Over 100 different kinds of molecules have been discovered in interstellar space. In addition to providing probes of the physical conditions in regions where new stars are forming, interstellar molecules provide a new laboratory for chemistry under unusual conditions (astrochemistry). Some of the molecules become stuck on interstellar dust grains, where they form icy mantles of carbon-rich material. In the process of forming a star and planets, these dust grains, with their mantles, may become incorporated into the icy moons and comets in the outer parts of planetary systems. Debris from comets in our solar system shows evidence of an interstellar origin. Since the materials on comets bombarding the early Earth may have provided the building blocks of life, we may trace the origins of life on Earth (and perhaps other planets) to interstellar molecules.

Current Projects

A current project is a detailed study of the chemical abundances in a cloud surrounding a young, massive star, called GL2591. One paper was published in the Astrophysical Journal (vol, 450, p. 667), and another, a collaboration with scientists at Leiden Observatory, is in preparation.




The goal of star formation research is to understand how stars and planetary systems form. We now know that stars form in giant clouds of molecules and dust grains by gravitational collapse, but the details of this process are far from clear. Our group is working to understand what allows part, but not all, of a giant cloud to make stars (Wenbin Li), the physical conditions leading to the formation of stars like the Sun (Erik Gregersen), and the differences in formation of stars of different mass (Neal Evans). We use both infrared and radio telescopes in this research. In particular, we use the Caltech Submillimeter Telescope on Mauna Kea, Hawaii on a regular basis.

Current Projects

Projects include the search for protostellar collapse in so-called Class 0 sources, thought to be in a very early stage of collapse that will lead to stars like the Sun. A paper has been submitted to the Astrophysical Journal.
Another project is a study of high-mass star formation using the CS molecule to trace densities. We find typical densitites of one million particles per cubic centimeter in these regions (Plume et al. 1997).

Publications

  • Plume, R., Jaffe, D. T., Evans II, N. J., Martin-Pintado J., & Gomez-Gonzalez 1997, ApJ, 476, 730
  • Gregersen, E. M., Evans II, N. J., Zhou, S., & Choi, M. 1997, ApJ in press,



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    This section is "under construction".



    Publications

  • Luhman, M. L., Jaffe, D. T., Keller, L. D., & Pak, S. 1995, 1995, PASP, 107, 184



    • -ISM PHYSICS-


    This section is "under construction".