I
I. Torniainen
Researcher at Helsinki University of Technology
Publications - 17
Citations - 626
I. Torniainen is an academic researcher from Helsinki University of Technology. The author has contributed to research in topics: Quasar & Blazar. The author has an hindex of 11, co-authored 17 publications receiving 583 citations. Previous affiliations of I. Torniainen include Aalto University.
Papers
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Journal ArticleDOI
WEBT and XMM-Newton observations of 3C 454.3 during the post-outburst phase Detection of the little and big blue bumps ⋆
C. M. Raiteri,M. Villata,Valeri M. Larionov,Valeri M. Larionov,T. Pursimo,Mansur Ibrahimov,Kari Nilsson,Margo F. Aller,Omar M. Kurtanidze,Luigi Foschini,J. M. Ohlert,I. E. Papadakis,I. E. Papadakis,Naoko Sumitomo,A. E. Volvach,Hugh D. Aller,Arkady A. Arkharov,Uwe Bach,Andrei Berdyugin,Markus Böttcher,Carla Buemi,P. Calcidese,P. Charlot,A. J Delgado Sanchez,A. Di Paola,A. A Djupvik,Mauro Dolci,N. V. Efimova,Jun-Hui Fan,E. Forné,C. A. Gomez,Alok C. Gupta,Vladimir A. Hagen-Thorn,L. Hooks,Talvikki Hovatta,Y Ishii,M. Kamada,Tatiana S. Konstantinova,E. N. Kopatskaya,Yu. A. Kovalev,Yuri Y. Kovalev,Yuri Y. Kovalev,Anne Lähteenmäki,L. Lanteri,J. F. Le Campion,C.-U. Lee,Paolo Leto,H. C. Lin,Elina Lindfors,M. G. Mingaliev,Sahori Mizoguchi,Fabrizio Nicastro,M. G. Nikolashvili,Shinji Nishiyama,Linda Ostman,Evgeni Ovcharov,Pertti Pääkkönen,M. Pasanen,Elena Pian,Travis A. Rector,J. A. Ros,Kozo Sadakane,J. H. Selj,Evgeni Semkov,D Sharapov,Auni Somero,I Stanev,Anton Strigachev,L. O. Takalo,Ken'ichi Tanaka,Marco Tavani,I. Torniainen,Merja Tornikoski,Corrado Trigilio,G. Umana,S. Vercellone,Antoniya Valcheva,Antoniya Valcheva,L. N. Volvach,Masayuki Yamanaka +79 more
TL;DR: In this article, the authors report on follow-up observations to study the multiwavelength emission in the post-outburst phase of 3C 454.3 and ascribe this redder-when-brighter behaviour to the presence of a ''little blue bump'' due to line emission from the broad line region, which is clearly visible in the source spectral energy distribution (SED) during faint states.
Journal ArticleDOI
Statistical analyses of long-term variability of AGN at high radio frequencies
Talvikki Hovatta,Merja Tornikoski,Markku Lainela,Harry J. Lehto,Esko Valtaoja,I. Torniainen,Margo F. Aller,H. D. Aller +7 more
TL;DR: In this paper, the authors present a study of variability time scales in a large sample of Active Galactic Nuclei at several frequencies between 4.8 and 230 GHz, and apply three different statistical methods to study the time scales: the structure function, the discrete correlation function and the Lomb-Scargle periodogram.
Journal ArticleDOI
Long term variability of gigahertz-peaked spectrum sources and candidates
TL;DR: In this article, the authors combined new data from observing campaigns and data from the literature to construct the radio continuum spectra for a sample of mostly quasar-type high peaking gigahertz-peaked spectrum (GPS) source candidates.
Journal ArticleDOI
Radio-to-UV monitoring of AO 0235+164 by the WEBT and Swift during the 2006-2007 outburst
C. M. Raiteri,M. Villata,Valeri M. Larionov,Valeri M. Larionov,Margo F. Aller,Uwe Bach,Mark Gurwell,Omar M. Kurtanidze,Anne Lähteenmäki,Kari Nilsson,Aleksander Volvach,Hugh D. Aller,Arkady A. Arkharov,Rumen Bachev,Andrei Berdyugin,Markus Böttcher,Carla Buemi,P. Calcidese,E. Cozzi,A. Di Paola,Mauro Dolci,Jun-Hui Fan,E. Forné,Luigi Foschini,Alok C. Gupta,Vladimir A. Hagen-Thorn,L. Hooks,Talvikki Hovatta,Manasvita Joshi,Matthias Kadler,Givi N. Kimeridze,Tatiana S. Konstantinova,A. Kostov,Thomas P. Krichbaum,L. Lanteri,L. V. Larionova,C.-U. Lee,Paolo Leto,Elina Lindfors,F. Montagni,Roberto Nesci,E. Nieppola,M. G. Nikolashvili,J. M. Ohlert,Arto Oksanen,Evgeni Ovcharov,Pertti Pääkkönen,M. Pasanen,T. Pursimo,J. A. Ros,Evgeni Semkov,Lorand A. Sigua,Richard L. Smart,A. Strigachev,L. O. Takalo,Ken'ichi Torii,I. Torniainen,Merja Tornikoski,Corrado Trigilio,Hiroshi Tsunemi,G. Umana,Antoniya Valcheva,Antoniya Valcheva +62 more
TL;DR: In this paper, the authors present the radio-to-optical data taken by the Whole Earth Blazar Telescope (WEBT) together with the UV data acquired by the Ultra Violet and Optical Telescope (UVOT) instrument onboard Swift to investigate both the outburst behaviour at different wavelengths and the nature of the extra emission component.
Journal ArticleDOI
Radio continuum spectra of gigahertz-peaked spectrum galaxies
I. Torniainen,Merja Tornikoski,Anne Lähteenmäki,Margo F. Aller,Hugh D. Aller,M. G. Mingaliev +5 more
TL;DR: In this article, the authors studied variability and the shape of the radio continuum spectra of a sample of 96 galaxy-type GPS sources and HFPs in order to find out whether there is a similar contamination in the galaxy type samples.