Possible Projects

Observational Stellar Astrophysics (Prof. Bob Mathieu):

As part of the NSF-supported WIYN Open Cluster Study, our group investigates the binary populations of stellar open clusters. Binary stars in clusters are not only the fuel behind cluster evolution, they also provide an intriguing opportunity to explore the interplay between stellar evolution and stellar dynamics.  We use knowledge of binary star populations to study non-standard stellar products for which a coherent picture of formation and evolution is not yet fully understood. Examples of such stellar anomalies include blue stragglers and sub-subgiants.

Another focus of our group is exploring accretion dynamics of young binary systems with circumstellar disks. Remnants from formation, these disks affect the orbits and eventual masses of binary systems. Despite being the most common products of star formation, binary evolution at this early phase remains an open topic of research.

Depending upon the particular interests of students, possible projects could involve measuring precise stellar radial velocities using the multi-object spectrograph of WIYN, developing new techniques to determine parameters for binaries, investigating triple systems using imaging and spectroscopic data, searching for faint stellar companions in anomalous stellar systems, or analyzing new data of pre-main-sequence binaries from the SALT high-resolution spectrograph. An observing run at the WIYN Observatory would be likely.

Galaxies and their environments (Prof. Jay Gallagher):

We are obtaining optical/infrared observations from a variety of ground-based telescopes, including the 3.5-m WIYN and the 4.2-m William Herschel Telescope, for a study of how the internal structures of galaxies are modified by their environments.

This project involves the quantitative analysis of galaxy images to define basic structures, the measurement of star formation rates, and determinations of internal stellar and ionized gas kinematics. We are applying these techniques to galaxies with special characteristics, such as those with signatures of recent disturbances, e.g., polar ring galaxies and starbursts, as well as to systems that appear to have been quiescent for long time periods (such as "super thin" disk galaxies).

This will provide an REU student with a range of opportunities for the collection, analysis, and interpretation of galaxy observations within the framework of dynamical constraints on their evolutionary processes.

Environmental Impacts on Galaxy Evolution in Groups (Prof. Eric Wilcots)

Professor Wilcots has a number of possible projects focused on understanding galaxy groups and the relationship between the evolution of the group environment and the evolution of the resident galaxies.  One theme is using observations at radio and optical wavelengths to measure the properties of the intergalactic medium in galaxy groups; this work could involve the analysis of the velocity distribution of galaxies in groups, the analysis of deep radio continuum observations, or using numerical simulations.  A second possible project would involve studying the stellar populations in group galaxies as a probe of the dynamical evolution of groups and rate at which the environment quenches star formation in galaxies.

X-ray astrophysics (Prof. Dan McCammon):

The last few years have seen a revolution in the spectroscopic and imaging sensitivity of astrophysical X-ray detectors. We have a very instrumentally-based program aimed at developing a new type of detector technology that measures the temperature rise produced by the absorption of single X-ray photons and can achieve energy resolutions 100 times better than a theoretically perfect CCD or solid state detector. 

We are using these detectors in a sounding rocket program to study the galactic and extragalactic soft X-ray backgrounds. Improvements in the detectors will allow a search for the "missing baryons" in intergalactic space, and improved studies of the very hot components of the interstellar medium in our galaxy.  We also support the deployment of similar detectors on general-purpose space-based observatories such as Astro-H.  Interested students can learn fabrication and cryogenic techniques needed to assemble and test detectors, and methods of X-ray data analysis.

Warm Ionized Medium (Dr. Matt Haffner):

Under the leadership of Prof. Ron Reynolds, Wisconsin has carried out the first survey of the entire galaxy in the H-alpha emission line of ionized hydrogen. These maps show the location and effect of hot ionizing stars, but also indicate the presence of a mysterious, low density ionized gas filling much of interstellar space. The velocity resolution provided by WHAM can allow astronomers to map out the distribution of this gas, while observing other diffuse optical emission lines can characterize the temperature, chemical state, and ionization level of the gas.

