APS Directory ~ Faculty and Their Research Interests

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Picture of Phil Armitage

Phil Armitage


I work on theoretical and computational astrophysics problems in the fields of planet formation, accretion physics, and black hole astrophysics. Topics of current interest include novel models for X-ray binary disk evolution, turbulence in protoplanetary disks, and planetesimal formation.

Selected Recent Publications:

Magnetically driven accretion in protoplanetary discs

Accretion disk dynamo as the trigger for X-ray binary state transitions

Physical processes in protoplanetary disks

Picture of Fran Bagenal

Fran Bagenal


My research interests are in the magnetic fields of planets, planetary plasmas and the interaction of planetary objects - from giant Jupiter down to tiny comets - with the solar wind or magnetospheric plasmas. I work with data from planetary missions (Galileo, Deep Space 1, New Horizons, Juno) as well as emissions observed remotely with telescopes (HST, Cassini).

Selected Recent Publications:

Jupiter: The Planet, Satellites and Magnetosphere, Fran Bagenal, Bill McKinnon, Tim Dowling (eds), Cambridge University Press 2004

Mass and Energy Flow Through the Magnetospheres of Jupiter and Saturn, Bagenal, F., P.A. Delamere, J. Geophys. Res., 116, A05209, 2011

Planetary Magnetospheres, Fran Bagenal, Planets, Stars and Stellar Systems.Volume 3: Solar and Stellar Planetary Systems, 2013,

Picture of Daniel Baker

Daniel Baker

(Professor & Director of LASP)

Daniel Baker has experience in the analysis of large data sets from spacecraft at geostationary orbit and has been involved in missions to the Earth's deep magnetotail and comets, in the study of solar wind-magnetospheric energy coupling, and thoretical modeling of the possible role of heavy ions in the development of magnetotail instabilities. He is presently working on the problem of magnetosphere-atmosphere coupling and is applying space plasma physics to the study of astrophysical systems. Daniel Baker has devoted much of his recent research effort to understanding magnetospheric substorms and to show how these disturbances contribute to anomalies in the operation of near- earth spacecraft and has developed nonlinear (chaos) models of substorm processes. His present interests include the use of computer systems and networks to enhance the acquisition, dissemination, and display of spacecraft data.

Selected Recent Publications:

Publications List

Picture of John Bally

John Bally


Observations and theory of star and planet formation. Jets, outflows, and Herbig-Haro objects. Protoplanetarydisks. The origin, evolution, and destruction of molecular clouds.The formation of massive stars and star clusters, and theirimpacts on lower mass star birth and planet formation.

Selected Recent Publications:

Bally, J., Walawender, J., Reipurth, B., and Megeath, S.T. 2009, "Outflows and Young Stars in Orion's Large Cometary Clouds L1622 and L1634", A.J., 137, 3843-3858.

Bally, J., Licht, D., Smith, N., and Walawender, J. 2006, "Irradiated and Bent Jets in the Orion Nebula", A.J., 131, 473-500.

Bally, J., Walawender, J., Luhman, K., and Fazio, G. 2006, "Deep Imaging Surveys of Star Forming Couds. IV. The Meek and the Mighty: Outflows from Young Stars in Chamaeleon I", A.J., 132, 1923-1937.

Picture of Mitchell C. Begelman

Mitchell C. Begelman


Theoretical and high energy astrophysics. Current interests include the formation and growth of supermassive black holes, analytic and computational studies of the hydrodynamics of accretion flows, and the role of feedback from Active Galactic Nuclei (AGN) on galaxies and clusters.

Selected Recent Publications:

Published papers

Picture of David Brain

David Brain

(Assistant Professor )

I study the plasma environments and atmospheres of unmagnetized planets. This includes Mars, Venus, and the Moon. I primarily use spacecraft data in my research (and am a Co-Investigator on the MAVEN mission to Mars), but sometimes also work with computer models. This topic is exciting to me because charged particles and magnetic fields from the Sun are believed to have fundamentally altered the atmospheres of these bodies over the past 4+ billion years. By studying processes that occur there today we hope to unravel how these planets evolved, and why their atmospheres are so different from our own. Also, little zippy charged particles do crazy things.

