Search Results - "Lahteenmaki, A"

The core shift effect in the blazar 3C 454.3 by Kutkin, A. M., Sokolovsky, K. V., Lisakov, M. M., Kovalev, Y. Y., Savolainen, T., Voytsik, P. A., Lobanov, A. P., Aller, H. D., Aller, M. F., Lahteenmaki, A., Tornikoski, M., Volvach, A. E., Volvach, L. N.

“…Opacity-driven shifts of the apparent very long baseline interferometry (VLBI) core position with frequency (the 'core shift' effect) probe physical conditions…”
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Unprecedented extreme high-frequency radio variability in early-stage active galactic nuclei by Järvelä, E, Savolainen, T, Berton, M, Lähteenmäki, A, Kiehlmann, S, Hovatta, T, Varglund, I, Readhead, A C S, Tornikoski, M, Max-Moerbeck, W, Reeves, R A, Suutarinen, S

“…ABSTRACT We report on the discovery of one of the most extreme cases of high-frequency radio variability ever measured in active galactic nuclei (AGNs),…”
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The extreme blazar AO 0235+164 as seen by extensive ground and space radio observations by Kutkin, A M, Pashchenko, I N, Lisakov, M M, Voytsik, P A, Sokolovsky, K V, Kovalev, Y Y, Lobanov, A P, Ipatov, A V, Aller, M F, Aller, H D, Lahteenmaki, A, Tornikoski, M, Gurvits, L I

“…Abstract Clues to the physical conditions in radio cores of blazars come from measurements of brightness temperatures as well as effects produced by intrinsic…”
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RAPID TeV GAMMA-RAY FLARING OF BL LACERTAE by Arlen, T, Aune, T, BEILICKE, M, Benbow, W, Bouvier, A, Buckley, J H, Bugaev, V, Cesarini, A, Ciupik, L, Connolly, M P

“…We report on the detection of a very rapid TeV gamma-ray flare from BL Lacertae on 2011 June 28 with the Very Energetic Radiation Imaging Telescope Array…”
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THE STRUCTURE AND EMISSION MODEL OF THE RELATIVISTIC JET IN THE QUASAR 3C 279 INFERRED FROM RADIO TO HIGH-ENERGY γ-RAY OBSERVATIONS IN 2008-2010 by HAYASHIDA, M, MADEJSKI, G. M, CHIANG, J, STAWARZ, L, BLANDFORD, R. D, RICHARDS, J. L, MAX-MOERBECK, W, READHEAD, A, BUEHLER, R, CAVAZZUTI, E, CIPRINI, S, GEHRELS, N, NALEWAJKO, K, REIMER, A, SZOSTEK, A, TANAKA, T, TOSTI, G, UCHIYAMA, Y, KAWABATA, K. S, KINO, M, SAKIMOTO, K, SASADA, M, SATO, S, SIKORA, M, UEMURA, M, YAMANAKA, M, GREINER, J, KRUEHLER, T, ROSSI, A, MACQUART, J. P, BOCK, D. C.-J, VILLATA, M, RAITERI, C. M, AGUDO, I, WEHRLE, A. E, ALLER, H. D, ALLER, M. F, ARKHAROV, A. A, BACH, U, BENITEZ, E, BERDYUGIN, A, BLINOV, D. A, BLUMENTHAL, K, BÖTTCHER, M, BUEMI, C. S, OGLE, P, CAROSAT, D, CHEN, W. P, DI PAOLA, A, DOLCI, M, EFIMOVA, N. V, FORNE, E, GOMEZ, J. L, GURWELL, M. A, HEIDT, J, HIRIART, D, COLLMAR, W, LARSSON, S, FUKAZAWA, Y, ITOH, R

