. We also conduct phenomenological modelling to investigate the basic source properties. We present the first VHE gamma-ray flare from M87 detected since 2010. The flux above 350 GeV has more than doubled within a period of about 36 hours. We find that the X-ray flux is enhanced by about a factor of two compared to 2017, while the radio and millimetre core fluxes are consistent between 2017 and 2018. We detect evidence for a monotonically increasing jet position angle that corresponds to variations in the bright spot of the EHT image. Our results show the value of continued MWL monitoring together with precision imaging for addressing the origins of high-energy particle acceleration. While we cannot currently pinpoint the precise location where such acceleration takes place, the new VHE gamma-ray flare already presents a challenge to simple one-zone leptonic emission model approaches, and emphasises the need for combined image and spectral modelling., Comment: 46 pages, 23 figures, accepted by Astronomy & Astrophysics on August. 29, 2024
Published: 2024
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2. Ordered magnetic fields around the 3C 84 central black hole

Author: Paraschos, G. F., Kim, J. -Y., Wielgus, M., Röder, J., Krichbaum, T. P., Ros, E., Agudo, I., Myserlis, I., Moscibrodzka, M., Traianou, E., Zensus, J. A., Blackburn, L., Chan, C. -K., Issaoun, S., Janssen, M., Johnson, M. D., Fish, V. L., Akiyama, K., Alberdi, A., Alef, W., Algaba, J. C., Anantua, R., Asada, K., Azulay, R., Bach, U., Baczko, A. -K., Ball, D., Baloković, M., Barrett, J., Bauböck, M., Benson, B. A., Bintley, D., Blundell, R., Bouman, K. L., Bower, G. C., Boyce, H., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Bustamante, S., Byun, D. -Y., Carlstrom, J. E., Ceccobello, C., Chael, A., Chang, D. O., Chatterjee, K., Chatterjee, S., Chen, M. T., Chen, Y., Cheng, X., Cho, I., Christian, P., Conroy, N. S., Conway, J. E., Cordes, J. M., Crawford, T. M., Crew, G. B., Cruz-Osorio, A., Cui, Y., Dahale, R., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Dhruv, V., Doeleman, S. S., Dougal, S., Dzib, S. A., Eatough, R. P., Emami, R., Falcke, H., Farah, J., Fomalont, E., Ford, H. A., Foschi, M., Fraga-Encinas, R., Freeman, W. T., Friberg, P., Fromm, C. M., Fuentes, A., Galison, P., Gammie, C. F., García, R., Gentaz, O., Georgiev, B., Goddi, C., Gold, R., Gómez-Ruiz, A. I., Gómez, J. L., Gu, M., Gurwell, M., Hada, K., Haggard, D., Haworth, K., Hecht, M. H., Hesper, R., Heumann, D., Ho, L. C., Ho, P., Honma, M., Huang, C. L., Huang, L., Hughes, D. H., Ikeda, S., Impellizzeri, C. M. V., Inoue, M., James, D. J., Jannuzi, B. T., Jeter, B., Jaing, W., Jiménez-Rosales, A., Jorstad, S., Joshi, A. V., Jung, T., Karami, M., Karuppusamy, R., Kawashima, T., Keating, G. K., Kettenis, M., Kim, D. -J., Kim, J., Kino, M., Koay, J. Y., Kocherlakota, P., Kofuji, Y., Koch, P. M., Koyama, S., Kramer, C., Kramer, J. A., Kramer, M., Kuo, C. -Y., La Bella, N., Lauer, T. R., Lee, D., Lee, S. -S., Leung, P. K., Levis, A., Li, Z., Lico, R., Lindahl, G., Lindqvist, M., Lisakov, M., Liu, J., Liu, K., Liuzzo, E., Lo, W. -P., Lobanov, A. P., Loinard, L., Lonsdale, C. J., Lowitz, A. E., Lu, R. -S., MacDonald, N. R., Mao, J., Marchili, N., Markoff, S., Marrone, D. P., Marscher, A. P., Martí-Vidal, I., Matsushita, S., Matthews, L. D., Medeiros, L., Menten, K. M., Michalik, D., Mizuno, I., Mizuno, Y., Moran, J. M., Moriyama, K., Mulaudzi, W., Müller, C., Müller, H., Mus, A., Musoke, G., Nadolski, A., Nagai, H., Nagar, N. M., Nakamura, M., Narayanan, G., Natarajan, I., Nathanail, A., Fuentes, S. Navarro, Neilsen, J., Neri, R., Ni, C., Noutsos, A., Nowak, M. A., Oh, J., Okino, H., Olivares, H., Ortiz-León, G. N., Oyama, T., Özel, F., Palumbo, D. C. M., Park, J., Parsons, H., Patel, N., Pen, U. -L., Piétu, V., Plambeck, R., PopStefanija, A., Porth, O., Pötzl, F. M., Prather, B., Preciado-López, J. A., Psaltis, D., Pu, H. -Y., Ramakrishnan, V., Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ricarte, A., Ripperda, B., Roelofs, F., Rogers, A., Romero-Cañizales, C., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruiz, I., Ruszczyk, C., Rygl, K. L. J., Sánchez, S., Sánchez-Argüelles, D., Sánchez-Portal, M., Sasada, M., Satapathy, K., Savolainen, T., Schloerb, F. P., Schonfeld, J., Schuster, K., Shao, L., Shen, Z., Small, D., Sohn, B. W., SooHoo, J., Salas, L. D. Sosapanta, Souccar, K., Sun, H., Tazaki, F., Tetarenko, A. J., Tiede, P., Tilanus, R. P. J., Titus, M., Torne, P., Toscano, T., Trent, T., Trippe, S., Turk, M., van Bemmel, I., van Langevelde, H. J., van Rossum, D. R., Vos, J., Wagner, J., Ward-Thompson, D., Wardle, J., Washington, J. E., Weintroub, J., Wharton, R., Wiik, K., Witzel, G., Wondrak, M. F., Wong, G. N., Wu, Q., Yadlapalli, N., Yamaguchi, P., Yfantis, A., Yoon, D., Young, A., Young, K., Younsi, Z., Yu, W., Yuan, F., Yuan, Y. -F., Zhang, S., Zhao, G. Y., and Zhao, S. -S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract: 3C84 is a nearby radio source with a complex total intensity structure, showing linear polarisation and spectral patterns. A detailed investigation of the central engine region necessitates the use of VLBI above the hitherto available maximum frequency of 86GHz. Using ultrahigh resolution VLBI observations at the highest available frequency of 228GHz, we aim to directly detect compact structures and understand the physical conditions in the compact region of 3C84. We used EHT 228GHz observations and, given the limited (u,v)-coverage, applied geometric model fitting to the data. We also employed quasi-simultaneously observed, multi-frequency VLBI data for the source in order to carry out a comprehensive analysis of the core structure. We report the detection of a highly ordered, strong magnetic field around the central, SMBH of 3C84. The brightness temperature analysis suggests that the system is in equipartition. We determined a turnover frequency of $\nu_m=(113\pm4)$GHz, a corresponding synchrotron self-absorbed magnetic field of $B_{SSA}=(2.9\pm1.6)$G, and an equipartition magnetic field of $B_{eq}=(5.2\pm0.6)$G. Three components are resolved with the highest fractional polarisation detected for this object ($m_\textrm{net}=(17.0\pm3.9)$%). The positions of the components are compatible with those seen in low-frequency VLBI observations since 2017-2018. We report a steeply negative slope of the spectrum at 228GHz. We used these findings to test models of jet formation, propagation, and Faraday rotation in 3C84. The findings of our investigation into different flow geometries and black hole spins support an advection-dominated accretion flow in a magnetically arrested state around a rapidly rotating supermassive black hole as a model of the jet-launching system in the core of 3C84. However, systematic uncertainties due to the limited (u,v)-coverage, however, cannot be ignored., Comment: 15 pages, 6 figures, published in A&A
Published: 2024
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3. Metadata for the Flux Density Calibration of the April 2018 Event Horizon Telescope Data

Author: Koay, J. Y., Romero-Cañizales, C., Matthews, L. D., Janssen, M., Blackburn, L., Tilanus, R. P. J., Park, J., Asada, K., Matsushita, S., Baczko, A. -K., La Bella, N., Chan, C. -K., Crew, G. B., Fish, V., Patel, N., Ramakrishnan, V., Rottmann, H., Wagner, J., Wiik, K., Friberg, P., Goddi, C., Issaoun, S., Keating, G., Kim, J., Krichbaum, T. P., Marrone, D., Narayanan, G., Roy, A., Ruíz, I., Sánchez, S., Torne, P., and Weintroub, J.
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: The Event Horizon Telescope (EHT) observations carried out in 2018 April at 1.3 mm wavelengths included 9 stations in the array, comprising 7 single-dish telescopes and 2 phased arrays. The metadata package for the 2018 EHT observing campaign contains calibration tables required for the a-priori amplitude calibration of the 2018 April visibility data. This memo is the official documentation accompanying the release of the 2018 EHT metadata package, providing an overview of the contents of the package. We describe how telescope sensitivities, gain curves and other relevant parameters for each station in the EHT array were collected, processed, and validated to produce the calibration tables., Comment: 26 pages, 7 figures, EHT Memo Series 2023-L1-01
Published: 2023

4. Observational constraints on the optical and near-infrared emission from the neutron star-black hole binary merger S190814bv

