ausblenden:
Schlagwörter:
Astrophysics, High Energy Astrophysical Phenomena, astro-ph.HE
MPINP:
HESS - Abteilung Hofmann
Zusammenfassung:
Microquasars, Galactic binary systems showing extended and variable radio
emission, are potential gamma-ray emitters. Indications of gamma-ray transient
episodes have been reported in at least two systems, Cyg X-1 and Cyg X-3. The
identification of additional gamma-ray emitting microquasars is key for a
better understanding of these systems. Very-high-energy gamma-ray emission from
microquasars has been predicted to happen during periods of transient outbursts
potentially connected with the formation of a jet-like outflow. Contemporaneous
observations using the H.E.S.S. telescope array and the RXTE satellite were
obtained on three microquasars: GRS 1915+105, Circinus X-1 and V4641 Sgr with
the aim of detecting a broadband flaring event in the very-high-energy
gamma-ray and X-ray bands. We report here on the analysis of these data for
each system, including a detailed X-ray analysis assessing the location of the
sources in a hardness-intensity diagram during the observations. Finally we
discuss the derived upper limits on their very-high-energy gamma-ray flux.