The 40% Arecibo Legacy Fast ALFA survey catalog (α.40) of 10,150 H I-selected galaxies is used to analyze the clustering properties of gas-rich galaxies. By employing the Landy-Szalay estimator and a full covariance analysis for the two-point galaxy-galaxy correlation function, we obtain the real-space correlation function and model it as a power law, ξ(r) = (r/r 0)-γ, on scales <10 h -1Mpc. As the largest sample of blindly H I-selected galaxies to date, α.40 provides detailed understanding of the clustering of this population. We find γ = 1.51 ± 0.09 and r0 = 3.3 + 0.3, -0.2 h -1Mpc, reinforcing the understanding that gas-rich galaxies represent the most weakly clustered galaxy population known; we also observe a departure from a pure power-law shape at intermediate scales, as predicted in ΛCDM halo occupation distribution models. Furthermore, we measure the bias parameter for the α.40 galaxy sample and find that H I galaxies are severely antibiased on small scales, but only weakly antibiased on large scales. The robust measurement of the correlation function for gas-rich galaxies obtained via the α.40 sample constrains models of the distribution of H I in simulated galaxies, and will be employed to better understand the role of gas in environmentally dependent galaxy evolution. © 2012 The American Astronomical Society. All rights reserved.

The clustering characteristics of H I-selected galaxies from the 40% alfalfa survey / A.M. Martin, R. Giovanelli, M.P. Haynes, L. Guzzo. - In: THE ASTROPHYSICAL JOURNAL. - ISSN 0004-637X. - 750:1(2012), p. 38.38.

The clustering characteristics of H I-selected galaxies from the 40% alfalfa survey

L. Guzzo
Ultimo
2012

Abstract

The 40% Arecibo Legacy Fast ALFA survey catalog (α.40) of 10,150 H I-selected galaxies is used to analyze the clustering properties of gas-rich galaxies. By employing the Landy-Szalay estimator and a full covariance analysis for the two-point galaxy-galaxy correlation function, we obtain the real-space correlation function and model it as a power law, ξ(r) = (r/r 0)-γ, on scales <10 h -1Mpc. As the largest sample of blindly H I-selected galaxies to date, α.40 provides detailed understanding of the clustering of this population. We find γ = 1.51 ± 0.09 and r0 = 3.3 + 0.3, -0.2 h -1Mpc, reinforcing the understanding that gas-rich galaxies represent the most weakly clustered galaxy population known; we also observe a departure from a pure power-law shape at intermediate scales, as predicted in ΛCDM halo occupation distribution models. Furthermore, we measure the bias parameter for the α.40 galaxy sample and find that H I galaxies are severely antibiased on small scales, but only weakly antibiased on large scales. The robust measurement of the correlation function for gas-rich galaxies obtained via the α.40 sample constrains models of the distribution of H I in simulated galaxies, and will be employed to better understand the role of gas in environmentally dependent galaxy evolution. © 2012 The American Astronomical Society. All rights reserved.
galaxies: clusters: general; galaxies: distances and redshifts; large-scale structure of universe; radio lines: galaxies; surveys; Astronomy and Astrophysics; Space and Planetary Science
Settore FIS/05 - Astronomia e Astrofisica
http://iopscience.iop.org/0004-637X/750/1/38/pdf/0004-637X_750_1_38.pdf
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/484499
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