Author: Ackley, K., Amati, L., Barbieri, C., Bauer, F. E., Benetti, S., Bernardini, M. G., Bhirombhakdi, K., Botticella, M. T., Branchesi, M., Brocato, E., Bruun, S. H., Bulla, M., Campana, S., Cappellaro, E., Castro-Tirado, A. J., Chambers, K. C., Chaty, S., Chen, T. -W., Ciolfi, R., Coleiro, A., Copperwheat, C. M., Covino, S., Cutter, R., D'Ammando, F., D'Avanzo, P., De Cesare, G., D'Elia, V., Della Valle, M., Denneau, L., De Pasquale, M., Dhillon, V. S., Dyer, M. J., Elias-Rosa, N., Evans, P. A., Eyles-Ferris, R. A. J., Fiore, A., Fraser, M., Fruchter, A. S., Fynbo, J. P. U., Galbany, L., Gall, C., Galloway, D. K., Getman, F. I., Ghirlanda, G., Gillanders, J. H., Gomboc, A., Gompertz, B. P., González-Fernández, C., González-Gaitán, S., Grado, A., Greco, G., Gromadzki, M., Groot, P. J., Gutiérrez, C. P., Heikkilä, T., Heintz, K. E., Hjorth, J., Hu, Y. -D., Huber, M. E., Inserra, C., Izzo, L., Japelj, J., Jerkstrand, A., Jin, Z. P., Jonker, P. G., Kankare, E., Kann, D. A., Kennedy, M., Kim, S., Klose, S., Kool, E. C., Kotak, R., Kuncarayakti, H., Lamb, G. P., Leloudas, G., Levan, A. J., Longo, F., Lowe, T. B., Lyman, J. D., Magnier, E., Maguire, K., Maiorano, E., Mandel, I., Mapelli, M., Mattila, S., McBrien, O. R., Melandri, A., Michałowski, M. J., Milvang-Jensen, B., Moran, S., Nicastro, L., Nicholl, M., Guelbenzu, A. Nicuesa, Nuttal, L., Oates, S. R., O'Brien, P. T., Onori, F., Palazzi, E., Patricelli, B., Perego, A., Torres, M. A. P., Perley, D. A., Pian, E., Pignata, G., Piranomonte, S., Poshyachinda, S., Possenti, A., Pumo, M. L., Quirola-Vásquez, J., Ragosta, F., Ramsay, G., Rau, A., Rest, A., Reynolds, T. M., Rosetti, S. S., Rossi, A., Rosswog, S., Sabha, N. B., Carracedo, A. Sagués, Salafia, O. S., Salmon, L., Salvaterra, R., Savaglio, S., Sbordone, L., Schady, P., Schipani, P., Schultz, A. S. B., Schweyer, T., Smartt, S. J., Smith, K. W., Smith, M., Sollerman, J., Srivastav, S., Stanway, E. R., Starling, R. L. C., Steeghs, D., Stratta, G., Stubbs, C. W., Tanvir, N. R., Testa, V., Thrane, E., Tonry, J. L., Turatto, M., Ulaczyk, K., van der Horst, A. J., Vergani, S. D., Walton, N. A., Watson, D., Wiersema, K., Wiik, K., Wyrzykowski, L., Yang, S., Yi, S. -X., and Young, D. R.
Subjects: Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics - High Energy Astrophysical Phenomena
Abstract: On 2019 August 14, the LIGO and Virgo interferometers detected a high-significance event labelled S190814bv. Preliminary analysis of the GW data suggests that the event was likely due to the merger of a compact binary system formed by a BH and a NS. ElectromagNetic counterparts of GRAvitational wave sources at the VEry Large Telescope (ENGRAVE) collaboration members carried out an intensive multi-epoch, multi-instrument observational campaign to identify the possible optical/near infrared counterpart of the event. In addition, the ATLAS, GOTO, GRAWITA-VST, Pan-STARRS and VINROUGE projects also carried out a search on this event. Our observations allow us to place limits on the presence of any counterpart and discuss the implications for the kilonova (KN) possibly generated by this NS-BH merger, and for the strategy of future searches. Altogether, our observations allow us to exclude a KN with large ejecta mass $M\gtrsim 0.1\,\mathrm{M_\odot}$ to a high ($>90\%$) confidence, and we can exclude much smaller masses in a subsample of our observations. This disfavours the tidal disruption of the neutron star during the merger. Despite the sensitive instruments involved in the campaign, given the distance of S190814bv we could not reach sufficiently deep limits to constrain a KN comparable in luminosity to AT 2017gfo on a large fraction of the localisation probability. This suggests that future (likely common) events at a few hundreds Mpc will be detected only by large facilities with both high sensitivity and large field of view. Galaxy-targeted observations can reach the needed depth over a relevant portion of the localisation probability with a smaller investment of resources, but the number of galaxies to be targeted in order to get a fairly complete coverage is large, even in the case of a localisation as good as that of this event., Comment: 52 pages, revised version now accepted for publication in A&A. Abstract abridged to meet arXiv requirements
Published: 2020
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5. A dust-enshrouded tidal disruption event with a resolved radio jet in a galaxy merger

Author: Mattila, S., Pérez-Torres, M., Efstathiou, A., Mimica, P., Fraser, M., Kankare, E., Alberdi, A., Aloy, M. Á., Heikkilä, T., Jonker, P. G., Lundqvist, P., Martí-Vidal, I., Meikle, W. P. S., Romero-Cañizales, C., Smartt, S. J., Tsygankov, S., Varenius, E., Alonso-Herrero, A., Bondi, M., Fransson, C., Herrero-Illana, R., Kangas, T., Kotak, R., Ramírez-Olivencia, N., Väisänen, P., Beswick, R. J., Clements, D. L., Greimel, R., Harmanen, J., Kotilainen, J., Nandra, K., Reynolds, T., Ryder, S., Walton, N. A., Wiik, K., and Östlin, G.
Subjects: Astrophysics - Astrophysics of Galaxies, Astrophysics - High Energy Astrophysical Phenomena
Abstract: Tidal disruption events (TDEs) are transient flares produced when a star is ripped apart by the gravitational field of a supermassive black hole (SMBH). We have observed a transient source in the western nucleus of the merging galaxy pair Arp 299 that radiated >1.5x10^52 erg in the infrared and radio, but was not luminous at optical or X-ray wavelengths. We interpret this as a TDE with much of its emission re-radiated at infrared wavelengths by dust. Efficient reprocessing by dense gas and dust may explain the difference between theoretical predictions and observed luminosities of TDEs. The radio observations resolve an expanding and decelerating jet, probing the jet formation and evolution around a SMBH., Comment: Published online by Science on 14 Jun 2018
Published: 2018
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6. A combined radio and GeV gamma-ray view of the 2012 and 2013 flares of Mrk 421

Author: Hovatta, T., Petropoulou, M., Richards, J. L., Giannios, D., Wiik, K., Baloković, M., Lähteenmäki, A., Lott, B., Max-Moerbeck, W., Ramakrishnan, V., and Readhead, A. C. S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: In 2012 Markarian 421 underwent the largest flare ever observed in this blazar at radio frequencies. In the present study, we start exploring this unique event and compare it to a less extreme event in 2013. We use 15 GHz radio data obtained with the Owens Valley Radio Observatory 40-m telescope, 95 GHz millimeter data from the Combined Array for Research in Millimeter-Wave Astronomy, and GeV gamma-ray data from the Fermi Gamma-ray Space Telescope. The radio light curves during the flaring periods in 2012 and 2013 have very different appearances, both in shape and peak flux density. Assuming that the radio and gamma-ray flares are physically connected, we attempt to model the most prominent sub-flares of the 2012 and 2013 activity periods by using the simplest possible theoretical framework. We first fit a one-zone synchrotron self-Compton (SSC) model to the less extreme 2013 flare and estimate parameters describing the emission region. We then model the major gamma-ray and radio flares of 2012 using the same framework. The 2012 gamma-ray flare shows two distinct spikes of similar amplitude, so we examine scenarios associating the radio flare with each spike in turn. In the first scenario, we cannot explain the sharp radio flare with a simple SSC model, but we can accommodate this by adding plausible time variations to the Doppler beaming factor. In the second scenario, a varying Doppler factor is not needed, but the SSC model parameters require fine tuning. Both alternatives indicate that the sharp radio flare, if physically connected to the preceding gamma-ray flares, can be reproduced only for a very specific choice of parameters., Comment: 11 pages, 5 figures, MNRAS accepted
Published: 2015
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7. Ordered magnetic fields around the 3C 84 central black hole

Author: Paraschos, G. F., primary, Kim, J.-Y., additional, Wielgus, M., additional, Röder, J., additional, Krichbaum, T. P., additional, Ros, E., additional, Agudo, I., additional, Myserlis, I., additional, Moscibrodzka, M., additional, Traianou, E., additional, Zensus, J. A., additional, Blackburn, L., additional, Chan, C.-K., additional, Issaoun, S., additional, Janssen, M., additional, Johnson, M. D., additional, Fish, V. L., additional, Akiyama, K., additional, Alberdi, A., additional, Alef, W., additional, Algaba, J. C., additional, Anantua, R., additional, Asada, K., additional, Azulay, R., additional, Bach, U., additional, Baczko, A.-K., additional, Ball, D., additional, Baloković, M., additional, Barrett, J., additional, Bauböck, M., additional, Benson, B. A., additional, Bintley, D., additional, Blundell, R., additional, Bouman, K. L., additional, Bower, G. C., additional, Boyce, H., additional, Bremer, M., additional, Brinkerink, C. D., additional, Brissenden, R., additional, Britzen, S., additional, Broderick, A. E., additional, Broguiere, D., additional, Bronzwaer, T., additional, Bustamante, S., additional, Byun, D.-Y., additional, Carlstrom, J. E., additional, Ceccobello, C., additional, Chael, A., additional, Chang, D. O., additional, Chatterjee, K., additional, Chatterjee, S., additional, Chen, M. T., additional, Chen, Y., additional, Cheng, X., additional, Cho, I., additional, Christian, P., additional, Conroy, N. S., additional, Conway, J. E., additional, Cordes, J. M., additional, Crawford, T. M., additional, Crew, G. B., additional, Cruz-Osorio, A., additional, Cui, Y., additional, Dahale, R., additional, Davelaar, J., additional, De Laurentis, M., additional, Deane, R., additional, Dempsey, J., additional, Desvignes, G., additional, Dexter, J., additional, Dhruv, V., additional, Doeleman, S. S., additional, Dougal, S., additional, Dzib, S. A., additional, Eatough, R. P., additional, Emami, R., additional, Falcke, H., additional, Farah, J., additional, Fomalont, E., additional, Ford, H. A., additional, Foschi, M., additional, Fraga-Encinas, R., additional, Freeman, W. T., additional, Friberg, P., additional, Fromm, C. M., additional, Fuentes, A., additional, Galison, P., additional, Gammie, C. F., additional, García, R., additional, Gentaz, O., additional, Georgiev, B., additional, Goddi, C., additional, Gold, R., additional, Gómez-Ruiz, A. I., additional, Gómez, J. L., additional, Gu, M., additional, Gurwell, M., additional, Hada, K., additional, Haggard, D., additional, Haworth, K., additional, Hecht, M. H., additional, Hesper, R., additional, Heumann, D., additional, Ho, L. C., additional, Ho, P., additional, Honma, M., additional, Huang, C. L., additional, Huang, L., additional, Hughes, D. H., additional, Ikeda, S., additional, Impellizzeri, C. M. V., additional, Inoue, M., additional, James, D. J., additional, Jannuzi, B. T., additional, Jeter, B., additional, Jaing, W., additional, Jiménez-Rosales, A., additional, Jorstad, S., additional, Joshi, A. V., additional, Jung, T., additional, Karami, M., additional, Karuppusamy, R., additional, Kawashima, T., additional, Keating, G. K., additional, Kettenis, M., additional, Kim, D.-J., additional, Kim, J., additional, Kino, M., additional, Koay, J. Y., additional, Kocherlakota, P., additional, Kofuji, Y., additional, Koch, P. M., additional, Koyama, S., additional, Kramer, C., additional, Kramer, J. A., additional, Kramer, M., additional, Kuo, C.-Y., additional, La Bella, N., additional, Lauer, T. R., additional, Lee, D., additional, Lee, S.-S., additional, Leung, P. K., additional, Levis, A., additional, Li, Z., additional, Lico, R., additional, Lindahl, G., additional, Lindqvist, M., additional, Lisakov, M., additional, Liu, J., additional, Liu, K., additional, Liuzzo, E., additional, Lo, W.-P., additional, Lobanov, A. P., additional, Loinard, L., additional, Lonsdale, C. J., additional, Lowitz, A. E., additional, Lu, R.-S., additional, MacDonald, N. R., additional, Mao, J., additional, Marchili, N., additional, Markoff, S., additional, Marrone, D. P., additional, Marscher, A. P., additional, Martí-Vidal, I., additional, Matsushita, S., additional, Matthews, L. D., additional, Medeiros, L., additional, Menten, K. M., additional, Michalik, D., additional, Mizuno, I., additional, Mizuno, Y., additional, Moran, J. M., additional, Moriyama, K., additional, Mulaudzi, W., additional, Müller, C., additional, Müller, H., additional, Mus, A., additional, Musoke, G., additional, Nadolski, A., additional, Nagai, H., additional, Nagar, N. M., additional, Nakamura, M., additional, Narayanan, G., additional, Natarajan, I., additional, Nathanail, A., additional, Navarro Fuentes, S., additional, Neilsen, J., additional, Neri, R., additional, Ni, C., additional, Noutsos, A., additional, Nowak, M. A., additional, Oh, J., additional, Okino, H., additional, Olivares, H., additional, Ortiz-León, G. N., additional, Oyama, T., additional, Özel, F., additional, Palumbo, D. C. M., additional, Park, J., additional, Parsons, H., additional, Patel, N., additional, Pen, U.-L., additional, Piétu, V., additional, Plambeck, R., additional, PopStefanija, A., additional, Porth, O., additional, Pötzl, F. M., additional, Prather, B., additional, Preciado-López, J. A., additional, Psaltis, D., additional, Pu, H.-Y., additional, Ramakrishnan, V., additional, Rao, R., additional, Rawlings, M. G., additional, Raymond, A. W., additional, Rezzolla, L., additional, Ricarte, A., additional, Ripperda, B., additional, Roelofs, F., additional, Rogers, A., additional, Romero-Cañizales, C., additional, Roshanineshat, A., additional, Rottmann, H., additional, Roy, A. L., additional, Ruiz, I., additional, Ruszczyk, C., additional, Rygl, K. L. J., additional, Sánchez, S., additional, Sánchez-Argüelles, D., additional, Sánchez-Portal, M., additional, Sasada, M., additional, Satapathy, K., additional, Savolainen, T., additional, Schloerb, F. P., additional, Schonfeld, J., additional, Schuster, K., additional, Shao, L., additional, Shen, Z., additional, Small, D., additional, Sohn, B. W., additional, SooHoo, J., additional, Sosapanta Salas, L. D., additional, Souccar, K., additional, Sun, H., additional, Tazaki, F., additional, Tetarenko, A. J., additional, Tiede, P., additional, Tilanus, R. P. J., additional, Titus, M., additional, Torne, P., additional, Toscano, T., additional, Trent, T., additional, Trippe, S., additional, Turk, M., additional, van Bemmel, I., additional, van Langevelde, H. J., additional, van Rossum, D. R., additional, Vos, J., additional, Wagner, J., additional, Ward-Thompson, D., additional, Wardle, J., additional, Washington, J. E., additional, Weintroub, J., additional, Wharton, R., additional, Wiik, K., additional, Witzel, G., additional, Wondrak, M. F., additional, Wong, G. N., additional, Wu, Q., additional, Yadlapalli, N., additional, Yamaguchi, P., additional, Yfantis, A., additional, Yoon, D., additional, Young, A., additional, Young, K., additional, Younsi, Z., additional, Yu, W., additional, Yuan, F., additional, Yuan, Y.-F., additional, Zhang, S., additional, Zhao, G. Y., additional, and Zhao, S.-S., additional
Published: 2024
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8. Future mmVLBI Research with ALMA: A European vision

