Schedule Oct 03, 2008
Discovery of New Kinematic Stellar Streams in the Solar Neighborhood
Rainer Klement (MPIA)

I report on the detection of new kinematic stellar streams in the Solar neighborhood using data provided by the SEGUE project in the seventh SDSS data relaease. The analysis is based on distances to SDSS stars estimated from a photometric parallax relation including a metallicity correction taken from Ivezic et al. 2008. The final sample consists of 22321 metal-poor ([Fe/H]<-0.5) dwarfs (log >3.5) with full 6d-phase space information. We characterize the orbits of these stars through the inclination angles of their orbital plane and suitable proxies for their angular momentum and eccentricity. We identify several "phase-space overdensities" of stars on very similar orbits and confirm their tidal origin from their [Fe/H]-distributions. Besides at least five new features we have a very strong signal of the stream discovered in 1999 by Helmi et al., which peaks at an orbital inclination with respect to the North Galactic Cap of ~150 and a metallicity of [Fe/H]~ -2.0. The investigated streams sample the whole range of orbital inclination angles and give strong hints on the accretion history of the Milky Way's halo.

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