Patricia BurchatDepartment of Physics

Stanford University

Dark Matter, Dark Energy: Mysteries of the Universe

Hubble Space TelescopeUltra Deep Field

1

Patricia BurchatDepartment of Physics

Stanford University

Dark Matter, Dark Energy: Mysteries of the Universe

Dark Energy70%

Dark Matter26%

Ordinary Matter4%

Hubble Space TelescopeUltra Deep Field

2

http://janus.astro.umd.edu/javadir/orbits/ssv.html

Planetary Motion

Credit: The Astronomy WorkshopA collection of interactive web-based programs for introductory astronomy as well as more advanced courses.

Written by Doug Hamilton and Mike Asbury, http://www.astro.umd.edu/education/education.html

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The Andromeda Galaxy4

Doppler Shift

Windows to the Universe: http://www.windows.ucar.edu

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Doppler Shift

JPL Planet Quest: http://planetquest.jpl.nasa.gov/science/finding_planets.cfm

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The Andromeda Galaxy7

The Coma Cluster of Galaxies(visible light)

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The Coma Cluster of Galaxies(x ray, ROSAT image)

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Gravitational Lensing

http://www.goshen.edu/nasc/NaSc200/Notes/Galaxies/GravLensDiagram.JPG

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Gravitational Lensing by Galaxy Cluster Abell 2218

Hubble Space Telescope, WFPC2 and ACS

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The Bullet Cluster

PINK = gas; BLUE = dark matter

Clowe et al., astro-ph/0608407

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Simulation from Center for Cosmological Physics, University of Chicago

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Dark Energy70%

Dark Matter26%

Ordinary Matter4%

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Expanding Universe

© 1998 Edward L. Wright.

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Redshift due to the Expansion of Space

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Standard Candles in the Universe:Type Ia Supernovae

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Evolution of a Supernova

Supernova Cosmology Project (P. Nugent: spectral sequence; A. Conley: image sequence) with the help of Lawrence Berkeley National Laboratory's Computer Visualization Laboratory

(N. Johnston: animation) at the National Energy Research Scientific Computing Center.

Time

Wavelength

Brightness

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Calan/Tololo (Hamuy et al, A.J. 1996)

Supernova Cosmology Project

effe

ctiv

e m

B

(0.5,0.5) (0, 0)

( 1, 0 ) (1, 0)(1.5,–0.5) (2, 0)

!!""!##$%$$

( 0, 1 )

Fla

t

#$%$&

redshift z

14

16

18

20

22

24

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0.02 0.05 0.1 0.2 0.5 1.00.02 0.05 0.1 0.2 0.5 1.0

Perlmutter, et al. (1998)

FA

INT

ER

(Far

ther

)(F

urt

her

bac

k in

tim

e)

MORE REDSHIFT(More total expansion of universe since the supernova explosion)

In flat universe: !M = 0.28 [' 0.085 statistical] [' 0.05 systematic]

Prob. of fit to # = 0 universe: $()

• For a given brightness (distance), redshift is less than expected.• Universe was expanding at less than the “expected” rate in the past.• Universe is actually expanding at an ever-increasing rate today!

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Future Investigations of Dark Matter

andDark Energy:

An Example

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Large Synoptic Survey Telescope

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Large Synoptic Survey Telescope

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Dark Energy70%

Dark Matter26%

Ordinary Matter4%

Dark Matter, Dark Energy: Mysteries of the Universe

Hubble Space TelescopeUltra Deep Field

26