Microwave

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DIRBE (Diffuse InfraRed Experiment)

FIRAS (Far-InfaRed Absolute Spectrophotometer)

DMR (Differential Microwave Radiometers)

DMR Receiver

Slide 8

Differential Microwave Radiometer

Variations in intensity of the cosmic microwave background, show the post-Big Bang matter and energy distribution.

Uniformity / Isotropic CMB (top)

temperature of CMB

Black body curve (middle)

One hot and cold spot in the sky coming from our Solar System's motion through the galaxy.

Density Ripples (bottom)

Further contrast “with our local motion removed.” hot red stripe through the center marks the galactic plane and above and below are variations in microwaves of the CMB!

COBE’s findings at different levels of contrast:

2.728 K

3.353 mK

18µK

Slide 9

Slide 10

What are Microwaves used for?

Heating, transmitting information, remote sensing

Shorter microwaves used for remote sensing

Doppler radar

Active remote sensing system

Microwaves pierce through all cloud covering of earth

Satellite images

http://imagers.gsfc.nasa.gov/ems/micro.html

Slide 11

Archeops

Balloon Born Telescope

Aims

High quality CMB data with unmatched sky coverage

Competitive results on CMB anisotropy measurements

Testbed for data analysis to be used in PLANCK

http://journal.archeops.org/First_results/index.html

Slide 12

Boomerang

Balloon born telescope

Dec. 29, 1998 – Jan. 9, 1999

10.5 days around antarctica

120,000 ft

1.2 m primary mirror

Measured sky at 4 frequencies

90, 150, 240, 400

Covered 1800 square degrees (3% of sky)

http://cmb.phys.cwru.edu/boomerang/press_images/cmbfacts/cmbfacts.html

Slide 13

Cosmic background Imager

radio telescope to study CMB radiation

Measure the statistical properties on angular scales from 5 arc minutes to one degree

13 element interferometer

Field of view – 44 arcmin

Resolution – 4.5-10 arcmin

Looks at foreground

Unresolved sources measured by 40 m telescope in Owens Valley Radio Observatory

http://www.astro.caltech.edu/~tjp/CBI/pictures/cbi-frontview.html

Slide 14

DASI

http://astro.uchicago.edu/dasi/

Degree Angular Scale Interferometer

13 elemental interferometer

Measure temp and angular power spectrum