Details

Autor(en) / Beteiligte

• Jing, Y. P
• Zhang, Pengjie
• Lin, W. P
• Gao, L
• Springel, V

Titel

The Influence of Baryons on the Clustering of Matter and Weak-Lensing Surveys

Ist Teil von

• The Astrophysical journal, 2006-04, Vol.640 (2), p.L119-L122

Ort / Verlag

Chicago, IL: IOP Publishing

Erscheinungsjahr

2006

Link zum Volltext

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• Future weak-lensing measurements of cosmic shear will reach such high accuracy that second-order effects in weak-lensing modeling, such as the influence of baryons on structure formation, become important. We use a controlled set of high-resolution cosmological simulations to quantify this effect by comparing pure N-body dark matter runs with corresponding hydrodynamic simulations, carried out both in nonradiative form and in dissipative form with cooling and star formation. In both hydrodynamic simulations, the clustering of the gas is suppressed while that of dark matter is boosted at scales k > 1 h Mpc super(-1). Despite this counterbalance between dark matter and gas, the clustering of the total matter is suppressed by up to 1% at 1 h Mpc super(-1) k 10 h Mpc super(-1), while for k - 20 h Mpc super(-1) it is boosted, up to 2% in the nonradiative run and 10% in the run with star formation. The stellar mass formed in the latter is highly biased relative to the dark matter in the pure TV-body simulation. Using our power spectrum measurements to predict the effect of baryons on the weak-lensing signal at scales corresponding to multipole moments 100 < l < 10,000, we find that baryons may change the lensing power spectrum by less than 0.5% at l < 1000, but by 1% to 10% at 1000 < l < 10,000. The size of the effect exceeds the predicted accuracy of fixture lensing power spectrum measurements and will likely be detected. Precise determinations of cosmological parameters with weak lensing, and studies of small-scale fluctuations and clustering, therefore rely on properly including baryonic physics.