Author: Tilanus, R. P. J., Krichbaum, T. P., Zensus, J. A., Baudry, A., Bremer, M., Falcke, H., Giovannini, G., Laing, R., van Langevelde, H. J., Vlemmings, W., Abraham, Z., Afonso, J., Agudo, I., Alberdi, A., Alcolea, J., Altamirano, D., Asadi, S., Assaf, K., Augusto, P., Baczko, A-K., Boeck, M., Boller, T., Bondi, M., Boone, F., Bourda, G., Brajsa, R., Brand, J., Britzen, S., Bujarrabal, V., Cales, S., Casadio, C., Casasola, V., Castangia, P., Cernicharo, J., Charlot, P., Chemin, L., Clenet, Y., Colomer, F., Combes, F., Cordes, J., Coriat, M., Cross, N., D'Ammando, F., Dallacasa, D., Desmurs, J-F., Eatough, R., Eckart, A., Eisenacher, D., Etoka, S., Felix, M., Fender, R., Ferreira, M., Freeland, E., Frey, S., Fromm, C., Fuhrmann, L., Gabanyi, K., Galvan-Madrid, R., Giroletti, M., Goddi, C., Gomez, J., Gourgoulhon, E., Gray, M., di Gregorio, I., Greimel, R., Grosso, N., Guirado, J., Hada, K., Hanslmeier, A., Henkel, C., Herpin, F., Hess, P., Hodgson, J., Horns, D., Humphreys, E., Kramer, B. Hutawarakorn, Ilyushin, V., Impellizzeri, V., Ivanov, V., Julião, M., Kadler, M., Kerins, E., Klaassen, P., Klooster, K. van 't, Kording, E., Kozlov, M., Kramer, M., Kreikenbohm, A., Kurtanidze, O., Lazio, J., Leite, A., Leitzinger, M., Lepine, J., Levshakov, S., Lico, R., Lindqvist, M., Liuzzo, E., Lobanov, A., Lucas, P., Mannheim, K., Marcaide, J., Markoff, S., Martí-Vidal, I., Martins, C., Masetti, N., Massardi, M., Menten, K., Messias, H., Migliari, S., Mignano, A., Miller-Jones, J., Minniti, D., Molaro, P., Molina, S., Monteiro, A., Moscadelli, L., Mueller, C., Müller, A., Muller, S., Niederhofer, F., Odert, P., Olofsson, H., Orienti, M., Paladino, R., Panessa, F., Paragi, Z., Paumard, T., Pedrosa, P., Pérez-Torres, M., Perrin, G., Perucho, M., Porquet, D., Prandoni, I., Ransom, S., Reimers, D., Rejkuba, M., Rezzolla, L., Richards, A., Ros, E., Roy, A., Rushton, A., Savolainen, T., Schulz, R., Silva, M., Sivakoff, G., Soria-Ruiz, R., Soria, R., Spaans, M., Spencer, R., Stappers, B., Surcis, G., Tarchi, A., Temmer, M., Thompson, M., Torrelles, J., Truestedt, J., Tudose, V., Venturi, T., Verbiest, J., Vieira, J., Vielzeuf, P., Vincent, F., Wex, N., Wiik, K., Wiklind, T., Wilms, J., Zackrisson, E., and Zechlin, H.
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: Very long baseline interferometry at millimetre/submillimetre wavelengths (mmVLBI) offers the highest achievable spatial resolution at any wavelength in astronomy. The anticipated inclusion of ALMA as a phased array into a global VLBI network will bring unprecedented sensitivity and a transformational leap in capabilities for mmVLBI. Building on years of pioneering efforts in the US and Europe the ongoing ALMA Phasing Project (APP), a US-led international collaboration with MPIfR-led European contributions, is expected to deliver a beamformer and VLBI capability to ALMA by the end of 2014 (APP: Fish et al. 2013, arXiv:1309.3519). This report focuses on the future use of mmVLBI by the international users community from a European viewpoint. Firstly, it highlights the intense science interest in Europe in future mmVLBI observations as compiled from the responses to a general call to the European community for future research projects. A wide range of research is presented that includes, amongst others: - Imaging the event horizon of the black hole at the centre of the Galaxy - Testing the theory of General Relativity an/or searching for alternative theories - Studying the origin of AGN jets and jet formation - Cosmological evolution of galaxies and BHs, AGN feedback - Masers in the Milky Way (in stars and star-forming regions) - Extragalactic emission lines and astro-chemistry - Redshifted absorption lines in distant galaxies and study of the ISM and circumnuclear gas - Pulsars, neutron stars, X-ray binaries - Testing cosmology - Testing fundamental physical constants, Comment: Replaced figures 2 and 3: corrected position SRT. Corrected minor typo in 5.1
Published: 2014

9. Intrinsic brightness temperatures of blazar jets at 15 GHz

Author: Hovatta, T., Leitch, E. M., Homan, D. C., Wiik, K., Lister, M. L., Max-Moerbeck, W., Richards, J. L., and Readhead, A. C. S.
Subjects: Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract: We have developed a new Bayesian Markov Chain Monte Carlo method to deconvolve light curves of blazars into individual flares, including proper estimation of the fit errors. We use the method to fit 15\,GHz light curves obtained within the OVRO 40-m blazar monitoring program where a large number of AGN have been monitored since 2008 in support of the Fermi Gamma-Ray Space Telescope mission. The time scales obtained from the fitted models are used to calculate the variability brightness temperature of the sources. Additionally, we have calculated brightness temperatures of a sample of these objects using Very Long Baseline Array data from the MOJAVE survey. Combining these two data sets enables us to study the intrinsic brightness temperature distribution in these blazars at 15 GHz. Our preliminary results indicate that the mean intrinsic brightness temperature in a sample of 14 sources is near the equipartition brightness temperature of $\sim 10^{11}$K., Comment: 4 pages, 3 figures. To appear in the proceedings of "The Innermost Regions of Relativistic Jets and Their Magnetic Fields", Granada, Spain
Published: 2013
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10. Black hole binary OJ287 as a testing platform for general relativity

Author: Valtonen, M. J., Gopakumar, A., Mikkola, S., Wiik, K., and Lehto, H. J.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The blazar OJ287 is the most promising (and the only) case for an extragalactic binary black hole system inspiralling under the action of gravitational radiation reaction. At present, though it is not possible to directly observe the binary components, it is possible to observe the jet emanating form the primary black hole. We argue that the orbital motion of the secondary black hole is reflected in the wobble of the jet and demonstrate that the wobble is orbital position dependent. The erratic wobble of the jet, reported in Agudo et al. (2012), is analyzed by taking into account the binary nature of the system and we find that the erratic component of jet wobble is very small., Comment: Proceeding of the ICGC international conference, Goa, December 2012
Published: 2012

11. Strong Lensing by Subhalos in the Dwarf-Galaxy Mass Range II: Detection Probabilities

Author: Riehm, T., Zackrisson, E., Mortsell, E., and Wiik, K.
Subjects: Astrophysics - Cosmology and Extragalactic Astrophysics
Abstract: The dark halo substructures predicted by current cold dark matter simulations may in principle be detectable through strong-lensing image splitting of quasars on small angular scales (0.01 arcseconds or below). Here, we estimate the overall probabilities for lensing by substructures in a host halo closely aligned to the line of sight to a background quasar. Under the assumption that the quasar can be approximated as a point source, the optical depth for strong gravitational lensing by subhalos typically turns out to be very small (tau < 0.01), contrary to previous claims. We therefore conclude that it is currently not feasible to use this strategy to put the simulation predictions for the dark matter subhalo population to the test. However, if one assumes the source to be spatially extended, as is the case for a quasar observed at radio wavelengths, there is a reasonable probability for witnessing substructure lensing effects even at rather large projected distances from the host galaxy, provided that the angular resolution is sufficient. While multiply-imaged, radio-loud quasars would be the best targets for unambiguously detecting dark matter subhalos, even singly-imaged radio quasars might be useful for setting upper limits on the abundance and central surface mass density of subhalos., Comment: 8 pages, 7 figures, accepted for publication in the Astrophysical Journal
Published: 2009
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12. Conclusions from the image analysis of the VSOP Survey

Author: Dodson, R., Fomalont, E., and Wiik, K.
Subjects: Astrophysics - Galaxy Astrophysics
Abstract: In February 1997, the Japanese radio astronomy satellite HALCA was launched to provide the space-bourne element for the VLBI Space Observatory Programme (VSOP) mission. A significant fraction of the mission time was to be dedicated to the VSOP Survey of bright compact Active Galactic Nuclei (AGN) at 5 GHz, which was lead by ISAS. The VSOP Survey Sources are an unbiased dataset of 294 targets, of which 82% were successfully observed. These are now undergoing statistical analysis to tease out the characteristics of typical AGN sources. We present here the summary of the imaging and conclusions we have reached., Comment: Approaching Micro-Arcsecond Resolution with VSOP-2 Symposium, Dec 2007
Published: 2009

