MWL observations of VHE blazars in 2006

TL;DR

This paper reports on MAGIC telescope observations of VHE blazars Mrk 421 and Mrk 501 in 2006, revealing flux variability, intra-night changes, and multi-wavelength correlations during campaigns.

Contribution

It provides detailed multi-wavelength observational results of VHE blazars, highlighting flux variability and intra-night changes in 2006, with simultaneous optical, X-ray, and VHE data.

Findings

Detected nightly flux variability in Mrk 421

Observed low flux state of Mrk 501 with increased X-ray flux

No significant correlation between spectral index and flux

Abstract

In 2006 the MAGIC telescope observed the well known very high energy (VHE, > 80 GeV) blazars Mrk 421 and Mrk 501 in the course of multi-wavelength campaigns, comprising measurements in the optical, X-ray and VHE regime. MAGIC performed additional snapshot observations on Mrk 421 around the MWL campaigns and detected the source each night with high significance, establishing once more flux variability on nightly scales for this object. For certain nights, the integral flux exceeded the one of Crab significantly, whereas the truly simultaneous observations have been conducted in a rather low flux state. The MAGIC observations contemporaneous to XMM-Newton revealed clear intra-night variability. No significant correlation between the spectral index and the flux could be found for the nine days of observations. The VHE observations of Mrk 501 have been conducted during one of the lowest flux states ever measured by MAGIC for this object. The VHE and optical light curves do not show significant variability, whereas the flux in X-rays increased by about 50 %. In this contribution, the results of the MAGIC observations will be presented in detail.