RT Journal Article T1 Multiwavelength observations of the blazar 1ES 1011+496 in Spring 2008 A1 Antoranz Canales, Pedro A1 Barrio Uña, Juan Abel A1 Contreras González, José Luis A1 Fonseca González, María Victoria A1 López Moya, Marcos A1 Miranda Pantoja, José Miguel A1 Nievas Rosillo, Mireia A1 Satalecka, Konstanzja A1 Scapin, Valeria AB The BL Lac object 1ES 1011+496 was discovered at Very High Energy (VHE, E>100GeV) γ-rays by MAGIC in spring 2007. Before that the source was little studied in different wavelengths. Therefore a multi-wavelength (MWL) campaign was organized in spring 2008. Along MAGIC, the MWL campaign included the Mets¨ahovi radio observatory, Bell and KVA optical telescopes and the Swift and AGILE satellites. MAGIC observations span from March to May, 2008 for a total of 27.9 hours, of which 19.4 hours remained after quality cuts. The light curve showed no significant variability yielding an integral flux above 200 GeV of (1.3 ± 0.3) × 10^(−11) photons cm^(−2) s^( −1) . The differential VHE spectrum could be described with a power-law function with a spectral index of 3.3 ± 0.4. Both results were similar to those obtained during the discovery. Swift XRT observations revealed an X-ray flare, characterized by a harder-when-brighter trend, as is typical for high synchrotron peak BL Lac objects (HBL). Strong optical variability was found during the campaign, but no conclusion on the connection between the optical and VHE γ-ray bands could be drawn. The contemporaneous SED shows a synchrotron dominated source, unlike concluded in previous work based on non-simultaneous data, and is well described by a standard one–zone synchrotron self–Compton model. We also performed a study on the source classification. While the optical and X-ray data taken during our campaign show typical characteristics of an HBL, we suggest, based on archival data, that 1ES 1011+496 is actually a borderline case between intermediate and high synchrotron peak frequency BL Lac objects. PB Wiley SN 0035-8711 YR 2016 FD 2016-07-01 LK https://hdl.handle.net/20.500.14352/24599 UL https://hdl.handle.net/20.500.14352/24599 LA eng NO © 2016 RAS. Artículo firmado por 160 autores. We would like to thank the Instituto de Astrofísica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The financial support of the German BMBF and MPG, the Italian INFN and INAF, the Swiss National Fund SNF, the ERDF under the Spanish MINECO (FPA2012-39502), and the Japanese JSPS and MEXT is gratefully acknowledged. This work was also supported by the Centro de Excelencia Severo Ochoa SEV-2012-0234, CPAN CSD2007-00042, and MultiDark CSD2009-00064 projects of the Spanish Consolider-Ingenio 2010 programme, by grant 268740 of the Academy of Finland, by the Croatian Science Foundation (HrZZ) Project 09/176 and the University of Rijeka Project 13.12.1.3.02, by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, and by the Polish MNiSzW grant 745/N-HESS-MAGIC/2010/0. The AGILE Mission is funded by the Italian Space Agency (ASI), with scientific and programmatic participation by the Italian Institute of Astrophysics (INAF) and the Italian Institute of Nuclear Physics (INFN). Research partially supported through the ASI grants no. I/089/06/2, I/042/10/0 and I/028/12/0. We gratefully acknowledge the entire Swift team, the duty scientists and science planners for the dedicated support, making these observations possible. This research has made use of the XRT Data Analysis Software (XRTDAS) developed under the responsibility of the ASI Science Data Center (ASDC), Italy. M. T. Carini, Richard Walters, April Pease acknowledge support from the Institute for Astrophysics and Space Science at Western Kentucky University. The Metsähovi team acknowledges the support from the Academy of Finland to our observing projects (numbers 212656, 210338, 121148, and others). This research has made use of NASA’s Astrophysics Data System. Part of this work is based on archival data, software or on-line services provided by the ASI Science Data Center (ASDC). This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France. We thank the anonymous referee for a careful reading and useful questions and suggestions that improved the presentation of this paper. NO Ministerio de Economía y Competitividad (MINECO) NO German BMBF and MPG NO Swiss National Fund SNF NO Italian INFN and INAF NO Japanese JSPS and MEXT NO Centro de Excelencia Severo Ochoa NO Spanish Consolider-Ingenio 2010 programme NO Academy of Finland NO Croatian Science Foundation (HrZZ) NO University of Rijeka NO DFG Collaborative Research Centers NO Polish MNiSzW NO ASI NO Institute for Astrophysics and Space Science at Western Kentucky University DS Docta Complutense RD 21 abr 2025