Radio Astronomy Listening to the Sky

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The Galactic Center

Multiwavelength overlay

red = radio, green = infrared, blue = x-rays

Slide 20

Radio Galaxies: Supermassive Black Holes

Centaurus A (NGC 5128), overlay of

radio and visible images

PKS 2536-61. Radio (red), optical (blue).

Slide 21

The CMB: Echo of the Big Bang

Key prediction of Big Bang Theory

Peak ~ 200 GHz

Penzias & Wilson, 1964 1976 Nobel Prize

COBE (1989) 2006 Nobel Prize, Smoot & Mather

WMAP (2001), Planck (2009)

The size scale and intensity

of these fluctuations place

stringent limits on cosmological models.

Tuniverse = 13.7 Gy

Slide 22

SETI: The Search for Intelligent Life

Proposed ~ 1960: use radio/microwave frequencies to listen for signals from extraterrestrial civilizations, or send signals for them to receive!

Jury’s still out…

?

Slide 23

Summary

Radio provides a valuable and unique source of information about the universe:

Radar mapping of moon & planets

Following solar activity

Tracing cold gas clouds & star forming regions

Seeing “through” dust & gas to distant objects

High angular resolution through interferometry

Detecting expired stars & stellar remnants

Precision cosmology via the CMBR

SETI