Selected Recent Publications:

Brain, D.A., F. Leblanc, J. Luhmann, T. Moore, and F. Tian, Planetary Magnetic Fields and Climate Evolution, in "Comparative Climatology of Terrestrial Planets" edited by S. Mackwell, J. Harder, and M. Bullock, University of Arizona Press, 2013.

Brain, D.A., Baker, A. H., Briggs, J., Eastwood, J.P. Halekas, J.S. Phan, T.-D. (2010), Episodic detachment of Martian crustal magnetic fields leading to bulk atmospheric plasma escape, Geophys. Res. Lett., 37, L14108, doi:10.1029GL043916.

Brain, D.; Barabash, S.; Boesswetter, A.; Bougher, S.; Brecht, S.; Chanteur, G.; Hurley, D.; Dubinin, E.; Fang, X.; Fraenz, M.; and 17 coauthors (2010), A comparison of global models for the solar wind interaction with Mars, Icarus, 206(1), doi:10.1016/j.icarus.2009.06.030.

Axel Brandenburg

Picture of Ben Brown

Ben Brown

(Assistant Professor)

I am interested in fluid dynamics in stars and exoplanets. Convection in these systems provides turbulent transport and mixing, drives waves, and builds magnetic fields. We use modern open-source tools on massively parallel supercomputers to study these systems.

Selected Recent Publications:

Angular momentum transport via internal gravity waves in evolving stars Fuller, J, Lecoanet, D, Cantiello, M, & Brown, B P, 2014, ApJ, 796, 17:1–12

Conduction in low Mach number flows: Part I Linear and weakly nonlinear regimes Lecoanet, D, Brown, B P, Zweibel, E G, Burns, K J, Oishi, J S, & Vasil, G M,, 2014, ApJ, 797, 94:1–16

Energy conservation and gravity waves in sound-proof treatments of stellar interiors: Part I anelastic approximations Brown, B P, Vasil, G M, & Zweibel, E G, 2012, ApJ, 756, 109:1–20

Picture of Jack Burns

Jack Burns


My research focuses on extragalactic astronomy and cosmology; observations of active galaxies and galaxy clusters using radio interferometers, optical telescopes, and x-ray satellites; supercomputer numerical simulations of astrophysical jets and large scale structures in the universe; and, design of next-generation observatories in space and on the Moon. I direct the Lunar University Network for Astrophysics (LUNAR), a multi-university center of excellence funded by the NASA Lunar Science Institute.

Selected Recent Publications:

A lunar L2-Farside exploration and science mission concept with the Orion Multi-Purpose Crew Vehicle and a teleoperated lander/rover, Burns, J. O., et al. (2013)

Interpreting the Global 21 cm Signal from High Redshifts. I. Model-independent constraints, Mirocha, J., Harker, Geraint J. A., Burns, J. O. (2013)

Cosmological Magnetohydrodynamic Simulations of Galaxy Cluster Radio Relics: Insights and Warnings for Observations, Skillman, S. W., et al. (2013)

Picture of Webster C. Cash

Webster C. Cash


My research is in developing new technologies for space observatories. I am actively involved in providing reflection gratings for the spectrographs on the Constellation-X Mission. I am also developing techniques of x-ray interferometry with the eventual goal of imaging black holes from the MAXIM Mission. Currently I emphasizing work on external occulters for the purpose of suppressing starlight to reveal planets around stars. Direct study of exoplanets may be thereby enabled in the next decade.

Selected Recent Publications:

Oakley, P. and Cash, W. 2009, "Construction of an Earth Model: Analysis of Exoplanet Light Curves and Mapping the Next Earth with the New Worlds Observer", Ap.J., 700, 1428-1439.

Cash, W. 2006, "Detection of Earth-like Planets Around Other Stars Using Petal-Shaped Occulters", Nature, 442, 51-53.

