Herschel Space Observatory

In summary, current observations indicate that most circumstellar gas mass disperses quickly on a timescale similar to (or maybe even shorter than) the dustclearing timescale. Significant progress in this field is expected to occur in the next years with the launch of the Herschel Space Observatory. In particular, the... 

NASA s Spitzer space telescope (Werner et al. 2004), and more recently ESA s Herschel space observatory, both provide large area survey atlases across this FIR wavelength range. However, for most science cases, neither telescope has sufficient angular resolution to probe individual targets of interest in detail, and thereby study the physical processes which govern these sources. 

J. Fischer, T. Klaassen, N. Hovenier, G. Jtikob, A. Poglitsch, O. Sternberg, Cryogenic far-infrared laser absorptivity measurements of the herschel space observatory telescope mirror coatings. Appl. Opt. 43(19), 3765-3771 (2004). doi 10.1364/A0.43.003765. http //ao.osa.oig/abstract. cfm URI=ao-43-19-3765... 

After the recent successes of the far-IR missions IRAS, ISO and the Herschel Space Observatory, the era of space interferometry beckons. Indeed interferometry is indicated as the way forward in many fields and at all wavelengths with far-infrared having the possibility of leading the way, thanks to the reduced metrology requirements. Interferometry in space is on the other hand extremely challenging and many attempts to jump-start studies and mission concepts have proven in many cases ahead of their time or in dire need of technology development to raise the feasibility of the proposed concepts. 

Fig. 2.9 Subset of the full spectral survey of the Orion-KL region performed with the Herschel space observatory. The first panel shows the frequency coverage with two successive zooms on a small subset of the data, where the carriers of the strongest lines are identified. In the bottom panel, all lines with numbers ranging from 1 to 27 are produced by CH3OH. The second panel shows a collection of lines from HDO and HD 0. The line profile is fitted with four separate spectral components, corresponding to four spatially distinct sources of emission, that are too close to be spatially separated at the moderate angular resolution allowed by Herschel [57]...

Both reactions occur in star forming regions. These reaction take place in star and planet forming gas irradiated by far UV or X-rays. The forth form of water has been detected outside the solar system by the satellite mission Herschel Space Observatory with the HIFI instrument (a high resolution spectrometer for the far IR).6 For example Bonev et al., 2002 [37] measured H2O+ in the plasma tails of comets at a wavelength of 615.886 nm. Further earlier observations of H2O+ in other comets (e.g. Halley s comet) are given in that paper. 

On the last three decades, several space experiments with parts at very low temperatures have been flown. Among these, we mention IRAS (Infrared Astronomical Satellite) launched in 1983 (see Fig. 14.1), COBE (Cosmic Background Explorer) launched in 1989, ISO (Infrared Space Observatory) launched in 1995 and Astro-E (X-ray Observatory), launched in 2000 with instrumentation at 65 mK [35], Some cryogenic space missions are in the preparation or in final phase in Europe, USA and Japan. For example, ESA is going to fly Planck (for the mapping of the cosmic background radiation) and Herschel (called before FIRST Far Infrared and Submillimetre Telescope ) [36], These missions will carry experiments at 0.1 and 0.3 K respectively. 

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