13. Studying the continuum spectrum of the parsec scale jets by multi-frequency VLBI measurements

Author: Savolainen, T., Wiik, K., Valtaoja, E., and Tornikoski, M.
Subjects: Astrophysics
Abstract: Multi-frequency VLBI observations allow studies of the continuum spectrum in the different parts of the parsec scale jets of AGN, providing information on the physical properties of the plasma and magnetic fields in them. Since VLBI networks cannot be scaled, the range of spatial frequencies observed differs significantly between the different observing frequencies, which makes it difficult to obtain a broadband spectrum of the individual emission features in the jet. In this paper we discuss a model-fitting based spectral extraction method, which can significantly relieve this problem. The method uses a priori knowledge of the source structure, measured at high frequencies, to allow at lower frequencies the derivation of the sizes and flux densities of even those emission features that have mutual separations significantly less than the Rayleigh limit at the given frequency. We have successfully used this method in the analysis of 5-86 GHz VLBA data of 3C273. The spectra and sizes of several individual jet features were measured, thus allowing derivation of the magnetic flux density and the energy density of the relativistic electrons in the different parts of the jet. We discuss the results, which include e.g. a detection of a strong gradient in the magnetic field across the jet of 3C273., Comment: To appear in the proceedings of the 9th European VLBI Network Symposium: "The role of VLBI in the Golden Age for Radio Astronomy"
Published: 2008

14. Multi-frequency VLBA study of the blazar S5 0716+714 during the active state in 2004: I. Inner jet kinematics

Author: Rastorgueva, E. A., Wiik, K., Savolainen, T., Takalo, L. O., Valtaoja, E., Vetukhnovskaya, Y. N., and Sokolovsky, K. V.
Subjects: Astrophysics
Abstract: We observed the blazar \object{0716+714} with the VLBA during its active state in 2003-2004. In this paper we discuss multi-frequency analysis of the inner jet (first 1 mas) kinematics. The unprecedentedly dense time sampling allows us to trace jet components without misidentification and to calculate the component speeds with good accuracy. In the smooth superluminal jet we were able to identify and track three components over time moving outwards with relatively high apparent superluminal speeds (8.5-19.4 $c$), which contradicts the hypothesis of a stationary oscillating jet in this source. Component ejections occur at a relatively high rate (once in two months), and they are accompanied by mm-continuum outbursts. Superluminal jet components move along wiggling trajectories, which is an indication of actual helical motion. Fast proper motion and rapid decay of the components suggest that this source should be observed with the VLBI at a rate of at least once in one or two months in order to trace superluminal jet components without confusion., Comment: 4 pages, 3 figures, Astronomy & Astrophysics Letter, language corrections added
Published: 2008
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15. Prospects for CDM sub-halo detection using high angular resolution observations

Author: Riehm, T., Zackrisson, E., Moeller, O., Mortsell, E., and Wiik, K.
Subjects: Astrophysics
Abstract: In the CDM scenario, dark matter halos are assembled hierarchically from smaller subunits. A long-standing problem with this picture is that the number of sub-halos predicted by CDM simulations is orders of magnitudes higher than the known number of satellite galaxies in the vicinity of the Milky Way. A plausible way out of this problem could be that the majority of these sub-halos somehow have so far evaded detection. If such "dark galaxies" do indeed exist, gravitational lensing may offer one of the most promising ways to detect them. Dark matter sub-halos in the 1e6 - 1e10 solar mass range should cause strong gravitational lensing on (sub)milliarcsecond scales. We study the feasibility of a strong lensing detection of dark sub-halos by deriving the image separations expected for density profiles favoured by recent simulations and comparing these to the angular resolution of both existing and upcoming observational facilities. We find that there is a reasonable probability to detect sub-halo lensing effects in high resolution observations at radio wavelengths, such as produced by the upcoming VSOP-2 satellite, and thereby test the existence of dark galaxies., Comment: 9 pages, 5 figures, Proceedings for "The Universe under the Microscope" (AHAR 2008), held in Bad Honnef (Germany) in April 2008, to be published in Journal of Physics: Conference Series by Institute of Physics Publishing, R. Schoedel, A. Eckart, S. Pfalzner, and E. Ros (eds.)
Published: 2008
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16. Strong lensing by subhalos in the dwarf-galaxy mass range I: Image separations

Author: Zackrisson, E., Riehm, T., Moeller, O., Wiik, K., and Nurmi, P.
Subjects: Astrophysics
Abstract: The cold dark matter scenario predicts that a large number of dark subhalos should be located within the halo of each Milky-way sized galaxy. One tell-tale signature of such dark subhalos could be additional milliarcsecond-scale image splitting of quasars previously known to be multiply-imaged on arcsecond scales. Here, we estimate the image separations for the subhalo density profiles favoured by recent N-body simulations, and compare these to the angular resolution of both existing and upcoming observational facilities. We find, that the image separations produced are very sensitive to the exact subhalo density profile assumed, but in all cases considerably smaller than previous estimates based on the premise that subhalos can be approximated by singular isothermal spheres. Only the most optimistic subhalo models produce image separations that would be detectable with current technology, and many models produce image separations that will remain unresolved with all telescopes expected to become available in the foreseeable future. Detections of dark subhalos through image-splitting effects will therefore be far more challenging than currently believed, albeit not necessarily impossible., Comment: 7 pages, 3 figures, accepted for publication in ApJ
Published: 2008
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17. The VSOP 5 GHz Active Galactic Nucleus Survey: V. Imaging Results for the Remaining 140 sources

Author: Dodson, R., Fomalont, E. B., Wiik, K., Horiuchi, S., Hirabayashi, H., Edwards, P. G., Murata, Y., Asaki, Y., Moellenbrock, G. A., Scott, W. K., Taylor, A. R., Gurvits, L. I., Paragi, Z., Frey, S., Shen, Z. -Q., Lovell, J. E. J., Tingay, S. J., Rioja, M. J., Fodor, S., Lister, M. L., Mosoni, L., Coldwell, G., Piner, B. G., and Yang, J.
Subjects: Astrophysics
Abstract: In February 1997, the Japanese radio astronomy satellite HALCA was launched to provide the space-bourne element for the VLBI Space Observatory Programme (VSOP) mission. Approximately twenty-five percent of the mission time was dedicated to the VSOP Survey of bright compact Active Galactic Nuclei (AGN) at 5 GHz. This paper, the fifth in the series, presents images and models for the remaining 140 sources not included in Paper III, which contained 102 sources. For most sources, the plots of the uv-coverage, the visibility amplitude versus uv-distance, and the high resolution image are presented. Model fit parameters to the major radio components are determined, and the brightness temperature of the core component for each source is calculated. The brightness temperature distributions for all of the sources in the VSOP AGN survey are discussed., Comment: Accepted ApJS
Published: 2007
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18. Magnetic Field Structure in the Parsec Scale Jet of 3C273 from Multifrequency VLBA Observations

Author: Savolainen, T., Wiik, K., Valtaoja, E., and Tornikoski, M.
Subjects: Astrophysics
Abstract: We present first results from a multifrequency VLBA observations of 3C273 in 2003. The source was observed simultaneously at 5.0, 8.4, 15.3, 22.2, 43.2 and 86.2 GHz, and from this multifrequency data set, spectra of 16 emission features in the parsec scale jet were carefully constructed by using a new model-fitting based method. The measured spectra and sizes of the emission features were used to calculate the magnetic field density and the energy density of the relativistic electrons in the different parts of the parsec scale jet, independent of any equipartition assumption. We measure magnetic field density of an order of 1 Gauss in the core. The magnetic energy density in the core dominates over that of the relativistic electrons, while in the downstream region our data are roughly consistent with an equipartition. A strong gradient in the magnetic field density across the jet width, coincident with a transverse velocity structure at about 1.5 mas from the core, was found: the slower superluminal component B2 on the northern side of the jet has a magnetic field density two orders of magnitude lower than the faster southern components B3 and B4., Comment: 7 pages, to appear in "Extragalactic Jets: Theory and Observation from Radio to Gamma Ray", eds. T. A. Rector and D. S. De Young, ASP conference series
Published: 2007

19. The VSOP Survey: Final individual results + Final aggregate results

Author: Dodson, R., Horiuchi, S., Scott, W., Fomalont, E., Paragi, Z., Frey, S., Wiik, K., Hirabayashi, H., Edwards, P., Murata, Y., Moellenbrock, G., Gurvits, L., and Tingay, S.
Subjects: Astrophysics
Abstract: In February 1997 the Japanese radio astronomy satellite HALCA was launched to provide the space-borne element for the VSOP mission. HALCA provided linear baselines three-times greater than that of ground arrays, thus providing higher resolution and higher AGN brightness temperature measurements and limits. Twenty-five percent of the scientific time of the mission was devoted to the ``VSOP survey'' of bright, compact, extra-galactic radio sources at 5 GHz. A complete list of 294 survey targets were selected from pre-launch surveys, 91% of which were observed during the satellite's lifetime. The major goals of the VSOP Survey are statistical in nature: to determine the brightness temperature and approximate structure, to provide a source list for use with future space VLBI missions, and to compare radio properties with other data throughout the electromagnetic spectrum. All the data collected have now been analysed and is being prepared for the final image Survey paper. In these papers we present details of the mission, images of the sources, and some statistics of the contributions and completeness plus some statistics of the images and brightness temperatures. Full resolution images are to be found on http://www.vsop.isas.jaxa.jp/survey/publications/evn.ps.gz, Comment: 8th EVN Symposium, to appear in PoS + IAU Symposium No. 238
Published: 2006

20. Multifrequency VLBA Monitoring of 3C 273 during the INTEGRAL Campaign in 2003 - I. Kinematics of the Parsec Scale Jet from 43 GHz Data

Author: Savolainen, T., Wiik, K., Valtaoja, E., and Tornikoski, M.
Subjects: Astrophysics
Abstract: In this first of a series of papers describing polarimetric multifrequency Very Long Baseline Array (VLBA) monitoring of 3C 273 during a simultaneous campaign with the INTEGRAL gamma-ray satellite in 2003, we present 5 Stokes I images and source models at 7 mm. We show that a part of the inner jet (1-2 milliarcseconds from the core) is resolved in a direction transverse to the flow, and we analyse the kinematics of the jet within the first 10 mas. Based on the VLBA data and simultaneous single-dish flux density monitoring, we determine an accurate value for the Doppler factor of the parsec scale jet, and using this value with observed proper motions, we calculate the Lorentz factors and the viewing angles for the emission components in the jet. Our data indicates a significant velocity gradient across the jet with the components travelling near the southern edge being faster than the components with more northern path. We discuss our observations in the light of jet precession model and growing plasma instabilities., Comment: Accepted for publication in Astronomy & Astrophysics, 16 pages, 15 figures
Published: 2005
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21. An extremely curved relativistic jet in PKS 2136+141

