Europe plays a leading role in astronomical discovery
Have you ever wondered where galaxies come from? Well, you
are not the only one: scientists now believe that one of the fundamental questions
of cosmology can be answered within the next ten years, or even sooner. This
will require an international effort as some of the observations must be taken
from space, beyond the interference of the earth’s atmosphere. Europe will
play a key role, with three new instruments, including the EUR 1 billion Herschel
Space Observatory (HSO). The European Science Foundation (ESF) has brought
together many of the principle users of these facilities at an international
conference, including leading specialists in all aspects of galaxy and star
Previous observations have been obscured by clouds of interstellar dust.
Previous observations of galaxy formation from optical telescopes have been hampered
by clouds of interstellar dust that absorb visible light. However, the dust re-emits
this visible light absorbed from galaxies at longer wavelengths, and the latest
instruments are now sensitive enough to detect it and unravel the processes being
studied, as Eelco van Kampen, chair of the ESF Research Conference 'The
Origin of Galaxies: Exploring Galaxy Evolution with the New Generation of Infrared-Millimetre
Facilities', underlined. ‘The main reason for a new golden age is the sheer
number of new instruments that will become available over the next few years,
literally opening up the universe in the far-infrared to millimetre wavelengths,’ stated
Dr van Kampen.
Although galaxy formation can be observed indirectly (with the radiation emitted from dust obscuring a direct view), the latest generation of telescopes can span a broader spectrum of wavelengths. This is vital for understanding the many processes and chemical elements involved, which can only be identified via the radiation they emit across multiple wavelengths, rather than their intensity at a particular point of the spectrum, or single ‘colour’.
The main advantage is that the entire ‘spectral energy distribution’ (SED) can
be mapped for each source, allowing astronomers to measure emissions from specific
molecules and ‘colours’ as well as total luminosity. ‘From the SED one can derive
many properties of the sources, including temperatures and composition,’ says
Dr van Kampen. Scientists are now confident that dramatic progress will be made,
and eagerly await new discoveries. As Eelco van Kampden likes to point out, ‘There
will be many surprises, as this is still a relatively uncharted wavelength range’.
Apart from the Herschel Space Observatory, Europe is also contributing towards two other instruments used as part of the international observing effort. These are SCUBA-2, which is a wide-field camera for the James Clerk Maxwell Telescope (JCMT) on Mauna Kea, Hawaii, and the Atacama Large Millimetre Array (ALMA), 16,400 feet up in the Andes Mountains of Chile.