“…We present time-resolved broadband observations of the quasar 3C 279 obtained from multi-wavelength campaigns conducted during the first two years of the Fermi…”
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The Whole Earth Blazar Telescope Campaign on the Intermediate BL Lac Object 3C 66A in 2007-2008 by Böttcher, M, Fultz, K, Aller, H. D, Aller, M. F, Apodaca, J, Arkharov, A. A, Bach, U, Bachev, R, Berdyugin, A, Buemi, C, Calcidese, P, Carosati, D, Charlot, P, Ciprini, S, Paola, A. Di, Dolci, M, Efimova, N. V, Scurrats, E. Forné, Frasca, A, Gupta, A. C, Hagen-Thorn, V. A, Heidt, J, Hiriart, D, Konstantinova, T. S, Kopatskaya, E. N, Lähteenmäki, A, Lanteri, L, Larionov, V. M, Le Campion, J.-F, Leto, P, Lindfors, E, Mihov, E. Marilli B, Nieppola, E, Nilsson, K, Ovcharov, J. M. Ohlert E, Pääkkönen, P, Pasanen, M, Ragozzine, B, Raiteri, C. M, Ros, J. A, Sadun, A, Sanchez, A, Semkov, E, Sorcia, M, Strigachev, A, Takalo, L, Tornikoski, M, Trigilio, C, Umana, G, Valcheva, A, Villata, M, Volvach, A, Wu, J.-H, Zhou, X

“…Prompted by a high optical state in 2007 September, the Whole Earth Blazar Telescope consortium organized an intensive optical, near-IR (JHK) and radio…”
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The First Fermi Multifrequency Campaign on BL Lacertae: Characterizing the Low-activity State of the Eponymous Blazar by Ajello, M, Antolini, E, Baldini, L, Ballet, J, Bastieri, D, Bellazzini, R, Bonamente, E, Bregeon, J, Brez, A, Bruel, P, Cameron, R. A, Cannon, A, Caraveo, P. A, Charles, E, Chekhtman, A, Cheung, C. C, Ciprini, S, Claus, R, Conrad, J, Cutini, S, Dermer, C. D, de Palma, F, Donato, D, Dubois, R, Escande, L, Fegan, S. J, Finke, J, Focke, W. B, Frailis, M, Fusco, P, Gargano, F, Gasparrini, D, Giglietto, N, Giordano, F, Godfrey, G, Grenier, I. A, Guiriec, S, Hadasch, D, Hayashida, M, Hays, E, Johnson, W. N, Kataoka, J, Knödlseder, J, Kuss, M, Latronico, L, Longo, F, Lott, B, Lovellette, M. N, Lubrano, P, Mazziotta, M. N, McEnery, J. E, Mehault, J, Mizuno, T, Monte, C, Monzani, M. E, Murgia, S, Nakamori, T, Nolan, P. L, Ohsugi, T, Okumura, A, Omodei, N, Ozaki, M, Panetta, J. H, Pelassa, V, Piron, F, Rainò, S, Rando, R, Sadrozinski, H. F.-W, Sander, A, Siskind, E. J, Smith, P. D, Spandre, G, Spinelli, P, Strickman, M. S, Takahashi, H, Tanaka, T, Thayer, J. B, Thompson, D. J, Uehara, T, Usher, T. L, Vandenbroucke, J, Vasileiou, V, Vilchez, N, Vitale, V, Waite, A. P, Wallace, E, Wood, K. S, Ylinen, T, Ziegler, M, Boettcher, M, Carramiñana, A, de la Fuente, E, Diltz, C, Lähteenmäki, A, Lindfors, E, Marscher, A. P, Nilsson, K, Pereira, D, Reinthal, R, Takalo, L. O

