First broadband characterization and redshift determination of the VHE blazar MAGIC J2001+439
Abstract
We aim to characterize the broadband emission from 2FGL J2001.1+4352, which has been associated with the unknown-redshift blazar MG4 J200112+4352. Based on its gamma-ray spectral properties, it was identified as a potential very high energy (VHE; E > 100 GeV) gamma-ray emitter. The source was observed with MAGIC first in 2009 and later in 2010 within a multi-instrument observation campaign. The MAGIC observations yielded 14.8 hours of good quality stereoscopic data. The object was monitored at radio, optical and gamma-ray energies during the years 2010 and 2011. The source, named MAGIC J2001+439, is detected for the first time at VHE with MAGIC at a statistical significance of 6.3 {\sigma} (E > 70 GeV) during a 1.3-hour long observation on 2010 July 16. The multi-instrument observations show variability in all energy bands with the highest amplitude of variability in the X-ray and VHE bands. We also organized deep imaging optical observations with the Nordic Optical Telescope in 2013 to determine the source redshift. We determine for the first time the redshift of this BL Lac object through the measurement of its host galaxy during low blazar activity. Using the observational evidence that the luminosities of BL Lac host galaxies are confined to a relatively narrow range, we obtain z = 0.18 +/- 0.04. Additionally, we use the Fermi-LAT and MAGIC gamma-ray spectra to provide an independent redshift estimation, z = 0.17 +/- 0.10. Using the former (more accurate) redshift value, we adequately describe the broadband emission with a one-zone SSC model for different activity states and interpret the few-day timescale variability as produced by changes in the high-energy component of the electron energy distribution.
Keywords
Cite
@article{arxiv.1409.3389,
title = {First broadband characterization and redshift determination of the VHE blazar MAGIC J2001+439},
author = {MAGIC Collaboration and J. Aleksić and S. Ansoldi and L. A. Antonelli and P. Antoranz and A. Babic and P. Bangale and U. Barres de Almeida and J. A. Barrio and J. Becerra González and W. Bednarek and E. Bernardini and A. Biland and O. Blanch and S. Bonnefoy and G. Bonnoli and F. Borracci and T. Bretz and E. Carmona and A. Carosi and D. Carreto Fidalgo and P. Colin and E. Colombo and J. L. Contreras and J. Cortina and S. Covino and P. Da Vela and F. Dazzi and A. De Angelis and G. De Caneva and B. De Lotto and C. Delgado Mendez and M. Doert and A. Domínguez and D. Dominis Prester and D. Dorner and M. Doro and S. Einecke and D. Eisenacher and D. Elsaesser and E. Farina and D. Ferenc and M. V. Fonseca and L. Font and K. Frantzen and C. Fruck and R. J. García López and M. Garczarczyk and D. Garrido Terrats and M. Gaug and N. Godinović and A. González Muñoz and S. R. Gozzini and D. Hadasch and M. Hayashida and J. Herrera and A. Herrero and D. Hildebrand and J. Hose and D. Hrupec and W. Idec and V. Kadenius and H. Kellermann and K. Kodani and Y. Konno and J. Krause and H. Kubo and J. Kushida and A. La Barbera and D. Lelas and N. Lewandowska and E. Lindfors and S. Lombardi and M. López and R. López-Coto and A. López-Oramas and E. Lorenz and I. Lozano and M. Makariev and K. Mallot and G. Maneva and N. Mankuzhiyil and K. Mannheim and L. Maraschi and B. Marcote and M. Mariotti and M. Martínez and D. Mazin and U. Menzel and M. Meucci and J. M. Miranda and R. Mirzoyan and A. Moralejo and P. Munar-Adrover and D. Nakajima and A. Niedzwiecki and K. Nilsson and K. Nishijima and K. Noda and N. Nowak and R. Orito and A. Overkemping and S. Paiano and M. Palatiello and D. Paneque and R. Paoletti and J. M. Paredes and X. Paredes-Fortuny and S. Partini and M. Persic and F. Prada and P. G. Prada Moroni and E. Prandini and S. Preziuso and I. Puljak and R. Reinthal and W. Rhode and M. Ribó and J. Rico and J. Rodriguez Garcia and S. Rügamer and A. Saggion and T. Saito and K. Saito and K. Satalecka and V. Scalzotto and V. Scapin and C. Schultz and T. Schweizer and S. N. Shore and A. Sillanpää and J. Sitarek and I. Snidaric and D. Sobczynska and F. Spanier and V. Stamatescu and A. Stamerra and T. Steinbring and J. Storz and M. Strzys and S. Sun and T. Surić and L. Takalo and H. Takami and F. Tavecchio and P. Temnikov and T. Terzić and D. Tescaro and M. Teshima and J. Thaele and O. Tibolla and D. F. Torres and T. Toyama and A. Treves and M. Uellenbeck and P. Vogler and R. M. Wagner and F. Zandanel and R. Zanin and F. D'Ammando and T. Hovatta and V. M. Larionov and W. Max-Moerbeck and M. Perri and A. C. S. Readhead and J. L. Richards and T. Sakamoto and R. D. Schwartz and F. Verrecchia and L. C. Reyes},
journal= {arXiv preprint arXiv:1409.3389},
year = {2014}
}
Comments
17 pages, 15 figures, Accepted for publication in A&A