greetings from the observatory for infrared · pdf filethe nature of white dwarf stars, ashes...
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GREETINGSFROMTHEFOUNDINGDIRECTOR
By Robert D. Gehrz
I am extremely pleased to
announce the formation of
the Minnesota Institute for
Astrophysics. The Institute
brings together 24 faculty
members of the School of
Physics and Astronomy
conducting research in
astrophysics, cosmology, planetary science, and space
science under a unified banner within the School. The
Institute will administer the University’s undergraduate
and graduate programs in astrophysics, and will help
coordinate astrophysics research in the former
Department of Astronomy with the growing astrophysics
program in the physics portion of the School.
The Minnesota Institute for Astrophysics consolidates the
University of Minnesota’s multimillion dollar annual
investment in astrophysics research. It will help to make
Minnesota be a star on the world stage of astrophysical
research by raising substantially our visibility in the
national and international science communities, within
the University itself, and in the public eye. Minnesota’s
world‐class Institute will elevate the University’s
pioneering research to a new level of excellence in
advancing fundamental understanding of the universe.
Institute scientists and their collaborators around the
world will work together at the forefront of science to
further their investigations of the origin, contents,
structure, and evolution of the Universe, the nature of
dark matter and dark energy, the origins of planets and
life, and astrophysical investigations of the fundamental
laws of physics. Astronomy has entered a “golden age”
with the advent of powerful new ground‐based telescopes
like the Large Binocular Telescope (LBT) and its
complimentary space‐based and airborne telescopes such
as the Hubble Space Telescope (HST), the Stratospheric
Observatory for Infrared Astronomy (SOFIA), and the
James Webb Space Telescope (JWST). Unexpected
discoveries leading to major new research areas in
astronomy and astrophysics are being reported on an
unprecedented scale. We will work actively to develop
new research funding opportunities that pave the way for
the creation of new knowledge and to seek endowed
support for the Institute’s key functions, including the
University’s involvement in the LBT project that is
facilitated by a generous $5.75 million gift from Hubbard
Broadcasting, Inc. Our long‐range plans are to expand the
current infrastructure that supports our scientists, attract
more top talent, and provide University of Minnesota
astrophysicists with state‐of‐the art resources to conduct
research at the forefront of discovery. Over the next
decade, the Institute faces a period of great opportunity.
Our partnership with the LBT increases our access to
observing time on the NASA facilities mentioned above,
and offers unparalleled opportunities to collaborate with
top scientists from many disciplines.
Minnesota has a proud history of research in astronomy
and astrophysics. The nature of white dwarf stars, ashes
of stars like the Sun, was discovered here early in the
1900’s. Minnesota’s astrophysicists pioneered the field of
infrared astronomy in the 1960’s. During the last three
decades, Minnesota’s astronomers have played key roles
in cutting‐edge scientific discoveries made with ground‐
and space‐based observatories operating at wavelengths
from the ultraviolet to the radio. Recently, our access to
the powerful LBT, currently the world’s largest
astronomical optical/infrared telescope on a single mount,
is a unique design that provides our students and faculty
with unprecedented scientific opportunities. In this
inaugural newsletter, we highlight the recent research and
other activities of the current faculty and staff of the
Minnesota Institute for Astrophysics.
_________________________________________________ Robert D. Gehrz, a graduate of the University of Minnesota (BA,
Physics 1967; PhD, Physics 1971), has been a member of the
faculty of the School of Physics and Astronomy since 1985. He
was Chairman of the Department of Astronomy from 2005‐2012.
___________________________________________________
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SOLIDBUCKYBALLSDISCOVEREDINSPACE
Minnesota Institute for Astrophysics professors Robert
Gehrz and Charles Woodward are part of an international
team that has, for the first time, discovered buckyballs in a
solid form in space. The discovery of these carbon
molecules in space may provide clues about the origins of
the Universe and if life could exist on other planets.
Formally named buckminsterfullerene, buckyballs are
named after their resemblance to the late architect
Buckminster Fullerʹs geodesic domes. They are made up
of 60 carbon molecules arranged into a hollow sphere, like
a soccer ball. Their unusual structure makes them ideal
candidates for electrical and chemical applications on
Earth, including superconducting materials, medicines,
water purification and armor.
Prior to this discovery, the microscopic carbon spheres
had been found only in gas form in the cosmos. In the
latest discovery, scientists used data from NASA’s Spitzer
Space Telescope to detect tiny specks of matter, or
particles, consisting of stacked buckyballs. They found the
particles around a pair of stars called ʺXX Ophiuchiʺ or
ʺXX Ophʺ that are 6,500 light‐years from Earth, and
detected enough to fill the equivalent in volume to 10,000
Mount Everests. ʺThese buckyballs are stacked together
to form a solid, like oranges in a crate,ʺ said Nye Evans of
Keele University in England, lead author of a paper
appearing in the Monthly Notices of the Royal
Astronomical Society. ʺThe particles we detected are
miniscule, far smaller than the width of a hair, but each
one would contain stacks of millions of buckyballs.ʺ
Buckyballs were detected definitively in space for the first
time by Spitzer in 2010. Spitzer later identified the
molecules in a host of different cosmic environments. It
even found them in staggering quantities, the equivalent
in mass to 15 Earth moons, in a nearby galaxy called the
Small Magellanic Cloud. In all of those cases, the
molecules were in the form of gas. The recent discovery of
buckyballs particles means that large quantities of these
molecules must be present in some stellar environments in
order to link up and form solid particles. The research
team was able to identify the solid form of buckyballs in
the Spitzer data because they emit light in a unique way
that differs from the gaseous form. University of
Minnesota astronomers Gehrz and Woodward were
involved in designing the program of infrared
spectroscopic observations using Spitzer to determine the
mineral content of the grains being produced in the XX
Oph system. Such information helps scientists determine
the essential building blocks of our Universe. Gehrz and
Woodward also were involved in analyzing and
interpreting the data. Some of the information they
uncovered was surprising.
