The Extravagant Universe:
Exploding Stars, Dark Energy, and the Accelerating
Cosmos
List of Illustrations: March 27, 2002
87A
area
Author Photograph
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RPK image
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Chapter 1
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Figure 1.1
(Figure A in January 21 list)
Chapter 1 (p.2 of 15)
The 4-meter Victor and Betty Blanco telescope at Cerro Tololo in Chile,
silhouetted against the Milky Way Galaxy. In 1917, when Einstein first
considered the effects of gravity on the universe as a whole, astronomers
of the day thought the Milky Way was the entire universe. Today we
think of it as one galaxy among 100 billion similar systems. The
Large and Small Magellanic Clouds are to the left.
Photo credit: Roger Smith/NOAO/AURA/NSF.
ctiogalaxy.tiff
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Figure 1.2
(Figure B in Jan 21 list)
Chapter 1 (p. 3 of 15)
Karl Friedrich Gauss on the German10 mark note. Gauss had early
success in predicting orbits and became Director of the Observatory at
Göttingen. The bell-shaped curve of probability looming over
Gauss's shoulder describes the likelihood of obtaining, by chance, an experimental
result that differs from the true value. When astronomers quote the
age of the universe with a band of uncertainty, or the odds that the data
imply a cosmological constant, they use the ideas of Gauss.
Gauss
on the 10 Deutschmark Note
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Figure 1.3.
(Figure C)
Chapter 1 (p. 9 of 15)
In 1917, Einstein was advised that the Milky Way was the universe.
Mistaking a part for the whole is common with large entities.
Credit: © 2002 The New Yorker Collection from cartoonbank.com.
All Rights Reserved.
The Milky Way--detail
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Figure 1.4
Figure D.
Chapter 1 (p. 11 of 15) COLOR INSERT
The spiral galaxy pair NGC 2207 and IC 2163. Distances between
galaxies are not always large compared to the sizes of galaxies.
These two are colliding. Note the absorption of light from one galaxy
by dust lanes in the other.
Credit: NASA and the Hubble Heritage Team (STScI/AURA)
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Figure 1.5
Figure E.
Chapter 1 (p. 11 of 15)
The nearby spiral M31. M31 is part of the Local Group of galaxies.
In the 1920's Hubble observed individual cepheid variable stars in this
spiral galaxy that showed it was too distant to be part of the Milky Way,
and must be a distant system as about as big as the Milky Way
Credit: P.Challis, Harvard-Smithsonian Center for Astrophysics from
the Digital Sky Survey
m31_3dbgrey_300dpi.tif
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Figure 1.6
Chapter 1 (p. 12 of 15) COLOR INSERT
{Figure F}
The Hubble Deep Field. Composed from 342 images taken over 10 days
at the end of 1995, the Hubble Deep Field represents the limit of present
methods for observing faint, distant, and young objects. Almost every
dot and smudge in this picture is a galaxy, with light from the most distant
ones traveling 12 billion light years to reach us.
Photo credit R. Williams/NASA/STScI/AURA
HDF.tif
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Chapter 2
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Figure 2.1
Chapter 2 (p. 5 of 27) COLOR INSERT
{Figure G.}
Galaxy Spectra. Astronomers take the light from a galaxy and
spread it into a rainbow. Then they construct a graph as shown at
the top and the bottom. The galaxy spectra at the top of this rainbow
have absorption lines, those near the bottom have emission lines that come
from gas clouds whose atoms are excited by the ultraviolet light from stars.
Credit: Barbara Carter, Harvard-Smithsonian Center for Astrophysics
quicker-loading version (jpeg)
galspec.tiff
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Figure 2.2
Chapter 2 (p. 13 of 27) COLOR INSERT
{Figure H.}
The Globular Cluster NGC 6093. A globular cluster contains many
thousands of stars that formed at the same time, early in our galaxy's
history. By measuring the properties of stars that have recently
become red giants (visible in this color image as reddish, bright stars
in the cluster) the age of the cluster can be inferred. The oldest
globular clusters have ages of 12 +/- 1 billion years.
Credit : NASA and the Hubble Heritage Team (STScI/AURA)
globular.tiff
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Figure 2.3
Chapter 2 (p. 17/27) COLOR INSERT
{Figure I}
Planetary nebula NGC 6751. After about a billion years as a red
giant, a star like the sun will puff off its outer envelope while the core
shrinks to become a white dwarf. A planetary nebula is the beautiful
transition from a gaseous star with nuclear fusion to a solid star with
no energy source.
Credit: NASA and the Hubble Heritage Team (STScI/AURA)
planetary.tif
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Figure 2.4
Chapter 2 (p. 22/27) COLOR INSERT
{Figure J}
Supernova 1994D. This Type Ia supernova is in a galaxy at a distance
of about 50 million light years in the Virgo cluster of galaxies.