Neutrino Astrophysics and Astronomy (Prof. Francis Halzen, Prof. Albrecht Karle, Prof. Justin Vandenbroucke, Prof. Stefan Westerhoff and Scientist Dr. John Kelley):

The completed IceCube neutrino detector at the South Pole is the first instrument with the sensitivity required to capture signals of cosmic neutrinos. Rather than collecting light, it probes the high-energy Universe by detecting neutrinos. Since the 1950s, scientists have built a compelling case for using high-energy neutrinos as ideal messengers from the most interesting, violent, and least understood phenomena in the Universe.  Throughout the previous decade, an international collaboration of scientists has designed, constructed, and operated the first kilometer-scale neutrino telescope. Originally conceived at the University of Wisconsin, IceCube has transformed a cubic kilometer of natural Antarctic ice into a Cherenkov detector. Optical sensors embedded in the ice detect the photons radiated by charged particles produced in neutrino interactions. They detect the faint flashes of light created by neutrino interactions in the transparent ice.

Since early construction of the detector, the IceCube group has employed about 5 to 10 undergraduates. Although work is ongoing on the development of a next-generation detector, data analysis is a priority focused on the origin of cosmic neutrinos as well as on the study of the neutrino itself.

Additionally, students will have the option to work on the development of the Askaryan Radio Array (ARA). ARA is a pioneering neutrino detector located at the South Pole designed to detect ultra-high-energy neutrinos from cosmic ray interactions with the cosmic microwave background.  Our current research is focused on separating potential neutrino signals detected by the ARA antenna arrays from the large background of thermal noise, as well as developing directional and energy reconstruction algorithms that can be used to estimate neutrino properties once such rare events are detected.  REU students on this project will learn the necessary techniques in radio signal analysis, interferometric beamforming, data analysis and reduction in Python and C++, and parallel processing with graphics processing units (GPUs) in order to contribute to our research.  Specific projects include, but are not limited to: raytracing of radio signals in the Antarctic ice sheet; accelerating interferometric neutrino directional reconstruction with GPUs; and optimization of detector triggers and neutrino event filters running at the South Pole.

TeV gamma-ray astronomy (Prof. Justin Vandenbroucke)

The student in this project will work with Prof. Justin Vandenbroucke’s group on the camera for a gamma-ray telescope under construction in Arizona. The telescope will detect Cherenkov flashes from very-high-energy (TeV) gamma rays that collide with Earth’s atmosphere and is a prototype for the upcoming Cherenkov Telescope Array.  The camera features 1024 channels of silicon photomultipliers and custom electronics and is five feet across with a mass of 500 kg.  Images, movies, and a live webcam of the telescope are available at http://cta-psct.physics.ucla.edu.

Observational Cosmology (Prof. Peter Timbie):

The Observational Cosmology group uses two astrophysical tools to study the evolution and structure of the universe: 1) the ancient photons that make up the 2.7 K cosmic microwave background (CMB) allow us to explore cosmological history as far back as a redshift of z = 1400, some 300,000 years after the Big Bang; 2) radiation from neutral hydrogen gas at a wavelength of 21-cm traces the large-scale distribution of matter and dark matter, which in turn probes dark energy, neutrino mass, etc.

Students in the Observational Cosmology group assist in building the most sensitive detectors of microwave and radio radiation possible and can learn about radio astronomy, cryogenics, superconductivity, microwave circuits and antennas, and data analysis.

REU students can choose to work on the development of a superconducting microwave sensor called a microwave kinetic inductance detector (MKID), specifically designed for measurements of the polarization of the CMB. CMB polarization is expected to arise from gravitational waves released during the inflation process during the Big Bang. Another project is to design and test antennas and receivers for the Hydrogen Structure Array, a radio interferometer under development for measuring 21-cm radiation.