Author: Savolainen, T., Wiik, K., Valtaoja, E., and Tornikoski, M.
Subjects: Astrophysics
Abstract: We report the discovery of an extremely curved jet in the high frequency peaking GPS quasar PKS 2136+141. Our multi-frequency VLBA images show a bending jet making a turn-around of 210 degrees on the plane of the sky, which is, to our knowledge, the largest ever observed change in a structural position angle of an extragalactic jet. Images taken at six different frequencies, from 2 to 43 GHz, beautifully reveal a spiral-like trajectory. We discuss possibilities to constrain the 3-D geometry of the source and suggest that it could be used as a testbed for models describing the bending of the relativistic jets., Comment: 4 pages. 3 figures. Proceedings of the 7th European VLBI Network Symposium held in Toledo, Spain on October 12-15, 2004. Editors: R. Bachiller, F. Colomer, J.-F. Desmurs, P. de Vicente (Observatorio Astronomico Nacional), p. 107-110. Needs evn2004.cls
Published: 2004

22. Multifrequency Observations of the Gamma-Ray Blazar 3C 279 in Low-State during Integral AO-1

Author: Collmar, W., Böttcher, M., Burwitz, V., Courvoisier, T., Komossa, S., Kretschmar, P., Nieppola, E., Nilsson, K., Ojala, T., Pottschmidt, K., Pasanen, M., Pursimo, T., Sillanpää, A., Takalo, L., Tornikoski, M., Ungerechts, H., Valtaoja, E., Walter, R., Webster, R., Whiting, M., Wiik, K., and Wong, I.
Subjects: Astrophysics
Abstract: We report first results of a multifrequency campaign from radio to hard X-ray energies of the prominent gamma-ray blazar 3C 279 during the first year of the INTEGRAL mission. The variable blazar was found at a low activity level, but was detected by all participating instruments. Subsequently a multifrequency spectrum could be compiled. The individual measurements as well as the compiled multifrequency spectrum are presented. In addition, this 2003 broadband spectrum is compared to one measured in 1999 during a high activity period of 3C 279., Comment: 4 pages including 6 figures, to appear in: 'Proc. of the 5th INTEGRAL Workshop', ESA SP-552, in press
Published: 2004

23. The VSOP 2 mission: Imaging capabilities

Author: Dodson, R., Hirabayashi, H., Murata, Y., Edwards, P. G., Wiik, K., Murphy, D., and Kameno, S.
Subjects: Astrophysics
Abstract: Given the scientific goals of VSOP-2, including the possibility of observations of the shadows of black holes, we have investigated the fidelity of the recovered images given a typical uv-coverage. We find that we can achieve a dynamic range of better than 1000:1., Comment: Poster presentation at the Space Science Symposium, ISAS, Jan 2004
Published: 2004

24. The VSOP 5 GHz Continuum Survey, recent results

Author: Dodson, R., Hirabayashi, H., Edwards, P. G., Wiik, K., Fomalont, E. B., Lovell, J. E. J., Moellenbrock, G. A., and Scott, W. K.
Subjects: Astrophysics
Abstract: In February 1997 the Japanese radio astronomy satellite Halca was launched to provide the space-bourne element for the VSOP mission. Approximately twenty-five percent of the mission time has been dedicated to the VSOP Survey, a 5 GHz survey of bright, compact AGN. Both the final, calibrated, high resolution images and plots of visibility amplitude versus uv distance for the first 102 of the sources have been prepared and has been submitted. Papers on the methods and the models from fitting the cumulative {\em uv} amplitudes will also be submitted. The analysis of the second half is well underway., Comment: Poster presentation at the Space Science Symposium, ISAS, Jan 2004
Published: 2004

25. Synthesis and oxygen transport properties of La2 − ySryNi1 − xMoxO4 + δ

Author: Gómez, S.Y., Gurauskis, J., Øygarden, V., Hotza, D., Grande, T., and Wiik, K.
Published: 2016
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26. Time variability of the core-shift effect in the blazar 3C 454.3

Author: Chamani, W., primary, Savolainen, T., additional, Ros, E., additional, Kovalev, Y.Y., additional, Wiik, K., additional, Lähteenmäki, A., additional, Tornikoski, M., additional, and Tammi, J., additional
Published: 2023
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27. Shaping of advanced asymmetric structures of proton conducting ceramic materials for SOFC and membrane-based process applications

Author: Fontaine, M.L., Larring, Y., Smith, J.B., Raeder, H., Andersen, Ø.S., Einarsrud, M.-A., Wiik, K., and Bredesen, R.
Published: 2009
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28. Densification and properties of zirconia prepared by three different sintering techniques

Author: Dahl, P., Kaus, I., Zhao, Z., Johnsson, M., Nygren, M., Wiik, K., Grande, T., and Einarsrud, M.-A.
Published: 2007
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29. Reactions between La1−x CaxMnO3 and CaO-stabilized ZrO2 Part II Diffusion couples

Author: Faaland, S., Einarsrud, M.-A., Wiik, K., Grande, T., and Høier, R.
Published: 1999
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30. Reactions between La1−x CaxMnO3 and CaO-stabilized ZrO2 part I Powder mixtures

Author: Faaland, S., Einarsrud, M.-A., Wiik, K., and Grande, T.
Published: 1999
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31. Observational constraints on the optical and near-infrared emission from the neutron star–black hole binary merger candidate S190814bv

Author: Ackley, K., primary, Amati, L., additional, Barbieri, C., additional, Bauer, F. E., additional, Benetti, S., additional, Bernardini, M. G., additional, Bhirombhakdi, K., additional, Botticella, M. T., additional, Branchesi, M., additional, Brocato, E., additional, Bruun, S. H., additional, Bulla, M., additional, Campana, S., additional, Cappellaro, E., additional, Castro-Tirado, A. J., additional, Chambers, K. C., additional, Chaty, S., additional, Chen, T.-W., additional, Ciolfi, R., additional, Coleiro, A., additional, Copperwheat, C. M., additional, Covino, S., additional, Cutter, R., additional, D’Ammando, F., additional, D’Avanzo, P., additional, De Cesare, G., additional, D’Elia, V., additional, Della Valle, M., additional, Denneau, L., additional, De Pasquale, M., additional, Dhillon, V. S., additional, Dyer, M. J., additional, Elias-Rosa, N., additional, Evans, P. A., additional, Eyles-Ferris, R. A. J., additional, Fiore, A., additional, Fraser, M., additional, Fruchter, A. S., additional, Fynbo, J. P. U., additional, Galbany, L., additional, Gall, C., additional, Galloway, D. K., additional, Getman, F. I., additional, Ghirlanda, G., additional, Gillanders, J. H., additional, Gomboc, A., additional, Gompertz, B. P., additional, González-Fernández, C., additional, González-Gaitán, S., additional, Grado, A., additional, Greco, G., additional, Gromadzki, M., additional, Groot, P. J., additional, Gutiérrez, C. P., additional, Heikkilä, T., additional, Heintz, K. E., additional, Hjorth, J., additional, Hu, Y.-D., additional, Huber, M. E., additional, Inserra, C., additional, Izzo, L., additional, Japelj, J., additional, Jerkstrand, A., additional, Jin, Z. P., additional, Jonker, P. G., additional, Kankare, E., additional, Kann, D. A., additional, Kennedy, M., additional, Kim, S., additional, Klose, S., additional, Kool, E. C., additional, Kotak, R., additional, Kuncarayakti, H., additional, Lamb, G. P., additional, Leloudas, G., additional, Levan, A. J., additional, Longo, F., additional, Lowe, T. B., additional, Lyman, J. D., additional, Magnier, E., additional, Maguire, K., additional, Maiorano, E., additional, Mandel, I., additional, Mapelli, M., additional, Mattila, S., additional, McBrien, O. R., additional, Melandri, A., additional, Michałowski, M. J., additional, Milvang-Jensen, B., additional, Moran, S., additional, Nicastro, L., additional, Nicholl, M., additional, Nicuesa Guelbenzu, A., additional, Nuttal, L., additional, Oates, S. R., additional, O’Brien, P. T., additional, Onori, F., additional, Palazzi, E., additional, Patricelli, B., additional, Perego, A., additional, Torres, M. A. P., additional, Perley, D. A., additional, Pian, E., additional, Pignata, G., additional, Piranomonte, S., additional, Poshyachinda, S., additional, Possenti, A., additional, Pumo, M. L., additional, Quirola-Vásquez, J., additional, Ragosta, F., additional, Ramsay, G., additional, Rau, A., additional, Rest, A., additional, Reynolds, T. M., additional, Rosetti, S. S., additional, Rossi, A., additional, Rosswog, S., additional, Sabha, N. B., additional, Sagués Carracedo, A., additional, Salafia, O. S., additional, Salmon, L., additional, Salvaterra, R., additional, Savaglio, S., additional, Sbordone, L., additional, Schady, P., additional, Schipani, P., additional, Schultz, A. S. B., additional, Schweyer, T., additional, Smartt, S. J., additional, Smith, K. W., additional, Smith, M., additional, Sollerman, J., additional, Srivastav, S., additional, Stanway, E. R., additional, Starling, R. L. C., additional, Steeghs, D., additional, Stratta, G., additional, Stubbs, C. W., additional, Tanvir, N. R., additional, Testa, V., additional, Thrane, E., additional, Tonry, J. L., additional, Turatto, M., additional, Ulaczyk, K., additional, van der Horst, A. J., additional, Vergani, S. D., additional, Walton, N. A., additional, Watson, D., additional, Wiersema, K., additional, Wiik, K., additional, Wyrzykowski, Ł., additional, Yang, S., additional, Yi, S.-X., additional, and Young, D. R., additional
Published: 2020
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32. A study of cosmic ray secondaries induced by the Mir space station using AMS-01