Cash, W. 2004, "X-ray Interferometry", Exp. Astr., 16, 91-136.

Picture of Julie Comerford

Julie Comerford

(Assistant Professor )

My research focuses on galaxy evolution and AGNs. Specifically, I am interested in pairs of supermassive black holes that are brought together during galaxy mergers. These black hole pairs can be observable as AGNs with kpc-scale separations, and they are useful as tracers of galaxy mergers and supermassive black hole growth.

Selected Recent Publications:

Publications via NASA ADS

Picture of Steven Cranmer

Steven Cranmer

(Associate Professor)

My research interests include solar and stellar astrophysics. Specifically, I study the heating and energization of particles in the solar corona, the acceleration of the solar wind, and waves and turbulence in all kinds of astrophysical plasmas. Understanding the hot, expanding outer atmosphere of the Sun is a necessary precursor to being able to predict the Sun's long-term effects on the Earth's climate and local space environment. Other research includes radiative transfer in stellar atmospheres, kinetic plasma physics, the dynamics of winds from rotating hot (O, B, Wolf-Rayet) stars, and nonradial stellar pulsations.

Selected Recent Publications:

Cranmer, S. R. 2014, "Suprathermal Electrons in the Solar Corona: Can Nonlocal Transport Explain Heliospheric Charge States?" ApJ Letters, 791, L31.

Cranmer, S. R., Bastien, F. A., Stassun, K. G., and Saar, S. H. 2014, "Stellar Granulation as the Source of High-Frequency Flicker in Kepler Light Curves," ApJ, 781, 124.

Cranmer, S. R., van Ballegooijen, A. A., and Woolsey, L. N. 2013, "Connecting the Sun's High-Resolution Magnetic Carpet to the Turbulent Heliosphere," ApJ, 767, 125.

Picture of Jeremy Darling

Jeremy Darling

(Associate Professor and Associate Department Chair)

I work on topics in galaxy evolution, massive black holes, star formation, and cosmology. Most of my research is observational, lately focusing on precise measurements, both spectral and spatial, to study cosmology, gravity, and fundamental physics.

Selected Recent Publications:

Darling, J. 2014, "The Hubble Expansion is Isotropic in the Epoch of Dark Energy," MNRAS, 442, L66

Darling, J. 2013, "Objects Appear Smaller as they Recede: How Proper Motions can Directly Reveal the Cosmic Expansion, Provide Geometric Distances, and Measure the Hubble Constant," ApJ, 777, L21

Darling, J. 2012, "Toward a Direct Measurement of the Cosmic Acceleration," ApJ, 761, L26

Picture of Jean-Michel Desert

Jean-Michel Desert

(Assistant Professor)

My main research focuses on detecting and characterizing planets orbiting other stars (exoplanets). I use a variety of ground- and space-based facilities to detect and characterize exoplanets with the ultimate goals of understanding their formation, evolution and of assessing their habitability. I am a collaborator on the Kepler mission, a space telescope designed to search for habitable planets.

Selected Recent Publications:

Published Papers (from ADS)

Picture of Doug (Douglas) Duncan

Doug (Douglas) Duncan

(Sr Instructor, Dir Fiske Planetarium)

My research interests include stellar spectroscopy, testing the BigBang by studying abundances in the oldest stars, galactic chemicalevolution, stellar rotation, and the evolution of stars like thesun. Some work is in conjunction with my recent Ph. D. studentsFrancesca Primas (now at the European Southern Observatory, in Germanyand Chile ) and Luisa Rebull (now at NASA's Infrared Processing andAnalysis Center, Pasadena, CA).An additional interest is teaching and communication of science. Iserved for 4 years as national Education Coordinator of the AAS, and 5years as science commentator on National Public Radio. Research showsthat there are much more effective ways to teach science than justlecturing. At CU I oversee TA training designed to help our studentsbecome excellent teachers and give them the knowledge and ability tocompete for any job which includes teaching.