“…We report on observations of BL Lacertae during the first 18 months of Fermi LAT science operations and present results from a 48 day multifrequency…”
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Blazar spectral variability as explained by a twisted inhomogeneous jet by Raiteri, C. M., Villata, M., Acosta-Pulido, J. A., Agudo, I., Arkharov, A. A., Bachev, R., Baida, G. V., Benítez, E., Borman, G. A., Boschin, W., Bozhilov, V., Butuzova, M. S., Calcidese, P., Carnerero, M. I., Carosati, D., Casadio, C., Castro-Segura, N., Chen, W.-P., Damljanovic, G., D’Ammando, F., Di Paola, A., Echevarría, J., Efimova, N. V., Ehgamberdiev, Sh. A., Espinosa, C., Fuentes, A., Giunta, A., Gómez, J. L., Grishina, T. S., Gurwell, M. A., Hiriart, D., Jermak, H., Jordan, B., Jorstad, S. G., Joshi, M., Kopatskaya, E. N., Kuratov, K., Kurtanidze, O. M., Kurtanidze, S. O., Lähteenmäki, A., Larionov, V. M., Larionova, E. G., Larionova, L. V., Lázaro, C., Lin, C. S., Malmrose, M. P., Marscher, A. P., Matsumoto, K., McBreen, B., Michel, R., Mihov, B., Minev, M., Mirzaqulov, D. O., Mokrushina, A. A., Molina, S. N., Moody, J. W., Morozova, D. A., Nazarov, S. V., Nikolashvili, M. G., Ohlert, J. M., Okhmat, D. N., Ovcharov, E., Pinna, F., Polakis, T. A., Protasio, C., Pursimo, T., Redondo-Lorenzo, F. J., Rizzi, N., Rodriguez-Coira, G., Sadakane, K., Sadun, A. C., Samal, M. R., Savchenko, S. S., Semkov, E., Skiff, B. A., Slavcheva-Mihova, L., Smith, P. S., Steele, I. A., Strigachev, A., Tammi, J., Thum, C., Tornikoski, M., Troitskaya, Yu. V., Troitsky, I. S., Vasilyev, A. A., Vince, O.

“…The spectral variability of the blazar CTA 102 during a recent extreme outburst could be explained by a twisted, inhomogeneous jet containing regions of…”
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Coordinated Multiwavelength Observation of 3C 66A during the WEBT Campaign of 2003-2004 by Böttcher, 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, Benítez, 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, Lähteenmäki, 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, Teräsranta, H, Tosti, G, Walters, R, Wiik, K, Wilking, B. A, Wills, W, Xilouris, E, Fletcher, A. B, Gu, M, Lee, C.-U, Pak, S, Yim, H.-S

“…The BL Lac object 3C 66A was the target of an extensive multiwavelength monitoring campaign from 2003 July through 2004 April (with a core campaign from 2003…”
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Investigating the Mini and Giant Radio Flare Episodes of Cygnus X-3 by Egron, Elise, Pellizzoni, Alberto, Righini, Simona, Giroletti, Marcello, Koljonen, Karri, Pottschmidt, Katja, Trushkin, Sergei, Lobina, Jessica, Pilia, Maura, Wilms, Joern, Corbel, Stéphane, Grinberg, Victoria, Loru, Sara, Trois, Alessio, Rodriguez, Jérome, Lähteenmäki, A., Tornikoski, M., Enestam, S., Järvelä, E.

“…The microquasar Cygnus X-3 underwent a giant radio flare in 2017 April, reaching a maximum flux of ∼16.5 Jy at 8.5 GHz. We present results from a long…”
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Long-term Variability and Correlation Study of the Blazar 3C 454.3 in the Radio, NIR, and Optical Wavebands by Sarkar, A., Chitnis, V. R., Gupta, A. C., Gaur, H., Patel, S. R., Wiita, P. J., Volvach, A. E., Tornikoski, M., Chamani, W., Enestam, S., Lähteenmäki, A., Tammi, J., Vera, R. J. C, Volvach, L. N.

“…We performed a long-term optical (B, V, R bands), infrared (J and K bands), and radio band (15, 22, 37 GHz band) study of the flat spectrum radio quasar, 3C…”
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Symmetric Achromatic Variability in Active Galaxies: A Powerful New Gravitational Lensing Probe? by Vedantham, H. K., Readhead, A. C. S., Hovatta, T., Pearson, T. J., Blandford, R. D., Gurwell, M. A., Lähteenmäki, A., Max-Moerbeck, W., Pavlidou, V., Ravi, V., Reeves, R. A., Richards, J. L., Tornikoski, M., Zensus, J. A.

“…We report the discovery of a rare new form of long-term radio variability in the light curves of active galaxies (AG)-symmetric achromatic variability (SAV)-a…”
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Probing the Innermost Regions of AGN Jets and Their Magnetic Fields with RadioAstron. III. Blazar S5 0716+71 at Microarcsecond Resolution by Kravchenko, E. V., Gómez, J. L., Kovalev, Y. Y., Lobanov, A. P., Savolainen, T., Bruni, G., Fuentes, A., Anderson, J. M., Jorstad, S. G., Marscher, A. P., Tornikoski, M., Lähteenmäki, A., Lisakov, M. M.

