Compact Groups of Galaxies
How does star formation and gas processing proceed in these systems reminiscent of the era of galaxy formation? What is the relationship between the evolutionary states of compact groups and their gas and dust content? How is this affected by multiple simultaneous interactions?Recent Papers
Walker et al. (2012) "Examining the Role of Environment in a Comprehensive Sample of Compact Groups"Walker et al. (2010) "Mid-Infrared Evidence for Accelerated Evolution in Compact Group Galaxies"
Gallagher, Johnson, et al. (2008) "The Revealing Dust: Mid-Infrared Activity in Hickson Compact Group Galaxy Nuclei"
Johnson et al. (2007) "The Infrared Properties of Hickson Compact Groups"
Resolved Nearby Galaxies: Star Formation
What determines the rates and history of star formation within galaxies? What are the extremes of this process, for example star formation at low metallicity (SMC) and tidal features (Magellanic Bridge)?SAGE and HERITAGE projects
Recent Papers
Andrews & Martini (2012) "The Mass-Metallicity Relation with the Direct Method on Stacked Spectra of SDSS Galaxies"Leroy et al. (2012) "Estimating the Star Formation Rate at 1 kpc Scales in nearby Galaxies"
Schruba, Leroy et al. (2012) "Low CO Luminosities in Dwarf Galaxies"
Bolatto, Leroy et al. (2011) "The State of the Gas and the Relation between Gas and Star Formation at Low Metallicity: The Small Magellanic Cloud"
Leroy et al. (2011) "The CO-to-H2 Conversion Factor from Infrared Dust Emission across the Local Group"
Kepley et al. (2011) "Unveiling Extragalactic Star Formation Using Radio Recombination Lines: An Expanded Very Large Array Pilot Study with NGC 253"
Lawton et al. (2010) "Spitzer Analysis of H II Region Complexes in the Magellanic Clouds: Determining a Suitable Monochromatic Obscured Star Formation Indicator"
Bigiel, Leroy et al.(2010) "Tightly Correlated H I and FUV Emission in the Outskirts of M83"
Super Star Clusters
What causes this most extreme mode of star formation? Where and what kinds of super star clusters form, what are their properties at the earliest evolutionary stages? What special physics arises in and near these extraordinary objects?Recent Papers
Whelan et al. (2011) "The Infrared Properties of Super Star Clusters: Predictions from Three-Dimensional Radiative Transfer Models."Brogan, Johnson, & Darling (2010) "Water Masers associated with Star Formation in the Antennae Galaxies"
Reines et al. (2010) "The Importance of Nebular Continuum and Line Emission in Observations of Young Massive Star Clusters"
Johnson, Hunt, & Reines (2009) "Probing Star Formation at Low Metallicity: The Radio Emission of Super Star Clusters in SBS 0335-052"
(Proto)stellar Feedback
What effects do protostars and young massive stars have on their circumstellar and interstellar medium? How does this regular further star formation? We are studying this in the Magellanic System on region and galaxy scales using primarily Spitzer and Herschel, and in Galactic molecular clouds with our own near-IR narrow-band survey of outflow activity. Under what circumstances does feedback lead to triggered star formation?Recent Papers
Dirienzo et al. (2012) "Testing Triggered Star Formation in Six H II Regions"Desai et al. (2010) "Supernova Remnants and Star Formation in the Large Magellanic Cloud"
Hony et al. (2010) "The Herschel revolution: Unveiling the morphology of the high-mass star-formation sites N44 and N63 in the LMC"
Meixner et al. (2010) "HERschel Inventory of The Agents of Galaxy Evolution (HERITAGE): The Large Magellanic Cloud dust"
Kemper et al. (2010) "The SAGE-Spec Spitzer Legacy Program: The Life Cycle of Dust and Gas in the Large Magellanic Cloud"
Indebetouw et al. (2009) "Physical Conditions in the Ionized Gas of 30 Doradus"
Rubin et al. (2009) "A spatially resolved study of photoelectric heating and [C II] cooling in the LMC. Comparison with dust emission as seen by SAGE"
Formation of Massive Stars
Massive stars drive the evolution of the visible universe - does their formation require different physics from solar-mass stars? What can we learn from the highest-resolution observations of young massive stars, and from their outflows and environments in our Galaxy and the Magellanic System? What properties of a molecular cloud lead to massive star and cluster formation, contrasted with distributed low-mass star formation?Recent Papers
Chen et al. (2010) "Spitzer View of Young Massive Stars in the Large Magellanic Cloud H II Complexes. II. N 159"Romita et al. (2010) "Young Stellar Objects in the Large Magellanic Cloud Star-forming Region N206"
Sewiło, Indebetouw et al. (2010) "The youngest massive protostars in the Large Magellanic Cloud"
Fleener et al. (2010) "Massive Star Formation in NGC 2074"
Vaidya et al. (2009) "A Hubble Space Telescope View of the Interstellar Environments of Young Stellar Objects in the Large Magellanic Cloud"
Oliveira et al. (2009) "Ice Chemistry in Embedded Young Stellar Objects in the Large Magellanic Cloud"
Brogan et al. (2009) "Digging Into NGC 6334 I(N): Multiwavelength Imaging of a Massive Protostellar Cluster"
Seale et al. (2009) "The Evolution Of Massive Young Stellar Objects in the Large Magellanic Cloud. I. Identification and Spectral Classification"
Povich et al. (2009) "The Extended Environment of M17: A Star Formation History"
Chen et al. (2009) "Spitzer View of Young Massive Stars in the Large Magellanic Cloud H II Complex N 44"
Churchwell et al. (2009) "The Spitzer/GLIMPSE Surveys: A New View of the Milky Way"
Chemistry and Star Formation
The formation of stars (and planets) is accompanied by molecular formation and destruction. The chemistry of many species depends strongly on the local environment and how this environment has evolved. Molecular spectra can therefore be used as probes of key aspects of star formation, from cloud formation and evolution, through cloud collapse and the protostellar phase, to the formation of accretion disks and planetary systems. Within the star formation group we observe molecular spectral features from IR to mm wavelengths to explore the evolution of molecular clouds and protostars, and to test our chemical understanding of proposed molecular probes.Astrochemistry Group
Recent Papers
Öberg et al. (2011) "The Spitzer Ice Legacy: Ice Evolution from Cores to Protostars"Öberg et al. (2011) "Complex Molecules toward Low-mass Protostars: The Serpens Core"
Öberg et al. (2010) "A Cold Complex Chemistry Toward the Low-mass Protostar B1-b: Evidence for Complex Molecule Production in Ices"
Schnee et al. (2012) "An Observed Lack of Substructure in Starless Cores. II. Super-Jeans Cores"
Schnee et al. (2012) "How Starless are Starless Cores?"
Schnee et al. (2010) "An Observed Lack of Substructure in Starless Cores"
Schnee et al. (2010) "The Dust Emissivity Spectral Index in the Starless Core TMC-1C"
