Cosmic glows Universe`s oldest objects

Iran Materials 21 December 2006 18:00 (UTC +04:00)
Cosmic glows Universe`s oldest objects

(zeenews) - For long, researchers thought that the faint cosmic glows seen by the Spitzer Space Telescope were the remnant radiation from first stars or black holes born in our universe.

But now, according to a new study, they might actually be clusters of the first objects to emerge from the Big Bang, reports Trend.

Astronomers have teased apart overlapping signals from that cosmic infrared background, and building upon an earlier study, showed that uneven patches of energy may actually be clusters of the first objects to emerge from the Big Bang.

According to them, the objects are either extremely bright stars; 1,000 times more massive than our sun, or quasars, large black holes that consume enormous amounts of gas and debris and re-emit the materials in almost unparalleled bursts of energy.

If the patches are star clusters, they may be the first galaxies, smaller than most known galaxies yet containing a mass on the scale of one million suns, says Alexander Kashlinsky of NASA`s Goddard Space Flight Center in Greenbelt, and lead author of the study.

"Observing the cosmic infrared background is like watching distant fireworks from within a brightly lit city. It`s as if we have turned off the city lights one by one to see the bursts more clearly. While we can`t resolve each spark in the fireworks, we can see the large scale structures and their glow," he adds.

For their study, researchers poured over archival data from the calibration of the NASA Spitzer Telescope and conducted several stages of cleaning to remove signals from more recent galaxies and other objects to get to the underlying signals.

They added observations of four regions of the night sky, two from each hemisphere, with exposure times of up to 25-26 hours per pixel, to the data collected by the telescope during a calibration last year.

"Once we remove pixels in the Spitzer images corresponding to the locations of these galaxies, the background infrared light level mostly disappears. We think, therefore, the infrared light seen in Spitzer images is mostly due to the faint infrared glow from these dwarf galaxies," added Asantha Cooray, a cosmologist at the University of California in Irvine.