ʺAlthough gaseous C60 molecules had already been
detected in space in low density vapor form, it was a big
surprise to find that they actually had condensed into
solid grains,” Gehrz said. “Our research suggests that
buckyballs are even more common in space than we ever
imagined.ʺ
ʺWe are all still surprised by nature,ʺ Woodward said.
ʺThe presence of C60 and other organic molecules in space
hold some interesting clues to whether life in the Universe
may also be common.ʺ
Buckyballs have been found on Earth in various forms.
They form as a gas from burning candles and exist as
solids in certain types of rock, such as the mineral
shungite found in Russia, and fulgurite, a glassy rock
from Colorado that forms when lightning strikes the
ground. In a test tube, the solids take on the form of dark,
brown ʺgoo.ʺ To read the full paper in the Monthly
Notices of the Royal Astronomical Society, visit:
http://onlinelibrary.wiley.com/doi/10.1111/j.1745‐
3933.2012.01213.x/abstract
NASAʹs Spitzer Space Telescope has detected the solid
form of buckyballs in space for the first time. Image
credit: NASA/JPL‐Caltech
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COMBININGTHEBEAMSOFTHELBT
Astronomers like to build large telescopes because they
can gather more light from objects in the heavens. In
addition to light gathering power, bigger diameter
telescopes can, in principle, produce sharper images as
well. Unfortunately, the Earthʹs atmosphere causes these
images to be blurred, essentially robbing us of the sharp
images we should be getting from our large telescopes.
During the last decade, new technology has allowed large
ground‐based telescopes to cancel the effects of the Earthʹs
atmosphere and produce very sharp images comparable
to space‐based telescopes. On the LBT, this is achieved
using a deformable mirror that can rapidly change its
shape to compensate for the blurring effects of the
atmosphere. This technique is called “Adaptive Optics”,
or AO. The AO system on the LBT is special because the
deformable mirror is not an extra set of mirrors in the
light path, but the telescope secondary mirror itself. This
eliminates the extra reflections necessary with other AO
systems. In addition, the LBT has two very large primary
mirrors, and we can bring the light from both together
and create even sharper images than would be possible
from each mirror alone. The combining of beams from
different primary mirrors is called “interferometry”. The
beams from the two primaries are combined with optics
that are held at liquid nitrogen temperatures, ‐321 degrees
Fahrenheit! With fewer reflections and very cold optics,
the LBT Interferometer can work at thermal infrared
wavelengths with far less unwanted background emission
from the telescope optics than is possible on other large
telescopes. The University of Minnesota helped build a
camera called LMIRCam, that images the universe at
infrared wavelengths, and operates at the combined focus
of the LBT. With LMIRCam we have been able to achieve
images as sharp as the Hubble Space Telescope can
achieve in visible light, but at wavelengths of 3‐5 microns,
much further into the infrared than is possible with the
Hubble. With this instrument we hope to image newly
forming solar systems and the winds from luminous stars,
search for warm Jupiters orbiting nearby Sun‐like stars,
and probe the space near super‐massive black holes at the
centers of other galaxies.
EDNEYANDTHEO’BRIENOBSERVATORY
The University of Minnesota’s O’Brien Observatory, in
Marine‐on‐St. Croix, was one of the world’s first infrared
(IR) telescopes. The 30” Cassagrain telescope serves as the
local research telescope for the Twin Cities campus.
Former Physics Professor Ed Ney realized that UM could
actually compete at infrared astronomy with observatories
built on high mountains that are above most of the
atmospheric water vapor that absorbs infrared light
coming from space. How could Minnesota play in this
game? During the Minnesota winter, when the dew point
falls well below zero, the air is as free of water as a 10,000
The Large Binocular Telescope Observatory
LBTI and its beam combiner (green frame) at the
combined focus of the LBT. LMIRCam, partly
designed built at the University of Minnesota, is
the blue box circled in yellow.
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‐foot high mountain top! Thus, Ed reasoned, one could
compete with the “Big Boys” by observing under the right
conditions with superior detectors using a rather small
(30‐inch) telescope. His proposal to build an IR
observatory in Minnesota was reviewed favorably at
NASA, and Ed set about to find an observatory site with
superior seeing and sky darkness qualities not too far
from the UM campus. The high hills of the St. Croix River
valley seemed an ideal place to search. With the aid of his
Jaguar XKE and a home‐made sky brightness meter, Ed
soon located the ideal site on a high hill in Marine on St.
Croix. The land was owned by a local named Thomond
“Thomy” O’Brien, a descendant of lumber baron William
O’Brien whose daughter had donated the land for nearby
O’Brien State Park in 1947. Ed soon had Thomy
enthralled with the prospect of being involved in the
project. Over martinis on Thomy’s front porch in July of
1966, the two cemented a deal whereby O’Brien
Observatory (OBO) would be constructed on a parcel of
land donated by Thomy to the University of Minnesota.
The North‐South line was laid on June 27, 1967.
Construction was completed and first light achieved
during August of 1967.
Over many years, the telescope has provided an esteemed
history of infra‐red and spectroscopy research and
discoveries. Today, OʹBrien Observatory is used
primarily for instrument testing and undergraduate and
graduate student instruction. However, Minnesota’s cold,
dry winter climate still offers opportunities for infra‐red
research thereby enabling the University to instruct
undergraduate and graduate students in the process of
collecting important, conclusive data without incurring
larger costs of traveling to one of the world’s major
observatories. This telescope’s utility holds true for
instrument testing as well since it features excellent
pointing and tracking capabilities. In addition to direct
support of University classroom instruction, O’Brien
Observatory’s close proximity to the Twin Cities
metropolitan area also offers a convenient location to host
various outreach events for local colleges and the general
public.
MT.LEMMONOBSERVINGFACILITY
Despite the early success of O’Brien Observatory, the
Minnesota Infrared Group and their collaborators at the
University of California at San Diego (UCSD) realized that
they needed regular access to a larger aperture, infrared‐
optimized telescope located at a dry, high altitude site
with clear sky. Two problems presented themselves: How
to fund the project and where to locate the observatory.
