Destiny: The Dark Energy Space Telescope
Tod Lauer
National Optical Astronomy Observatory
lauer@noao.edu
Additional authors: Tod R. Lauer (NOAO)
We describe a mission concept for a 2-meter class near-infrared (NIR) grism-mode space telescope optimized to return richly sampled Hubble diagrams of Type Ia and Type II supernovae (SNe) over the redshift range 0.5 < z < 1.7$ for determining cosmological distances, measuring the expansion rate of the Universe as a function of time, and characterizing the nature of dark energy. The central concept for our proposed Dark Energy Space Telescope (DESTINY) is an all-grism NIR survey camera. SNe will be discovered by repeated imaging of an area located at the north ecliptic pole. Grism spectra with resolving power R=75 will provide broad-band spectrophotometry, redshifts, SNe classification, as well as valuable time-resolved diagnostic data for understanding the SN explosion physics. Our approach features only a single observing mode with no time-critical operations, a single detector technology, and a single instrument. Although grism spectroscopy is slow compared to SN detection in any single broad-band filter for photometry, or to conventional slit spectra for spectral diagnostics, the multiplex advantage of observing a large field-of-view over a full octave in wavelength simultaneously makes this approach highly competitive.