For a month, the light from a single exploding white dwarf is as bright
a 4 billion stars like the sun.
Credit: P. Challis, Center for Astrophysics/STScI/NASA
sn94d_300dpiv2.tif
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Chapter 3
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Figure 3.1
Chapter 3 (p. 5/18)
{Figure K}
Be Scientific with Ol'Doc Dabble. Zwicky's compact 1934 publication
of a wild speculation for the origin of supernovae in the gravitational
collapse of stars to form neutron stars: "little spheres 14 miles
thick." This is now thought to be the mechanism for Type II supernovae,
though, in 1934, Zwicky was talking about Type I supernovae.
Photo credit: Associated Press
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Figure 3.2
Chapter 3 (p. 17/18) COLOR INSERT
{Figure M.}
Supernova 1987A. Space telescope image of the site of SN 1987A,
seen 10 years later. The exploded star itself is the dot in the center
of the bright inner ring, heated by the decay of radioactive elements produced
in the explosion. The inner ring is gas lost from the pre-supernova
star, excited and still glowing from the light of the outburst. This
ring was the source of the emission seen by the International Ultraviolet
Explorer satellite in 1987-1988.
Photo credit: P. Challis and the SINS collaboration, Harvard-Smithsonian
Center for Astrophysics/NASA/STScI
Supernova 1987A image
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Chapter 4
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Figure 4.1
Chapter 4 (p. 4/13) COLOR INSERT
{Figure N}
The Milky Way. This color image shows dust clouds silhouetted
against the bright bulge at the center of our galaxy. Notice that
the dust makes the bulge look dimmer and redder, as interstellar dust removes
more blue light than red light.
Photo credit: Axel Mellinger
Axel's Aitoff of the Milky Way (jpeg)
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Figure 4.2
Chapter 4 (p. 11/13) COLOR INSERT
{Figure N}
Gravitational lensing by the galaxy cluster Abell 2218. The curved
arcs are gravitationally lensed images of background galaxies, whose light
is bent by the matter (mostly dark) in this cluster of galaxies.
Credit: NASA, A. Fruchter and the ERO
Team (STScI, ST-ECF)
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Chapter 5
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Figure 5.1
Chapter 5 (p. 2/24)
{Figure O}
Galaxy redshifts. The redshift of a galaxy can be measured from
the change in wavelength of emission or absorption lines in its spectrum.
Cosmic expansion stretches the entire spectrum to the red. Here are
two galaxies, one at low redshift, and another at a higher redshift.
The spectra are similar, just stretched to the red.
Credit: Barbara Carter, Harvard-Smithsonian Center for Astrophysics
easier to load (and read!) version
(postscript)
galaxy
redshifts
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Figure 5.2
Chapter 5 (p8/24)
{Figure P}
The 100-inch telescope at Mount Wilson. This telescope was the
largest in the world for thirty years after it went into operation in November,
1917. Edwin Hubble used the 100-inch to find and measure cepheids
in nearby spirals and to obtain galaxy redshifts.Though Mount Wilson is
no longer a dark site, telescope is still in use.
Credit: Courtesy of The Observatories of the Carnegie Institution
of Washington
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Figure 5.3
Chapter 5 (p9/24)
{Figure Q.}
Hubble observing at the 100-inch telescope. Hubble, clad in jodhpurs,
wearing cavalry boots, is perched on a bentwood chair at the Newtonian
focus of the 100-inch telescope in 1923. He is holding the controls
of the plateholder, which needed constant guiding during the exposure of
a photographic plate to compensate for small errors in the telescope drive
mechanism.
Credit: Courtesy of The Observatories of the Carnegie Institution
of Washington
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Figure 5.4
Chapter 5 (p. 10/24)
{Figure R}
The very first Hubble diagram. In 1929, Edwin Hubble plotted
the velocities of galaxies, determined from their redshifts, against their
distances, measured from cepheids and other methods. This diagram
shows that the velocity is proportional to the distance, though individual
galaxies depart noticeably from this relation, and a few very nearby galaxies
(like M31) are approaching us. The slope of the Hubble diagram is
the Hubble constant, measured in kilometers per second per megaparsec.
Hubble's original work showed a slope of 528 kilometers per second per
megaparsec, over seven times larger than the modern value near 70 kilometers
per second per megaparsec.
Credit: Publications of the National Academy of Sciences
Hubble's
own Hubble diagram
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Figure 5.5
Chapter 5 (p.12/24)
{Figure T}
The Las Campanas Redshift Survey. The redshifts of 23,697 galaxies
were measured by a single Harvard graduate student, Huan Lin, as part of
this collaboration. The galaxies were selected by their apparent
brightness in six thin slices across the sky. This plot, with Las
Campanas at the center, uses the redshift and position on the sky to show
where the galaxies are located in space. They are clumped, with great
voids, great sheets, and great clusters, all on scales less than about
7000 kilometer per second (about 100 megaparsecs for a Hubble constant
of 70). On larger scales, the structure seems to even out--this survey
was the first that was large enough to see the end of greatness and the
beginning of cosmic homgeneity.