“…We present RadioAstron Space VLBI imaging observations of the BL Lac object S5 0716+71 made on 2015 January 3-4 at a frequency of 22 GHz (wavelength λ = 1.3…”
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The complex variability of blazars: time-scales and periodicity analysis in S4 0954+65 by Raiteri, C M, Villata, M, Larionov, V M, Jorstad, S G, Marscher, A P, Weaver, Z R, Acosta-Pulido, J A, Agudo, I, Andreeva, T, Arkharov, A, Bachev, R, Benítez, E, Berton, M, Björklund, I, Borman, G A, Bozhilov, V, Carnerero, M I, Carosati, D, Casadio, C, Chen, W P, Damljanovic, G, D’Ammando, F, Escudero, J, Fuentes, A, Giroletti, M, Grishina, T S, Gupta, A C, Hagen-Thorn, V A, Hart, M, Hiriart, D, Hou, W-J, Ivanov, D, Kim, J-Y, Kimeridze, G N, Konstantopoulou, C, Kopatskaya, E N, Kurtanidze, O M, Kurtanidze, S O, Lähteenmäki, A, Larionova, E G, Larionova, L V, Marchili, N, Markovic, G, Minev, M, Morozova, D A, Myserlis, I, Nakamura, M, Nikiforova, A A, Nikolashvili, M G, Otero-Santos, J, Ovcharov, E, Pursimo, T, Rahimov, I, Righini, S, Sakamoto, T, Savchenko, S S, Semkov, E H, Shakhovskoy, D, Sigua, L A, Stojanovic, M, Strigachev, A, Thum, C, Tornikoski, M, Traianou, E, Troitskaya, Y V, Troitskiy, I S, Tsai, A, Valcheva, A, Vasilyev, A A, Vince, O, Zaharieva, E

“…ABSTRACT Among active galactic nuclei, blazars show extreme variability properties. We here investigate the case of the BL Lac object S4 0954+65 with data…”
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Locating the γ-ray emission site in Fermi/LAT blazars from correlation analysis between 37 GHz radio and γ-ray light curves by Ramakrishnan, V., Hovatta, T., Nieppola, E., Tornikoski, M., Lähteenmäki, A., Valtaoja, E.

“…We address the highly debated issue of constraining the γ-ray emission region in blazars from cross-correlation analysis using discrete correlation function…”
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A Decade of Multiwavelength Observations of the TeV Blazar 1ES 1215+303: Extreme Shift of the Synchrotron Peak Frequency and Long-term Optical-Gamma-Ray Flux Increase by Valverde, Janeth, Horan, Deirdre, Bernard, Denis, Fegan, Stephen, Abeysekara, A. U., Archer, A., Benbow, W., Bird, R., Brill, A., Brose, R., Buchovecky, M., Buckley, J. H., Christiansen, J. L., Cui, W., Falcone, A., Feng, Q., Finley, J. P., Fortson, L., Furniss, A., Gent, A., Gillanders, G. H., Giuri, C., Gueta, O., Hanna, D., Hassan, T., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Kaaret, P., Kelley-Hoskins, N., Kertzman, M., Kieda, D., Krause, M., Krennrich, F., Lang, M. J., Maier, G., Moriarty, P., Mukherjee, R., Nieto, D., Nievas-Rosillo, M., O'Brien, S., Ong, R. A., Otte, A. N., Park, N., Petrashyk, A., Pfrang, K., Pichel, A., Pohl, M., Prado, R. R., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Ribeiro, D., Richards, G. T., Roache, E., Sadeh, I., Santander, M., Scott, S. S., Sembroski, G. H., Shahinyan, K., Shang, R., Sushch, I., Vassiliev, V. V., Weinstein, A., Wells, R. M., Wilcox, P., Wilhelm, A., Williams, D. A., Williamson, T. J, Noto, Giuliana, Edwards, P. G., Piner, B. G., Ramazani, V. Fallah, Hovatta, T., Jormanainen, J., Lindfors, E., Nilsson, K., Takalo, L., Kovalev, Y. Y., Lister, M. L., Pushkarev, A. B., Savolainen, T., Kiehlmann, S., Max-Moerbeck, W., Readhead, A. C. S., Lähteenmäki, A., Tornikoski, M.

