|Speaker:||Issha Kayo (IPMU)|
|Title:||A model independent method to measure velocity dispersion of galaxies|
|Date (JST):||Thu, Oct 22, 2009, 13:30 - 14:30|
|Place:||Seminar Room at IPMU Prefab. B|
Although velocity information of galaxy is usually considered as
a source of noise for cosmological study, it could be important for
study of formation and evolution of galaxies. In this talk I will
present a method to measure large-scale velocity dispersion of galaxies.
This method is based on Peebles(1980) and improved so as to handle the
feature of the two-point correlation function at large scale more
properly. It does not require strong assumptions on the shape of the
probability distribution function of the pairwise velocity contrary to
ordinary methods where Gaussian or exponetial forms are often adopted.
We checked and tuned the method using N-body simulations and applied it
to the SDSS galaxy data. Using the method, we evaluated the luminosity
dependence of the velocity dispersion of the SDSS galaxies and confirmed
the non-monotonic feature found by Jing & Boerner (2004).