Selected Recent Publications:

Published Papers

Picture of Erica Ellingson

Erica Ellingson

(Assoc. Professor)

My research interests include observational cosmology, galaxy evolution and active galactic nuclei. Current programs include multi-wavelength observations of high redshift galaxy clusters to measure dark matter mass distributions and quantify the effects of environment on galaxy formation and evolution.

Selected Recent Publications:

Ellingson, E., Burke, D., Mrockowski, T, et al., SPARCS J161315+564930: X-ray and Sunyaev-Zeldovich Confirmation of an Extremely Massive Cluster at Z=0.87, 2013, ApJS,submitted

Faloon, A., Webb, T, Ellingson E., et al., "The Structure of the Merging RCS 231953+00 Supercluster at z ~ 0.9,"2013, ApJ 768, 104

Loh, Y-S, Ellingson, E., Yee, H.K.C., et al., "Color Bi-Modality in Galaxy Clusters since z=0.9," 2009, ApJ 680, 214

Picture of Robert Ergun

Robert Ergun


My research is on heliospheric and astrophysical plasmas. Our research group at LASP has built, or is currently building, electric field and wave instruments on five NASA missions including, FAST (Earth's aurora), THEMIS (Earth's magnetosphere), RBSP (Earth's radiation belts), MMS (magnetic reconnection mission), and MAVEN (Mars atmosphere). We also contribute to STEREO (solar wind) and JUNO (Jupiter's aurora). Theoretical work is on (1) double layers, electron phase-space holes, and other nonlinear plasma structures, associated with particle acceleration (2) magnetic reconnection, (3) wave generation and cosmic radio sources, and (4) solar wind turbulence.

Selected Recent Publications:

R. E. Ergun, D. M. Malaspina, Iver H. Cairns, M. V. Goldman, D. L. Newman, P. A. Robinson, S. Eriksson, J. L. Bougeret, C. Briand, S. D. Bale, C. A. Cattell, P. J. Kellogg, and M. L. Kaiser, Eigenmode Structure in Solar Wind Langmuir Waves, Phys. Rev. Lett. 101, 051101, 2008.

R. E. Ergun, L. Andersson, J. Tao, V. Angelopoulos, J. Bonnell, J. P. McFadden, D. E. Larson, S. Eriksson, T. Johansson, C. M. Cully, D. N. Newman, M. V. Goldman, A. Roux, O. LeContel, K.-H. Glassmeier, and W. Baumjohann, Observations of Double Layers in Earth's Plasma Sheet, Phys. Rev. Lett. 102, 155002, 2009.

R. E. Ergun, L. Andersson, L., W. K. Peterson, D. Brain, G. T. Delory, D. L. Mitchell, R. P. Lin, and A. W. Yau, The role of plasma waves in Mars' atmospheric loss, Geophys. Res. Lett. 33, L14103, 2006.

Picture of Larry Esposito

Larry Esposito


Observational and theoretical studies of planetary atmospheres and rings; chemistry and dynamics of the Venus clouds; waves in Saturn's rings; numerical methods for radiation transfer.

Selected Recent Publications:

Esposito, L.W., E.R. Stofan, T. Cravens. 2007. Exploring Venus. Introductory chapter to “Exploring Venus as a terrestrial planet”, AGU Monograph Series, Volume 176, 1-6.

Esposito, L.W., B. K. Meinke, J.E. Colwell, P.D. Nicholson, M.M. Hedman. 2008. Moonlets and Clumps in Saturn’s F Ring. Icarus. Vol 194/1, 278-289.

Esposito, L.W. 2010. Composition, Structure, Dynamics and Evolution of Saturn’s rings. Annual Review of Earth & Planetary Sciences, Vol. 38 (In press January 2010)

Picture of Kevin France

Kevin France

(Assistant Professor)

Dr. France studies protoplanetary disks and the atmospheres of extrasolar planets with several guest observing programs on the Hubble Space Telescope. He also leads the UV Astrophysics Sounding Rocket Group at LASP where he and his students develop astronomical instrumentation for future NASA ultraviolet/optical astronomy missions.