Author: Aguilar, M., Alcaraz, J., Allaby, J., Alpat, B., Ambrosi, G., Anderhub, H., Ao, L., Arefiev, A., Azzarello, P., Babucci, E., Baldini, L., Basile, M., Barancourt, D., Barao, F., Barbier, G., Barreira, G., Battiston, R., Becker, R., Becker, U., Bellagamba, L., Béné, P., Berdugo, J., Berges, P., Bertucci, B., Biland, A., Bizzaglia, S., Blasko, S., Boella, G., Boschini, M., Bourquin, M., Brocco, L., Bruni, G., Buénerd, M., Burger, J.D., Burger, W.J., Cai, X.D., Camps, C., Cannarsa, P., Capell, M., Carosi, G., Casadei, D., Casaus, J., Castellini, G., Cecchi, C., Chang, Y.H., Chen, H.F., Chen, H.S., Chen, Z.G., Chernoplekov, N.A., Chiueh, T.H., Cho, K., Choi, M.J., Choi, Y.Y., Chuang, Y.L., Cindolo, F., Commichau, V., Contin, A., Cortina-Gil, E., Cristinziani, M., da Cunha, J.P., Dai, T.S., Delgado, C., Demirköz, B., Deus, J.D., Dinu, N., Djambazov, L., D’Antone, I., Dong, Z.R., Emonet, P., Engelberg, J., Eppling, F.J., Eronen, T., Esposito, G., Extermann, P., Favier, J., Fiandrini, E., Fisher, P.H., Fluegge, G., Fouque, N., Galaktionov, Yu., Gervasi, M., Giusti, P., Grandi, D., Grimm, O., Gu, W.Q., Hangarter, K., Hasan, A., Henning, R., Hermel, V., Hofer, H., Huang, M.A., Hungerford, W., Ionica, M., Ionica, R., Jongmanns, M., Karlamaa, K., Karpinski, W., Kenney, G., Kenny, J., Kim, D.H., Kim, G.N., Kim, K.S., Kim, M.Y., Klimentov, A., Kossakowski, R., Koutsenko, V., Kraeber, M., Laborie, G., Laitinen, T., Lamanna, G., Lanciotti, E., Laurenti, G., Lebedev, A., Lechanoine-Leluc, C., Lee, M.W., Lee, S.C., Levi, G., Levtchenko, P., Liu, C.L., Liu, H.T., Lopes, I., Lu, G., Lu, Y.S., Lübelsmeyer, K., Luckey, D., Lustermann, W., Maña, C., Margotti, A., Mayet, F., McNeil, R.R., Meillon, B., Menichelli, M., Mihul, A., Monreal, B., Mourao, A., Mujunen, A., Palmonari, F., Papi, A., Park, H.B., Park, W.H., Pauluzzi, M., Pauss, F., Perrin, E., Pesci, A., Pevsner, A., Pimenta, M., Plyaskin, V., Pojidaev, V., Pohl, M., Postolache, V., Produit, N., Rancoita, P.G., Rapin, D., Raupach, F., Ren, D., Ren, Z., Ribordy, M., Richeux, J.P., Riihonen, E., Ritakari, J., Ro, S., Roeser, U., Rossin, C., Sagdeev, R., Santos, D., Sartorelli, G., Sbarra, C., Schael, S., Schultz von Dratzig, A., Schwering, G., Scolieri, G., Seo, E.S., Shin, J.W., Shoumilov, E., Shoutko, V., Siedling, R., Son, D., Song, T., Steuer, M., Sun, G.S., Suter, H., Tang, X.W., Ting, Samuel C.C., Ting, S.M., Tornikoski, M., Torsti, J., Trümper, J., Ulbricht, J., Urpo, S., Valtonen, E., Vandenhirtz, J., Velcea, F., Velikhov, E., Verlaat, B., Vetlitsky, I., Vezzu, F., Vialle, J.P., Viertel, G., Vité, D., Von Gunten, H., Waldmeier Wicki, S., Wallraff, W., Wang, B.C., Wang, J.Z., Wang, Y.H., Wiik, K., Williams, C., Wu, S.X., Xia, P.C., Yan, J.L., Yan, L.G., Yang, C.G., Yang, J., Yang, M., Ye, S.W., Yeh, P., Xu, Z.Z., Zhang, H.Y., Zhang, Z.P., Zhao, D.X., Zhu, G.Y., Zhu, W.Z., Zhuang, H.L., Zichichi, A., Zimmermann, B., and Zuccon, P.
Published: 2005
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33. Observational constraints on the optical and near-infrared emission from the neutron star-black hole binary merger candidate S190814bv

Author: Ackley, K., Amati, L., Barbieri, C., Bauer, F. E., Benetti, S., Bernardini, M. G., Bhirombhakdi, K., Botticella, M. T., Branchesi, M., Brocato, E., Bruun, S. H., Bulla, Mattia, Campana, S., Cappellaro, E., Castro-Tirado, A. J., Chambers, K. C., Chaty, S., Chen, Ting-Wan, Ciolfi, R., Coleiro, A., Copperwheat, C. M., Covino, S., Cutter, R., D'Ammando, F., D'Avanzo, P., De Cesare, G., D'Elia, V., Della Valle, M., Denneau, L., De Pasquale, M., Dhillon, V. S., Dyer, M. J., Elias-Rosa, N., Evans, P. A., Eyles-Ferris, R. A. J., Fiore, A., Fraser, M., Fruchter, A. S., Fynbo, J. P. U., Galbany, L., Gall, C., Galloway, D. K., Getman, F., Ghirlanda, G., Gillanders, J. H., Gomboc, A., Gompertz, B. P., Gonzalez-Fernandez, C., Gonzalez-Gaitan, S., Grado, A., Greco, G., Gromadzki, M., Groot, P. J., Gutierrez, C. P., Heikkila, T., Heintz, K. E., Hjorth, J., Hu, Y.-D., Huber, M. E., Inserra, C., Izzo, L., Japelj, J., Jerkstrand, Anders, Jin, Z. P., Jonker, P. G., Kankare, E., Kann, D. A., Kennedy, M., Kim, S., Klose, S., Kool, Erik C., Kotak, R., Kuncarayakti, H., Lamb, G. P., Leloudas, G., Levan, A. J., Longo, F., Lowe, T. B., Lyman, J. D., Magnier, E., Maguire, K., Maiorano, E., Mandel, I., Mapelli, M., Mattila, S., McBrien, O. R., Melandri, A., Michalowski, M. J., Milvang-Jensen, B., Moran, S., Nicastro, L., Nicholl, M., Nicuesa Guelbenzu, A., Nuttal, L., Oates, S. R., O'Brien, P. T., Onori, F., Palazzi, E., Patricelli, B., Perego, A., Torres, M. A. P., Perley, D. A., Pian, E., Pignata, G., Piranomonte, S., Poshyachinda, S., Possenti, A., Pumo, M. L., Quirola-Vasquez, J., Ragosta, F., Ramsay, G., Rau, A., Rest, A., Reynolds, T. M., Rosetti, S. S., Rossi, A., Rosswog, Stephan, Sabha, N. B., Sagués Carracedo, Ana, Salafia, O. S., Salmon, L., Salvaterra, R., Savaglio, S., Sbordone, L., Schady, P., Schipani, P., Schultz, A. S. B., Schweyer, Tassilo, Smartt, S. J., Smith, K. W., Smith, M., Sollerman, Jesper, Srivastav, S., Stanway, E. R., Starling, R. L. C., Steeghs, D., Stratta, G., Stubbs, C. W., Tanvir, N. R., Testa, V., Thrane, E., Tonry, J. L., Turatto, M., Ulaczyk, K., van der Horst, A. J., Vergani, S. D., Walton, N. A., Watson, D., Wiersema, K., Wiik, K., Wyrzykowski, L., Yang, Sheng, Yi, S.-X., Young, D. R., Ackley, K., Amati, L., Barbieri, C., Bauer, F. E., Benetti, S., Bernardini, M. G., Bhirombhakdi, K., Botticella, M. T., Branchesi, M., Brocato, E., Bruun, S. H., Bulla, Mattia, Campana, S., Cappellaro, E., Castro-Tirado, A. J., Chambers, K. C., Chaty, S., Chen, Ting-Wan, Ciolfi, R., Coleiro, A., Copperwheat, C. M., Covino, S., Cutter, R., D'Ammando, F., D'Avanzo, P., De Cesare, G., D'Elia, V., Della Valle, M., Denneau, L., De Pasquale, M., Dhillon, V. S., Dyer, M. J., Elias-Rosa, N., Evans, P. A., Eyles-Ferris, R. A. J., Fiore, A., Fraser, M., Fruchter, A. S., Fynbo, J. P. U., Galbany, L., Gall, C., Galloway, D. K., Getman, F., Ghirlanda, G., Gillanders, J. H., Gomboc, A., Gompertz, B. P., Gonzalez-Fernandez, C., Gonzalez-Gaitan, S., Grado, A., Greco, G., Gromadzki, M., Groot, P. J., Gutierrez, C. P., Heikkila, T., Heintz, K. E., Hjorth, J., Hu, Y.-D., Huber, M. E., Inserra, C., Izzo, L., Japelj, J., Jerkstrand, Anders, Jin, Z. P., Jonker, P. G., Kankare, E., Kann, D. A., Kennedy, M., Kim, S., Klose, S., Kool, Erik C., Kotak, R., Kuncarayakti, H., Lamb, G. P., Leloudas, G., Levan, A. J., Longo, F., Lowe, T. B., Lyman, J. D., Magnier, E., Maguire, K., Maiorano, E., Mandel, I., Mapelli, M., Mattila, S., McBrien, O. R., Melandri, A., Michalowski, M. J., Milvang-Jensen, B., Moran, S., Nicastro, L., Nicholl, M., Nicuesa Guelbenzu, A., Nuttal, L., Oates, S. R., O'Brien, P. T., Onori, F., Palazzi, E., Patricelli, B., Perego, A., Torres, M. A. P., Perley, D. A., Pian, E., Pignata, G., Piranomonte, S., Poshyachinda, S., Possenti, A., Pumo, M. L., Quirola-Vasquez, J., Ragosta, F., Ramsay, G., Rau, A., Rest, A., Reynolds, T. M., Rosetti, S. S., Rossi, A., Rosswog, Stephan, Sabha, N. B., Sagués Carracedo, Ana, Salafia, O. S., Salmon, L., Salvaterra, R., Savaglio, S., Sbordone, L., Schady, P., Schipani, P., Schultz, A. S. B., Schweyer, Tassilo, Smartt, S. J., Smith, K. W., Smith, M., Sollerman, Jesper, Srivastav, S., Stanway, E. R., Starling, R. L. C., Steeghs, D., Stratta, G., Stubbs, C. W., Tanvir, N. R., Testa, V., Thrane, E., Tonry, J. L., Turatto, M., Ulaczyk, K., van der Horst, A. J., Vergani, S. D., Walton, N. A., Watson, D., Wiersema, K., Wiik, K., Wyrzykowski, L., Yang, Sheng, Yi, S.-X., and Young, D. R.
Abstract: Context. Gravitational wave (GW) astronomy has rapidly reached maturity, becoming a fundamental observing window for modern astrophysics. The coalescences of a few tens of black hole (BH) binaries have been detected, while the number of events possibly including a neutron star (NS) is still limited to a few. On 2019 August 14, the LIGO and Virgo interferometers detected a high-significance event labelled S190814bv. A preliminary analysis of the GW data suggests that the event was likely due to the merger of a compact binary system formed by a BH and a NS. Aims. In this paper, we present our extensive search campaign aimed at uncovering the potential optical and near infrared electromagnetic counterpart of S190814bv. We found no convincing electromagnetic counterpart in our data. We therefore use our non-detection to place limits on the properties of the putative outflows that could have been produced by the binary during and after the merger. Methods. Thanks to the three-detector observation of S190814bv, and given the characteristics of the signal, the LIGO and Virgo Collaborations delivered a relatively narrow localisation in low latency - a 50% (90%) credible area of 5 deg(2) (23 deg(2)) - despite the relatively large distance of 26752 Mpc. ElectromagNetic counterparts of GRAvitational wave sources at the VEry Large Telescope collaboration members carried out an intensive multi-epoch, multi-instrument observational campaign to identify the possible optical and near infrared counterpart of the event. In addition, the ATLAS, GOTO, GRAWITA-VST, Pan-STARRS, and VINROUGE projects also carried out a search on this event. In this paper, we describe the combined observational campaign of these groups. Results. Our observations allow us to place limits on the presence of any counterpart and discuss the implications for the kilonova (KN), which was possibly generated by this NS-BH merger, and for the strategy of future searches. The typical depth of our wide-field observat
Published: 2020
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34. High temperature transport kinetics in heteroepitaxial LaFeO 3 thin films

Author: Hole, I., Tybell, T., Grepstad, J.K., Wærnhus, I., Grande, T., and Wiik, K.
Published: 2003
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35. The Alpha Magnetic Spectrometer (AMS)

