Five relatively close galaxies appear to harbor buried quasars deep within their cores, according to infrared data gathered by the 200-inch Hale Telescope at the California Institute of Technology's Palomar Observatory, scientists said Tuesday.
The quasars - the brightest, most energetic objects in the universe, and also the most distant objects known - are hidden from view due to the orientation of the galaxies relative to the Earth and because they are enshrouded by thick, doughnut-shape clouds of dust, Caltech astronomers said.The results, based on observations in the near-infrared region of the spectrum seen by the Palomar Observatory in San Diego, provide considerable support for "grand unified" quasar theories, S. George Djorgovski, associate professor of astronomy, told the national meeting of the American Astronomical Society.
While quasars are "only" about the size of our solar system, they outshine entire galaxies containing hundreds of billions of stars.
One problem in the study of quasars is that observers see a bewildering variety of quasars, active galaxies and related objects in the celestial sky, astronomers said.
Many astronomers believe these may be different aspects of the same basic physical phenomenon. Grand-unified theories of active galactic nuclei state that much of this diversity is due to different viewing angles.
Virtually all theoretical models of active galactic nuclei postulate a massive black hole in the galactic center, surrounded by an "accretion disc" of material that gradually falls into the black hole. As large amounts of matter fall into a black hole, enormous amounts of energy are released.
In some cases, the center of the black hole, or "central engine," might be obscured by a thick, opaque torus (doughnut-shape object) of dust.