CHANDRA X-RAY OBSERVATORY The Chandra X-ray Observatory is the third in NASA's family of Great Observatories that includes the Hubble Space Telescope and the Compton Gamma Ray Observatory. NASA's Marshall Space Flight Center manages the Chandra program. TRW is the prime contractor for the spacecraft. Key subcontractors include Ball Aerospace & Technologies, Inc., Eastman Kodak Company, and Raytheon Optical Systems, Inc. The scientific instruments were built by teams from MIT, Pennsylvania State University, the Smithsonian Astrophysical Observatory, the Laboratory for Space Research in the Netherlands, and the Max Planck Institute in Germany. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. The Chandra X-ray Observatory & First Light Table of Contents I. Press Guide to Chandra Contacts II. Fact Sheets & Biographies A. Fact Sheets: 1. Cassiopeia A, CXC 2. PKS 0637-752, CXC 3. Chandra X-ray Observatory Center, CXC 4. Exploring the Invisible Universe, MSFC 5. Chandra Quick Facts, MSFC B. Biographies: 1. Dr. Robert Kirshner, Associate Director, Harvard-Smithsonian Center for Astrophysics 2. Dr. Harvey Tananbaum, Director, Chandra X-ray Center 3. Dr. Edward J. Weiler, Associate Administrator for Space Science, NASA 4. Dr. Martin C. Weisskopf, Project Scientist, Chandra X-ray Observatory A PRESS GUIDE TO CHANDRA CONTACTS Dr. Wallace Tucker, Chandra Science Spokesperson. Smithsonian Astrophysical Observatory, Cambridge, MA 617.496.7998; FAX: 617.495.7356 e-mail: [email protected] KEY CHANDRA SCIENTISTS: Dr. Harvey Tananbaum, Director, Chandra X-ray Observatory Center (CXC) Smithsonian Astrophysical Observatory, Cambridge, MA 617.495. 7248 FAX: 617.495.7356 email: [email protected] Dr. Claude R. Canizares, Associate Director, Chandra X-ray Observatory Center Principal Investigator, High Energy Transmission Grating Center for Space Research Massachusetts Institute of Technology, Cambridge, MA 617.253.7501 FAX: 617.253.3111 email: [email protected] Dr. Martin C. Weisskopf, Chandra Project Scientist Chief Scientist for X-Ray Astronomy Marshall Space Flight Center, Huntsville, AL 205.544.7740 FAX: 205.544.7754 e-mail: [email protected] Dr. Roger Brissenden, Program Manager, Chandra X-ray Observatory Center Smithsonian Astrophysical Observatory, Cambridge, MA 617 495 7387 FAX: 617.496.7067 email: [email protected] Dr. Gordon Garmire, Principal Investigator, AXAF CCD Imaging Spectrometer (ACIS) Penn State Univ., University Park, PA 814. 865.1117 FAX: 814.865.2977 email: [email protected] Dr. Stephen S. Murray, Principal Investigator, High Resolution Camera (HRC) Associate Director, High Energy Astrophysics Division Smithsonian Astrophysical Observatory, Cambridge, MA 617.495.7205 FAX: 617.495.7356 e-mail: [email protected] Dr. Albert Brinkman, Principal Investigator, Low Energy Transmission Grating Space Research Organization of Netherlands e-mail: [email protected] NASA CONTACTS Dr. Edward J. Weiler, Associate Administrator for Space Science Code S NASA Headquarters, Washington, DC 20546 202.358.1409 FAX: 202.358.3092 email: [email protected] Dr. Alan N. Bunner Science Program Director, Structure and Evolution of the Universe NASA Headquarters, Washington D.C. 20546 Phone 202.358.0364 FAX: 202.358.3096 email: [email protected] Donald Savage, Public Affairs Officer Office of Space Science NASA Headquarters, Washington D.C. Phone 202.358.1727 FAX: 202.358.3093 email: [email protected] Dave Drachlis, Media Relations Office Marshall Space Flight Center, Huntsville, AL Phone 256.544.6538 FAX: 256.881.9302 email: [email protected] Fact Sheet CASSIOPEIA A Cassiopeia A (Cas A) is the remnant of a massive star that exploded about 300 years ago. The X-ray image shows an expanding shell of hot gas produced by the explosion. This gaseous shell is about 10 light years in diameter, and has a temperature of about 50 million degrees. The material from the explosion is rushing outward at supersonic speeds in excess of ten million miles per hour. As this matter crashes into gas that surrounds the former star, shock waves analogous to awesome sonic booms heat the gas and heat the ejected matter. The Cas A Supernova A supernova occurs when a massive star has used up its nuclear fuel and the pressure drops in the central core of the star. The matter in the core is crushed by gravity to higher and higher densities, and temperatures reach billions of degrees. Under these extreme conditions, nuclear reactions occur violently and catastrophically reversing the collapse. A thermonuclear shock wave races through the now expanding stellar debris, fusing lighter elements into heavier ones and producing a brilliant visual outburst. About every fifty years in our galaxy, a massive star explodes. The shell of matter thrown off by the supernova creates a bubble of multi-million degree gas called a supernova