The funding problem was solved by gaining support from
four parties. The National Science Foundation (NSF)
The 60‐inch infrared telescope at Mt. Lemmon, Arizona.
The O'Brien Observatory and its 30‐inch infrared telescope.
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agreed to put in $100,000 in return for $50,000 matches
from UM and UCSD. The British offered to contribute an
unrestricted $100,000 to the group through the National
Research Council of Great Britain on the agreement that
the training of aspiring British infrared astronomers be
conducted at Minnesota. The three eventually trained
under this agreement were David Allen, John Hackwell,
and Martin Cohen.
The location problem was tackled by conducting an
extensive survey of a dozen mountain sites in the
southwestern United States and Hawaii, with data on
weather, thermal infrared emission, water vapor content,
and logistical support being collected primarily by
graduate students Bob Gehrz and Don Strecker. Two of
the best sites meteorologically, Mauna Kea, Hawaii and
the Snowy Range, Wyoming were ruled out on logistical
grounds given the realities of the project budget. Mt.
Lemmon was chosen after much soul searching, primarily
because it came with an existing dormitory/laboratory
building on an abandoned Strategic Air Command radar
base and easy access to liquid helium at the nearby
University of Arizona. The observatory, named the Mt.
Lemmon Observing Facility (MLOF), was constructed
during 1970 and first light was achieved in December,
1970. It has had a long and productive life and is still in
regular use. Originally manually slewed and pointed
because of the low construction budget, the MLOF
telescope was modified by Gehrz and Terry J. Jones in
1989 to be completely automated under computer control
with the capability of being remotely operated by
observers anywhere in the world using a phone modem.
DISCOVERYOFMASSIVEGALAXYCLUSTERS
Graduate student Damon Farnsworth, working with
Professor Lawrence Rudnick and Shea Brown (UMN PhD
2009), has discovered the first radio emission from
immense clusters of galaxies billions of years after
colliding with other clusters. These clusters have masses
equivalent to a million billion Suns. When they collide,
enormous shocks pump energy into protons and
electrons, speeding them up to nearly the speed of light.
But long after the collision, the radiation from these
particles dies away, and no clusters had ever been
detected in this quiescent state. Using the very sensitive
Green Bank Telescope, Farnsworth has discovered this
quiescent emission, which is important for understanding
the physics of the hot gas in these massive systems.
STUDENTSSTUDYTHESCIENCEOFNOTHING
Can you go to the U and study nothing? Absolutely, if
you enroll in Professor Lawrence Rudnickʹs Freshman
Seminar entitled, you guessed it, ʺNothingʺ. In this class,
students explore ancient and modern ideas about the
vacuum ‐ a surprisingly rich place teeming with radiation
and quantum particles, out of which the entire universe
may have emerged. They also look at the history of the
number zero, and struggle with nothing as seen through
the eyes of guests from many academic disciplines. From
the nothing of placebos, to minimalist art, to logical
paradoxes in the definition of the empty set, to blindness,
to nothing as a Shakespearean theme, students learn a
whole new way of looking at the world. These freshman
seminars, limited to 15 students, are a wonderful place
where students can get to know each other and faculty
members, even at the sometimes overwhelming U.
THESCIENCEOFHOCKEY
Minnesota Institute for Astrophysics Professor Bob Gehrz
participated in a series of short films for NBC Sports
called ʺThe Science of NHL Hockey.ʺ Gehrz contributes to
segments on Kinematics, Force, Impulse, & Collision,
Newton’s Three Laws of Motion, and Projectile Motion.
Morris Aizenman, senior scientist for the National Science
Foundation’s Directorate for Mathematical and Physical
Sciences, an adviser for the joint NSF‐NBC venture, knew
that Gehrz was a physicist who plays hockey and invited
him to participate. Gehrz has been skating since childhood
and has played organized adult hockey in many leagues
since 1980. He currently plays in an Over‐60 league with
several other employees of the School of Physics and
Astronomy.
http://www.nbclearn.com/portal/site/learn/science‐of‐nhl‐
hockey
UNDERSTANDINGTHEMAGNETIZEDUNIVERSEONVERYLARGESCALES
Magnetic fields pervade the universe and influence its
evolution on many scales. This is especially true in
clusters of galaxies that are just now collapsing by their
gravity out of the large scale expansion of the universe.
Galaxy clusters are the largest bound objects in the
universe. They provide unique information about the
history of the universe as a whole. The gravity of those
clusters is dominated by otherwise unseen ‘dark matter’,
whose nature is still a mystery. Most of the ordinary
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matter in galaxy clusters is very diffuse, hot and ionized
gas, which we can see by its X‐ray emissions. Weak
magnetic fields in that gas control many of its physical
properties, such as thermal conduction. They are also
responsible for energizing cosmic rays, very energetic
charged particles, seen in clusters through radio emissions
they produce. The physics that drives development of
these magnetic fields is very complex, so is best studied
through computer simulations. Professor Tom Jones,
along with Minnesota Institute for Astrophysics alumnus,
Dr. Francesco Miniati, now at the Swiss Federal Institute
of Technology in Zurich, Switzerland, is conducting a
study of the formation of galaxy clusters including the
physics of magnetic fields. The computer simulations are
being carried out on a computer in the Minnesota
Supercomputing Institute at the University of Minnesota.
This research aims to establish a clear understanding of
how magnetic fields develop in galaxy clusters and what
properties of those magnetic fields are most important to
the evolution of the clusters.
THEINTERFACEBETWEENPARTICLEPHYSICSANDCOSMOLOGY
Professor Marco Peloso works on the interplay between
elementary particle physics and cosmology. He focuses on
the imprint that particle physics processes could have left
in the early universe, and how cosmological data can be
used to learn about new fundamental physics. Pelosoʹs
main area of research is inflationary cosmology, a period
of accelerated expansion that took place in the first few
instances after the big‐bang, and during which the
universe underwent an enormous period of expansion: in
fact, the expansion occurred during inflation is
comparable to that in the next 14 billion years of existence
of the universe. Inflation is the only theory that can
explain (i) why the universe is overall so homogeneous
and isotropic, but also (ii) how the primordial small
perturbations were `generated on subatomic scales as
quantum mechanical fluctuations of the energy that drove
the inflationary expansion, and were then stretched to
cosmological scales by the inflationary expansions. They
then became the poles of attraction for the gravitational
collapse of matter that eventually resulted into the current
galaxies.
