JELT is expect to take advantage its large primary mirror diameter to perform :
high-resolution imaging using adaptive optics (AO),
and high-dispersion spectroscopy on faint objects.
JELT is also anticipated to play a complementary role in next-generation
space missions such as James Webb Space Telescope (JWST) and
Space Infrared Telescope for Cosmology and Astrophysics (SPICA) projects,
which will perform wide-field surveys in infrared wavelength.
Scientific goals for JELT are briefly presented here based on current research
trends and future planning.
It should be noted that topics presented here are just a part of
achievement realized with capability of JELT.
Historically, such observational innovation has always brought with
it unexpected new discoveries, suggesting that JELT may discover
completely unknown classes of objects.
Frontiers of science will also be expanded during construction of JELT,
and new research targets are expected to emerge.
The context in which construction of the 8-10m telescopes took
place in the 1980s and '90s can be readily seen in science cases proposed
in the blue-book for Subaru Telescope :
Determination of cosmological parameters
- Loh & Spillar test
- Hubble Diagram
- SN Ia and q0
- θ-z relation
Search for dark matter
- M/L in cluster of galaxies
- Large-scale structure at high redshifts
Birth and evolution of galaxies
- Discovery of protogalaxies (Lyα emitters, QSO absorbers)
- Origin of the Hubble sequence
- Structure of the galaxy and its evolution
Formation of stars and planetary systems
- Distribution of interstellar medium and its characteristics
- Origin of dust and its characteristics
- Molecular clouds
- Formation and evolution of protoplanetary disks
- Discovery of extra-solar planets
- Characteristics of protostars
- Connection between starburst and AGNs
- Solar planets
- Organic systems in space and origins of life
- Birth and evolution of AGNs
- Structure of AGNs
- Measurement of cosmological parameters using gravitational lensing
Stellar evolution and nucleosynthesis
- Search for population III stars
- Nucleosynthesis of supernovae
- Stellar seismology
While active research continues in most of the areas shown above,
there has been substantial progress in a range of new areas
that were not conceived in the design of the 8m-class telescopes.
For example, no high-redshift populations such as Lyman Break galaxies,
extremely red objects, and submillimeter galaxies had yet been discovered,
nor had gamma ray bursts. Little was known about an early history of the universe,
and of course, there had been no sign of dark energy.
The relationship between mass of supermassive black holes
at the center of galaxies and bulge mass was also unknown,
and extra-solar planets had not been detected.
Nobody dreamed of heteromorphous planets such as hot Jupiters.
Even in the solar neighborhood, the existence of outer-rim objects
such as Edgeworth Kuiper Belt Objects was not expected.