Microquasar observations with the MAGIC telescope

T. Y. Saito, R. Zanin, P. Bordas, V. Bosch-Ramon, T. Jogler, J. M. Paredes, M. Ribo, M. Rissi, J. Rico, D. F. Torres, for the MAGIC Collaboration

Published 2009-07-06, updated 2009-07-07Version 2

Microquasars, X-ray binaries displaying relativistic jets driven by accretion onto a compact object, are some of the most efficient accelerators in the Galaxy. Theoretical models predict Very High Energy (VHE) emission at the base of the jet where particles are accelerated to multi-TeV energies. This emission could be detected by present IACTs. %Moreover, gamma-ray fluxes should increase during flaring events when accretion rates are enhanced. The MAGIC telescope observed the microquasars GRS 1915+105, Cyg X-3, Cyg X-1 and SS433 for ~ 150 hours in total from 2005 to 2008. We triggered our observations by using multi wavelength information through radio flaring alerts with the RATAN telescope as well as by ensuring the low/hard state of the source through RXTE/ASM and Swift/BAT monitoring data. We report on the upper limits on steady and variable emission from these sources over this long period.