Placeholder for headline figure. For details, see Figure 1 below.

Reference: J. Aleksic et al. (The MAGIC and VERITAS Collaborations and others), Astronomy & Astrophysics 578: A22, 2015

Full text version

ArXiv: ArXiV:1412.3576

Contacts: Amy Furniss

The broadband spectral energy distribution of the TeV blazar Mrk421 was observed for 13 consecutive days from radio to very high energy gamma-rays with MAGIC, VERITAS, Whipple, FermiLAT, MAXI, RXTE, Swift, GASP-WEBT, and several optical and radio telescopes, during an multi-instrument campaign in 2010. The flux variability, which was remarkable in the X-ray and VHE bands while it was minor or not significant in the other bands, was associated to variations in the underlying particle population within two distinct leptonic scenarios, a one-zone synchrotron self-Compton (SSC) model, and a two-zone SSC model, where one zone is responsible for the quiescent emission while the other smaller zone (spatially separated from the first one) contributes to the daily-variable emission occurring in X-rays and VHE gamma-rays. This observation suggests that the particle acceleration and cooling mechanism producing the radiating particles could be the main one responsible for the broadband flux variations during the flaring episodes in