TeV and X-ray Monitoring of LS I +61 303 With VERITAS, Swift, and RXTE

TL;DR

This study presents simultaneous TeV gamma-ray and X-ray observations of LS I +61 303, confirming its variable emission and correlating outbursts across these energy bands for the first time.

Contribution

First simultaneous TeV and X-ray observational campaign of LS I +61 303 providing new insights into its emission variability.

Findings

TeV emission peaks between orbital phases 0.6 and 0.7.

X-ray outbursts occur near the TeV peak phases.

First concurrent multi-band monitoring of this source.

Abstract

Between September 2006 and February 2007, the galactic binary LS I +61 303 was monitored in the TeV band with the VERITAS array of imaging Cherenkov telescopes. These observations confirm LS I +61 303 as a variable TeV gamma-ray source, with emission peaking between orbital phase 0.6 and 0.7. During this observational period, monitoring in the X-ray regime was also carried out using both the RXTE and Swift detectors, which offered complementary coverage of the source. Outbursts in the 0.2-10 keV band were observed by both satellites at close to the same orbital phase as the TeV peak during the 2 orbital cycles covered simultaneously in both bands. While this source has been extensively studied in the X-ray band in the past, this is the first observational campaign to utilize contemporaneous X-ray and TeV data on LS I +61 303.