Astronomy and Astrophysics – Astronomy
Scientific paper
Aug 2011
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011mnras.415.1093z&link_type=abstract
Monthly Notices of the Royal Astronomical Society, Volume 415, Issue 2, pp. 1093-1104.
Astronomy and Astrophysics
Astronomy
3
Methods: Numerical, Intergalactic Medium, Cosmology: Theory, Large-Scale Structure Of Universe
Scientific paper
We investigate the dynamical effect of turbulence in the baryonic intergalactic medium (IGM) on the baryon fraction distribution. In the fully developed non-linear regime, the IGM will evolve into a state of turbulence, containing strong and curved shocks, vorticity and complex structures. Turbulence would mean that the density and velocity fields of the IGM would be different from those of the underlying collisionless dark matter. Consequently, the baryon fraction fb will deviate from its cosmic mean fcosmicb. We study these phenomena with simulation samples produced by the weighted essentially non-oscillatory (WENO) hybrid cosmological hydrodynamic/N-body code, which is effective for capturing shocks and complex structures. We find that the distribution of the baryon fraction is highly non-uniform on scales from hundreds of kpc to a few Mpc, and fb varies from as low as 1 per cent to a few times the cosmic mean. We further show that the turbulence pressure in the IGM is weakly scale-dependent and comparable to the gravitational energy density of haloes with mass around 1011 h-1 M&sun;. The baryon fraction in haloes with mass equal to or smaller than 1011 h-1 M&sun; should be substantially lower than fcosmicb. Numerical results show that fb is decreasing from 0.8fcosmicb at halo mass scales around 1012 h-1 M&sun; to 0.3fcosmicb at 1011 h-1 M&sun; and shows further decrease when halo mass is less than 1011 h-1 M&sun;. The strong mass dependence of fb is similar to the observed results. Although the simulated fb in haloes are higher than the observed value by a factor of 2, the turbulence of the IGM should be an important dynamical reason for the remarkable lack of baryonic matter in haloes with mass ≤1012 h-1 M&sun;.
Fang Li-zhi
Feng Long-Long
Zhu Weishan
No associations
LandOfFree
Dynamical effect of the turbulence of the intergalactic medium on the baryon fraction distribution 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 Dynamical effect of the turbulence of the intergalactic medium on the baryon fraction distribution, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dynamical effect of the turbulence of the intergalactic medium on the baryon fraction distribution will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1681702