Multiwavelength observations of Mrk 501 in 2008
Abstract
Mrk 501 is one of the brightest blazars at TeV energies and has been extensively studied since its first VHE detection in 1996. Our goal is to characterize in detail the source gamma-ray emission, together with the radio-to-X-ray emission, during the non-flaring (low) activity, which is less often studied than the occasional flaring (high) activity. We organized a multiwavelength (MW) campaign on Mrk 501 between March and May 2008. This multi-instrument effort included the most sensitive VHE gamma-ray instruments in the northern hemisphere, namely the imaging atmospheric Cherenkov telescopes MAGIC and VERITAS, as well as Swift, RXTE, the F-GAMMA, GASP-WEBT, and other collaborations and instruments. Mrk 501 was found to be in a low state of activity during the campaign, with a VHE flux in the range of 10%-20% of the Crab nebula flux. Nevertheless, significant flux variations were detected with various instruments, with a trend of increasing variability with energy. The broadband spectral energy distribution during the two different emission states of the campaign can be adequately described within the homogeneous one-zone synchrotron self-Compton model, with the (slightly) higher state described by an increase in the electron number density. This agrees with previous studies of the broadband emission of this source during flaring and non-flaring states. We report for the first time a tentative X-ray-to-VHE correlation during a low VHE activity. Although marginally significant, this positive correlation between X-ray and VHE, which has been reported many times during flaring activity, suggests that the mechanisms that dominate the X-ray/VHE emission during non-flaring-activity are not substantially different from those that are responsible for the emission during flaring activity.
Keywords
Cite
@article{arxiv.1410.6391,
title = {Multiwavelength observations of Mrk 501 in 2008},
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 K. Berger and E. Bernardini and A. Biland and O. Blanch and R. K. Bock 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 G. Giavitto and N. Godinović and A. González Muñoz and S. R. Gozzini and A. Hadamek and D. Hadasch and A. Herrero and D. Hildebrand and J. Hose and D. Hrupec and W. Idec and V. Kadenius and H. Kellermann and M. L. Knoetig and J. Krause 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 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 M. Salvati 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 S. Sun and T. Surić and L. Takalo 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 VERITAS Collaboration and : and B. Behera and M. Beilicke and W. Benbow and K. Berger and R. Bird and A. Bouvier and V. Bugaev and M. Cerruti and X. Chen and L. Ciupik and E. Collins-Hughes and W. Cui and C. Duke and J. Dumm and A. Falcone and S. Federici and Q. Feng and J. P. Finley and L. Fortson and A. Furniss and N. Galante and G. H. Gillanders and S. Griffin and S. T. Griffiths and J. Grube and G. Gyuk and D. Hanna and J. Holder and C. A. Johnson and P. Kaaret and M. Kertzman and D. Kieda and H. Krawczynski and M. J. Lang and A. S Madhavan and G. Maier and P. Majumdar and K. Meagher and P. Moriarty and R. Mukherjee and D. Nieto and A. O'Faoláin de Bhróithe and R. A. Ong and A. N. Otte and A. Pichel and M. Pohl and A. Popkow and H. Prokoph and J. Quinn and J. Rajotte and G. Ratliff and L. C. Reyes and P. T. Reynolds and G. T. Richards and E. Roache and G. H. Sembroski and K. Shahinyan and F. Sheidaei and A. W. Smith and D. Staszak and I. Telezhinsky and M. Theiling and J. Tyler and A. Varlotta and S. Vincent and S. P. Wakely and T. C. Weekes and R. Welsing and D. A. Williams and A. Zajczyk and B. Zitzer and External Collaborators and : and M. Villata and C. M. Raiteri and M. Ajello and M. Perri and H. D. Aller and M. F. Aller and V. M. Larionov and N. V. Efimova and T. S. Konstantinova and E. N. Kopatskaya and W. P. Chen and E. Koptelova and H. Y. Hsiao and O. M. Kurtanidze and M. G. Nikolashvili and G. N. Kimeridze and B. Jordan and P. Leto and C. S. Buemi and C. Trigilio and G. Umana and A. Lahtenmaki and E. Nieppola and M. Tornikoski and J. Sainio and V. Kadenius and M. Giroletti and A. Cesarini and L. Fuhrmann and Yu. A. Kovalev and Y. Y. Kovalev},
journal= {arXiv preprint arXiv:1410.6391},
year = {2015}
}
Comments
Accepted for publication in A&A