These primordial perturbations left their imprint in the
temperature anisotropies of the Cosmic Microwave
Background (CMB) radiation that is now observed by
balloons and satellites like the Wilkinson Microwave
Anisotropy Probe (WMAP). The Figure shows the data
from WMAP; different colors correspond to different
temperatures of the radiation, as observed by the satellite
in different directions on the sky. This radiation was
emitted when the universe was about 400,000 years old.
The statistical properties of these anisotropies encode a
great deal of information on inflation and the following
cosmological evolution. Particle physics processes that
took place during inflation (for instance the decay of the
The image here shows a network of galaxy clusters
from one of the computer simulations. The largest of
those clusters are just about to collide and merge
together. That process lasts for roughly a billion
years. Many smaller clusters are also visible in the
image. Some of those will also be incorporated into
the final large clusters. Others will end up being
expelled.
The infrared sky as seen by the WMAP satellite.
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source that drove the inflationary expansion into ordinary
radiation and matter) produce small distortions of the
CMB fluctuations; Prof. Peloso computes that precise
signatures of these processes.
DARKMATTERANDBIGBANGNUCLEOSYNTHESIS
Minnesota Institute for Astrophysics Professor Keith Olive
does research in the area of particle physics and
cosmology. His basic objectives are to discover the nature
of the mysterious dark matter and the production of light
elements like hydrogen and helium in the Big Bang.
Much of his work on dark matter deals specifically with
“supersymmetric” dark matter that lend hope to new and
major experimental discoveries around the corner.
Supersymmetry predicts the existence of a multitude of
new particles with masses. The search for these is the
subject of a major experimental effort. In addition, the
minimal supersymmetric model also predicts that one of
these new particles is stable and could be an important
candidate for the dark matter of the Universe. Olive’s
recent work has concentrated on providing very detailed
benchmark points that satisfy all phenomenological and
cosmological constraints of supersymmetric theories.
These points are then used to study potential signatures of
super symmetry at the Large Hadron Collider and
potential future linear colliders.
Big bang nucleosynthesis (BBN) is one of the cornerstones
of big bang cosmology and an area Olive has worked in
since 1979. As part of the foundation of our
understanding of the early Universe, the need to test and
scrutinize the standard model of BBN is essential.
Fortunately, it is a testable theory because there are a
number of astrophysical environments where primordial
or near primordial abundance determinations can be
made. The consistency of the standard nucleosynthesis
model rests on the ability of the model to ``predictʺ the
abundances of the light elements in these environments.
With improved measurements of the neutron half‐life,
and given the number of neutrino types, the baryon
(regular matter)‐to‐photon ratio is left as the key
parameter in big bang nucleosynthesis calculations. The
recent results from the WMAP microwave background
experiment, has now yielded very precise knowledge of
the baryon density. This result can then be used to further
scrutinize BBN. Recent progress on both the theoretical
and observational fronts have allowed BBN to thrive as
one of the more active areas in cosmology.
LYMAN‐ALPHABLOBSANDGALAXYFORMATION
Some of the most intriguing sources we can find in the
starry sky are the so called Lyman‐alpha blobs. These
ʺblobsʺ have nothing to do with the gooey monster in the
horror classic movie ʺThe Blobʺ but are instead enormous
hydrogen gas clouds, that can reach diameters of
hundreds of thousands of light years, and can emit as
much energy in a single emission line (Lyman‐alpha) as
our own Milky way emits in the full electromagnetic
spectrum. Typically found at large distances (when the
Universe was only a few billion years old), these objects
often have an enhanced number of galaxies nearby,
compared to normal objects at similar distances, and can
therefore provide useful clues on how massive galaxies
formed. What has been puzzling astronomers since the
discovery of the blobs about 10 years ago is the source of
energy for their extreme luminosity. There are primarily
two competing possibilities: on one hand blobs shine
when gas is pulled in by the blobʹs powerful gravity, and
cools down emitting Lyman‐alpha radiation. Another idea
is that the blob luminosity is the result of light emitted by
galaxies within it that scatters off the neutral gas in the
cloud. New observations we performed at the Very Large
Telescope in Chile show that the second explanation is the
right one. Institute Professor Claudia Scarlata and her
colleagues tested the two theories by measuring whether
The Lyman‐Alpha blob LAB‐1
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or not the light from one of the best‐studied blobs (LAB‐1)
was polarized. Polarization can result from light reflection
or scattering, so it should be observed if the blobʹs light is
actually light coming from galaxies within it and scattered
by the gas cloud. Instead, if the light is coming from the
gas itself, the light is expected not to be polarized. The
signal in these distant sources is extremely subtle and only
the largest, most sensitive telescopes could perform this
measurement. They found a clear ring of polarization in
the edges of the blob, strongly supporting the idea that
LAB‐1 shines with light produced by the galaxies and
reflected off the hydrogen gas cloud.
OBSERVINGNEARBYSPIRALGALAXIESWITHLBT Professor Evan Skillman has initiated a new project using
the University of Minnesotaʹs share in the Large Binocular
Telescope (LBT). A new spectrograph, the MOdular
Double Spectrograph (MODS), built by Professor Richard
Pogge (Ohio State) and commissioned last year, was
designed to be the best spectrograph in the world for
chemical abundance spectroscopy of star forming regions.
