Constraining the Halo Mass of Damped Ly$\alpha$ Absorption Systems (DLAs) at $z=2-3.5$ using the Quasar-CMB Lensing Cross-correlation

TL;DR

This study uses quasar-CMB lensing cross-correlation to constrain the halo mass of DLAs at redshifts 2-3.5, providing new limits on their bias and demonstrating the potential of future CMB experiments for high-redshift halo mass measurements.

Contribution

It introduces a novel cross-correlation method with updated data to constrain DLA halo masses, improving upon previous measurements.

Findings

DLA bias $b_{DLA}$ is less than 3.1

Halo mass $ ext{log}(M/M_\odot h^{-1})$ is less than or equal to 12.3

Results are consistent with previous studies

Abstract

We study the cross correlation of damped Ly$\alpha$ systems (DLAs) and their background quasars, using the most updated DLA catalog and the Planck 2018 CMB lensing convergence field. Our measurement suggests that the DLA bias $b_{\rm DLA}$ is smaller than $3.1$, corresponding to $\log(M/M_\odot h^{-1})\leq 12.3$ at a confidence of $90\%$. These constraints are broadly consistent with Alonso et al. (2018) and previous measurements by cross-correlation between DLAs and the Ly$\alpha$ forest (e.g. Font-Ribera et al. 2012; Perez-Rafols et al. 2018). Further, our results demonstrate the potential of obtaining a more precise measurement of the halo mass of high-redshift sources using next generation CMB experiments with a higher angular resolution. The python-based codes and data products of our analysis are available at https://github.com/LittleLin1999/CMB-lensingxDLA.