Cosmic ray observations and their propagation in magnetic fields (Dr. Paolo Desiati):

After more than one hundred years from the discovery of penetrating cosmic particles from space, we still have quite a lot to learn about the origin and journey from their sources to us. The observation of cosmic ray particle energy, mass and arrival direction distributions can provide useful information on their history, especially if combined with the detection of high energy neutrinos and electromagnetic emissions such as gamma rays. To reconstruct their history it is necessary to disentangle the effects of their production at the sources with those of propagation in interstellar magnetic fields. One way to do so is to analyze experimental data collected by IceCube and IceTop and the South Pole and compare them with results from other experiments and relate them with scenarios of cosmic ray production and propagation. In addition, the study of particle trajectories in magnetic fields can provide the necessary information to reconstruct the more complicated puzzle of cosmic ray propagation in magnetized plasmas. Thus we may be able to utilize cosmic ray distributions in a given energy and mass range to probe interstellar magnetic fields within a defined distance scale and infer their diffusion coefficients.

Project:  Mapping the Disk of the Milky Way Galaxy (Prof. Bob Benjamin):

Using data from NASA’s Spitzer Space Telescope, WISE (Widefield Infrared Survey Explorer), and two ground-based infrared surveys (UKIDSS-Galactic Plane Survey) and VVV, you will help develop new three dimensional maps of the stellar density  and star-forming regions of our own Milky Way Galaxy  Distances to these stellar sources will be calibrated with data  from the (European Space Agency) Gaia satellite which will release parallax and proper motion information for up to a billion stars in April of 2018. Depending on the pace of discoveries, you may also have an opportunity to measure the circular and non-circular motion of stars in the Galactic disk.

Th/Ar Spectra for Wavelength Calibration in the Search for Exoplanets (Dr. Elizabeth Den Hartog and Prof. Jim Lawler)

Thorium-Argon (Th/Ar) hollow cathode lamps are commonly used as optical wavelength calibration lamps for high-resolution spectrographs on ground-based astronomical telescopes.  The high atomic weight of thorium and its complex atomic spectrum provide over 20,000 narrow calibration lines, covering wavelengths from 277 nm to 5400 nm. (see the Th/Ar atlas at:  www.nist.gov/pml/spectrum-th-ar-hollow-cathode-lamps) This has made Th/Ar lamps an ideal calibration source for the calibration of optical spectra from high-resolution spectrographs used for exoplanet detection.  Uranium containing lamps are similarly used as calibration sources in the near-infrared. (Redman et al. 2011, ApJS 195:24; Redman et al. 2012, ApJS 199:2)

Recently, however, the quality of commercially available Th/Ar lamps has deteriorated, with molecular bands of ThO that are strong enough to obscure the thorium spectral lines used for calibration. This has become a major concern for the use of these lamps in the future for calibration of astronomical spectrographs. However, if the positions of the ThO lines can be measured, it will be possible to use them in addition to the atomic thorium lines for wavelength calibration.

Previous laboratory measurements of the spectra of Th/Ar hollow cathode lamps have been made using Fourier transform (FT) spectrometry. This technique provides the most accurate wavelength calibration standards. However, this is not a suitable technique for the measurement of weak molecular lines in hollow cathode lamps, as the noise in a spectrum from a FT spectrometer is dominated by the strong lines and is spread out equally throughout the spectrum to obscure the weaker molecular lines. An alternative instrument for measuring the Th/Ar spectrum is the University of Wisconsin high-resolution echelle spectrograph.  This spectrograph has a resolving power of 250,000, and as a dispersive instrument, does not suffer from the noise constraints of an interferometric device like an FT spectrometer.  It is ideal for the measurement and characterization of the weak ThO molecular lines.

This project will involve measuring the spectrum of the Th/Ar hollow cathode lamp with the high-resolution echelle spectrograph.  The spectrum will then be carefully characterized: line wavelengths and relative intensities will be measured; known lines will be identified with their respective energy levels, etc.  Some programming may be required to turn the 2-D CCD spectra into 1-D spectra and extract the wavelength and intensity information.  In collaboration with National Institute of Standards and Technology (NIST) personnel, this data will be added to the Th/Ar atlas cited above.  This NIST atlas will be an important resource for the wavelength calibration of planet-finding spectrographs as well as other high-resolution spectrographs on ground-based telescopes.

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