The
European Space Agency's Herschel telescope is up and running, with its first
observations revealing water and carbon as well as dozens of distant galaxies.
The new
space telescope, which launched on May 14 with its sibling Planck, has now
carried out its first test observations with all of its instruments.
Herschel is
the largest, most
powerful infrared telescope ever launched into space. Its observations in
the far-infrared to sub-millimeter wavelengths of light will allow astronomers
to study some of the coldest objects in space, not visible in other wavelengths.
Herschel
took a "sneak preview" image of the distant galaxy M51 in June in an
early attempt to demonstrate that its camera eye works. In particular, scientists
wanted to be sure the telescope is focused and correctly aligned with the
science instruments
While
Herschel was making its test observations, Planck cooled
its instruments down to their operational temperature of minus 459.49
degrees Fahrenheit (minus 273.05 Celsius). This temperature is just 0.1 Celsius
above absolute zero, the coldest temperature theoretically possible in our
universe.
On June 24,
Herschel's Spectral and Photometric Imaging Receiver (SPIRE) was trained on two
galaxies for its first look at the Universe. The galaxies showed up
prominently, providing astronomers with their best images yet at these
wavelengths, and revealing other, more distant galaxies in the background of
the images.
The
pictures show galaxies M66 and M74 at a wavelength of 250 microns, longer than
any previous infrared space observatory, but still the shortest SPIRE
wavelength.
SPIRE is
designed to look at star formation in our own Milky Way galaxy and in nearby
galaxies, but it will also search for star-forming galaxies in the very distant
universe.
"These
quick first light observations have produced dramatic results when we consider
that they were made on day one," said SPIRE Principal Investigator Matt
Griffin of Cardiff University of Wales.
Scientists
used Herschel's Heterodyne Instrument for the Far-Infrared (HIFI) on June 22 to
look for warm molecular gas heated by newborn massive stars in the DR21
star-forming region in the constellation Cygnus, or the Swan.
It works by
zooming in on specific wavelengths, revealing the spectral fingerprints of
atoms and molecules and even the physical conditions of the object observed.
This makes it a powerful tool to study the role of gas and dust in the
formation of stars and planets and the evolution of galaxies.
Herschel
observed ionized carbon, carbon monoxide, and water in DR21.
The first
observation with Herschel's Photodetector Array Camera and Spectrometer (PACS)
instrument was carried out on June 23. It targeted a dying star known as the
Cat's Eye Nebula. Discovered by William Herschel in 1786, this nebula consists
of a complex shell of gas thrown off by a dying star.
With the
PACS spectrometer it is possible for the first time to take images in spectral
lines and see how the wind from the star shapes the nebula in three dimensions.
Following
these images, Herschel is now in the performance verification phase, where the
instruments will be further tested and calibrated. This phase will last until
the end of November, after which the mission will begin its routine science
phase.
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