Monster redshift surveys through dispersive slitless imaging: the Baryon Oscillation Probe

Wide-field imaging from space should not forget the dispersive dimension. We consider the capability of space-based imaging with a slitless grism: because of the low near-infrared background in space and the high sky-density of high redshift emission line galaxies this makes for a very powerful redshift machine with no moving parts. A small 1m space telescope with a 0.5 degree field of view could measure redshifts for 10 7 galaxies at 0.5 < z < 2 per year, this is a MIDEX class concept which we have dubbed ‘The Baryon Oscillation Probe’ as the primary science case would be constraining dark energy evolution via measurement of the baryonic oscillations in the galaxy power spectrum. These ideas are generalizable to other missions such as SNAP and DESTINY.