Other
Scientific paper
Jan 2010
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010aas...21535406w&link_type=abstract
American Astronomical Society, AAS Meeting #215, #354.06; Bulletin of the American Astronomical Society, Vol. 42, p.538
Other
Scientific paper
(Abridged) The primary concern of this thesis is the measurement of the stellar velocity ellipsoid (SVE) in galaxy disks. While a few attempts exist in the literature, we know of no study providing as detailed a discussion of the empirical procedure nor of the associated errors in SVE measurements as that presented herein. This is despite the relevance of the SVE to galaxy-disk dynamics as it quantifies, in gross terms, the stellar phase-space distribution function, but largely due to the observational expense of the measurement. We address the observational obstacles by using the WIYN SparsePak integral-field unit, which is well-suited to measuring line-of-sight kinematics in the low-surface-brightness, low-velocity-dispersion regime presented by galaxy disks. Thus, we obtain ionized gas and stellar kinematics for seven galaxies and characterize the SVE using a set of six decomposition methods resulting from consideration of four dynamical relations pulled from the literature and theories of galactic dynamics. These analyses have resulted in the following conclusions: (1) We find general agreement with the results of previous SVE studies; however, we do not confirm a cold-to-hot progression of "disk temperature'' from late- to early-type (Sa) galaxies due to the dominance of different secular processes. The mean vertical-to-radial axial ratio is 0.66 for our sample. (2) Five of seven galaxies show a Toomre stability criterion of Q˜3 the others are only marginally stable with Q˜1. (3) We find indications of a nearly constant line-of-sight velocity dispersion in the extended parts of at least three galaxies, implying an increase in the mass-to-light ratio by factors of a few at these radii. We acknowledge support from the NSF (AST-9970780, AST-0307417, AST-0607516), UW Graduate School (PRJ13SL, 050167, and the Vilas Associate award), and NASA/JPL/Spitzer (GO-30894). KBW is currently supported by an NSF International Research Fellowship (OISE-0754437).
No associations
LandOfFree
Observational Disk Dynamics of Late-Type Galaxies 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 Observational Disk Dynamics of Late-Type Galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Observational Disk Dynamics of Late-Type Galaxies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-963128