Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-03-20
Astronomy and Astrophysics
Astrophysics
Accepted for publication in the Astronomical Journal - 26 pages, 8 figures, (Figures 7 and 8 in lower resolution)
Scientific paper
10.1088/0004-6256/135/6/2013
We present a 3D kinematical analysis of stars located in Kapteyn Selected Area 71 (l = 167.1, b = -34.7), where previously a stellar excess was found (Dinescu et al. 2002, Newberg et al. 2002). Previous findings indicated that the stellar excess has a cold kinematical signature as inferred from proper motions, and was initially associated with debris from the Sagittarius dwarf galaxy (Sgr) -- namely the southern trailing tail. We have obtained radial velocities using the Hydra multiobject spectrograph on the WIYN 3.5 m telescope. Results for 183 proper-motion selected stars indicate that the dominant population in this stellar excess is not debris from Sgr, but rather a population that kinematically belongs to the ring-like stream that is now known as the Monoceros stream. The orbit determined for this population agrees very well with the predictions for the Monoceros stream from Penarrubia et al. (2005). The radial-velocity dispersion of this population is between 20 and 30 km/s, lower than that of the Galactic field. Also, the shape of the radial-velocity distribution shows a sharp cut-off on one side, which is more in line with model predictions of the disruption of a satellite rather than with the distribution of the Galactic field. Despite the fact that we now believe most of the stars in the stellar excess to be part of Monoceros, about ten stars in this stellar excess have highly negative radial velocities, which is a clear indication of their membership to the Sgr trailing tidal tail.
Carlin Jeffrey L.
Casetti-Dinescu Dana I.
Girard Terrence M.
Majewski Steven R.
Patterson Richard J.
No associations
LandOfFree
Kinematics of Stars in Kapteyn Selected Area 71: Sampling the Monoceros and Sagittarius Tidal Streams 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 Kinematics of Stars in Kapteyn Selected Area 71: Sampling the Monoceros and Sagittarius Tidal Streams, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Kinematics of Stars in Kapteyn Selected Area 71: Sampling the Monoceros and Sagittarius Tidal Streams will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-578329