remnant. Cas A is a prime example. The hot gas will expand and produce X-rays for thousands of years. The nature of the explosion that produced Cas A has been an enigma. Although radio, optical and x-ray observations of the remnant indicate that it was a powerful event, the visual brightness of the outburst was much less than a normal supernova. Apparently Cas A was produced by the explosion of an unusual massive star that had previously ejected most of its outer layers. Probing Cas A Mysteries with NASA's Chandra X-ray Observatory Chandra's spectacularly vivid images of Cas A allow scientists to trace the dynamics of the remnant and its collision with any material ejected by the star before it exploded. Chandra detectors provide scientists with precise x-ray spectra– measurements of the energies of individual x-rays–from the Cas A remnant. These measurements make it possible to identify which heavy elements are present and in what quantities. Chandra's observations should help astronomers to resolve the long-standing mystery as to the nature and origin of Cas A. A related mystery is whether the explosion that produced Cas A left behind a neutron star, black hole, or nothing at all. This "First Light" Chandra image of Cas A shows a bright object near the center of the remnant! Longer observations with Chandra can determine if this is the long sought for neutron star or black hole. Importance of Supernovae The study of remnants of exploded stars, or supernovae, is essential for our understanding of the origin of life on Earth. The cloud of gas and dust that collapsed to form the sun, Earth and other planets was composed mostly of hydrogen and helium, with a small amount of heavier elements such as carbon, nitrogen, oxygen and iron. The only place where these and other heavy elements necessary for life are made, is deep in the interior of a massive star. There they remain until a catastrophic explosion spreads them throughout space. Supernovae are the creative flashes that renew the galaxy. They seed the interstellar gas with heavy elements, heat it with the energy of their radiation, stir it up with the force of their blast waves and cause new stars to form. Fact Sheet PKS 0637-752 PKS 0637-72 is so distant that we see it as it was 6 billion years ago. It is a luminous quasar that radiates with the power of 10 trillion suns from a region smaller than our solar system. The source of this prodigious energy is believed to be a supermassive black hole. Radio observations of PKS 0637-752 show that it has an extended radio jet that stretches across several hundred thousand light years. Chandra's x-ray image reveals a powerful x-ray jet of similar size that is probably due to a beam of extremely high-energy particles. Quasars Quasars are distant, energetic objects. They are compact intense sources of X-rays as well as visible light, and can be brighter than hundreds of galaxies put together. Through an optical telescope quasars look star-like. It wasn't until the 1950's, when radio astronomy was first developed, that astronomers realized these were extra-galactic objects that were emitting enormous amounts of radio energy. This important discovery caused them to be named quasars, short for "Quasi-stellar radio sources". Since then, many quasars have been discovered that produce little or no radio emission. They are sometimes called quasi-stellar objects or QSO's, but the name quasars is generally used to describe both types of objects. The power of a quasar depends on the mass of its central black hole and the rate at which it swallows or accretes matter. Almost all galaxies, including our own, are thought to contain a supermassive black hole in their centers. Quasars represent the extreme cases where the rate of accretion is so high that the energy output due to the infalling matter is a thousand times greater than the galaxy itself. One of the most intriguing features of supermassive black holes is that they do not suck up all the matter that falls within their sphere of influence. Most of the matter falls inexorably toward the black hole, but some explodes away from the black hole in high energy jets that move at near the speed of light. Radio observations have revealed that these jets are a common feature of quasars. NASA's Chandra X-ray Observatory Reveals Powerful X-ray Jet in PKS 0637-752 The x-ray jet observed for the first time by Chandra in PKS 0637-752, is a dramatic example of a cosmic jet. It has blasted outward from the quasar into intergalactic space for a distance of at least 200,000 light years! The jet's presence means that electromagnetic forces are continually accelerating electrons to extremely high energies over enormous distances. Chandra observations, combined with radio observations, should provide insight into this important cosmic energy conversion process.