Astronomy and Astrophysics – Astrophysics – Galaxy Astrophysics
Scientific paper
2010-06-30
ApJ, 719, 1582 (2010)
Astronomy and Astrophysics
Astrophysics
Galaxy Astrophysics
Accepted for publication in the Astrophysical Journal Requires emulateapj to process
Scientific paper
We use 666 blue horizontal branch (BHB) stars from the 2Qz redshift survey to map the Galactic halo in four dimensions (position, distance and velocity). We find that the halo extends to at least 100 kpc in Galactocentric distance, and obeys a single power-law density profile of index ~-2.5 in two different directions separated by 150 degrees on the sky. This suggests that the halo is spherical. Our map shows no large kinematically coherent structures (streams, clouds or plumes) and appears homogeneous. However, we find that at least 20% of the stars in the halo reside in substructures and that these substructures are dynamically young. The velocity dispersion profile of the halo appears to increase towards large radii while the stellar velocity distribution is non Gaussian beyond 60 kpc. We argue that the outer halo consists of a multitude of low luminosity overlapping tidal streams from recently accreted objects.
CTIO
de Propris Roberto
Harrison Craig D.
Mares Peter J.
University Cornell
No associations
LandOfFree
Mapping the Galactic Halo with blue horizontal branch stars from the 2dF quasar redshift survey does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Mapping the Galactic Halo with blue horizontal branch stars from the 2dF quasar redshift survey, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mapping the Galactic Halo with blue horizontal branch stars from the 2dF quasar redshift survey will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-428055