The contribution of star-forming galaxies to fluctuations in the cosmic background light

Understand

Star-forming galaxies which are too faint to be detected individually produce intensity fluctuations in the cosmic background light.

• This contribution needs to be taken into account as a foreground when using the primordial signal to constrain cosmological parameters.
• The extragalactic fluctuations are also interesting in their own right as they depend on the star formation history of the Universe and the way in which this connects with the formation of cosmic structure.
• We present a new framework which allows us to predict the occupation of dark matter haloes by star-forming galaxies and uses this information, in conjunction with an N-body simulation of structure formation, to predict the power spectrum of intensity fluctuations in the infrared background.