MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology. Department of Physics, Wolz, Laura, Pourtsidou, Alkistis, Masui, Kiyoshi W, Chang, Tzu-Ching, Bautista, Julian E, Müller, Eva-Maria, Avila, Santiago, Bacon, David, Percival, Will J, Cunnington, Steven, Anderson, Chris, Chen, Xuelei, Kneib, Jean-Paul, Li, Yi-Chao, Liao, Yu-Wei, Pen, Ue-Li, Peterson, Jeffrey B, Rossi, Graziano, Schneider, Donald P, Yadav, Jaswant, Zhao, Gong-Bo, MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology. Department of Physics, Wolz, Laura, Pourtsidou, Alkistis, Masui, Kiyoshi W, Chang, Tzu-Ching, Bautista, Julian E, Müller, Eva-Maria, Avila, Santiago, Bacon, David, Percival, Will J, Cunnington, Steven, Anderson, Chris, Chen, Xuelei, Kneib, Jean-Paul, Li, Yi-Chao, Liao, Yu-Wei, Pen, Ue-Li, Peterson, Jeffrey B, Rossi, Graziano, Schneider, Donald P, Yadav, Jaswant, and Zhao, Gong-Bo
ABSTRACT We present the joint analysis of Neutral Hydrogen (H i) Intensity Mapping observations with three galaxy samples: the Luminous Red Galaxy (LRG) and Emission Line Galaxy (ELG) samples from the eBOSS survey, and the WiggleZ Dark Energy Survey sample. The H i intensity maps are Green Bank Telescope observations of the redshifted $21\rm cm$ emission on $100 \, {\rm deg}^2$ covering the redshift range 0.6 < z < 1.0. We process the data by separating and removing the foregrounds present in the radio frequencies with FastI ICA. We verify the quality of the foreground separation with mock realizations, and construct a transfer function to correct for the effects of foreground removal on the H i signal. We cross-correlate the cleaned H i data with the galaxy samples and study the overall amplitude as well as the scale dependence of the power spectrum. We also qualitatively compare our findings with the predictions by a semianalytical galaxy evolution simulation. The cross-correlations constrain the quantity $\Omega _{\rm {H\,\small {I}}} b_{\rm {H\,\small {I}}} r_{\rm {H\,\small {I}},{\rm opt}}$ at an effective scale keff, where $\Omega _\rm {H\,\small {I}}$ is the H i density fraction, $b_\rm {H\,\small {I}}$ is the H i bias, and $r_{\rm {H\,\small {I}},{\rm opt}}$ the galaxy–hydrogen correlation coefficient, which is dependent on the H i content of the optical galaxy sample. At $k_{\rm eff}=0.31 \, h\,{\rm Mpc^{-1}}$ we find $\Omega _{\rm {H\,\small {I}}} b_{\rm {H\,\small {I}}} r_{\rm {H\,\small {I}},{\rm Wig}} = [0.58 \pm 0.09 \, {\rm (stat) \pm 0.05 \, {\rm (sys)}}] \times 10^{-3}$ for GBT-WiggleZ, $\Omega _{\rm {H\,\small {I}}} b_{\rm {H\,\small {I}}} r_{\rm {H\,\small {I}},{\rm ELG}} = [0.40 \pm 0.09 \, {\rm (stat) \pm 0.04 \, {\rm (sys)}}] \times 10^{-3}$ for GBT-ELG, and $\Omega _{\rm {H\,\small {I}}} b_{\rm {H\,\small {I}}} r_{\rm {H\,\small {I}},{\rm LRG}} = [0.35 \pm 0.08 \, {\rm (stat) \pm 0.03 \, {\rm (s