Observations of Mrk 421 and Mrk 501 in Spring 2006 with VERITAS

TL;DR

This paper reports early observations of the blazars Mrk 421 and Mrk 501 using the VERITAS array, highlighting the instrument's sensitivity to different flux states and providing insights into these VHE gamma-ray sources.

Contribution

First observations of Mrk 421 and Mrk 501 with VERITAS during commissioning, demonstrating sensitivity to varying source flux levels.

Findings

Mrk 421 was in an active state during observations.

Mrk 501 was in a low flux state.

Instrument sensitivity was confirmed for strong and weak sources.

Abstract

VERITAS, the Very Energetic Radiation Telescope Imaging Array System, is an array of four imaging Atmospheric Cherenkov telescopes in southern Arizona. It is sensitive to gamma rays at energies above 100 GeV. Here, we discuss the results of observations of two well known VHE blazars, Markarian 421 and Markarian 501, during Spring 2006 which were made with the first two telescopes during the comissioning phase of VERITAS. During most of this time Mrk 421 was in an unusually active state while Mrk 501 was in a much lower flux state. As such, these observations provided an opportunity to test the sensitivity of the instrument to strong and weak sources. We discuss implications of these observations on our understanding of these objects.