“…Blazars are known for their variability on a wide range of timescales at all wavelengths. Most studies of TeV gamma-ray blazars focus on short timescales,…”
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The Relativistic Jet Orientation and Host Galaxy of the Peculiar Blazar PKS 1413+135 by Readhead, A. C. S., Ravi, V., Liodakis, I., Lister, M. L., Singh, V., Aller, M. F., Blandford, R. D., Browne, I. W. A., Gorjian, V., Grainge, K. J. B., Gurwell, M. A., Hodges, M. W., Hovatta, T., Kiehlmann, S., Lähteenmäki, A., Mcaloone, T., Max-Moerbeck, W., Pavlidou, V., Pearson, T. J., Peirson, A. L., Perlman, E. S., Reeves, R. A., Soifer, B. T., Taylor, G. B., Tornikoski, M., Vedantham, H. K., Werner, M., Wilkinson, P. N., Zensus, J. A.

“…PKS 1413+135 is one of the most peculiar blazars known. Its strange properties led to the hypothesis almost four decades ago that it is gravitationally lensed…”
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The Unanticipated Phenomenology of the Blazar PKS 2131–021: A Unique Supermassive Black Hole Binary Candidate by O’Neill, S., Kiehlmann, S., Readhead, A. C. S., Aller, M. F., Blandford, R. D., Liodakis, I., Lister, M. L., Mróz, P., O’Dea, C. P., Pearson, T. J., Ravi, V., Vallisneri, M., Cleary, K. A., Graham, M. J., Grainge, K. J. B., Hodges, M. W., Hovatta, T., Lähteenmäki, A., Lamb, J. W., Lazio, T. J. W., Max-Moerbeck, W., Pavlidou, V., Prince, T. A., Reeves, R. A., Tornikoski, M., Vergara de la Parra, P., Zensus, J. A.

“…Abstract Most large galaxies host supermassive black holes in their nuclei and are subject to mergers, which can produce a supermassive black hole binary…”
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Total Flux Density Variations in Extragalactic Radio Sources. III. Doppler Boosting Factors, Lorentz Factors, and Viewing Angles for Active Galactic Nuclei by Lähteenmäki, A, Valtaoja, E

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Multiwavelength Observations of the Blazar BL Lacertae: A New Fast TeV Gamma-Ray Flare by Abeysekara, A. U., Benbow, W., Bird, R., Brantseg, T., Brose, R., Buchovecky, M., Buckley, J. H., Bugaev, V., Connolly, M. P., Cui, W., Daniel, M. K., Falcone, A., Feng, Q., Finley, J. P., Fortson, L., Furniss, A., Gillanders, G. H., Gunawardhana, I., Hütten, M., Hanna, D., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kertzman, M., Krennrich, F., Lang, M. J., Lin, T. T. Y., McArthur, S., Moriarty, P., Mukherjee, R., O'Brien, S., Ong, R. A., Otte, A. N., Park, N., Petrashyk, A., Pohl, M., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rulten, C., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Wakely, S. P., Weinstein, A., Wells, R. M., Wilcox, P., Williams, D. A., Zitzer, B., Jorstad, S. G., Marscher, A. P., Lister, M. L., Kovalev, Y. Y., Pushkarev, A. B., Savolainen, T., Agudo, I., Molina, S. N., Gómez, J. L., Larionov, V. M., Borman, G. A., Mokrushina, A. A., Tornikoski, M., Lähteenmäki, A., Chamani, W., Enestam, S., Kiehlmann, S., Hovatta, T., Smith, P. S., Pontrelli, P.

“…Combined with measurements made by very-long-baseline interferometry, the observations of fast TeV gamma-ray flares probe the structure and emission mechanism…”
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