Author: Alcaraz, J., Alpat, B., Ambrosi, G., Anderhub, H., Ao, L., Arefiev, A., Azzarello, P., Babucci, E., Baldini, L., Basile, M., Barancourt, D., Barao, F., Barbier, G., Barreira, G., Battiston, R., Becker, R., Becker, U., Bellagamba, L., Bene, P., Berdugo, J., Berges, P., Bertucci, B., Biland, A., Bizzaglia, S., Blasko, S., Boella, G., Boschini, M., Bourquin, M., Brocco, L., Bruni, G., Buenerd, M., Burger, J.D., Burger, W.J., Cai, X.D., Camps, C., Cannarsa, P., Capell, M., Casadei, D., Casaus, J., Castellini, G., Cecchi, C., Chang, Y.H., Chen, H.F., Chen, H.S., Chen, Z.G., Chernoplekov, N.A., Chiueh, T.H., Chuang, Y.L., Cindolo, F., Commichau, V., Contin, A., Crespo, P., Cristinziani, M., da Cunha, J.P., Dai, T.S., Deus, J.D., Dinu, N., Djambazov, L., DAntone, I., Dong, Z.R., Emonet, P., Engelberg, J., Eppling, F.J., Eronen, T., Esposito, G., Extermann, P., Favier, J., Fiandrini, E., Fisher, P.H., Fluegge, G., Fouque, N., Galaktionov, Yu., Gervasi, M., Giusti, P., Grandi, D., Grimm, O., Gu, W.Q., Hangarter, K., Hasan, A., Hermel, V., Hofer, H., Huang, M.A., Hungerford, W., Ionica, M., Ionica, R., Jongmanns, M., Karlamaa, K., Karpinski, W., Kenney, G., Kenny, J., Kim, W., Klimentov, A., Kossakowski, R., Koutsenko, V., Kraeber, M., Laborie, G., Laitinen, T., Lamanna, G., Laurenti, G., Lebedev, A., Lee, S.C., Levi, G., Levtchenko, P., Liu, C.L., Liu, H.T., Lopes, I., Lu, G., Lu, Y.S., Lübelsmeyer, K., Luckey, D., Lustermann, W., Maña, C., Margotti, A., Mayet, F., McNeil, R.R., Meillon, B., Menichelli, M., Mihul, A., Mourao, A., Mujunen, A., Palmonari, F., Papi, A., Park, I.H., Pauluzzi, M., Pauss, F., Perrin, E., Pesci, A., Pevsner, A., Pimenta, M., Plyaskin, V., Pojidaev, V., Postolache, V., Produit, N., Rancoita, P.G., Rapin, D., Raupach, F., Ren, D., Ren, Z., Ribordy, M., Richeux, J.P., Riihonen, E., Ritakari, J., Roeser, U., Roissin, C., Sagdeev, R., Sartorelli, G., Schultz von Dratzig, A., Schwering, G., Scolieri, G., Seo, E.S., Shoutko, V., Shoumilov, E., Siedling, R., Son, D., Song, T., Steuer, M., Sun, G.S., Suter, H., Tang, X.W., Ting, Samuel C.C., Ting, S.M., Tornikoski, M., Torsti, J., Tr umper, J., Ulbricht, J., Urpo, S., Usoskin, I., Valtonen, E., Vandenhirtz, J., Velcea, F., Velikhov, E., Verlaat, B., Vetlitsky, I., Vezzu, F., Vialle, J.P., Viertel, G., Vite, D., Gunten, H.Von, Wicki, S.Waldmeier, Wallraff, W., Wang, B.C., Wang, J.Z., Wang, Y.H., Wiik, K., Williams, C., Wu, S.X., Xia, P.C., Yan, J.L., Yan, L.G., Yang, C.G., Yang, M., Ye, S.W., Yeh, P., Xu, Z.Z., Zhang, H.Y., Zhang, Z.P., Zhao, D.X., Zhu, G.Y., Zhu, W.Z., Zhuang, H.L., Zichichi, A., and Zimmermann, B.
Published: 2002
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36. Oxygen permeation in the system SrFeO 3− x–SrCoO 3− y

Author: Wiik, K, Aasland, S, Hansen, H.L, Tangen, I.L, and Ødegård, R
Published: 2002
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37. Phase equilibria and microstructure in Sr 4Fe 6− xCo xO 13 0≤ x≤4 mixed conductors

Author: Fossdal, A., Sagdahl, L.T., Einarsrud, M.-A., Wiik, K., Grande, T., Larsen, P.H., and Poulsen, F.W.
Published: 2001
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38. Oxygen permeation of SrFe 0.67Co 0.33O 3− d

Author: Aasland, S, Tangen, I.L, Wiik, K, and Ødegård, R
Published: 2000
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39. A dust-enshrouded tidal disruption event with a resolved radio jet in a galaxy merger

Author: Mattila, S., primary, Pérez-Torres, M., additional, Efstathiou, A., additional, Mimica, P., additional, Fraser, M., additional, Kankare, E., additional, Alberdi, A., additional, Aloy, M. Á., additional, Heikkilä, T., additional, Jonker, P. G., additional, Lundqvist, P., additional, Martí-Vidal, I., additional, Meikle, W. P. S., additional, Romero-Cañizales, C., additional, Smartt, S. J., additional, Tsygankov, S., additional, Varenius, E., additional, Alonso-Herrero, A., additional, Bondi, M., additional, Fransson, C., additional, Herrero-Illana, R., additional, Kangas, T., additional, Kotak, R., additional, Ramírez-Olivencia, N., additional, Väisänen, P., additional, Beswick, R. J., additional, Clements, D. L., additional, Greimel, R., additional, Harmanen, J., additional, Kotilainen, J., additional, Nandra, K., additional, Reynolds, T., additional, Ryder, S., additional, Walton, N. A., additional, Wiik, K., additional, and Östlin, G., additional
Published: 2018
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40. An Empirical Linear Model for Water Quality Management: Pilot Study for Four Regions in the Ruhr Basin

Author: Thoss, R., Wiik, K., Rothenberg, Jerome, editor, and Heggie, Ian G., editor
Published: 1974
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41. Orbit determination for VSOP-2

Author: Wiik, K., Edwards, P., Dodson, R., BarSever, Y., Wu, S., Hirabayashi, Hisashi, Murata, Yasuhiro, and Mochizuki, Nanako
Subjects: VSOP-2, 地上支援システム, orbit determination, satellite tracking, GPS, astronomical satellite, phase referencing technique, Astrophysics::Instrumentation and Methods for Astrophysics, 天文学衛星, ground support system, 衛星追跡, very long base interferometry, 軌道上天文学, spaceborne astronomy, 軌道決定, 位相参照技術, Astrophysics::Earth and Planetary Astrophysics, 超長基線干渉法
Abstract: Very accurate determination of the VSOP-2 satellite orbit is required to utilize the power of phase referencing techniques. Phase referencing allows fainter sources to be observed and will also make accurate astrometry possible. Different position determination methods are compared and the resulting orbit determination accuracy is simulated., 資料番号: AA0047899036
Published: 2004

42. VSOPの5GHz連続サーベイ、最近の結果

Author: Dodson, R., Edwards, P. G., Wiik, K., Fomalont, E. B., Lovell, J. E. J., Moellenbrock, G. A., Scott, W., and Hirabayashi, Hisashi
Subjects: active galactic nucleus, orbit determination, astronomical satellite, 活動銀河核, 天文学衛星, HALCA, very long base interferometry, 電波望遠鏡, radio telescope, 若い恒星状天体, 軌道決定, young stellar object, はるか, VSOP, 超長基線干渉法
Abstract: In February 1997 the Japanese radio astronomy satellite Halca was launched to provide the space-bourne element for the VSOP mission. Approximately twenty-five percent of the mission time has been dedicated to the VSOP Survey, a 5 GHz survey of bright, compact AGN. The results from the ongoing analysis are presented. Both the final, calibrated, high resolution images and plots of visibility amplitude versus uv distance for the first half of the sources have been prepared and will be submitted shortly. Papers on the methods and the models from fitting the cumulative uv amplitudes will also be submitted. The analysis of the second half is well underway., 資料番号: AA0047899168
Published: 2004

43. VSOP-2ミッション:撮像能力

Author: Dodson, R., Edwards, P. G., Wiik, K., Murphy, D., Hirabayashi, Hisashi, Murata, Yasuhiro, and Kameno, Seiji
Subjects: active galactic nucleus, VSOP-2, astronomical satellite, 活動銀河核, 天文学衛星, imaging technique, 撮像技術, very long base interferometry, 降着円盤, 電波望遠鏡, radio telescope, 軌道上天文学, spaceborne astronomy, 若い恒星状天体, young stellar object, accretion disk, 超長基線干渉法
Abstract: Given the scientific goals of VSOP-2, including the possibility of observations of the shadows of black holes, the fidelity of the recovered images given a typical uv coverage has been investigated. It is found that a dynamic range of better than 1: 1,000 can be achieved., 資料番号: AA0047899038
Published: 2004

