The Planck Satellite Matthew Trimble 10112 Useful Physics

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 20 N thrusters, 4 1 N thrusters

Special Orbit • Lissajous Orbit around L 2 • 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 3000 K at matter began thermally radiating photons • This radiation is the CMB, which has now increased wavelength to the microwave, and ‘cooled’ to ~2. 7 K • 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, 3 D 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/SEMWN 20 YUFF_0. html 2. http: //en. wikipedia. org/wiki/Lissajous_orbit 3. http: //en. wikipedia. org/wiki/Lagrangian_point#L 2 4. http: //www. esa. int/SPECIALS/Planck/SEMQ 05 XX 3 RF_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/guestpost-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-plancksatellites-fi. html • •