Professors Skillman and Pogge have received funding
from the NSF to conduct a large survey of nearby galaxies
which have been well studied in many ways, but lack
accurate chemical abundance studies. Our program,
CHAOS (Chemical Abundances Of Spiral galaxies), will
be the first large program to use MODS. Graduate
student Danielle Berg has already started obtaining
observations for this program and she will use these
observations in her Ph.D. thesis. In the next year, the
second MODS module will be installed on the LBT, and
thus, observing will become twice as efficient. The
completed study of roughly 1000 star forming regions in
thirteen spiral galaxies will provide an order of
magnitude more high quality spectra than any previous
study. This project with be a showcase for the
phenomenal capabilities of LBT/MODS.
HSTSURVEYOFTHEANDROMEDAGALAXY
Professor Skillman is part of a very large program using
the Hubble Space Telescope (HST) to gather observations
of our neighbor galaxy Andromeda. The Panchromatic
Hubble Andromeda Treasury (PHAT) is one of three
successful proposals granted under a special, one‐time
only call for multi‐cycle HST programs. The programs
had to be too ambitious to be considered for a normal
single year cycle. The program is led by Julianne
Dalcanton (University of Washington). They are just
finishing the second year of a three year program to
collect observations of the northeast quadrant of M31 (the
Andromeda Nebulae) to deep limits in the UV, optical,
and near‐IR. The HST imaging will resolve the galaxy into
more than 100 million stars. The central science drivers
are to: understand high‐mass variations in the stellar
initial mass function as a function of star formation rate
and metallicity; capture the spatially‐resolved star
formation history of M31; study a vast sample of stellar
clusters with a range of ages and metallicities. These are
central to understanding stellar evolution and clustered
star formation; constraining interstellar medium
energetics; and understanding the counterparts and
environments of transient objects (novae, supernovae,
variable stars, x‐ray sources, etc.). Previous UofM
graduate student Dan Weis is a postdoctoral researcher in
Seattle, and he is taking the lead on the main science goal
of studying the initial mass function. UofM graduate
student Jake Simones is working on understanding which
stars produce the ultraviolet radiation from M31 and how
well this UV radiation can be used as a measure of the star
formation rate. UofM graduate student Danielle Berg has
also observed star forming regions in M31 with the MMT
and Palomar telescopes and is producing accurate
measurements of the interstellar medium chemical
abundances. As the final data are acquired in the next
year, we will transfer from the current activities of testing
data reduction pipelines, verifying data products, and
producing prototype studies to producing the main
science papers.
LBTIMAGESTHEORIONTRAPEZIUM
The formation mechanism of stars, in particular those of
the lowest mass, is still a poorly understood process.
Computer simulations of star formation suggest that
stellar embryos frequently form into “mini‐clusters” that
“eject” the lowest mass members by tidal interactions.
Despite the success of these theoretical models, current
observations have not yet confirmed the existence of
“mini‐clusters” in the early stages of star formation. To
better understand whether such “mini‐clusters” exist, a
team of Large Binocular Observatory (LBT) astronomers,
including Minnesota Institute for Astrophysics Professor
Chick Woodward, have examined the Orion star
formation cluster for signs of such “mini‐clusters” using
advanced technology adaptive optics (AO) techniques.
The team focused their efforts on the famous Orion
Trapezium cluster to determine if some of the tight star
groups in the Trapezium cluster are gravitationally
bound, a first step toward determining whether bound
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“mini‐clusters” exist. In addition, this study was also
designed to assess and understand the true number of
real, physical binaries in this cluster.
The 8.4m LBT telescope has a unique AO system. To
reduce the image smearing caused by atmospheric
turbulence, the LBT AO system has a deformable
secondary mirror whose shape is updated 500 times a
second. The observations of the Orion cluster stars were
conducted with the AO science camera at near infrared
wavelengths. The image below, obtained on the night of
October 16, 2011, shows a view of four young stars in the
Orion Trapezium cluster 1,350 light‐years away as seen
through the LBT’s AO system. The closest binaries in the
system are separated by an angle equal to one half the
width of a human hair observed at a distance of 2.3 miles.
The image shows that all five members of the Trapezium
system appear to be a gravitationally bound “mini‐
cluster”. The very lowest mass member of the system
appears to be in an unstable orbit that will result in its
ejection from the “mini‐cluster”. This “ejection” process
could play a major role in the formation of low mass stars
and brown dwarfs.
WELCOMETOTHEZOONIVERSE!
Imagine a website where anyone with an interest in
astronomy, but no training, could participate in real
research – where six year olds and their grandparents
could exclaim at the beauty of the millions of galaxies that
fill our universe while helping astronomers untangle the
science behind the galaxies’ shapes. Welcome to Galaxy
Zoo! This online site (and its sister projects) has over
600,000 volunteers from 130 countries around the world
classifying galaxies from voluminous catalogs such as
those from the Sloan Digital Sky Survey or the Hubble
Space Telescope. Started five years ago by astronomers
from Oxford University in England and recently joined by
the University of Minnesota, the Galaxy Zoo project has
led to nearly thirty science publications. Several describe
discoveries made by members of the general public.
Galaxy Zoo was such a big success that the team decided
to extend the method of utilizing the capabilities of
human classifiers to multiple areas of research. As of
Spring 2012, fourteen “Zoos” have been launched with
plans for many more. The new projects range from
Planethunters.org where the public is invited to discover
planets orbiting stars observed by the Kepler satellite to
the Milky Way Project which asks people to aid in the
understanding of star formation in our own galaxy by
identifying certain types of objects seen in the infrared
data from the Spitzer Space Telescope. This “universe of
zoos” is called the Zooniverse (www.zooniverse.org) and
we invite you to help University of Minnesota researchers,
led by Professor Lucy Fortson, explore the universe from
the comfort of your own home. Who knows, you might
just be the next Hanny Van Arkel, a Dutch schoolteacher
who discovered a new kind of galaxy. Happy clicking!
A view of four young stars in the Orion Trapezium
cluster 1,350 light‐years away, as seen through the LBT’s
Adaptive Optics (AO). This is the best image ever taken
of these stars, which are all tightly located within 1
arcsecond of each other. By comparing this 2.16μm
infrared image to past images of this group over the last
15 years, astronomers can now see the motion of each
star with respect to the others. The movements show
that the mini‐cluster of young stars were born together,
but will likely fall apart as the stars age and interact
with each other (adopted from Close et al. 2012,
Astrophysical Journal).
