The Universe in the Infrared
What is the Spitzer Space Telescope, and how does it work?
Funded by NASA’s Spitzer Science Center
Images courtesy NASA/JPL - Caltech
Pilachowski / August 2005
The Universe in the Infrared
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Outline
NASA’s Great ObservatoriesIntroducing SpitzerSpitzer’s LaunchOrbitNaming SpitzerThe TelescopeInstrumentsFuture IR Telescopes
Pilachowski / August 2005
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NASA’s Great Observatories
Spitzer is the final spacecraft in NASA's Great Observatories program
HST 1990
Compton GRO 1991
Chandra 1999
Pilachowski / August 2005
The Universe in the Infrared
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Introducing Spitzer
The Spitzer Space Telescope is a cryogenically cooled, infrared observatory in space.
Spitzer can study objects ranging from our Solar System to the distant reaches of the Universe.
Pilachowski / August 2005
The Universe in the Infrared
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Launch
• Launched from KSC on25 August 2003
• Lifetime:2.5 years (minimum); 5+ years (goal)
Pilachowski / August 2005
The Universe in the Infrared
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Heliocentric Orbit
• Most space telescopes orbit the Earth
• Spitzer orbits the Sun - trailing the Earth as it moves around the Sun
• Spitzer is receding from Earth at 9.3 million miles (15 million kilometers) per year
• Spitzer now trails the Earth in its orbit by about 20 million miles (~ 32 million kilometers)
• By 2008, Spitzer will be about 56 million miles or 90 million kilometers away
Pilachowski / August 2005
The Universe in the Infrared
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Named for Lyman Spitzer
Lyman Spitzer was the driving force behind HST
Founded the study of the interstellar medium
Studied interstellar dust and star formation
Pilachowski / August 2005
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Introducing the Telescope
Pilachowski / August 2005
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Spitzer Specs
Mirror:85 cm (33.5”) diameterlightweight beryllium f/12 curvature
Weight: Telescope: 851.5 kgHe cryogen: 50.4 kgN propellent: 15.6 kg
Pilachowski / August 2005
The Universe in the Infrared
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Keeping Spitzer Cold
• Telescope operates at 5.5 K
• Why? - Spitzer is itself a black body radiator, and must be colder than the astronomical sources it detects
• How?– Heliocentric orbit– Solar shield/solar cells– Outer shell insulates
and cools the telescope
Pilachowski / August 2005
The Universe in the Infrared
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Keeping Spitzer’s Instruments Even Colder
A tank of liquid helium is used to keep Spitzer’s instruments and detectors at 1.5 K
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Spitzer’s Instruments
• IRAC – InfraRed Array Camera– images at 3.6, 4.5, 5.8, and 8 m
• IRS – InfraRed Spectrograph– mid-IR spectroscopy
• MIPS – Multiband Imaging Photometer for Spitzer– images at 24, 70, and 160 m
IRS
MIPS IRAC
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The Universe in the Infrared
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InfraRed Array Camera (IRAC)
• Built at the Smithsonian Astrophysical Observatory
• Simultaneous images in four IR passbands
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InfraRed Spectrometer
• Built at Cornell University• Spectroscopy in the mid-IR
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The Universe in the Infrared
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Multiband Imaging Photometer for Spitzer (MIPS)
• Three detector arrays– 128x128 pixel Si:As for 24 mm– 32x32 pixel Ge:Ga for 70 mm– 2x20 pixel Ge:Ga for 160 mm
Built at the University of Arizona
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Spitzer Focal Plane
Spitzer instruments are arranged in fixed locations on the Spitzer focal planeThe telescope is rotated to move a particular science target to the right position for the instrument to be usedOther instruments record data for “serendipitous” fields
Pilachowski / August 2005
The Universe in the Infrared
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Spitzer Operations
www.spitzer.caltech.edu/about/now.shtml
What Is Spitzer Doing Now?
Pilachowski / August 2005
The Universe in the Infrared
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Future Infrared Satellites
2007: Herschel Space Observatory - a European Space Agency infrared-submillimeter mission planned for 2007 to study galaxy formation, interstellar matter, star formation and the atmospheres of comets and planets.
2007: Planck Surveyor - European Space Agency far infrared-submillimeter mission planned for 2007 to study Cosmic Background Radiation.
2010: The James Webb Space Telescope, planned for launch in about 2011, is a visible/infrared space mission to study the early universe and the formation of galaxies, stars and planets.