Animation: This animation shows
how a galaxy like the Milky Way is built up according
to the cold dark matter model, as well as how many dwarf
galaxies (the small bright dots) there should be surrounding
the Milky Way.
Courtesy of J. Diemand, M. Kuhlen, P. Madau, Zemp, Moore,
Potter and Stadel (UCSC)
Send your comments on this issue of Cosmic Matters to advancement@keck.hawaii.edu.
Image: This dwarf galaxy
known as Leo II, seen in the Sloan Digital Sky Survey
(SDSS), is one of the brighter dwarf galaxies near
the Milky Way. The newly discovered dwarfs recently
studied at Keck are up to 100 times fainter than Leo
II. Courtesy of SDSS.
Since the first light of the Keck telescopes in 1992 and 1996
respectively, our understanding of the cosmos has grown enormously.
One of the largest and still unexplained mysteries remains,
however: dark matter. “Ordinary” matter, which we learned
about in chemistry class, is made up of atoms and molecules
and their constituent parts --- protons, neutrons, electrons,
and various other subatomic particles that high energy physicists
have discovered over the past 70 years. But in total, this
regular matter makes up only about 15% of the matter in our
Universe. The other 85% is dark matter, a mysterious substance
that has not yet been detected directly because it does not
give off any light. Astronomers first recognized its existence
about 30 years ago by detecting its gravitational pull on things
that they could see, such as stars and gas. According to the
best current cosmological models, dark matter plays a crucial
role in the early universe in pulling together ordinary matter
to form the first galaxies, and even today remains the dominant
component of galaxies like our Milky Way.
Photo: Observations
made by Keck astronomer Josh Simon are being used to
further understand the nature of dark matter. Credit:
S. Anderson/WMKO.
Recent measurements of stars' velocities using the Keck II
telescope and its leading wide field multi-object spectrograph,
DEIMOS, have provided new clues to the behavior of dark matter
in nearby “dwarf” galaxies. These observations by Caltech astronomer
Josh Simon and his Yale colleague Marla Geha have demonstrated
that at least twice as many dwarf galaxies orbit around the
Milky Way as was previously recognized, and are reshaping our
understanding of the link between our Galaxy and its smallest
neighbors.
Image: Fly-by of Daphne
with Satellite. Click the image above, or click
here to view an animation. The fly-by begins with
our vantage point from Earth on the night of the discovery,
We then fly up to view the satellite's orbit edge-on,
being occasionally eclipsed by Daphne. Lastly, we fly
directly above the orbit to see that the orbit is circular.
The 3-dimensional shape of Daphne used here was determined
from past light curves analysis (Kaasalainen, et al)
and confirmed with the Keck AO images. Animation courtesy
of Jack Drummond/PSI and Al Conrad/WMKO.
An image flashed up on the display. It was the second group
of exposures of the night for a large main-belt asteroid called
Daphne. W. M. Keck Observatory Support Astronomer Al Conrad
had been working from a remote control room in Waimea while
his research partner, Principal Scientist Bill Merline, looked
at the same image from his computer at the Southwest Research
Institute in Boulder, Colorado.
The scientists were working on two research programs, one to
learn about the shapes and sizes of asteroids, and the other
to look for moons. The two programs use different approaches
to determine the basic properties of asteroids.
Conrad had been helping Merline use an image-correction technology
called adaptive
optics (AO)
on the 10-meter Keck II telescope. This world-leading system
uses high-speed computers and deformable optics to correct
the blurring effects of the Earth's atmosphere.
Tonight, Merline and Conrad were looking at four large main-belt
asteroids: Sylvia, Camilla, Kalliope, and Daphne. The plan
was to look at each asteroid in round-robin fashion. They would
make a “group” of exposures of one asteroid, consisting of
perhaps a dozen pictures, taking a total of about 10 minutes.
Then they would move to the next asteroid, cycling through
all four every 40 minutes.
Each
asteroid would rotate on its axis once every four to six
hours. By the end of the night, the researchers would have
enough data to see the outline of each asteroid. From there,
they could begin to narrow down important and elusive characteristics
of these cosmic targets.
Conrad and Merline had just looked at three asteroids and were
finishing the fourth. It was time for Daphne’s second session.
They moved the telescope to Daphne, and set the exposure time.
A minute or so passed. When the first image appeared on the
screen, something unusual appeared on the display.
“Holy Cow,” Merline said. Conrad looked up. He saw a dot, just
a few pixels wide, very close to the outer edge of the asteroid,
near the two-o’clock position.
Photo: Richard Ellis, whose research focuses
on galaxy evolution and observational cosmology, is pictured
here with his wife, Barbara, at Buckingham Palace following
the ceremony where he became a member of the Order of
the British Empire. Courtesy of Caltech.
Richard Ellis, whose research focuses on galaxy evolution and
observational cosmology, recently travelled not to the Hawaiian
Isles but to the British Isles to be invested as a Commander
of the British Empire (CBE). In a ceremony at Buckingham Palace
on July 3, Ellis was honored for "for services to international
science." The CBE is Great Britain's highest civilian honor
other than knighthood, and dates back to a British order of
chivalry established by King George V in 1917. It is rarely
given to nonresident British citizens.
Ellis, who is Caltech's Steele Family Professor of Astronomy,
is a senior observer at Keck and was recently a presenter for
the Observatory’s distinguished Evenings
with Astronomers lecture series in January, 2008.