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THEUNIVERSETHROUGHGAMMARAYEYES
The VERITAS telescope array, shown above, is located at
Mt. Hopkins near Tucson, Arizona. It comprises four 12‐m
telescopes sensitive to the ultraviolet flashes seen when
gamma rays from astrophysical objects arrive at Earth and
crash into air molecules. The four telescopes act in tandem
focusing on a target source of gamma rays such as
supernova remnants or an Active Galactic Nucleus like
that in the galaxy Mrk 421. The University of Minnesota
VERITAS group, led by Dr. Lucy Fortson, uses the
VERITAS data to study gamma rays that probe the most
extreme environments known to exist such as the beams
of material ejected out into jets from a giant black hole at
the center of a galaxy like Mrk 421.
POLARIZATIONOFTHECOSMICBACKGROUND
What were the physical processes in the beginning of the
Universe? We have reasonably firm answers for times that
are as short as a millionth of a billionth of a second after
the big bang. But for much shorter time scales our notions
of the precise physical conditions become somewhat
murky. The most widely prevalent paradigm is that the
Universe had undergone immense inflation at times as
short as a trillionth of a trillionth of a trillionth of a second
after the bang. Within a tiny fraction of a second it had
apparently expanded by trillions of trillions fold. There is
ample observational evidence that is consistent with this
paradigm. Now, there are ongoing efforts to detect a
direct signal from this epoch of tremendous inflation. The
E and B Observatory (EBEX) is a NASA‐supported
balloon‐borne experiment that is led by Minnesota
Institute for Astrophysics Professor Shaul Hanany. EBEX
consists of a telescope and millimeter‐wave receiver with
some 1500 state‐of‐the‐art bolometric detectors. Its goal is
to measure the polarization of the cosmic microwave
background radiation, a relic radiation from the big bang.
If inflation has in fact occurred it should leave a footprint
on the pattern of the polarization of the CMB. If it
occurred early enough after the bang, the footprint would
be sufficiently large that EBEX and other experiments
searching for this signal, have a chance of detecting it.
EBEX had a test flight in 2009 and the experimental team,
which includes collaborators at Berkeley, Brown, Cardiff,
Columbia University, and McGill, is getting ready for a
launch from McMurdo Base in Antarctica in December
2012. NASA conducts flights over Antarctica because the
wind pattern is such that the balloon circumnavigates the
continent and returns to the vicinity of McMurdo base
after more than ten days. Some balloon payloads have
even done three rounds accumulating more than 40 days
of flight. These are the longest balloon flights available
anywhere on the planet.
EBEX and the EBEX Team
OUTREACH:UNIVERSEINTHEPARK
At the conclusion of a talk by a guest speaker, when the
sky is dark, we set up two moderate aperture (8”‐10”)
telescopes and provide the park visitors the opportunity
to view whatever astronomical objects are available. Most
of the question and answer period takes place around the
telescopes. “UitP” sessions run as long as there are people
interested in looking through the telescope, and the parks
typically close before the interest has been sated.
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Scheduling for the summer of 2012 is presently under
way, so check the website: We are now entering the
twelfth year of “Universe in the Park”, the extremely
popular outreach program of the Minnesota Institute for
Astrophysics. “UitP” is predicated on a very simple idea
that the best environment in which to introduce the
general public to astronomy is outside under dark skies.
For the past eleven years we have taken UitP to Minnesota
state parks during the summer camping season, giving
talks and slide shows, answering questions, and letting
the general public view the heavens through one of the
UitP telescopes. In the course of a summer, UitP reaches
well over a thousand people in more than ten state parks
and several nature centers.
A typical UitP session begins just after sunset (about
9:00pm in June, 8:30pm in July & August) with a 20‐30
minute talk and slide show about astronomy. While the
particular topic is left up to the graduate student speaker,
we usually present a broad overview of astronomy or
recent astronomical news.
See: https://www.astro.umn.edu/outreach/uitp/
GRANTREMMENWINS$250,000FELLOWSHIP
The Fannie and John Hertz Foundation has awarded
University of Minnesota Institute for Astrophysics student
Grant Remmen a prestigious Hertz Fellowship to support
his future graduate studies. Considered to be the nation’s
most prestigious and
generous support for
graduate education in
applied sciences and
engineering, the Hertz
Fellowship is valued at
more than $250,000 per
student, with support
lasting up to five years.
Remmen will graduate summa cum laude from the
University of Minnesota’s College of Science and
Engineering this spring in each of his three majors:
astrophysics, physics, and mathematics. He has been
admitted to numerous top Ph.D. programs across the
country in physics and astrophysics and will begin
graduate study this fall.
Remmen has been conducting original research since his
freshman year, and his work on the Milky Way’s dark
matter and on the cosmic ray muon velocity distribution
has appeared in two publications in the Journal of
Undergraduate Research in Physics. At the University of
Minnesota‐Twin Cities, Remmen has investigated
aspherical black holes under the mentorship of Professor
Robert Gehrz and is currently conducting Hubble Space
Telescope research on Eta Carinae, a complex star system,
with Professor Kris Davidson. Last summer, with the
support of an international student scholarship from
University College London, he engaged in research on
general relativistic spin orbit coupling and its effect on
multiple‐body gravitational systems with Professor
Kinwah Wu, head of theory at Mullard Space Science Lab
in England. For his work on galactic dark matter, he was
awarded the American Astronomical Society’s Chambliss
Medal for exemplary student research. Remmen was
named a Goldwater Scholar in his sophomore year. He is
also a U.S. Presidential Scholar and a National Merit
Scholar, and has received many awards and honors at the
University of Minnesota. Remmen was one of 15 students
selected nationwide for the Hertz Fellowship from over
600 applications. The highly competitive selection process
includes a comprehensive written application, four
references, and two rounds of technical interviews by
recognized leaders in applied science and engineering.
