Mashian, NatalieLoeb, AbrahamSternberg, Amiel2017-05-312016Mashian, Natalie, Abraham Loeb, and Amiel Sternberg. 2016. “Spectral Distortion of the CMB by the Cumulative CO Emission from Galaxies Throughout Cosmic History.” Monthly Notices of the Royal Astronomical Society: Letters 458 (1) (February 17): L99–L103. doi:10.1093/mnrasl/slw027.1745-3925http://nrs.harvard.edu/urn-3:HUL.InstRepos:32750962We show that the cumulative CO emission from galaxies throughout cosmic history distorts the spectrum of the cosmic microwave background (CMB) at a level that is well above the detection limit of future instruments, such as the Primordial Inflation Explorer (PIXIE). The modeled CO signal has a prominent bump in the frequency interval 100-200 GHz, with a characteristic peak intensity of ~ 2×10−23 W m−2 Hz−1 sr−1. Most of the CO foreground originates from modest redshifts, z ~ 2-5, and needs to be efficiently removed for more subtle distortions from the earlier universe to be detected.en-UScosmology: cosmic background radiationcosmology: theory, early universegalaxies: intergalactic mediumJournal Article2017-02-1420162017-05-3110.1093/mnrasl/slw027