Credit: Huan Lin and the Las Campanas Redshift Survey
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Figure 5.6
Chapter 5 (p. 17/24)
{Figure U}
Einstein visits the Mount Wilson Observatory offices. In 1931,
Einstein visited the Pasadena offices of the Mount Wilson Obsevartory.
George Ellery Hale, builder of the 100-inch telescope and founder of the
observatory, looks down from his portrait in the library. Hubble (apparently
being patted on the head by Hale) is at the left; Einstein, holding chalk,
is in front of the blackboard.
Photo credit: Courtesy of The Observatories of the Carnegie
Institution of Washington
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Figure 5.7
Chapter 5 (p 18/24)
{Figure V}
The blackboard from Einstein's talk at the Mount Wilson Observatory
offices. This shows Einstein was still using Lambda in1931!
Cradit: Courtesy of the Archives, Californian Institute of Technology
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Chapter 6
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Figure 6.1.
Chapter 6 (15/37)
{Figure X}
Accuracy and precision. Accurate measurements have the right
average value. Precise measurements are tightly bunched. High
accuracy and high precision is best. High accuracy and low precision
isn't so great, but it is better than high precision and low accuracy,
which conveys a meretricious air of authority to a misleading result.
This .tiff version is unsatisfactory.
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Figure 6.2
Chapter 6 (p. 28/37)
{Figure Y}
The Hubble diagram for Type Ia supernovae. Note that the velocity
is proportional to distance, as noted in 1929. Hubble's original Hubble
diagram (Figure R) extended only out to 2000 kilometers per second, where
the individual motions of galaxies added to the scatter. This Hubble diagram
extends out to 30,000 kilometers per second, 1/10 the speed of light, where
the cosmological Hubble flow is large compared to any galaxy's individual
motion among its neighbors.
Credit: Adam Riess, Harvard-Smithsonian Center for Astrophysics
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Figure 6.3
Chapter 6 (p. 35/37)
{Figure Z}
Brian Schmidt explains the expanding photosphere method to his Ph.D.
advisor in 1994. The computer screen shows Schmidt's Hubble diagram
for Type II supernovae, derived using the expanding photosphere method
to measure distances.
Credit: Harvard News Office
Brian
Schmidt and RPK
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Chapter 7
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Figure 7.1
Chapter 7 (p.12/30)
{Figure ab}
The growth of structure. Once baryons recombined, they could
move under the force of gravity. Matter that could form galaxies,
stars, planets, and people drained into the valleys that dark matter formed,
as shown in these computer simulations. The distribution of luminous
matter traces the presence of dark matter.
Credit: The VIRGO Consortium
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Chapter 8
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Figure 8.1
Chapter 8 (p. 6 /28)
{Figure ac}
Spectra of Type I and Type II supernovae. Type I supernovae do
not have lines of hydrogen while Type II supernovae have prominent hydrogen
lines. Although this does not exhaust the possibilities, with Type
Ib (and Type Ic) being introduced later, most supernova spectra we observe
are of these two general types.
Credt: Tom Matheson, Harvard-Smithsonian Center for Astrophysics
snspectra.tiff
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Figure 8.2
Chapter 8 (p. 11/28)
{Figure ad}
Fritz Zwicky in 1971. Here Fritz demonstrates the symmetry of
a spherical bastard, "A bastard any way you look at it."
Credit: Photo by Floyd Clark, courtesy of
the Archives, California Institute of Technology
Zwicky gestures
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Figure 9.1
Chapter 9 (p. 23/45)
{Figure af}
The lightcurve of a Type Ia supernova. Measurements
made at the Smithsonian's Whipple Observatory in Arizona of SN 2001V, discovered
by Perry Berlind of the observatory staff. Measurements were made
in five different colors, displaced here for clarity. The slope of the
declining light curve in the "B" (for blue) filter contains powerful information
about the supernova's true brightness. Observations in other filters
contribute to the precision of the luminosity determination and also tell
the amount of reddening by dust.
Credit: Saurabh Jha, Kaisey Mandel, Tom Matheson;
Harvard-Smithsonian Center for Astrophysics
Lightcurve
for SN 2001V
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Figure 9.2
Chapter 9 (p. 40/45)
{figure ah }
The good effect of using the light curve shape. The top panel shows
a Hubble diagram of the redshift versus the distance (in astronomers' units).
