The imprint of dissipation on the shapes of merger remnant LOSVDs

Details The imprint of dissipation on the shapes of merger remnant LOSVDs The imprint of dissipation on the shapes of merger remnant LOSVDs

2009-03-17

arxiv.org/abs/0903.3064v2

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

ApJ accepted - added some references and background on previous studies. 9 pages, 4 figures

Scientific paper

The properties of elliptical galaxies are broadly consistent with simulated remnants of gas-rich mergers between spirals, motivating more detailed studies of the imprint of this formation mechanism on the remnant distribution function. Gas has a strong impact on the non-Gaussian shapes of the line-of-sight velocity distributions (LOSVDs) of the merger remnant, owing to the embedded disk that forms out of the gas that retains its angular momentum during the merger, and the strong central mass concentration from the gas that falls to the center. The deviations from Gaussianity are parametrized by the Gauss-Hermite moments h_3 and h_4, which are related to the skewness and kurtosis of the LOSVDs. We quantify the dependence of the (h_3,h_4)-v/sigma relations on the initial gas fraction of the progenitor disks in 1:1 mergers, using Gadget-2 simulations including star formation, radiative cooling, and feedback from supernovae and AGN. For gas fractions f_gas < ~15% the overall correlation between h_3 and v/sigma is weak, consisting of a flat negatively correlated component arising from edge-on viewing angles plus a steep positively correlated part from face-on projections. The spread in v/sigma values decreases toward high positive h_4, and there is a trend toward lower h_4 as the gas fraction increases from 0 to 15%. For f_gas > ~20% the (h_3,4)- v/sigma distributions look quite different - there is a tight negative h_3- v/sigma correlation, and a wide spread in v/sigma values at all h_4, in better agreement with observations. Re-mergers of the high-f_gas remnants (dry mergers) produce slowly rotating systems with nearly Gaussian LOSVDs. We explain all of these trends in terms of the underlying orbit structure of the remnants, as molded by their dissipative formation histories.

Affiliated with

Also associated with

No associations

Rating

The imprint of dissipation on the shapes of merger remnant LOSVDs 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 The imprint of dissipation on the shapes of merger remnant LOSVDs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The imprint of dissipation on the shapes of merger remnant LOSVDs will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-400987