Halo masses of Mg ii absorbers at z∼ 0.5 from Sloan Digital Sky Survey Data Release 7
| Autor: | Jean-Rene Gauthier, Eduardo N. Seyffert, Hsiao-Wen Chen, John M. O'Meara, Robert A. Simcoe, Kathy L. Cooksey |
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| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | Monthly Notices of the Royal Astronomical Society. 439:342-353 |
| ISSN: | 1365-2966 0035-8711 |
| Popis: | We present the cross-correlation function of Mg ii absorbers with respect to a volume-limited sample of luminous red galaxies (LRGs) at z = 0.45–0.60 using the largest Mg ii absorber sample and a new LRG sample from Sloan Digital Sky Survey Data Release 7. We present the clustering signal of absorbers on projected scales r_p = 0.3-35 h^(−1) Mpc in four W^(λ2796)_(r) bins spanning W^(λ2796)_(r) =0.4−5.6 Å. We found that on average Mg ii absorbers reside in haloes 〈log Mh〉 ≈ 12.1, similar to the halo mass of an L_* galaxy. We report that the weakest absorbers in our sample with W^(λ2796)_(r)=0.4−1.1 Å reside in relatively massive haloes with ⟨logM_h⟩≈12.5+0.6−1.3, while stronger absorbers reside in haloes of similar or lower masses 〈log M_h〉 ≈ 11.6+ 0.9. We compared our bias data points, b, and the frequency distribution function of absorbers, fW_r, with a simple model incorporating an isothermal density profile to mimic the distribution of absorbing gas in haloes. We also compared the bias data points with Tinker & Chen who developed halo occupation distribution models of Mg ii absorbers that are constrained by b and fW_r. The simple isothermal model can be ruled at a ≈2.8σ level mostly because of its inability to reproduce fW_r. However, b values are consistent with both models, including Tinker & Chen. In addition, we show that the mean b of absorbers does not decrease beyond W^(λ2796)_(r)≈1.6 Å. The flat or potential upturn of b for W^(λ2796)_(r)≳1.6 Å absorbers suggests the presence of additional cool gas in massive haloes. |
| Databáze: | OpenAIRE |
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