Simultaneous Multiwavelength Observations of Markarian 421 During Outburst

VERITAS AND MAGIC COLLABORATION: SON 230 AUTORES. A. PICHEL

ASTROPHYSICAL JOURNAL

IOP PUBLISHING LTD

Año: 2009 vol. 703 p. 169 - 178

0004-637X

We report on the results of two coordinated multiwavelength campaigns that focused on the TeV gamma-ray blazar Markarian 421 during its 2006 and 2008 outbursts. These campaigns obtained optical and X-ray data using the XMM-Newton satellite, while the TeV gamma-ray data were obtained utilizing three imaging atmospheric Cerenkov telescopes, the Whipple 10m telescope and VERITAS, both based in Arizona, as well as the MAGIC telescope, based on La Palma in the Canary Islands. The coordinated effort between the TeV groups allowed for truly simultaneous data in optical/X-ray/TeV gamma-ray wavelengths during a significant portion of the XMM-Newton observations. This simultaneous coverage allowed for a reliable search for correlations between optical, X-ray and TeV gamma-ray variability over the course of the observations. Investigations of spectral hysteresis and modeling of the spectral energy distributions are also presented. Though current models can fit the spectral energy distributions well, the expected X-ray/gamma-ray correlation is not apparent.