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| Interstellar Medium and Formation of Stars | ||
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Associated Faculty and
Web Pages listed below.
Members of the Department use a wide variety of instruments to study molecular clouds, star formation, and the interstellar medium. They have special access to the 1.2-m diameter millimeter-wavelength telescope on the roof of the Observatory; the 37-m centimeter- and millimeter- wavelength telescope of Haystack Observatory in Westford, Massachusetts; the optical and infrared telescope of the Multiple Mirror Telescope Observatory (MMT), and the 1.2-m optical and infrared telescope of the Whipple Observatory, both on Mount Hopkins, Arizona. Other facilities operated by SAO are the NASA Submillimeter Wavelength Astronomical Satellite (SWAS) and the SAO Submillimeter Wavelength Telescope Array (SMA) in Hawaii. In addition, members of the Department use many other telescopes around the world, including those of the 27-antenna Very Large Array in New Mexico, the Very Long Baseline Array, and the 30-m telescope of the Institute de Radio Astronomie Millimetrique in Spain. Among the topics pursued by members of the Department in this area are theoretical calculations of the heating, cooling, ionization, and chemical reactions among atoms and molecules in molecular clouds; observations and analysis of the structure, motions, and energy balance of molecular clouds and their condensations; the structure and strength of the interstellar magnetic field and its role in cloud evolution; initial conditions for star formation and the collapse of cloud cores to form stars; very young stars and their circumstellar environs, including interstellar masers; physical conditions and processes in circumstellar disks and in the protosolar nebula; the structure and development of multiple star systems; and the origin of stellar populations. Magnetic Fields and Turbulence: Magnetism plays a critical role in many areas of astrophysics, because it controls both the bulk flow properties of interstellar gas as well as the motion of individual charged particles. However, we know surprisingly little about the properties of the Galactic magnetic field. Harvard researchers are making a concerted effort to redress this situation, using the Faraday rotation of the diffuse polarized radio background as a new way to study structure and turbulence in magnetized gas. Some of our current projects include using the power spectra of rotation measures to map the turbulent cascade of ionized gas in the Galactic plane, using the Faraday rotation of background point sources to map out the large-scale magnetic structure of the inner Galaxy, and analyzing polarization data on the Large Magellanic Cloud in order to carry out the most detailed study yet of the magnetic field of an external galaxy. Such data represent a whole new way of studying the ISM, and can allow a comprehensive study of interstellar magnetic fields on scales ranging from sub-parsec turbulence up to global galactic structure. See also the related area of young stellar objects and the origin of planetary systems. Associated Professors and Lecturers
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