NOVAGRAINSDISCOVEREDINCOMETDUST
Institute Professors Robert Pepin and Robert Gehrz, in
collaboration with Russell Palma (Minnesota State
University) and Sumner Starrfield (Arizona State
University), reported in the December 2011 issue of the
Astrophysical Journal their recent discovery that particles
released from several comets contain a number of dust
grains produced in a nova explosion. The comet particles
were collected using a high‐flying NASA U2 aircraft
during a period when the Earth was passing through the
dust trails of the periodic comets 26P/Grigg‐Skjellerup
and 55P/Tempel‐Tuttle. The group used a mass
spectrometer to measure the concentrations of isotopes of
the elements neon and helium in particles that were
ejected from these comets during their recent passages
near the Sun. They concluded that nine of the particles
contained dust grains that had a distinctive neon
signature suggesting that they were produced in
explosion of a nova system containing a neon‐rich white
dwarf. This exciting finding suggests that a nova
explosion near the interstellar cloud the Solar System
formed from could have been responsible for creating
some of the materials that contributed to the formation of
life and the planets.
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NASASOFIABEGINSSCIENCEFLIGHTS
Minnesota Institute for Astrophysics Professor Robert
Gehrz was the first Guest Investigator (GI) to fly on
NASA’s new Stratospheric Observatory for Infrared
Astronomy (SOFIA) when it took to the air from
Palmdale, CA for its inaugural Basic Science flight on May
5, 2011. The observatory consists of a 2.5‐meter (98‐inch)
diameter infrared (IR) telescope that flies at altitudes as
high as 45,000 feet to get above the atmospheric water
vapor that absorbs infrared radiation coming from space.
With its clear view of the infrared sky, SOFIA’s IR
spectrometers and imagers will help astronomers study
the origins of stars and planets, the characteristics of
comets and other Solar System bodies, and the chemical
evolution of the Universe.
When it becomes fully operational in 2014, the SOFIA
Observatory will fly more than 100 times per year until
the mid‐2030’s. It will be a valuable resource for
Minnesota faculty and their students. The Institute’s IR
group has a dozen SOFIA observing proposals pending
for the coming year and has also proposed to build a
second generation SOFIA spectrometer.
Gehrz represented two teams on the inaugural flight. The
first is a Minnesota team led by PI Roberta Humphreys
that is imaging the winds of dying supergiant stars using
the Cornell University FORCAST IR imager. The second
team, led by PI Mark Rushton if the University of Central
Lancashire (UK), is using FORCAST to detect dust
produced by explosions of recurrent novae. Both
programs aim to understand the fate of dying stars.
See: http://www.sofia.usra.edu
ALUMNINEWS
John M. Cannon, PhD, Astrophysics, 2004
After completing his thesis work at Minnesota in 2004,
Cannon did postdoctoral work at the Max Planck Institute
for Astronomy in Heidelberg, Germany, and at Wesleyan
University in Middletown, CT. He joined the faculty at
Macalester College in 2007, where he coordinates the
astronomy program. His research focuses on nearby, low‐
mass galaxies; together with Macalester students, he uses
data from ground and space‐based observatories to
explore these intriguing systems.
Jessica Ennis, MS, Astrophysics, 2008
I am an adjunct professor teaching astronomy at
Augsburg College and at Rasmussen College, tutoring
high school math and ACT for Sylvan Learning Center. In
November my husband Andy and I had a baby boy,
David. Hope all is well in the department!
Jeffrey Larsen, PhD, Astrophysics, 1996
After graduation in 1966, Jeffrey Larsen briefly did a
postdoc at the U of MN and then joined the staff of the
Spacewatch Project at the University of Arizona. Over the
next seven years he contributed to their Near Earth
Asteroid survey by revamping their detection software,
analyzing their data for new types of asteroid science and
observing one week every month using their telescopes on
Kitt Peak. During that time he discovered five comets, the
19th moon of Jupiter, the last lost numbered asteroid (719)
Albert and detected NASAʹs lost CONTOUR space probe.
He then joined the physics department faculty at the
SOFIA During its first open door test flight on 12/18/09.
Image courtesy of NASA.
Robert Gehrz and the FORCAST imager on SOFIA.
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United States Naval Academy. He is married with two
children and thoroughly enjoys getting out on the Bay as
much as possible.
Rodney Olson, B.S. Physics and Astrophysics 1993
I have been teaching high school physics since 1995. From
1995 to 2005 I taught at St. Francis High School in La
Canada, CA which is next door to JPL. My family moved
to Wisconsin for one year, and then we moved back to
California. Since 2006, I have been teaching physics, AP
Physics, chemistry, and astronomy at Crespi Carmelite
High School in Encino, CA. I founded the astronomy
program at Crespi, and hold monthly nighttime observing
sessions for the students with the school’s 11 inch
telescope at a dark sky location. I’m looking forward to
the annular solar eclipse on May 20, and the transit of
Venus on June 5! In August of 2011 I was promoted to
Science Department Chair.
After graduating from the U, I attended Winona State
University to obtain my teaching degree. I met my wife
there. Debbie is a registered nurse and we have two
children: Christopher who is 13 and in 8th grade, and
Marie who is 11 and in 6th grade. We flew back to
Minnesota in August of 2011 for my dad’s 80th birthday,
and stopped by the department before we left. I had a nice
visit with Professor Gehrz.
I would like to thank all of my excellent astronomy
professors who helped mold me into the science teacher
that I am today. I had so many good times teaching the
introductory lab, working in the IR Lab and going on
observing runs, and working on problem sets with friends
in the astronomy reading room. I appreciated the close‐
knit community that the department fostered, and I still
keep in touch with Brooks Rownd, Bill Ketzeback, Sean
Scully, and Jeff Larsen. I’d love to hear from others:
Elisha F. Polomski, Postdoctoral Associate
I am currently an assistant professor at the University of
Wisconsin‐Eau Claire Department of Physics and
Astronomy. I am heavily involved in both advising and
teaching and have taught astronomy as well as various
physics courses. Our department recently bought a new
camera for our observatory and this summer my student
and I will be conducting research on the Lagoon Nebula
star formation region. Iʹm also involved in public outreach
and have organized several astronomy public nights at
state parks. In addition I am currently in the process of
arranging a special astrogeology presentation at UWEC. I
have been granted permission from NASA to borrow
some lunar and meteorite samples and will have a
geologist give a talk on the specimens this May for
Astronomy Day. Other interesting notes: This March I will
be leading a trip to an internationally certified Dark Sky
site: Anza Borrego State Park in the Mojave desert. Trip
participants will be soaking up the sun during the day
and perusing the unusually dark, star filled skies after
sunset.
