Abstract
For nearly a century, imaging and spectroscopic surveys of galaxies have
given us information about the contents of the universe. We attempt to define
the logical endpoint of such surveys by defining not the next galaxy survey,
but the final galaxy survey at NIR wavelengths; this would be the galaxy survey
that exhausts the information content useful for addressing extant questions.
Such a survey would require incredible advances in a number of technologies and
the survey details will depend on the as yet poorly constrained properties of
the earliest galaxies. Using an exposure time calculator, we define nominal
surveys for extracting the useful information for three science cases: dark
energy cosmology, galaxy evolution, and supernovae. We define scaling relations
that trade off sky background, telescope aperture, and focal plane size to
allow for a survey of a given depth over a given area. For optimistic
assumptions, a 280m telescope with a marginally resolved focal plane of 20
deg$^2$ operating at L2 could potentially exhaust the cosmological information
content of galaxies in a 10 year survey. For galaxy evolution (making use of
gravitational lensing to magnify the earliest galaxies) and SN, the same
telescope would suffice. We discuss the technological advances needed to
complete the last galaxy survey. While the final galaxy survey remains well
outside of our technical reach today, we present scaling relations that show
how we can progress toward the goal of exhausting the information content
encoded in the shapes, positions, and colors of galaxies.
Users
Please
log in to take part in the discussion (add own reviews or comments).