Astronomers "Converge" on Galactic Center
November 6, 2002
Approximately 110 astronomers will meet in Kona during November 3-8, 2002, to discuss the nucleus of our Milky Way. Called "The Central 300 Parsecs," the conference has been locally organized mainly by Gemini-North staff and is sponsored by Gemini and several other observatories on Mauna Kea.
Gravity and frictional forces inevitably cause the centers of galaxies to acquire mass densities much higher than that of the outer regions. Even a normal-looking spiral galaxy such as ours might be expected to contain almost the entire galactic astronomical zoo: stars of all masses and evolutionary states, white dwarfs, nebulae, dust clouds, neutron stars, and even black holes - all packed together in a tight swarm. The nucleus of our galaxy is already known to contain a wide variety of astrophysical phenomena. Although it is 25,000 light years away, it is by far both the nearest and brightest galactic nucleus. Thus it can be studied in relatively great detail and can provide insights into the nuclei of much more distant galaxies, including those whose energy outputs dwarf it.
The center of the Milky Way is visually obscured from our view by dusty spiral arms along our line of sight, with only about one visible photon per 100 billion emitted in the nucleus reaching the earth. However much or virtually all of the radio, infrared, and x-rays emitted in the central regions pass unscathed through the dust and gas, and can be readily detected. Radio observations of the center have been made for half a century and infrared observations for more than three decades. X-ray observations by Chandra have recently provided an unprecedented view of violent activity in the central regions and will be a main focus of the conference. At the same time, the latest generation of infrared and radio sensitive instruments on ground-based telescopes have led to a great leap in our understanding of the multitude of fascinating phenomena occurring there.
At the conference scientists from over a dozen countries will share and discuss the most recent infrared observations of stars whirling rapidly about an ultradense central object that is generally believed to be a black hole with a mass equal to that of about 3 million suns. Others will report on and try to explain the origin of the x-ray and radio radiation emanating from the vicinity of that object. In addition to the central massive black hole, many members of the bizarre zoo of astronomical objects and phenomena will be the subject of lectures and discussions, as will the larger scale structure of the nucleus. The Gemini science verification AO infrared imaging of the Galactic Center has been part of the recent advance in our knowledge and understanding and some of those data will be reported at the conference.
