The Spitzer Space Telescope Benefits of Infrared

z IR can reveal objects that don't emit visible light

z IR provides different information than visible light

z IR is better than visible for viewing cold objects

Addison LeMessurier

Instruments/Components of Spitzer Cryostat

z IR instruments must be kept extremely cold

z Very slight temperature changes z Cryostat – cooling unit for scientific instruments can interfere with z MIC – Multiple Instrument Chamber observations z IRS – Infrared Spectrometer z MIPS – Multi-band Imaging Photometer z IRAC – Infrared Array Camera

Cryostat (continued)‏ Infrared Telescope

z Purpose: keep the z Much smaller than an spacecraft near optical telescope absolute zero z Aperture size of only

z Launched with 360 85 cm liters of liquid helium z Mirrors made of

z The instrument beryllium chamber is inside the z Total weight is less tank than 50kg

1 Telescope Design Telescope Under Construction

z Reduce thermal expansion by using the same materials for almost everything z Use a simple design to minimize the number of parts and lower costs z Use lightweight materials with high stiffness to density ratio

MIC IRAC

z Multiple Instrument z Infrared Array Chamber Camera

z Contains parts of z Takes pictures in near IRAC, IRS and MIPS to mid IR

z Chamber is kept z Multi-purpose, used in extremely cold using many different studies the cryostat

z 84 cm wide, 24 cm high

IRAC (continued)‏

z Contains four 256x256 detectors to image simultaneously at slightly different wavelengths

2 IRS MIPS

z Infrared Spectrograph z Multiband Imaging Photometer z Operates at mid-IR wavelengths z Imaging and spectroscopy at far IR z High and low wavelengths resolution images z Can image at 24, 70 z No moving parts and 160 microns using three separate z Both warm and cold components detector arrays

MIPS (continued)‏ Observing Black Holes with MIPS

z Shares some warm electronics with the IRS instrument

z Sensors are designed to work at -457 F

Origins Evolution of Design

z The concept of an IR space telescope dates z Spitzer was originally back to the early 1970s going to be huge z Originally called SIRTF (Space Shuttle Infrared z Technological Telescope Facility), it was to be an attachment advances and orbital to the shuttle innovations allowed it to carry much less z The success of earlier, simpler satellites led to a more ambitious approach to Spitzer cryogenic coolant than was originally planned

3 Orbital Innovation Launch of Spitzer

z Placed in heliocentric instead of geocentric orbit z Launched aboard a to make cooling easier Delta II from Cape Canaveral z Spitzer avoids large, reflective objects such as Earth and the Moon z August 25, 2003 z Enough solar energy still reaches the panels as z Placed in a long as it stays pointed within 120 degrees of heliocentric, Earth the Sun trailing orbit

Additional Details Some Observations

z Mass: 950 kg z Wavelength: 3 – 180 micrometers z Diameter: 0.85 m z Focal Length: 10.2 m z Orbital Period: 1 Earth year z Drifting away from Earth at: ~0.1 AU/year

4 Some Objects Viewable with Spitzer Planet Finding

z Spitzer is mainly designed for long range z Potential planet observations, similar to Hubble forming regions show up very well in IR z Only minor spectroscopy can be done on most objects within our solar system z Spitzer can also see thermal emissions z The galactic nucleus, star clusters, black holes and distant galaxies are particularly interesting from some distant gas targets giants z Some atmospheric z Circumstellar disks, where planets are believed to form show up nicely in IR measurements have also been done

Water Vapor on an Exoplanet ULIRGs

z In July, 2007 Spitzer z Ultra Luminous Infrared Galaxies found water vapor on z These galaxies emit more than 90% of their an extrasolar gas light in IR giant using IR spectroscopy z Vast clouds of cold interstellar dust are responsible for the low temperature IR z Similar instruments emissions could some day be z Spitzer is therefore a good tool for observing used to find water on these objects Earth-like planets

Star Formation Summary

z The Orion Nebula is z Spitzer is a multi billion dollar space-based shown in visible and infrared observatory IR z Combined with Hubble, Chandra and others, it z Notice how neither has provided very valuable scientific data one highlights z Spitzer has particularly increased everything by itself understanding of extra solar planets, galaxy structure and star formation

5 Bibliography

z www.nasa.gov/spitzer z spitzer.caltech.edu z www.news.cornell.edu/stories/Feb06/ULIRGs.S poon.lg.html

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