Selected Recent Publications:

France et al. (2015), ApJL, “Mapping High-velocity H-alpha and Lyman-alpha Emission from Supernova 1987A”

France et al. (2014), ApJ, “CO/H2 Abundance Ratio ≈ 10-4 in a Protoplanetary Disk”

France et al. (2013), ApJ, “The Ultraviolet Radiation Environment around M dwarf Exoplanet Host Stars”

Picture of Jason Glenn

Jason Glenn

(Professor and Director CASA)

Prof. Glenn studies cosmology, galaxy formation, and the interstellar medium with submillimeter and millimeter-wave observations. New instrumentation using sub-Kelvin bolometer arrays is being developed in Prof. Glenn's lab to enable these observations, including Bolocam which is used on the Caltech Submillimeter Observatory, the SPIRE instrument on the Herschel Space Observatory, and the Z-Spec instrument to measure redshifts of high-z submillimeter galaxies.

Selected Recent Publications:

Enoch, M., Evans, N., Sargent, A., and Glenn, J. 2009, "Properties of the Youngest Protostars in Perseus, Serpens, and Ophiuchus", Ap.J., 692, 973-997.

Laurent, G., Glenn, J., Egami, E., Rieke, G., Ivison, R., Yun, M., Aguirre, J., Maloney, P., and Haig, D. 2006, "The Bolocam 1.1 mm Lockman Hole Galaxy Survey: SHARC II 350 μm Photometry and Implications for Spectral Models, Dust Temperatures, and Redshift Estimation", Ap.J., 643, 38-58.

Glenn, J., Jewell, P., Fourre, R., and Miaja, L. 2003, "A Polarization Survey of SiO Maser Variability in Evolved Stars", Ap.J., 588, 478-485.

Picture of James Green

James Green


Instrumentation, including design and leadership of the Cosmic Origins Spectrograph for HST, FUSE, and the ultraviolet and planetary sounding rocket program. Astrophysical interests include the ISM, IGM, hot stars, and cosmology.

Selected Recent Publications:

Froning, C., and Green, J. 2009, "The Cosmic Origins Spectrograph: Capabilities and Prelaunch Performance", Astrophy. & Space Sci., 320, 181-185.

Finkelstein, S., Morse, J., Green, J., Linsky, J., Shull, M., Snow, T., Stocke, J. et al. 2006, "Optical Structure and Proper-Motion Age of the Oxygen-rich Supernova Remnant 1E 0102-7219 in the Small Magellanic Cloud", Ap.J., 641, 919-929.

Wakker, B., et al., Shull, M., Ake, T., Blair, W., Dixon, W., Friedman, S., Green, J. et al. 2003, "The Far Ultraviolet Spectroscopic Explorer Survey of O VI Absorption in and near the Galaxy", Ap.J.Suppl., 146, 1-123.

Picture of Nils Halverson

Nils Halverson

(Associate Professor)

Nils Halverson works in experimental cosmology, including observations of the Cosmic Microwave Background (CMB) and mm-wave instrumentation development efforts. His previous experience at Caltech, Chicago, and Berkeley has been in mm-wave studies of the CMB, including measurements of CMB temperature and polarization anisotropy with DASI (Degree Angular Scale Interferometer), and development of the APEX-SZ galaxy cluster survey instrument. His current interests include Sunyaev- Zel'dovich effect galaxy cluster surveys and fine scale CMB anisotropy measurements using the 12m APEX telescope (Chile/Atacama) and the 10m South Pole mm-wave Telescope.

Selected Recent Publications:

Halverson, N., Lanting, T., Ade, P., Basu, K., Bender, A. et al. 2009, "Sunyaev-Zel'Dovich Effect Observations of the Bullet Cluster (1E 0657-56) with APEX-SZ", Ap.J., 701, 42-51.

Dobbs, N., Halverson, N. et al. 2006, "APEX-SZ First Light and Instrument Status", New Astron. Rev., 50, 960-968.

