19. Cosmology - Cosmology Outline Our goals for this...

Info iconThis preview shows pages 1–25. Sign up to view the full content.

View Full Document Right Arrow Icon
Background image of page 1

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

View Full DocumentRight Arrow Icon
Background image of page 2
Background image of page 3

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

View Full DocumentRight Arrow Icon
Cosmology Outline Our goals for this section: To discern the large scale structure of the universe To understand the origin and fate of the universe Hopefully, to say “wow” a lot Questions?
Background image of page 4
Large Scale Structure This just has to be done pictorially to do it any justice…
Background image of page 5

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

View Full DocumentRight Arrow Icon
Background image of page 6
Background image of page 7

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

View Full DocumentRight Arrow Icon
Background image of page 8
Background image of page 9

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

View Full DocumentRight Arrow Icon
Background image of page 10
Background image of page 11

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

View Full DocumentRight Arrow Icon
Background image of page 12
Background image of page 13

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

View Full DocumentRight Arrow Icon
Background image of page 14
In the last section, we talked about galaxies and galaxy clusters We said that the Milky Way is part of a cluster of about 45 galaxies called the Local Group We also talked about the Virgo cluster, which comprises about 2500 galaxies Is there anything in the universe larger than a galaxy cluster? Think about the possibilities: – if galaxy clusters are the largest structures in the universe, we should expect them to be distributed randomly throughout the cosmos – if galaxy clusters are NOT the largest structures, we should see patterns in their spatial distribution
Background image of page 15

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

View Full DocumentRight Arrow Icon
Distribution of Galaxies within about 60 Mpc. NOT a real photograph! Virgo Cluster
Background image of page 16
The very largest cohesive structures discernable in the universe are galaxy superclusters , which are clusters of galaxy clusters Our parent supercluster is called the Virgo Supercluster As you should expect by now, the Local Group isn’t anywhere near the centre The Virgo Supercluster is about 40-50 Mpc across, and contains several tens of thousands of galaxies, totaling more than 10 15 solar masses (1 quadrillion!) What about larger scales, of 100 Mpc and larger?
Background image of page 17

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

View Full DocumentRight Arrow Icon
It is often said that the superclusters are the intersections of great cosmic filaments and walls , which themselves define a foam-like pattern around enormous voids To date, it looks like the walls are the largest structures in the universe Walls are not necessarily gravitationally bound, so it may be a stretch to call them “structures”…
Background image of page 18
Background image of page 19

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

View Full DocumentRight Arrow Icon
Modern computational capacity allows us to accurately simulate huge chunks of the universe This video zooms in on a slice through a simulation of the cosmos which is several Gpc on a side! Every tiny dot is a galaxy
Background image of page 20
Zooming through the universe at many, many times the speed of light
Background image of page 21

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

View Full DocumentRight Arrow Icon
Cosmology Cosmology: The study of the structure and evolution of the entire universe .
Background image of page 22
“Thus, we can conceive of the universe as a pile of overlapping grapefruits that stretches inFnitely in all directions.” —Charles H. Lineweaver, cosmologist, March 2005 Hold on to your hats, folks. This is going to get weird fast!
Background image of page 23

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

View Full DocumentRight Arrow Icon
The Cosmological Principle We have already established that, on very large scales, the universe has a uniformly foamy structure. Let’s formalize this idea: The large-scale universe is homogeneous —any very large volume of the universe (such as a cube 300 Mpc on a side) would have the same statistical properties (e.g. mean number of galaxies) as any
Background image of page 24
Image of page 25
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/01/2011 for the course ASTRO 1a03 taught by Professor Samantha during the Spring '11 term at McMaster University.

Page1 / 57

19. Cosmology - Cosmology Outline Our goals for this...

This preview shows document pages 1 - 25. Sign up to view the full document.

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