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arXiv · 1610.09060

Intensity mapping of H-alpha, H-beta, [OII] and [OIII] lines at z<5

Yan Gong·Asantha Cooray·Marta B. Silva·Michael Zemcov·Chang Feng·Mario G. Santos·Olivier Dore·Xuelei Chen
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Abstract

Intensity mapping is now becoming a useful tool to study the large-scale structure of the universe through spatial variations in the integrated emission from galaxies and the intergalactic medium. We study intensity mapping of the H-alpha 6563AA, [OIII]5007AA, [OII]3727AA and H-beta 4861AA lines at 0.8<z<5.2. The mean intensities of these four emission lines are estimated using the observed luminosity functions (LFs), cosmological simulations, and the star formation rate density (SFRD) derived from observations at z<5. We calculate the intensity power spectra and consider the foreground contamination of other lines at lower redshifts. We use the proposed NASA small explorer SPHEREx (the Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer) as a case study for the detectability of the intensity power spectra of the four emission lines. We also investigate the cross correlation with the 21-cm line probed by CHIME (the Canadian Hydrogen Intensity Mapping Experiment), Tianlai experiment and SKA (the Square Kilometer Array) at 0.8<z<2.4. We find both the auto and cross power spectra can be well measured for the H-alpha, [OIII] and [OII] lines at z<3, while it is more challenging for the H-beta line. Finally, we estimate the constraint on the SFRD from intensity mapping, and find we can reach accuracy higher than 7% at z<4, which is better than usual measurements using the LFs of galaxies.

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Yan Gong, Asantha Cooray, Marta B. Silva, Michael Zemcov, Chang Feng, Mario G. Santos, Olivier Dore, Xuelei Chen. 2016-10-28. Intensity mapping of H-alpha, H-beta, [OII] and [OIII] lines at z<5. https://doi.org/10.3847/1538-4357/835/2/273

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