Leitch, E., Kovac, J., Halverson, N., Carlstrom, J., Pryke, C., and Smith, M. 2005, "Degree Angular Scale Interferometer 3 Year Cosmic Microwave Background Polarization Results", Ap.J., 624, 10-20.

Picture of Andrew J.S. Hamilton

Andrew J.S. Hamilton

(Professor and Department Chair)

I am interested in Relativity, Cosmology, and Astrophysics. If you want to learn more about what I do, please visit my website.

Selected Recent Publications:

Pre-print Server

ADS Abstract Service Papers

Picture of Seth Hornstein

Seth Hornstein

(Sr Instructor, Dir Sommers Bausch Observatory)

Current research focuses on improving undergraduate astronomy education. Past research concentrated on infrared observations of the supermassive black hole at the Galactic Center using high angular-resolution (adaptive optics and speckle) imaging techniques.

Selected Recent Publications:

Marrone, D., et al., 2008, An X-Ray, Infrared, and Submillimeter Flare of Sagittarius A*, ApJ

Markoff, S., et al., 2008, Results from an Extensive Simultaneous Broadband Campaign on the Underluminous Active Nucleus M81*: Further Evidence for Mass-scaling Accretion in Black Holes, ApJ

Hornstein, S., Matthews, K., Ghez, A., Lu, J., Morris, M, Becklin, E, Rafelski, M, Baganoff, F., 2007, A Constant Spectral Index for Sagittarius A* during Infrared/X-Ray Intensity Variations, ApJ

Picture of Mark Rast

Mark Rast

(Associate Professor)

Astrophysical fluid dynamics with emphasis on convective dynamics and scale selection, turbulence, the excitation of the solar p-modes, and the origin of solar/stellar irradiance variations. In addition to theoretical and computational work, efforts include operation of the Precision Solar Photometric Telescope (PSPT) at Mauna Loa Solar Observatory (MLSO) which obtains full disk images of the Sun at five wavelengths with 0.1% photometric precision.

Selected Recent Publications:

Rast, M.P., Ortiz, A., and Meisner, R.W. 2008, “Latitudinal variation of the solar photospheric intensity,” ApJ. 673, 1209.

Rast, M.P. & Pinton, J.-F. 2009, "Point vortex model for Lagrangian intermittency in turbulence," PhysRevE 79, 046314.

Rast, M.P. & Pinton, J.-F. 2011, “Pair dispersion in turbulence: the subdominant role of scaling,” PRL 107, 214501.

Picture of Nick Schneider

Nick Schneider

(Assoc Professor)

My interests span planetary atmospheres, planetary astronomy, space physics, instrumentation, scientific visualization, and science education reform. Much of my research has involved atmospheric escape from Jupiter's moon Io, whose entire atmospheric is lost and replaced on human timescales. Since 2005 I have been heavily involved in CU's mission to Mars: MAVEN, (Mars Atmosphere and Volatile EvolutioN). I lead the Imaging UltraViolet Spectrograph (IUVS) which performs remote sensing of Mars upper atmosphere. MAVEN's goals are to (1) understand the current state of the Mars atmosphere; (2) determine how atmospheric escape depends on drivers such as the solar wind, solar radiation and dust storms; (3) extrapolate escape back in time to estimate the cumulative atmospheric loss to space.

Selected Recent Publications:

N.M. Schneider, and F. Bagenal, "Io's Neutral Clouds, Plasma Torus and Magnetospheric Interaction, in "Io After Galileo", R. Lopes, Ed., Praxis, 2006.

N. M. Schneider, M. H. Burger, E. L. Schaller, M. E. Brown, R. E. Johnson, J. S. Kargel, M. K. Dougherty & N. A. Achilleos, “No sodium in the vapour plumes of Enceladus”, Nature 459, 1102-1104, 2009.

J. Bennett, M. Donahue, N. Schneider, M. Voit, The Cosmic Perspective, a two-semester introductory astronomy textbook, 6th ed., 2010; The Essential Cosmic Perspective, a one-semester version now (5th ed. 2008); a condensed version The Cosmic Perspective: Fundamentals, (1st ed. 2009). All Pearson/Addison-Wesley.

