Dark energy and the mass of the Local Group

Details Dark energy and the mass of the Local Group Dark energy and the mass of the Local Group

2009-02-23

arxiv.org/abs/0902.3871v1

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

7 pages, 1 figure, submitted to ApJL

Scientific paper

Dark energy must be taken into account to estimate more reliably the amount of dark matter and how it is distributed in the local universe. For systems several Mpc across like the Local Group, we introduce three self-consistent independent mass estimators. These account for the antigravity effect of dark energy treated as Einstein's cosmological constant Lambda. The first is a modified Kahn-Woltjer model which gives a value of the Local Group mass via the particular motions of the two largest members, the Milky Way and M31. Inclusion of dark energy in this model increases the minimum mass estimate by a factor of three compared to the "classical estimate". The increase is less but still significant for different ways of using the timing argument. The second estimator is a modified virial theorem which also demonstrates how dark energy can "hide" from detection a part of the gravitating mass of the system. The third is a new zero-gravity method which gives an upper limit to the group mass which we calculate with high precision HST observations. In combination, the estimators lead to a robust and rather narrow range for a group's mass, M. For the Local Group, 3.2 < M < 3.7 x 10^{12} M_sun. Our result agrees well with the Millennium Simulation based on the LambdaCDM cosmology.

Affiliated with

Also associated with

No associations

Rating

Dark energy and the mass of the Local Group 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 Dark energy and the mass of the Local Group, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dark energy and the mass of the Local Group will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-584351