Thin filaments at the Galactic Center: identification and proper motions

Abstract

L'-band (3.8 μm) images of the Galactic Center show a large number of thin filaments in the mini-spiral, located close to the mini-cavity, along the inner edge of the northern arm and in the vicinity of some stars. We interpret them as shock fronts formed by the interaction of a central wind with the mini-spiral or, in some cases, extended dusty stellar envelopes. The observations have been carried out using the NACO adaptive optics system at the ESO VLT, in 5 subsequent epochs from 2002 to 2006. We present a proper motion study of the thin filaments observed in the central parsec around Sgr A*, obtained using the cross- correlation technique. Our interpretation is consistent with a collimated outfbw model from the central few arcseconds. Two possible mechanisms could produce the postulated outfbw: stellar winds originating from the high-mass-loosing He-star cluster as well as a wind from Sgr A* due to accretion from the surrounding disk of stars.