Picture of Michael Shull

Michael Shull


My research interests lie in theoretical astrophysics and UV/X-ray space astronomy. I work on theories of galaxy formation, reionization, first stars, primordial metal production, and numerical hydrodynamical simulations of high-redshift galaxies and the multi-phase intergalactic medium (IGM). With the Cosmic Origins Spectrograph on Hubble, we are conducting UV spectroscopic studies of missing baryons in the intergalactic medium, quasar ionizing spectra, mass estimates of super-massive black holes in quasars, and low-metallicity gas in the Galactic halo. We have found over 50% of the "missing baryons" in intergalactic Lyman-alpha and O VI absorbers. Recent research projects also include theoretical studies of escaping ionizing photons from galaxies, Galactic supernova shock- destruction of dust, and quasar outflows. I will be active in the Sloan-IV Digital Sky Survey and in planning for future NASA missions, including a large UV-Optical space telescope.

Selected Recent Publications:

Shull, J. M., Smith, B. D., & Danforth, C. W. 2012, Astrophys J, 759, 23, "The Baryon Census in a Multiphase Intergalactic Medium: 30% of the Baryons are Still Missing"

Shull, J. M., Harness, A., Trenti, M., & Smith, B. D. 2012, Astrophys. J., 747, 100, "Critical Star-Formation Rates for Reionization: Full Reionization Occurs at Redshift z = 7"

Shull, J. M. et al. 2013, Astrophys. J., 722, 1312. "Hubble Observations of Quasar HE2347-4342: Probing the Epoch of He II Patchy Reionization between Redshifts z = 2.4-2.9".

Picture of John T. Stocke

John T. Stocke


John Stocke is an extragalactic observer who uses all manner of space-based and ground-based telescopes to study normal and active galaxies, clusters of galaxies, and intergalactic gas. I am also carrying out a project aimed at detecting changes in fundamental constants (e.g., fine-structure-constant and proton-to-electron mass ratio) with cosmic time. Recently my primary research interest has been in using the Hubble Space Telescope's spectrographs to discover, inventory, and study intergalactic gas clouds and to figure out their relationship to galaxies. This study has led to the first-ever detection of matter in voids. I am a member of the science team for the Cosmic Origins Spectrograph (COS) which was successfully installed on the Hubble Space Telescope last May. We are already using COS to observe distant QSOs to map the structure and physical conditions in the Inter- Galactic Medium (IGM), study starburst galaxies, probe High Velocity Clouds in our own Galaxy and detect the atmosphere and aurora of an extra-solar planet (to name a few). We have guaranteed observing time on Hubble to carry out these projects. I am looking for graduate and undergraduate research students who want to be part of this exciting project. Just for fun I also study the star knowledge of ancient and indigenous cultures and teach an introductory undergraduate class called "Ancient Astronomies".

Selected Recent Publications:

Stocke, John T.; Keeney, Brian A.; Danforth, Charles W.; et al. 2014 "Absorption-line Detections of 105-106 K Gas in Spiral-rich Groups of Galaxies" ApJ 791, 128.

Stocke, John T.; Keeney, Brian A.; Danforth, Charles W.; Shull, J. Michael; et al. 2013 "Characterizing the Circumgalactic Medium of Nearby Galaxies with HST/COS and HST/STIS Absorption-line Spectroscopy" ApJ 763, 148.

Stocke, J., Danforth, C., Shull, J., Penton, S., and Giroux, M. 2007, "The Metallicity of Intergalactic Gas in Cosmic Voids", Ap.J., 671, 146-152.

Picture of Juri Toomre

Juri Toomre


Theoretical and computational astrophysics, including solar and stellar convection, magnetic dynamo action within stars, turbulence in many settings, and helioseismology. Central to this is theoretical work involving modern fluid dynamics, often based on 3-D simulations on supercomputers, that can be challenged and tested by astrophysical observations.

