SDSS analysis of Galactic stellar streams

Fliri, J.; Martínez-Delgado, D.; Jurić, M.
Referencia bibliográfica

CLASSIFICATION AND DISCOVERY IN LARGE ASTRONOMICAL SURVEYS: Proceedings of the International Conference: ``Classification and Discovery in Large Astronomical Surveys''. AIP Conference Proceedings, Volume 1082, pp. 221-225 (2008).

Fecha de publicación:
12
2008
Número de autores
3
Número de autores del IAC
2
Número de citas
0
Número de citas referidas
0
Descripción
The last years saw numerous detections of substructure in the Galactic halo, largely due to wide area surveys like the Sloan Digital Sky Survey (SDSS) or the Two Micron All Sky Survey (2MASS). The analysis of SDSS data revealed the `Field of Streams' which encompasses, among other features, the broad and extended Sagittarius tidal stream as well as the Monoceros and Orphan stellar streams. In this contribution we present first results from our analysis of Galactic tidal streams based on SDSS Data Release 6 (DR6) stellar photometry. We use the F star method to derive stellar density maps for various distance intervals. These maps reveal a heliocentric distance to the Sagittarius stream near the Galactic anticenter of ~13 kpc which is lower than previously claimed. The value also is smaller than predicted by current state-of the art N-body simulations of the disruption of the Sagittarius dwarf galaxy in the Galactic halo. Our maps furthermore yield a distance between 13 kpc and 16 kpc to the nearest part of the Virgo overdensity. Rather surprisingly, we found evidence for a discontinuity in the Orphan stream. The `disconnected' region extends over a projected length of ~6 degrees and appears at distances exceeding ~25 kpc. If confirmed, this feature would pose strong constraints on theoretical models trying to explain the origin of the Orphan stream.