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Richard Ellis

Astronomy 249-17, Caltech

Pasadena CA 91125

Overview of Research:

I am working primarily in observational cosmology addressing issues related to the nature of the world model, the origin and evolution of galaxies, the growth of large scale structure and the nature and distribution of dark matter. I am enthusiastic about the use of new instruments and observational opportunities when they further the progress that can be made in these areas.

Recent Press Releases:

  • Keck Telescope and "Cosmic Lens" Resolve Nature and Fate of Early Star-Forming Galaxy
  • Read the Nature scientific article!

    • Research Programmes

    My current interests at Caltech fall under 3 main headings:
     
  • Gravitational lensing: I have been interested in the role that gravitational lensing can play in cosmology and galaxy formation studies since the late 1980's. I am working with others in defining the weak lensing case and survey parameters for SNAP ,a contender for the Joint Dark Energy Mission (JDEM). On small scales I am using strong lensing to separate dark and baryonic matter distributions in clusters. On larger scales I am using weak lensing to map the distribution in panoramic survey fields. I have participated in a number of comparative studies to understand the prospects for precision measures of weak lensing using ground- and space-based facilities.

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  • Distant Supernovae: I took part in one of the earliest successful studies to locate and characterize cosmologically-distant Type Ia supernovae and later joined the Supernova Cosmology Project . The resulting "accelerating Universe" is a bewildering result which has motivated a number of more ambitious ongoing and future supernovae surveys. I am putting most of my effort into examining the validity of using Type Ia SNe for future studies. My research includes examining the environmental dependence of supernova properties as well as the question of possible spectral evolution such as might arise from changes in the progenitor composition. This work is of a long term nature and is being undertaken with Keck and HST.

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  • Galaxy Formation and Evolution: I have been interested in studying the properties of distant galaxies since I was a postdoc in the late 1970's. The facilities we have access to now make those early studies look so primitive! I use the combination of HST images, Spitzer photometry, ground-based K-band imaging and, most of all, Keck spectroscopy to better understand the origin of the wide diversity of galaxy morphologies. Key questions I am working on include the mass-dependent assembly of galaxies over the redshift range 0 to 6, the contribution of low luminosity galaxies to cosmic reionization, and the onset of ordered rotation and high velocity dispersions in spiral and elliptical galaxies respectively..I am a recent convert to the phenomenal advances being made in these areas through the use of adaptive optics.

    • Current Committees

  • Thirty Meter Telescope Board of Directors
  • Thirty Meter Telescope Science Advisory Committee
  • Joint Dark Energy Mission Science Coordinating Group
  • Science Steering Committee for Keck Observatory
  • Fachbeirat (Visiting Committee) for Max Planck Institute for Extraterrestrial Physics
  • Scientific Advisory Board, Dark Cosmology Centre, University of Copenhagen
  • Advisory Committee, Cosmology and Gravity Program, Canadian Institute of Advanced Research

    • Other Responsibilities:

  • Editorial Board for Philosophical Transactions A of the Royal Society

    • Teaching

  • Ay 123 Structure and Evolution of Stars

    • Latest Refereed Papers (2009 submissions)

  • HST/ACS Morphology of Lyman Alpha Emitters at Redshift 5.7 in the COSMOS Field
  • Comet C/2004 Q2 (Machholz): Parent Volatiles: a search for Deuterated Methane and Constraint on the CH4 Spin Temperature
  • Detection of PAH and Far-Infrared Emission from the Cosmic Eye: Probing the Dust and Star Formation of Lyman Break Galaxies
  • LoCuSS: Luminous infrared galaxies in the merging cluster Abell 1758 at z=0.28
  • The Evolutionary History of Lyman Break Galaxies between Redshift 4 and 6: Observing Successive Generations of Massive Galaxies in Formation
  • CO Interferometry of gas-rich spiral galaxies in the outskirts of an intermediate redshift cluster
  • The Greater Impact of Mergers on the Growth of Massive Galaxies: Implications for Mass Assembly and Evolution Since z~1
  • Photometric Properties of Ly alpha emitters at z=4.86 in the COSMOS 2 square degree field
  • The Mean Type Ia Supernova Spectrum over the Past 9 Gigayears

    • Recent Review Articles:

  • Panoramic Views of Galaxy Formation and Evolution (Conference Summary, Hayama, Japan)
  • Observations of the High Redshift Universe in `First Light' (Saas-Fee Lectures)

    • Other Information:

    Curriculum Vitae (MS Word)

    Publication List (PDF)

    Richard's Bookmarks

    Page maintained by Richard Ellis rse@astro.caltech.edu

    Last modified : 25th January 2009