November 28, 2009

Herschel’s Splendid Spectra

Herschel spectroscopy took center stage yesterday as new spectra, obtained with the SPIRE, PACS and HIFI instruments during the performance verification phase, were released by ESA and the instrument teams. Taken together with earlier images the observatory is now on the way to demonstrating that the promised imaging and spectroscopic capabilities are being met.

Since its launch in May this year the teams working on the Herschel Space Observatory have made steady progress as they prepare to hand over the observatory to the world's astronomical community.

Early reports on the mission focused on stunning images from the two cameras onboard.

Yesterday, the three Herschel spectrometers took center stage, as new spectra were released. In contrast to images that reveal the distribution of light across the field of view, spectra provide an astronomical fingerprint of the objects being studied. Detailed analyses of these spectra provide insight into the physical and chemical composition of the objects. 

The newly issued Herschel spectra, obtained with the SPIRE Fourier Transform Spectrometer, the PACS integral field spectrometer, and the HIFI heterodyne instrument touch on a number of key science goals for the mission and are an early demonstration of the capabilities of the observatory.

A broad spectrum of objects have been observed, including comets, massive stars, star-forming regions, and a variety of galaxies.

Fabulously detailed spectra reveal forests of emission lines and signatures of elements, some detected for the first time.

Since launch on May 14 this year, the Herschel Space Observatory has been subjected to a rigorous series of tests and preparatory activities leading to a fully operational observatory. Early emphasis was placed on performing observations with the SPIRE and PACS imaging photometers as this also provided the opportunity to test the optics and pointing characteristics of the telescope. With the confirmation provided by these observations of the excellent quality of the Herschel telescope, the way was cleared to include all three spectrometers in the regular operations planning.

The SPIRE and PACS instruments are now nearing the end of the science demonstration phase and will soon be entering routine operations phase.

During the performance verification phase the HIFI instrument suffered a setback which required it to be put into temporary hibernation while the nature of the problem was investigated and a solution found. A plan of action leading to HIFI full operations in January has been provisionally agreed.

Forthcoming workshop and symposium

Results from the science demonstration phase will be presented to the community at a dedicated workshop to be held at the European Space Astronomy Center, Spain, from December 17-18, 2009. A symposium dedicated to the first science results from Herschel will be held the European Space Research and Technology Center, in the Netherlands, from May 3-7, 2010.


Image 1: Messier 82. Composite of Chandra, HST and Spitzer images. X-ray data recorded by Chandra appears in blue; infrared light recorded by Spitzer appears in red; Hubble's observations of hydrogen emission appear in orange, and the bluest visible light appears in yellow-green. Credit: NASA/JPL-Caltech/STScI/CXC/UofA/ESA/AURA/JHU

Image 2: PACS spectrum of Messier 82. Credit: ESA & the PACS consortium; background: NASA/ESA/STScI/AURA/The Hubble Heritage Team


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