Spitzer telescope

Using IRAS" data. Jura, 2005 [176] searched for IR-signatures. With the Spitzer telescope the IR excess was measured around first ascent red giants. The data showed that this radiation seems to be caused by interstellar cirrus and not by KBO like objects. If there is any KBO like structure around these stars, then it must be less massive than the Solar System s. 

Fig. 7.7 This plot of infrared data shows the signatures of water vapor and simple organic molecules in the disk of gas and dust surrounding a young star AA Tauri. The star is at a distance of 140 pc. Credit Spitzer Telescope, NASA...

Fig. 3.8. Profiles of interstellar absorption lines observed in the line of sight to the star HD 93521 with the Goddard high resolution spectrograph at the Hubble Space Telescope. Solid lines are theoretical profiles based on cloud velocities indicated by the tick marks at the top dots indicate the data points. After Spitzer and Fitzpatrick (1993). Courtesy Ed Fitzpatrick.

Observations of near-infrared excess emission from hundreds of disks with ages covering the first 10 Myr demonstrate fundamental structural evolution and the eventual loss of the fine dust from the inner disk (< 1AU). The declining fraction of stars with dust disks suggests a disk half-life of 3 to 5 Myr (see Chapter 9, e.g. Hernandez et al. 2007). Longer-wavelength infrared observations, primarily from the Spitzer Space Telescope, show a similar picture for the intermediate disk radii (1-5 AU). The combination of these lines of evidence is interpreted as a rapid (< 1-3 Myr) dispersal of the fine dust in most systems, probably progressing inside-out. 

The recent detection of the [Nell] line emission at 12.81 pm from several disks by the Spitzer Space Telescope (e.g. Pascucci et al. 2007) has confirmed theoretical predictions that the disk atmosphere is heavily ionized and superheated, either by X-rays (Glassgold et al. 2007) or by extreme UV irradiation (Pascucci et al. 2007). However, X-rays and cosmic-ray particles (CRPs) may not be able to penetrate further toward the mid-plane of the planet-forming disk zone (r 3-20 AU), which makes the mid-plane essentially neutral and thus stable against accretion ( Dead Zone Gammie 1996 Dolginov Stepinski 1994). 

The superior sensitivity of the Spitzer Space Telescope also opened a new window to the study of silicate emission features around cool stars - too faint to be studied by other instruments. With typical luminosities of 1% and masses of 5% of... 

The sensitivity of the Infrared Array Camera (IRAC) camera on board the Spitzer Space Telescope (Fazio et al. 2004) recently allowed to characterize in detail the decrease in disk frequency with stellar age and trace dust slightly cooler than that observed in the L-band, out to about 1AU from T Tauri stars. Figure 9.2 shows the fraction of T Tauri stars (mostly K and M stars) with infrared excess at IRAC wavelengths (3.6, 4.5, 5.8, and 8 pm, full circles). In addition to the data (and references) presented in Hernandez et al. (2008) we have included the disk statistics... 

IRAC Infrared Array Camera, the short-wavelength (3-8 pm) imaging instrument on board the Spitzer Space Telescope. 

Spitzer Space Telescope a cryogenically cooled infrared space telescope on a thermally stable Earth-trailing orbit operated by NASA. The telescope has very sensitive imaging capabilities with the IRAC (3 to 8 pm) and MIPS (24— 160 pm) cameras as well as spectroscopic capability with the IRS instrument (5-40 pm). 

This book is the first comprehensive overview of planet formation, in which astronomers, cosmochemists, and laboratory astrophysicists jointly discuss the latest insights from the Spitzer and Hubble space telescopes, new interferometers, space missions including Stardust and Deep Impact, and laboratory techniques. Following the evolution of solids from their genesis through protoplanetary disks to rocky planets, the book discusses in detail how the latest results from these disciplines fit into a coherent picture. This volume provides a clear introduction and valuable reference for students and researchers in astronomy, cosmochemistry, laboratory astrophysics, and planetary sciences. 

RECENT RESULTS FROM THE SPITZER SPACE TELESCOPE A NEW VIEW OF THE INFRARED UNIVERSE... 

The following sections will describe the Spitzer Space Telescope and its three focal plane instruments and present a sample of the spectacular images and scientific results that have been produced. 

NASA s Infrared Astronomy Satellite (IRAS), which was launched in 1985, consisted of a liquid-helium cooled telescope (60-cm mirror) and produced the first all-sky maps of the infrared universe at 25, 60, and 100 pm wavelength. IRAS was followed in 1996 with another cooled telescope in space, the Infrared Satellite Observatory (ISO), an ESA mission, which was a true observatory that could carry out follow-up observations of the IRAS sources. In 2003, NASA s Spitzer Space Telescope, with an 85-cm mirror, achieved major advances in sensitivity, image quality and field-of-view over ISO. Although its mirror was only slightly larger than ISO s 60-cm mirror, the use of new, sensitive, and large-area infrared array detectors has permitted this new view of the infrared universe. 

Figure 2. Artist s conception of the Spitzer Space Telescope in earth-trailing solar orbit.

The Spitzer Space Telescope is managed by JPL for NASA. Science operations are conducted at the Spitzer Science Center at Caltech, Pasadena, CA. 

Addihonal information on the Spitzer Space Telescope and its instruments can be found at the Spitzer Science Center (SSC) web site.1... 

The data were taken with the Infrared Array Camera (IRAC Fazio et al. 2004) on the Spitzer Space Telescope during the hrst five IRAC campaigns of normal operations (2003 December - 2004 April). 

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