Milky Way Kinematics: Measurements at the Subcentral Point of the Fourth Quadrant

Details Milky Way Kinematics: Measurements at the Subcentral Point of the Fourth Quadrant Milky Way Kinematics: Measurements at the Subcentral Point of the Fourth Quadrant

2007-08-07

arxiv.org/abs/0708.0870v1

Astronomy and Astrophysics

Astrophysics

36 pages, 10 figures, accepted to ApJ. Full electronic version of table 1 available at ftp://ftp.atnf.csiro.au/pub/people/nm

Scientific paper

10.1086/522297

We use atomic hydrogen (HI) data from the Southern Galactic Plane Survey to study the kinematics of the fourth quadrant of the Milky Way. By measuring the terminal velocity as a function of longitude throughout the fourth Galactic quadrant we have derived the most densely sampled rotation curve available for the Milky Way between 3 < R < 8 kpc. We determine a new joint rotation curve fit for the first and fourth quadrants, which can be used for kinematic distances interior to the Solar circle. From our data we place new limits on the peak to peak variation of streaming motions in the fourth quadrant to be ~10 km/s. We show that the shape of the average HI profile beyond the terminal velocity is consistent with gas of three velocity dispersions, a cold component with $\Delta v=6.3$ km/s, a warmer component with $\Delta v=12.3$ km/s and a fast component with $\Delta v=25.9$ km/s. Examining the widths with Galactic radius we find that the narrowest two components show little variation with radius and their small scale fluctuations track each other very well, suggesting that they share the same cloud-to-cloud motions. The width of the widest component is constant until R<4 kpc, where it increases sharply.

Affiliated with

Also associated with

No associations

Rating

Milky Way Kinematics: Measurements at the Subcentral Point of the Fourth Quadrant 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 Milky Way Kinematics: Measurements at the Subcentral Point of the Fourth Quadrant, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Milky Way Kinematics: Measurements at the Subcentral Point of the Fourth Quadrant will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-170030