SIMBAD references

The intensity mapping of the [Cii] 157.7-µm fine-structure emission line represents an ideal experiment to probe star formation activity in galaxies, especially in those that are too faint to be individually detected. Here, we investigate the feasibility of such an experiment for z > 5 galaxies. We construct the L_C II - M_h relation from observations and simulations, then generate mock [Cii] intensity maps by applying this relation to halo catalogues built from large scale N-body simulations. Maps of the extragalactic far-infrared (FIR) continuum, referred to as `foreground', and CO rotational transition lines and [Ci] fine-structure lines referred to as `contamination', are produced as well. We find that, at 316 GHz (corresponding to z_C II = 5), the mean intensities of the extragalactic FIR continuum, [Cii] signal, all CO lines from J = 1 to 13 and two [Ci] lines are ∼ 3x10⁵, ∼ 1200, ∼ 800, and ∼ 100 Jy/sr, respectively. We discuss a method that allows us to subtract the FIR continuum foreground by removing a spectrally smooth component from each line of sight, and to suppress the CO/[Ci] contamination by discarding pixels that are bright in contamination emission. The z > 5 [Cii] signal comes mainly from haloes in the mass range 10¹¹-12M_☉; as this mass range is narrow, intensity mapping is an ideal experiment to investigate these early galaxies. In principle such signal is accessible to a ground-based telescope with a 6 m aperture, 150-K system temperature, a 128x128 pixels FIR camera in 5000-h total integration time; however, it is difficult to perform such an experiment by using currently available telescopes.