Brooks Rownd, Astrophysics
After my undergrad years in physics and astronomy at
Minnesota I went to grad school in Astronomy at the U of
Massachusetts in lovely Western Mass. In my later grad
school years I mostly worked on submm wavelength
bolometer arrays, including SuZIE and Bolocam at the
Caltech observatory on Mauna Kea. That led to a brief job
at the U of Colorado testing prototype components for the
SPIRE instrument of the Herschel Space Observatory.
After the SPIRE prototype testing ended I moved to the
Harvard‐Smithsonian Submillimeter Array (SMA) on
Mauna Kea. I initially ran the observatory at night, and I
currently maintain receiver systems at the summit during
the day. During my off‐time I explore Hawaiiʹs native
wilderness, volunteering as a bird surveyor and searching
for extremely rare native plants and snails.
Rodney Olson and family at Lake Winona in August 2011
14
THEFACULTYOFTHEISTITUTEANDTHEIRPRIMARYRESEARCHINTERESTS
Cynthia Cattell, Professor: Space plasma physics;
magnetic and electric field measurements; auroral particle
acceleration; particle acceleration processes.
Priscilla Cushman, Professor: Exploration into the
building blocks of matter through complementary
approaches.
Kris D. Davidson, Professor: Emission‐line analyses;
quasi‐stellar objects; supernova remnants; x‐ray sources;
massive stars.
John M. Dickey, Professor Emeritus: Radio astronomy;
spectral lines; structure of the interstellar medium.
Lucy Fortson, Associate Professor: High‐energy
astrophysics, gamma‐ray astronomy, extragalactic
astronomy including active galactic nuclei and barred
spirals; Developing online citizen science.
Robert D. Gehrz, Professor and Director: Infrared
Astronomy; novae; circumstellar and interstellar dust;
development of novel instrumentation.
Shaul Hanany, Professor: Studies of the early universe
through observations of the cosmic microwave
background, its anisotropy and polarization properties.
Alexander Heger, Associate Professor: Very massive
stars, the first generations of stars in the universe, stellar
structure, nucleosynthesis and the origin of elements.
Roberta M. Humphreys, Professor, Director of Under‐
graduate Studies: Stellar spectroscopy; galactic and
extragalactic studies; the cosmic distance scale. She heads
the Automated Plate Scanner Research Group.
Terry J. Jones, Professor, Director of Graduate Studies:
Infrared Astronomy; high‐resolution spectroscopy of
stars; interstellar medium; galaxies.
Thomas W. Jones, Professor: Theoretical Astrophysics;
numerical astrophysics; gas dynamics,
magnetohydrodynamics, active galaxies, supernova
remnants; cosmic ray acceleration.
Len Kuhi, Professor Emeritus: Stellar astrophysics
Robert Lysak Professor: Particle acceleration and the
dynamics of current flow in the earthʹs auroral zone.
Vuk Mandic, Assistant Professor: Gravitational wave
physics, observational cosmology, early universe physics.
Kieth Olive, Professor: Particle physics and cosmology,
big bang nucleosynthesis, the origin of the light element
isotopes through 7Li; particle dark matter; big bang
baryogenesis, and inflation.
Marco Peloso, Professor: Astroparticle physics, inflation,
cosmology of extra‐dimensions, physics beyond the
standard model.
Robert Pepin, Professor: Origin and early history of
volatile elements and compounds in the solar system as
revealed by mass spectrometer measurements of noble
gases and nitrogen in meteorites and lunar samples.
Clement Pryke, Associate Professor: Astrophysics and
cosmology; cosmic microwave background.
Yong‐Zhong Qian, Professor: Nuclear‐particle
astrophysics and cosmology, supernova explosion and
nucleosynthesis, chemical evolution of galaxies, neutrino
oscillations and their effects in astrophysical
environments.
Lawrence Rudnick, Professor: Research interests: Radio
Astronomy; radio galaxies and supernova remnants;
relativistic particle acceleration.
M. Claudia Scarlata, Assistant Professor: Observations of
high redshift galaxies, galaxy formation and evolution.
Evan D. Skillman, Professor: Chemical abundances; star
formation; evolution of galaxies.
Liliya L. R. Williams, Associate Professor, TA
Coordinator: Theoretical cosmology; cosmological
parameters; large scale structure; formation and evolution
of galaxies and clusters of galaxies; gravitational lensing
including computational techniques.
15
Charles E. Woodward, Professor Program Director,
LBT/SO: Infrared instrumentation and technology
development for observational astrophysics.
Paul R. Woodward, Professor, Director, LCSE:
Numerical Astrophysics; hydrodynamic simulations
applied to a wide range of astrophysical problems.
John Wygant, Professor of Physics: Spacecraft
measurement of electric fields and particle acceleration in
space plasmas.
VISITINGSCHOLARSANDRESEARCHASSOCIATES
Howard French, Honeywell, Inc., Adjunct Professor
Alejandro G. Bedregal, Postdoctoral Associate: Galaxy
formation and evolution, local universe and high‐redshift,
stellar populations, scaling relations, kinematics, galaxy
structure, morphology.
Attila Kovacs, Postdoctoral Associate: Submillimeter
astronomy.
Kristen McQuinn Postdoctoral Associate: Galactic
evolution, starburst galaxies, star formation histories
Peter Mendygral, Cray, Inc.,. Postdoctoral Associate:
Computational astrophysics, magnetohydrodynamics,
active galaxies, galaxy clusters,