Max Planck Institute for Astronomy - Annual Report 2007

edshifts z 2, that is, to a look-back time of 10 billion
years, thereby covering the entire period over which
dark energy played a significant role in accelerating the
expansion of the Universe. The observing strategy of
eu c L i D will be based on baryonic acoustic oscillations
measurements and weak gravitational lensing, two complementary
methods to probe dark energy. The Euclid
survey will produce 20,000 deg² visible and near-infrared
images of the extra-galactic sky at a spatial resolution of
0.3. It will also yield medium resolution (R 400) spectra
of about a third of all galaxies brighter than 22 mag in
the same survey area.
PL at o (PLAnetary Transits and Oscillations of stars)
is another esa Cosmic Visions mission. Its primary goal
is to provide the basis for statistical analyses of exoplanetary
systems around stars that are bright and nearby
enough to allow for simultaneous and/or later detailed
studies of their host stars. PL aT o will observe 100,000
stars with a photometric precision better than 1ppm/
month of observing and more than 500,000 stars to somewhat
less precision. Seismic analysis will lead to the determination
of stellar and planetary masses with up to
1 percent precision, and the detection of Earth-size plan-
I.2 Observatories, Telescopes, and Instruments 15
ets, with age determinations to within several 100 million
years. PL aT o will provide a very wide field of view (557
square degrees). The required short focal length led to the
concept of a bundle of 28 identical small telescopes each
of which has a collecting area of 0.01 m².
sP i c a, the Space Infrared Telescope for Cosmology
and Astrophysics, is the third astronomy mission of
esa’s Cosmic Vision, where MPIA is participating in
the study phase. The mission is planned to be the next
space astronomy mission observing in the far infrared after
he r s c h e L. The mission is planned to be launched in
2017 and will feature a cold 3.5 m telescope. This large
cold aperture will provide two orders of magnitude sensitivity
advantage over current far-infrared facilities like
he r s c h e L. sP i c a is led by the Japanese Space Agency
Ja x a. Europe will participate with the Spica Far Infrared
Instrument sa fa r i, the telescope mirror, and support to
the ground segment.
Figure I.7 gives an overview of the major instruments
which are already working or are about to be put into operation.
Sensitivity is shown as a function of wavelength
(left), and spatial resolution as a function of the size of
the field of view (right).