Andrew Yee
February 21st 06, 06:55 PM
ESA News
http://www.esa.int
14 Feb 2006
Cosmic Vision 2015 - 2025: The Universe
Theme 4 -- How did the Universe originate and what is it made of?
Since antiquity, the Earth's inhabitants have observed the sky with
curiosity and perspicacity, taking advantage of technological progress to
help understand what the Universe is made of. Our present knowledge is the
result of centuries of continuous cross-fertilisation between astronomical
observations and theoretical constructions.
Successive steps have taken mankind closer and closer to comprehending the
complexity, origin and evolution of the Universe: by recognising that we
live in a planetary system and that the Earth is orbiting the Sun; by
establishing that the Sun is embedded in a spiral galaxy, far from its
centre; by demonstrating that the Universe is expanding and later
discovering that this expansion is accelerating; and realising from
dynamic evidence that most of the matter in the Universe is in an unknown
form, called dark matter.
4.1 The early Universe
Astronomers have found strong evidence that the Universe underwent a
period of very strongly accelerated expansion a split-second after the Big
Bang, known as inflation. But probably the biggest surprise to astronomers
in the past decade has been the discovery that the current Universe has
entered another period of acceleration, albeit at a much slower pace. The
gravitational effect that would normally attract galaxies to each other is
being overwhelmed by an apparent repulsion driving galaxies apart faster
and faster.
Goals
1. Investigate the nature and origin of the Dark Energy that is
accelerating the expansion of the Universe
2. Investigate the physical processes that led to a phase of drastic
expansion in the early Universe
3. Directly detect gravitational waves from the first moments of the Big
Bang (This means operating in a new frequency window: 0.1-1.0 Hz)
Concepts
1. Gravitational lensing by cosmic large-scale structures, and the
luminosity-redshift relation of distant supernovae are the clues to the
nature of the Dark Energy
2. Gravitational waves from the Big Bang should leave imprints of
inflation in polarisation of the cosmic microwave background
Mission Scenarios
1. Wide-field optical-infrared imager
2. All-sky mapper for polarisation of cosmic microwave background
3. Gravitational wave cosmic surveyor
4.2 The Universe taking shape
Tracing cosmic history back to the time when the first luminous sources
ignited, thus ending the dark ages of the Universe, has just begun. At
that epoch the intergalactic medium was reionised, while large-scale
structures increased in complexity, leading to galaxies and their
supermassive black holes.
Goals
1. Find the very first gravitationally-bound structures that were
assembled in the Universe -- precursors to today's galaxies, groups and
clusters of galaxies -- and trace the subsequent co-evolution of galaxies
and super-massive black holes
2. Resolve the far-infrared background into discrete sources, and the
star-formation activity hidden by dust absorption
Mission Scenarios
1. Large-aperture X-ray observatory
2. Far-infrared observatory
4.3 The evolving violent Universe
Nature offers astrophysicists the possibility of observing objects under
much more extreme conditions, in terms of gravity, density and
temperature, than anything feasible on Earth. On the one hand, black holes
and neutron stars are unique laboratories where the laws of physics can be
probed under these extreme conditions. On the other hand, the same objects
were the driving engines of the birth and evolution of galaxies, of the
creation of heavy elements such as iron, and more generally, of the
transformation of the primordial hydrogen and helium from which stars and
galaxies were first being formed.
Goals
1. Trace the formation and evolution of the super-massive black holes at
galactic centres -- in relation to galaxy and star formation -- and trace
the life cycles of chemical elements through cosmic history
2. Examine the accretion process of matter falling into black holes by the
spectral and time variability of X-rays and gamma-rays, and look for clues
to the processes at work in gamma-ray bursts
3. Understand in detail the history of supernovae in our Galaxy and in the
Local Group of galaxies
Mission Scenarios
1. Large-aperture X-ray observatory
2. Gamma-ray imaging observatory
For further information please contact:
SEE ALSO:
* Cosmic Vision 2015-2025: Planets and Life
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=38646
* Cosmic Vision 2015-2025: The Solar System
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=38656
* Cosmic Vision 2015-2025: Fundamental Laws
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=38657
RELATED PUBLICATIONS
* ESA BR-247: Cosmic Vision - Space Science for Europe 2015-2025
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=38542
http://www.esa.int
14 Feb 2006
Cosmic Vision 2015 - 2025: The Universe
Theme 4 -- How did the Universe originate and what is it made of?
