Multiwavelength Observations of Markarian 421 in 2005 - 2006

TL;DR

This paper presents multiwavelength observations of the blazar Markarian 421 from 2005 to 2006, revealing variability across gamma-ray, X-ray, optical, and radio bands, and exploring correlations among these energy regimes.

Contribution

It provides the first detailed multiwavelength variability and correlation analysis of Markarian 421 during this period, including spectral energy distributions at different activity levels.

Findings

Detected variability at all wavelengths.

Tentative correlation between X-ray and gamma-ray bands.

No clear correlation among other energy bands.

Abstract

Since September 2005, the Whipple 10m Gamma-ray Telescope has been operated primarily as a blazar monitor. The five Northern Hemisphere blazars that have already been detected at the Whipple Observatory, Markarian 421, H1426+428, Markarian 501, 1ES 1959+650 and 1ES 2344+514, are monitored routinely each night that they are visible. We report on the Markarian 421 observations taken from November 2005 to June 2006 in the gamma-ray, X-ray, optical and radio bands. During this time, Markarian 421 was found to be variable at all wavelengths probed. Both the variability and the correlations among different energy regimes are studied in detail here. A tentative correlation, with large spread, was measured between the X-ray and gamma-ray bands, while no clear correlation was evident among the other energy bands. In addition to this, the well-sampled spectral energy distribution of Markarian 421 (1101+384) is presented for three different activity levels. The observations of the other blazar targets will be reported separately.