Selected Recent Publications:

Miesch, M.S., Brun, A.S., DeRosa, M.L., Toomre, J., 2008, "Structure and evolution of giant cells in global models of solar convection", Astrophys. J., 673, 556-575.

Miesch, M.S., Toomre, J., 2009, "Turbulence, magnetism and shear in stellar interiors", Ann. Rev. Fluid Mech., 41, 317-345.

Featherstone, N.A., Browning, M.K., Brun, A.S., Toomre, J., 2009, "Effects of fossil magnetic fields on convective core dynamos in A-type stars", Astrophys. J., 705, 1000-1018.

Charles Barth

(Professor Emeritus)

Peter S. Conti

(Professor Emeritus)

My research deals with understanding the nature and evolution of massive luminous stars, those of the hottest spectral types. These are primarily O-type and Wolf-Rayet stars found in the Galactic plane and in other galaxies. In starburst galaxies, the numbers of these stars are sufficient that they may be detected collectively, even in those objects at very large redshift. I am currently emphasizing photometry and spectroscopy of luminous stars in our Galaxy in the near infra-red, at about two microns, where the absorption of the intervening Galactic dust is low.

Selected Recent Publications:

Conti, P. & Crowther, P. (2004) MNRAS, 355, 899-917, "MSX mid-infrared imaging of massive star birth environments. II. Giant HII regions"

Conti, P. & Crowther, P. (2003) MNRAS, 343, 143-163, "MSX mid-infrared imaging of massive star birth environments. I. Ultracompact HII regions"

Indebetouw, R., Johnson, K., & Conti, P. (2004) AJ, 128, 2206-2233, "Australia Telescope Compact Array Survey of Candidate Ultracompact and Buried H II Regions in the Magellanic Clouds"

John E. Hart

(Professor of Atmospheric & Oceanic Sciences)

Dynamic oceanography, modeling of planetary and stellar atmospheres.

J.McKim Malville

(Professor Emeritus)

Kim Malville was trained as a solar physicist, but over the last several decades he has written extensive on topics of archaeoastronomy, particularly of the American Southwest and South America.

Selected Recent Publications:

Neolithic Skywatchers

Chaco Canyon Astronomy

Picture of Richard McCray

Richard McCray

(Distinguished Professor)

Theoretical astrophysics, including the physics of interstellar gas,Active Galactic Nuclei, binary X-ray systems, and supernova explosions.I also observe these systems with spacecraft such as the Hubble SpaceTelescope (HST) and the Chandra X-ray telescope.

Selected Recent Publications:

Published papers

Picture of Theodore (Ted) P. Snow

Theodore (Ted) P. Snow


The main theme of my research continues to be observational studies of the chemistry and physics of the diffuse and translucent interstellar medium. This includes analysis of the interaction between gas and dust, as indicated by depletion studies and by infrared solid-state absorption features; studies of dust extinction curves from the ultraviolet to the infrared; and molecular abundances. A very important part of this is my membership in the Science Team for the Cosmic Origins Spectrograph, which goes much deeper into interstellar clouds than previous instruments. I also have a grant for laboratory research on chemical reaction rates of astrophysical interest, emphasizing candidates for the molecular carriers of the unidentified diffuse interstellar bands.

Selected Recent Publications:

Destree, J. and Snow, T. 2009, "Unidentified Features in the Ultraviolet Spectrum of X Per", Ap.J., 697, 684-692.

Snow, T., Ross, T., Destree, J., Drosback, M., Jensen, A., Rachford, B., Sonnentrucker, P., and Ferlet, R. 2008, "A New FUSE Survey of Interstellar HD", Ap.J., 688, 1124-1136.

Jensen, A., Rachford, B., and Snow, T. 2007, "Is There Enhanced Depletion of Gas-Phase Nitrogen in Moderately Reddened Lines of Sight?", Ap.J., 654, 955-970.

Theodore W. Speiser

(Professor Emeritus)

Gary E. Thomas

(Professor Emeritus)

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