If allType I supernovae were identical, and you judged the distance from
the apparent brightness, you would get the Hubble diagram in the upper
panel. When a supernova is intrinsically dim, this approach mistakenly
assigns it an extra-large distance. The lower panel shows the Hubble
diagram after correcting for light curve shape and reddening using the
MLCS. The improvement is dramatic.The 1sigma error in the distance
drops from about 15% to 7%. This means each measurement becomes 4
times as useful.
Credit: Adam Riess, Harvard-Smithsonian Center for Astrophysics
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Chapter 10
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Figure 10.1
Chapter 10 (p. 5/51)
{Figure ai}.
The high-z team. A large fraction of the high-z team in a single
place for 1/30th of a second in the summer of 2001.
Photo Credit: Robert Kirshner, Harvard-Smithsonian Center for Astrophysics
High-Z
Team Photo
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Figure 10.2
Chapter 10 (p7/51)
{Figure ak}
Suprime: a giant CCD camera. The advent of very large electronic
cameras is the technical advance that made high-Z supernova searches practical.
These cameras have close to 100% efficiency using silicon charge coupled
devices (CCDs). This one has about 100 million pixels, compared
to 3 million in a high-end digital camera you can buy today.
Photo Credit: Subaru Observatory
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Figure 10.3
Chapter 10 (p 11/51)
{Figure al}
Subtracting images to find supernovae.The image from a month ago is
subtracted from last night's image to reveal a new supernova. The
image area shown is about 1/1000 of the full area provided by the CCD camera.
Rapid processing of dozens of image pairs demands nimble software and a
dedicated team of searchers.
Credit: Brian Schmidt, Australian National University
Before, After, and the Difference
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Figure 10.4
Chapter 10 (p. 12/51)
{Figure am}
HST and Ground-based images of SN 1997cj. Sharp images from the
Hubble Space Telescope make accurate measurements of supernovae much easier.
Credit: Peter Garnavich; University of Notre Dame/NASA
Ground-based and HST observations of
SN 1997cj
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Figure 10.5
Chapter 10 (p. 16/51)
{Figure an}
An International Astronomical Union Circular from the Bureau for Astronomical
Telegrams reporting the results of searching in 1998. Some of these
supernovae were observed with the Hubble Space Telescope.
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Figure 10.6
Chapter 10 (p.16/51) COLOR INSERT
{Figure ao}
High-z supernovae observed with the Hubble Space Telescope.
Credit: Peter Challis; High-Z team/NASA
Images
of High-Z Supernovae
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Figure 10.7
Chapter 10 (p. 39/51)
{Figure ar}
The Hubble diagram for high redshift supernovae.The small departure
from the dotted line in the upper panel is the evidence that we live in
an accelerating universe. In the lower panel, the 45 degree slope,
which is just the inverse square law, has been removed. The points
certainly lie above the downward curving line of long dashes, which is
the prediction for Wm
= 1 with no cosmological constant. Most of the points also lie above
the dashed horizontal line which is the prediction for Wm
= 0.3, with no cosmological constant. The only way to get up to the
solid line (which is formally the best fit to the data) is to include the
effects of acceleration.Points from both the high-Z team and the supernova
cosmology project are shown here.The high-Z team points are fewer, but
have equal weight because each point has smaller uncertainties.
Hubble
Diagram for High-Z Supernovae
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Figure 10.8
Chapter 10 (p. 44/51)
{Figure at}
Spectra of supernovae. The supernovae observed at high redshift,
SN 1999ff and SN 1999fv are, as near as we can tell, identical with those
seen nearby at similar ages. The spectra have been shifted back to
the wavelengths you would observe if you were in the same galaxy as each
of the supernovae.
Credit: Alison Coil, Alex Filippenko, and the High-Z supernova team.
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Figure 11.1
Chapter 11 (p.3/36)
{Figure au}
The work on the accelerating universe was Science Magazine's
"Science Breakthrough of the Year" for 1998.
need permission from AAAS
Science
Breakthrough of the Year
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Figure 11.2
Chapter 11 (p.25/36)
{Figure av}
Combining information from supernovae and from fluctuations in the
cosmic microwave background zeroes in on the values for Omega-M and Omega_Lambda.
Credit: Saurabh Jha; Harvard-Smithsonian Center for Astrophysics
Combining
Supernovae and the CMB
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Figure 11.3
Chapter 11 (p. 26/36) COLOR? ONLY
IF IT FITS!
{Figure aw}
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Figure 11.4
Chapter 11 (p. 27/36)
{Figure ax}
The Universal Pie. Although we can be proud that we have filled
up this diagram, the biggest slice of energy-density in the universe is
dark energy, which we don't understand, and the next biggest is dark matter,
which we don't understand. Visible matter amounts to only 1% of the
contents of the universe. There is plenty of work to be done.
Credit: Peter Garnavich; University of Notre Dame
