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The Planck Satellite. Matthew Trimble 10/1/12. Useful Physics. Observing at a redshift = looking at light from a very distant object that was emitted a long time ago The ‘temperature’ of the CMB is the temperature of a blackbody that would emit the energy spectrum seen by the photons
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The Planck Satellite Matthew Trimble 10/1/12
Useful Physics • Observing at a redshift = looking at light from a very distant object that was emitted a long time ago • The ‘temperature’ of the CMB is the temperature of a blackbody that would emit the energy spectrum seen by the photons • Fun Fact: CMB is most ideal blackbody spectrum ever recorded
Need For Planck • Space vs. Ground telescopes • Hubble: Launched 1990 • WMAP: Launched 2001, now in graveyard orbit • Planck: Launched 2009 • Better resolution of CMB
Spacecraft Design • ~4.2 m high X 4.2 m wide • 1.95 tonnes • Three stage cooling system and shielding from Sun to minimize background radiation • 1.9 m x 1.5 m primary mirror • Lifetime: 15+ months, dependant on cooling system degradation • Propulsion: 12 20N thrusters, 4 1N thrusters
Special Orbit • Lissajous Orbit around L2 • Propulsion only needed for corrections
Instruments • Telescope: 1.9 x 1.5 m primary mirror, effective aperture of 1.5 m. • Low Frequency Instrument: observes wavelengths from 3.9 mm to 11.1 mm. • High Frequency Instrument: observes from .3 mm to 3.6 mm.
Cosmic Microwave Background • After Big Bang, radiation and matter were coupled (no light emitted) • As expanding universe cooled, it reached 3000K at matter began thermally radiating photons • This radiation is the CMB, which has now increased wavelength to the microwave, and ‘cooled’ to ~2.7K • CMB temperature is not homogenous, but early measurements were not able to detect the tiny fluctuations
Large Scale Properties of Universe • Large scale properties: density, number of atoms in visible universe, etc. • Planck will be able to accurately measure how certain properties (density) evolved over time. • That data allows other properties (# atoms) to be determined with low uncertainty.
Dark Matter • Doesn’t interact with radiation, therefore it is literally dark. • Presence can only be inferred by gravitational interactions with luminous matter. • Planck will detect the gravitational lensing the CMB undergoes due to dark matter.
Inflation • The theorized extremely rapid expansion of the early universe. • Currently explains much of the Universe’s features. • Planck will investigate possible causes of inflation, and try to determine if expansion will continue, or if the universe will eventually collapse in a Big Crunch.
Primordial Gravitational Waves • Hypothesized to exist during inflation. • Gravitational waves carry information about the event that triggered the wave. • Detecting these ancient waves through the CMB would give strong evidence for Inflation.
Inhomogeneities of Early Space • Our universe is not homogenous: full of galaxy clusters and large voids. • Likely, there were inhomogeneities very early on, which formed into the complex structures we have today.
Microwave Study of Galaxies • Milky Way: create the first map the cold dust distributed along spiral arms, and the first detailed, 3D map of the Milky Way’s magnetic field. • Other: Using the Sunyaev- Zel'dovich effect, Planck can catalogue distant galaxy clusters.
Conclusion • “Planck will measure the fluctuations of the CMB with an accuracy set by fundamental astrophysical limits.” • Planck has the capabilities to verify a large portion of cosmology and particle physics that has yet to be figured out. • Data will not be released until 2013, but the astrophysical community overall expects good results from Planck.
References • 1. http://www.esa.int/SPECIALS/Planck/SEMWN20YUFF_0.html • 2. http://en.wikipedia.org/wiki/Lissajous_orbit • 3. http://en.wikipedia.org/wiki/Lagrangian_point#L2 • 4. http://www.esa.int/SPECIALS/Planck/SEMQ05XX3RF_0.html • 5. http://en.wikipedia.org/wiki/Planck_(spacecraft) • 6. http://en.wikipedia.org/wiki/Inflation_(cosmology) • 7. http://blogs.discovermagazine.com/cosmicvariance/2012/09/04/guest-post-doug-finkbeiner-on-fermi-bubbles-and-microwave-haze/ • 8. http://www.funtrivia.com/en/subtopics/Cosmic-Microwave-Background-Radiation-267543.html • 9. http://news.sciencemag.org/sciencenow/2010/07/scienceshot-planck-satellites-fi.html