Since antiquity, the Earth's inhabitants have observed the sky with
curiosity and perspicacity, taking advantage of technological progress to
help understand what the Universe is made of. Our present knowledge is the
result of centuries of continuous cross-fertilisation between astronomical
observations and theoretical constructions.
Successive steps have taken mankind closer and closer to comprehending the
complexity, origin and evolution of the Universe: by recognising that we
live in a planetary system and that the Earth is orbiting the Sun; by
establishing that the Sun is embedded in a spiral galaxy, far from its
centre; by demonstrating that the Universe is expanding and later
discovering that this expansion is accelerating; and realising from
dynamic evidence that most of the matter in the Universe is in an unknown
form, called dark matter.
4.1 The early Universe
Astronomers have found strong evidence that the Universe underwent a
period of very strongly accelerated expansion a split-second after the Big
Bang, known as inflation. But probably the biggest surprise to astronomers
in the past decade has been the discovery that the current Universe has
entered another period of acceleration, albeit at a much slower pace. The
gravitational effect that would normally attract galaxies to each other is
being overwhelmed by an apparent repulsion driving galaxies apart faster
and faster.
Goals
1. Investigate the nature and origin of the Dark Energy that is
accelerating the expansion of the Universe
2. Investigate the physical processes that led to a phase of drastic
expansion in the early Universe
3. Directly detect gravitational waves from the first moments of the Big
Bang (This means operating in a new frequency window: 0.1-1.0 Hz)
Concepts
1. Gravitational lensing by cosmic large-scale structures, and the
luminosity-redshift relation of distant supernovae are the clues to the
nature of the Dark Energy
2. Gravitational waves from the Big Bang should leave imprints of
inflation in polarisation of the cosmic microwave background
Mission Scenarios
1. Wide-field optical-infrared imager
2. All-sky mapper for polarisation of cosmic microwave background
3. Gravitational wave cosmic surveyor
4.2 The Universe taking shape
Tracing cosmic history back to the time when the first luminous sources
ignited, thus ending the dark ages of the Universe, has just begun. At
that epoch the intergalactic medium was reionised, while large-scale
structures increased in complexity, leading to galaxies and their
supermassive black holes.
Goals
1. Find the very first gravitationally-bound structures that were
assembled in the Universe -- precursors to today's galaxies, groups and
clusters of galaxies -- and trace the subsequent co-evolution of galaxies
and super-massive black holes
2. Resolve the far-infrared background into discrete sources, and the
star-formation activity hidden by dust absorption
Mission Scenarios
1. Large-aperture X-ray observatory
2. Far-infrared observatory
4.3 The evolving violent Universe
Nature offers astrophysicists the possibility of observing objects under
much more extreme conditions, in terms of gravity, density and
temperature, than anything feasible on Earth. On the one hand, black holes
and neutron stars are unique laboratories where the laws of physics can be
probed under these extreme conditions. On the other hand, the same objects
were the driving engines of the birth and evolution of galaxies, of the
creation of heavy elements such as iron, and more generally, of the
transformation of the primordial hydrogen and helium from which stars and
galaxies were first being formed.
Goals
1. Trace the formation and evolution of the super-massive black holes at
galactic centres -- in relation to galaxy and star formation -- and trace
the life cycles of chemical elements through cosmic history
2. Examine the accretion process of matter falling into black holes by the
spectral and time variability of X-rays and gamma-rays, and look for clues
to the processes at work in gamma-ray bursts
3. Understand in detail the history of supernovae in our Galaxy and in the
Local Group of galaxies
Mission Scenarios
1. Large-aperture X-ray observatory
2. Gamma-ray imaging observatory
For further information please contact:
SEE ALSO:
* Cosmic Vision 2015-2025: Planets and Life
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=38646
* Cosmic Vision 2015-2025: The Solar System
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=38656
* Cosmic Vision 2015-2025: Fundamental Laws
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=38657
RELATED PUBLICATIONS
* ESA BR-247: Cosmic Vision - Space Science for Europe 2015-2025
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=38542