Probing the Halo From the Solar Vicinity to the Outer Galaxy: Connecting Stars in Local Velocity Structures to Large-Scale Clouds

Details Probing the Halo From the Solar Vicinity to the Outer Galaxy: Connecting Stars in Local Velocity Structures to Large-Scale Clouds Probing the Halo From the Solar Vicinity to the Outer Galaxy: Connecting Stars in Local Velocity Structures to Large-Scale Clouds

2012-02-23

arxiv.org/abs/1202.5311v1

Astronomy and Astrophysics

Astrophysics

Galaxy Astrophysics

submitted to the Astrophysical Journal, 40 pages, 13 figures

Scientific paper

(Abridged) This paper presents the first connections made between two local features in velocity-space found in a survey of M giant stars and stellar spatial inhomogeneities on global scales. Comparison to cosmological, chemodynamical stellar halo models confirm that the M giant population is particularly sensitive to rare, recent and massive accretion events. These events can give rise to local observed velocity sequences - a signature of a small fraction of debris from a common progenitor, passing at high velocity through the survey volume, near the pericenters of their eccentric orbits. The majority of the debris is found in much larger structures, whose morphologies are more cloud-like than stream-like and which lie at the orbital apocenters. Adopting this interpretation, the full-space motions represented by the observed velocity features are derived under the assumption that the members within each sequence share a common velocity. Orbit integrations are then used to trace the past and future trajectories of these stars across the sky revealing plausible associations with large, previously-discovered, cloud-like structures. The connections made between nearby velocity structures and these distant clouds represent preliminary steps towards developing coherent maps of such giant debris systems. These maps promise to provide new insights into the origin of debris clouds, new probes of Galactic history and structure, and new constraints on the high-velocity tails of the local dark matter distribution that are essential for interpreting direct detection experiments.

Affiliated with

Also associated with

No associations

Rating

Probing the Halo From the Solar Vicinity to the Outer Galaxy: Connecting Stars in Local Velocity Structures to Large-Scale Clouds 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 Probing the Halo From the Solar Vicinity to the Outer Galaxy: Connecting Stars in Local Velocity Structures to Large-Scale Clouds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Probing the Halo From the Solar Vicinity to the Outer Galaxy: Connecting Stars in Local Velocity Structures to Large-Scale Clouds will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-77741