Lecture_20

Lecture_20 - Dark Energy and the Fate of the Universe DARK...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Dark Energy and the Dark Energy and the Fate of the Universe Fate of the Universe JUST 3 CLASSES TO GO! Big Bang and Search for ET next week The visible portion of a galaxy lies deep in the heart of a large, more or less spherical region of dark matter. DARK MATTER HALO The term “ dark matter ” comes from the fact that despite being 10x the mass of the Milky Way, no light or radiation of any kind , comes from this material! The mass we find from galaxy motions in a cluster is about 50 times larger than the mass in stars! These motions are much too great if they are due to the gravity of the luminous objects that we can detect. Structure Formation Structure Formation • What is the role of dark matter in galaxy formation? • What are the largest structures in the universe? Our Goals for Learning
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 The gravity of the dark matter is what caused protogalactic clouds to contract early in time. It, the dark matter, was the dominant source of gravity. This makes sense because, WIMPs can’t contract to the center because they don’t radiate away their orbital energy (to become luminous) as ordinary matter made of normal atoms and electrons does. The ordinary matter forms galaxies and stars, but the dark matter remains in an extended halo. Clumpy dark matter can get the gravitational collapse of normal matter started; but dark matter does not collapse. Dark matter is still pulling things together today over enormous distance scales. After correcting for Hubble’s Law, we see galaxies flowing toward the densest regions of space. The arrows show galaxy motions. Maps of galaxy positions reveal extremely large
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/20/2012 for the course ASTRO 3 taught by Professor Mclean during the Spring '11 term at UCLA.

Page1 / 7

Lecture_20 - Dark Energy and the Fate of the Universe DARK...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online