Top Level Science Drivers
(from Larry Ramsey,
HET Project Scientist)
- HET's large collecting area allows acquisition
of many spectra quickly, e.g., surveys.
- The telescope is tailored to spectroscopy.
- Spectroscopy allows study of temperature,
velocity, rotation, and composition.
- Telescopes are largely used for typically
one-hour exposures not too far from zenith; HET's unique design
is well matched to that fact.
- HET's modest image quality goals are well
matched to the median site seeing.
- HET's design is consistent with a survey
mission not requiring exceptional conditions.
- The goal is to maximize science output
for minimal cost in areas where HET can compete.
Conditions for which HET is Most Competitive
(from Larry Ramsey)
- Target classes are uniformly distributed
around the sky.
- Sky surface densities of targets are a
few per square degree or per square arcminute.
- Time-critical phenomena with time scales
of days and longer are of interest.
- The astrophysics of interest can be studied
with visible and near-IR spectroscopy.
- For problems where queue scheduling can
efficiently acquire surveys and temporal data.
Examples of Astronomy Planned for HET
(from Larry Ramsey,
Gary Hill, and Bob Tull)
- planetary searches based on radial velocity
- echo mapping active galactic nuclei
- measuring the interactions of black holes
with their environments
- spectroscopic monitoring of supernovae
with optimal time coverage
- precision abundance determinations for
- using Doppler imaging to study activity
and conditions in stars and accretion disks
- studying stellar populations and evolution
- studying dark matter properties from kinematical
measurements in elliptical galaxies
- measuring the age and dynamical evolution
of the Milky Way from white dwarf stars
- high-speed spectroscopy of X-ray binary
- distance determinations for local galaxies
using blue supergiant stars
- dynamics of galaxies using planetary nubulae
- confirmation of outer halo RR Lyrae candidates
- studies of the fundamental plane in galaxy
clusters at redshifts up to one
- optical identification of flux-limited
X-ray and EUV samples from space missions
- investigations of the intergalactic medium
- studies of stellar nucleosynthesis via
- monitoring G, K, and M stars for solar-like