Photo: Evenings
with Astronomers presenter Richard Ellis
captivates his Hawai’i audience with his presentation
on how he uses the Keck telescopes to find the most
distant galaxies in the universe. Courtesy of WMKO.
According to Observatory Director Taft Armandroff, “Richard
Ellis pushes the Keck telescopes and instruments to their absolute
limits to discover and understand the faintest and most distant
galaxies in the universe. The light that he measures from these
galaxies has been travelling to us for over 90% of the age
of the universe. He is a passionate initiator and contributor
to continually improving Keck’s capabilities. In addition,
he has served as a member of both the Keck Observatory’s Science
Steering Committee and our governing Board of Directors. His
scientific, technical, and organizational contributions to
Keck have played a significant role in the Observatory’s renown.
On behalf of the Observatory, congratulations Richard on this
well deserved recognition.”
Photo: Richard Ellis describes one of the
fascinating discoveries our universe holds to an inspired
lecture guest. Courtesy of WMKO.
Ellis received his undergraduate degree from University College
London and his Ph.D. from Oxford University. Before becoming
a professor at Caltech in 1999, he was a distinguished member
of the astronomical community in the United Kingdom. He served
as the prestigious Plumian Professor of Astronomy and Experimental
Philosophy at Cambridge.
He and his wife, Barbara, live in Pasadena, California.
Photo: Jon Lomberg created Cosmic Honu
to benefit the W. M. Keck Observatory in the Hawaii Island
public art exhibit called “It’s a Honu World.” On the
turtle’s back is a representation of the entire universe.
Courtesy of WMKO.
It started in Zurich, Switzerland in 1998. Large fiberglass
cows were painted into masterpieces by local artists and infused
the landscape with color and creativity. Quickly spreading
to America, the public art idea evolved and flourished — cows
in Chicago, salmon in Seattle, pigs in Petaluma, hearts in
San Francisco, and geckos in Honolulu, the whimsical collections
were later auctioned off to benefit local charities. Anyone
living on Hawai’i Island knows that this potent phenomenon
arrived in full living color in March, 2008, as It’s
a Honu World. Organized by Karen and Errol Kaufman, of
Hilo, the program garnered 35 Big Island artists to decorate
large sea turtle forms in support of local organizations including
the W. M. Keck Observatory. The painted turtles are on display
across the island through September, 2008.
Photo: At home in his Galaxy Garden, Jon
Lomberg stands in front of a fountain symbolizing the
massive black hole at the center of the Milky Way Galaxy.
Courtesy of Jon Lomberg.
Jon Lomberg, one of the world’s leading artists inspired by
science, created Cosmic Honu for Keck. Lomberg is a painter
who has lived with his family in Honaunau since 1987. Also
an Emmy Award winning art director for “Cosmos,” he was deeply
involved in Carl Sagan’s work for over 25 years, a journey
that culminated with designing the astronomical innovation
for the film, Contact.
According to Lomberg’s description
on the Honu exhibit page, “The artist has the unique distinction
of having created artwork carried aboard 5 different NASA spacecraft.
With work now on Mars and far beyond Pluto, Jon Lomberg can
claim the title of Earth’s most far-flung and enduring artist.
His work will last over a thousand millions years.” Lomberg
is also the creator of the Galaxy
Garden, a 100 foot diameter walk-through scale model of
our Galaxy at the Paleaku Peace Gardens Sanctuary.
Cosmic Honu is currently on exhibit at Keck Observatory headquarters
and will be available for purchase at an island wide Honu auction
in September. Please visit www.itsahonuworld.com for
auction details or call Joan Campbell at Keck Observatory at
808.881.3854.
Photo: An upside down reflection of Emily
Rice, graduate astronomy student at UCLA as she and other
workshop participants explore compelling ways to teach
basic principles in science and engineering. Credit:
S. Anderson/WMKO.
Since 2005 the W. M. Keck Observatory has participated in the
Akamai Observatory Internship Program, funded by the National
Science Foundation’s Center for Adaptive Optics (CfAO). The
Akamai education program is designed to rigorously prepare
Hawai’i undergraduate students for future Observatory careers
through a summer program that includes an intensive academic
short course, inquiry-based activities and workplace internships
with the observatories on Mauna Kea. To date Keck Observatory
has sponsored 17 students in the Akamai program and has also
participated in the CfAO’s Professional Development Program
(PDP), an initiative to improve science and technology teaching
methods and delivery. The 2008 CfAO PDP offered a workshop
which took place this past spring on Maui and some of the participants
took what they learned right into practice for the summer 2008
Akamai academic short course.
Emily Rice, a graduate student in astronomy at the University
of California at Los Angeles, summed up her CfAO experiences
by saying, “The CfAO professional development program is an
extraordinary opportunity to learn about the latest research
in cognitive science and learning theory and apply it to developing
curriculum and practicing facilitation techniques. It is wonderful
to meet other scientists and engineers who are passionate about
learning, teaching, and promoting a fair and diverse academic
community. The Akamai program is my favorite to work with because
it also helps me share my passion for astronomy and communicate
to students and the community the importance of the observatories
in Hawai’i. It sends the message that people with a variety
of backgrounds can make important contributions to a successful
observatory and that a successful observatory can have a positive
impact on the community.”
