Grupo de Sistemas Estelares

Zamaninasab, M.; Eckart, A.; Kunneriath, D.; Witzel, G.; Schödel, R.; Meyer, L.; Dovciak, M.; Karas, V.; König, S.; Krichbaum, T.; Lu, R. S.; Straubmeier, C.; Zensus, J. A.
Memorie della Società Astronomica Italiana, v.79, p.1054 (2008)
12/2008

ABSTRACT

Here we report on the results of our recent coordinated mm/sub-mm/NIR observations of Sagittarius A* (Sgr A*) in May 2007. The observations revealed several flare events in all wavelength domains. These flare emissions can be described with a combination of a synchrotron self-Compton model (SSC) followed by an adiabatic expansion of the source. The NIR observations can be interpreted in a model involving a temporary disk with a short jet. In the disk component the quasiperiodic flux variations can be explained due to the spots on relativistic orbits around the central supermassive black hole (SMBH). The 15 May 2007 NIR flare shows the highest subflare contrast observed until now. It shows also evidence for a variation of the profile of consecutive subflares. This profile variation could be successfully modeled through the variation of the spot structure due to differential rotation within the accretion disk.