Articles

"The Cosmological Bias Factor of Damped Lyman Alpha Systems: Dependence on
 Metal Line Stregth", MNRAS, 480, 4702. - I. Pérez-Ràfols, J. Miralda-Escudé, A. Arinyo-i-Prats,
 A. Font-Ribera, L. Mas-Ribas 2018.

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"A metal-line strength indicator for Damped Lyman Alpha Systems at low signal-to-noise", MNRAS, 481, 3921. - A. Arinyo-i-Prats, L. Mas-Ribas, J. Miralda-Escudé, I. Pérez-Ràfols, P. Noterdaeme 2018.

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 In these two papers, we computed the correlation amplitude of Damped Lyman Alpha Systems of different metallicity, meaning different abundance of the heavy elements (carbon and heavier) that are produced in stellar interiors instead of the Big Bang nucleosynthesis. The abundance of these elements increases with the fraction of matter that has been turned into stars in a galaxy. We generally expect that more massive galaxies have transformed a greater fraction of their matter into stars, and we also know that more massive galaxies are more strongly correlated with the large-scale density fluctuations of the Universe. The bias factor measures this amplitude of the large-scale correlation, so we expect that DLAs with greater metallicity have larger bias factor. We present a method to roughly estimate the metallicity of the DLAs in the BOSS spectra, and we show that the bias factor indeed increases with the DLA metallicity in a way that is consistent with expectations. We hope in the future it will be possible to do this measurement in much greater detail, as a function of various elements and not just an overall metal abundance.