Many quasars, distant bright objects that emit huge amounts of X-rays and other radiation, may be examples of black-hole mergings, he said.
And the answer you will come up with will probably be: a small percentage--most of the universe I am seeing is just darkness, accentuated here and there by distant bright objects.
But so far these have been the only objects in the distant universe bright enough for detailed spectroscopic studies.
The team used the 10-meter Keck Telescopes on Mauna Kea, Hawaii, to study distant quasars, bright beacons of energy unleashed by matter falling into huge black holes.
Set against a black wall with the suggestion of distant lights (Light-Bright pegs from a child's toy) and illuminated signs that are rather painterly in their execution, a solitary life-size cast figure in very dark colors walks mysteriously into the viewer's real space.
Before this study, astronomers had assumed that they could detect only the brightest distant galaxies from ground-based telescopes, Rauch notes.
To probe the cloud, the team used an even more distant quasar a hugely bright light source powered by a supermassive black hole as a backlight.
Furthermore, only in an even narrower set of cases, typical photographic images present enough repeated patterns (e.g., bright distant lights) to be used directly for characterizing the PSF field, similarly to the star field case.
While only a narrow set of typical photographic images present enough repeated patterns, such as bright distant lights, to be used directly for characterizing the PSF field, the presence of stars in astronomical images allows for a particularly simple way to locally estimate the PSF, by weighted averaging, after sub-pixel localization.
The galaxy, photographed by the Hubble Space Telescope and seen, magnified, in the box above, is much brighter than distant galaxies typically are.