44. The Alpha Magnetic Spectrometer (AMS)

Author: Alcaraz, J., Alpat, B., Ambrosi, G., Anderhub, H., Ao, L., Arefiev, A., Azzarello, P., Babucci, E., Luca Baldini, Basile, M., Barancourt, D., Barao, F., Barbier, G., Barreira, G., Battiston, R., Becker, R., Becker, U., Bellagamba, L., Bene, P., Berdugo, J., Berges, P., Bertucci, B., Biland, A., Bizzaglia, S., Blasko, S., Boella, G., Boschini, M., Bourquin, M., Brocco, L., Bruni, G., Buenerd, M., Burger, J. D., Burger, W. J., Cai, X. D., Camps, C., Cannarsa, P., Capell, M., Casadei, D., Casaus, J., Castellini, G., Cecchi, C., Chang, Y. H., Chen, H. F., Chen, H. S., Chen, Z. G., Chernoplekov, N. A., Chiueh, T. H., Chuang, Y. L., Cindolo, F., Commichau, V., Contin, A., Crespo, P., Cristinziani, M., Da Cunha, J. P., Dai, T. S., Deus, J. D., Dinu, N., Djambazov, L., Antone, I. D., Dong, Z. R., Emonet, P., Engelberg, J., Eppling, F. J., Eronen, T., Esposito, G., Extermann, P., Favier, J., Fiandrini, E., Fisher, P. H., Fluegge, G., Fouque, N., Yu. Galaktionov, Gervasi, M., Giusti, P., Grandi, D., Grimm, O., Gu, W. Q., Hangarter, K., Hasan, A., Hermel, V., Hofer, H., Huang, M. A., Hungerford, W., Ionica, M., Ionica, R., Jongmanns, M., Karlamaa, K., Karpinski, W., Kenney, G., Kenny, J., Kim, W., Klimentov, A., Kossakowski, R., Koutsenko, V., Kraber, M., Laborie, G., Laitinen, T., Giovanni Lamanna, Laurenti, G., Lebedev, A., Lee, S. C., Levi, G., Levtchenko, P., Liu, C. L., Liu, H. T., Lopes, I., Lu, G., Lu, Y. S., Luebelsmeyer, K., Luckey, D., Lustermann, W., Mana, C., Margotti, A., Mayet, F., Mcneil, R. R., Meillon, B., Menichelli, M., Mihul, A., Mourao, A., Mujunen, A., Palmonari, F., Papi, A., Park, I. H., Pauluzzi, M., Pauss, F., Perrin, E., Pesci, A., Pevsner, A., Pimenta, M., Plyaskin, V., Pozhidaev, V., Postolache, V., Produit, N., Rancoita, P. G., Rapin, D., Raupach, F., Ren, D., Zhuoxiang Ren, Ribordy, M., Richeux, J. P., Riihonen, E., Ritakari, J., Roser, U., Rossin, C., Sagdeev, R., Sartorelli, G., Schultz Dratzig, A., Schwering, G., Scolieri, G., Seo, E. S., Shoutko, V., Shumilov, E., Siedling, R., Son, D., Song, T., Steuer, M., Sun, G. S., Suter, H., Tang, X. W., Ting, S. C. C., Ting, S. M., Tornikoski, M., Torsti, J., Trumper, J., Ulbricht, J., Urpo, S., Usoskin, I., Valtonen, E., Vandenhirtz, J., Velcea, F., Velikhov, E., Verlaat, B., Vetlitsky, I., Vezzu, F., Vialle, J. P., Viertel, G., Vite, D., Gunten, H., Waldmeier Wicki, S., Wallraff, W., Wang, B. C., Wang, J. Z., Wang, Y. H., Wiik, K., Williams, C., Wu, S. X., Xia, P. C., Yan, J. L., Yan, L. G., Yang, C. G., Yang, M., Ye, S. W., Yeh, P., Xu, Z. Z., Zhang, H. Y., Zhang, Z. P., Zhao, D. X., Zhu, G. Y., Zhu, W. Z., Zhuang, H. L., Zichichi, A., Zimmermann, B., Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), AMS, Alcaraz, J, Alpat, B, Ambrosi, G, Anderhub, H, Ao, L, Arefiev, A, Azzarello, P, Babucci, E, Baldini, L, Basile, M, Barancourt, D, Barao, F, Barbier, G, Barreira, G, Battiston, R, Becker, R, Becker, U, Bellagamba, L, Bene, P, Berdugo, J, Berges, P, Bertucci, B, Biland, A, Bizzaglia, S, Blasko, S, Boella, G, Boschini, M, Bourquin, M, Brocco, L, Bruni, G, Buenerd, M, Burger, J, Burger, W, Cai, X, Camps, C, Cannarsa, P, Capell, M, Casadei, D, Casaus, J, Castellini, G, Cecchi, C, Chang, Y, Chen, H, Chen, Z, Chernoplekov, N, Chiueh, T, Chuang, Y, Cindolo, F, Commichau, V, Contin, A, Crespo, P, Cristinziani, M, da Cunha, J, Dai, T, Deus, J, Dinu, N, Djambazov, L, Dantone, I, Dong, Z, Emonet, P, Engelberg, J, Eppling, F, Eronen, T, Esposito, G, Extermann, P, Favier, J, Fiandrini, E, Fisher, P, Fluegge, G, Fouque, N, Galaktionov, Y, Gervasi, M, Giusti, P, Grandi, D, Grimm, O, Gu, W, Hangarter, K, Hasan, A, Hermel, V, Hofer, H, Huang, M, Hungerford, W, Ionica, M, Ionica, R, Jongmanns, M, Karlamaa, K, Karpinski, W, Kenney, G, Kenny, J, Kim, W, Klimentov, A, Kossakowski, R, Koutsenko, V, Kraeber, M, Laborie, G, Laitinen, T, Lamanna, G, Laurenti, G, Lebedev, A, Lee, S, Levi, G, Levtchenko, P, Liu, C, Liu, H, Lopes, I, Lu, G, Lu, Y, Lubelsmeyer, K, Luckey, D, Lustermann, W, Mana, C, Margotti, A, Mayet, F, Mcneil, R, Meillon, B, Menichelli, M, Mihul, A, Mourao, A, Mujunen, A, Palmonari, F, Papi, A, Park, I, Pauluzzi, M, Pauss, F, Perrin, E, Pesci, A, Pevsner, A, Pimenta, M, Plyaskin, V, Pojidaev, V, Postolache, V, Produit, N, Rancoita, P, Rapin, D, Raupach, F, Ren, D, Ren, Z, Ribordy, M, Richeux, J, Riihonen, E, Ritakari, J, Roeser, U, Roissin, C, Sagdeev, R, Sartorelli, G, von Dratzig, A, Schwering, G, Scolieri, G, Seo, E, Shoutko, V, Shoumilov, E, Siedling, R, Son, D, Song, T, Steuer, M, Sun, G, Suter, H, Tang, X, Ting, S, Tornikoski, M, Torsti, J, Trumper, J, Ulbricht, J, Urpo, S, Usoskin, I, Valtonen, E, Vandenhirtz, J, Velcea, F, Velikhov, E, Verlaat, B, Vetlitsky, I, Vezzu, F, Vialle, J, Viertel, G, Vite, D, Von Gunten, H, Wicki, S, Wallraff, W, Wang, B, Wang, J, Wang, Y, Wiik, K, Williams, C, Wu, S, Xia, P, Yan, J, Yan, L, Yang, C, Yang, M, Ye, S, Yeh, P, Xu, Z, Zhang, H, Zhang, Z, Zhao, D, Zhu, G, Zhu, W, Zhuang, H, Zichichi, A, and Zimmermann, B
Subjects: Physics, Nuclear and High Energy Physics, Spectrometer, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Dark matter, Cosmic ray, 01 natural sciences, Particle detector, Nuclear physics, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Physics::Popular Physics, FIS/05 - ASTRONOMIA E ASTROFISICA, FIS/01 - FISICA SPERIMENTALE, Antimatter, 0103 physical sciences, International Space Station, Alpha Magnetic Spectrometer, Measuring instrument, space-research instrumentation, 010306 general physics, Instrumentation, FIS/04 - FISICA NUCLEARE E SUBNUCLEARE
Abstract: The Alpha Magnetic Spectrometer (AMS) is a large acceptance (0.65 sr m(2)) detector designed to operate in the International Space Station (ISS) for three years. The purposes of the experiment are to search for cosmic antimatter and dark matter and to study the composition and energy spectrum of the primary cosmic rays. A "scated-down" version has been flown on the Space Shuttle Discovery for 10 days in June 1998. The complete AMS is programmed for installation on the ISS in October 2003 for an operational period of 3 yr. This contribution reports on the experimental configuration that will be installed on the ISS. (C) 2002 Elsevier Science B.V. All rights reserved.
Published: 2001

45. Processing of asymmetric membranes for high temperature oxygen separation

Author: Gurauskis, J., Wibe, P., Lohne, O.F., Grande, T., Bouwmeester, Henricus J.M., Wiik, K., and Inorganic Membranes
Subjects: METIS-287002
Published: 2012

46. The VSOP 5 GHz continuum survey, recent results

Author: Dodson, R., Hirabayashi, Hisashi, Edwards, P. G., Wiik, K., Fomalont, E. B., Lovell, J. E. J., Moellenbrock, G. A., Scott, W., 平林久, Dodson, R., Hirabayashi, Hisashi, Edwards, P. G., Wiik, K., Fomalont, E. B., Lovell, J. E. J., Moellenbrock, G. A., Scott, W., and 平林久
Abstract: In February 1997 the Japanese radio astronomy satellite Halca was launched to provide the space-bourne element for the VSOP mission. Approximately twenty-five percent of the mission time has been dedicated to the VSOP Survey, a 5 GHz survey of bright, compact AGN. The results from the ongoing analysis are presented. Both the final, calibrated, high resolution images and plots of visibility amplitude versus uv distance for the first half of the sources have been prepared and will be submitted shortly. Papers on the methods and the models from fitting the cumulative uv amplitudes will also be submitted. The analysis of the second half is well underway.
Published: 2015

47. Oxygen surface exchange kinetics of La0.2Sr0.8Fe0.8M0.2O3- (M = Fe, Cr, Ga, Ti, Zr, Nb, Ta)

Author: Phung, T.N., Lohne, O.F., Yoo, C.-Y., Wiik, K., Bouwmeester, Henricus J.M., and Inorganic Membranes
Subjects: METIS-293101
Published: 2010

48. Connection between parsec-scale radio jet and gamma-ray flares in the blazar 1156+295

Author: Ramakrishnan, Venkatessh, primary, Leon-Tavares, Jonathan, additional, Rastorgueva-Foi, Elizaveta, additional, Wiik, K., additional, Jorstad, Svetlana G., additional, Marscher, Alan, additional, Tornikoski, Merja, additional, Agudo, I., additional, Lahteenmaki, Anne, additional, Valtaoja, Esko, additional, Aller, M. F., additional, Blinov, Dmitry A., additional, Casadio, Carolina, additional, Efimova, Natalia V., additional, Gurwell, Mark A., additional, Gómez, José L., additional, Hagen-Thorn, Vladimir A., additional, Joshi, Manasvita, additional, Järvelä, Emilia, additional, Konstantinova, Tatiana S., additional, Kopatskaya, Evgenia N., additional, Larionov, Valeri M., additional, Larionova, Elena G., additional, Larionova, Liudmilla V., additional, Lavonen, Niko, additional, MacDonald, Nicholas R., additional, McHardy, Ian, additional, Molina, Sol N., additional, Morozova, Daria A., additional, Nieppola, Elina, additional, Tammi, Joni, additional, Taylor, Brian W., additional, and Troitsky, Ivan S., additional
Published: 2015
Full Text: View/download PDF

49. A combined radio and GeV γ-ray view of the 2012 and 2013 flares of Mrk 421

Author: Hovatta, T., primary, Petropoulou, M., additional, Richards, J. L., additional, Giannios, D., additional, Wiik, K., additional, Baloković, M., additional, Lähteenmäki, A., additional, Lott, B., additional, Max-Moerbeck, W., additional, Ramakrishnan, V., additional, and Readhead, A. C. S., additional
Published: 2015
Full Text: View/download PDF

50. Coordinated Multiwavelength Observation of 3C 66A during the WEBT Campaign of 2003-2004

Author: Bottcher, M., Harvey, J., Joshi, M., Villata, M., Raiteri, C. M., Bramel, D., Mukherjee, R., Savolainen, T., Cui, W., Fossati, G., Smith, I. A., Able, D., Aller, H. D., Aller, M. F., Arkharov, A. A., Augusteijn, T., Baliyan, K., Barnaby, D., Berdyugin, A., Benitez, E., Boltwood, P., Carini, M., Carosati, D., Ciprini, S., Coloma, J. M., Crapanzano, S., de, Diego J. A., Di, Paola A., Dolci, M., Fan, J., Frasca, A., Hagen-Thorn, V., Horan, D., Ibrahimov, M., Kimeridze, G. N., Kovalev, Y. A., Kovalev, Y. Y., Kurtanidze, O., Lahteenmaki, A., Lanteri, L., Larionov, V. M., Larionova, E. G., Lindfors, E., Marilli, E., Mirabal, N., Nikolashvili, M., Nilsson, K., Ohlert, J. M., Ohnishi, T., Oksanen, A., Ostorero, L., Oyer, G., Papadakis, I., Pasanen, M., Poteet, C., Pursimo, T., Sadakane, K., Sigua, L. A., Takalo, L., Tartar, J. B., Terasranta, H., Tosti, G., Walters, R., and Wiik, K.
Subjects: Physics, Brightness, Superluminal motion, Infrared, Electromagnetic spectrum, Astrophysics::High Energy Astrophysical Phenomena, Flux, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, STACEE, Astrophysics, Galaxies: Active, Magnetic field, Space and Planetary Science, Radiation Mechanisms: Nonthermal, bl lacertae objects : individual (3c 66a), galaxies : active, gamma rays : theory, radiation mechanisms : nonthermal, bl-lacertae objects, extragalactic radio-sources, tev gamma-rays, xmm-newton observations, light curves, lac objects, x-ray, background-radiation, bright blazars, variability, Galaxies: BL Lacertae Objects: Individual: Alphanumeric: 3C 66A, Gamma Rays: Theory, BL Lac object
Abstract: 著者人数: 72名, Accepted: 2005-06-09, 資料番号: SA1003396000
Published: 2005

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