Astronomers discover most primitive supermassive black holes known

Washington, March 19 (ANI): Astronomers, using NASA’s Spitzer Space Telescope, have discovered two of the earliest and most primitive supermassive black holes known.

The discovery will provide a better understanding of the roots of our universe, and how the very first black holes, galaxies and stars all came to be.

“We have found what are likely first-generation quasars, born in a dust-free medium and at the earliest stages of evolution,” said Linhua Jiang, a research associate at the University of Arizona’s Steward Observatory.

Quasars are basically hungry supermassive black holes.

As grimy and unkempt as our present-day universe is today, scientists believe the very early universe didn’t have any dust, which tells them that the most primitive quasars should also be dust-free.

But nobody had seen such pristine quasars – until now.

Spitzer has identified two such immaculate quasars – the smallest quasars on record – about 13 billion light-years away from Earth.

The two quasars, called J0005-0006 and J0303-0019, were first unveiled by Xiaohui Fan, a UA professor of astronomy who coauthored the paper.

NASA’s Chandra X-ray Observatory had also observed X-rays from one of the objects.

X-rays, ultraviolet and optical light stream out from quasars as the gas surrounding them is swallowed.

“As surrounding gas is swallowed by the supermassive black hole, it emits an enormous amount of light, making those quasars detectable literally at the edge of the observable universe,” said Fan.

When Jiang and his colleagues set out to observe J0005-0006 and J0303-0019 with Spitzer between 2006 and 2009, their targets didn’t stand out much from the usual quasar bunch.

Spitzer measured infrared light from the objects along with 18 others, all belonging to a class of the most distant quasars known.

Each quasar is anchored by a supermassive black hole weighing more than 100 million suns.

The Spitzer data showed that, of the 20 quasars, J0005-0006 and J0303-0019 lacked characteristic signatures of hot dust.

“We think these early black holes are forming around the time when the dust was first forming in the universe, less than one billion years after the Big Bang,” Fan said.

“The primordial universe did not contain any molecules that could coagulate to form dust. The elements necessary for this process were produced and pumped into the universe later by stars,” he added. (ANI)

Cosmic ‘whips’ may be detected with gravitational waves

London, July 6 (ANI): A new research has determined that cosmic ‘whips’, which are topological defects in space-time larger than the observable universe, can be detected with the help of gravitational waves.

Many theories predict the existence of cosmic strings.

They say that space-time should have universe-sized snags called ‘cosmic strings’ running across it, but none have yet been found.

That could be because they broke into a tangle of smaller strings and beads soon after the big bang, say scientists.

The imprint of their extremely high gravity was expected to be seen in the cosmic microwave background – the radiation left over from the big bang – or as gravitational lenses that bend distant light towards us.

But, no convincing evidence has been seen.

Ben Shlaer of Tufts University in Medford, Massachusetts, and colleagues, told New Scientist that the lack of evidence could be because the strings were unstable and split into smaller and smaller pieces soon after they formed.

The first strings could have been gigantic closed loops or extremely large fragments that terminated in “beads”.

These beads would have been so-called monopoles – analogous to a magnet’s north or south pole without its partner.

As the strings broke, the team’s analysis shows that their split ends would have been capped off by more monopoles, eventually leading to a universe filled with fragmented strings with beads at their ends.

In an infant universe, these high-tension strings would have been whipping around, accelerating the massive beads to relativistic speeds.

These would have generated tight beams of gravitational waves, which could still be traveling through space-time.

“It’s possible that if you wait long enough, one of those highly focused bursts would hit the Earth, and that would cause one of our gravitational wave detectors to chirp,” said Shlaer.

The first cosmic strings were unstable and split into small pieces capped by monopoles.

Those detectors include the Laser Interferometer Gravitational Observatory, which is currently being upgraded, and the upcoming Laser Interferometer Space Antenna.

“The possible frequency range of the waves is exceptionally large, “raising the hope of detection” of cosmic strings,” said theoretical physicist Henry Tye at Cornell University in Ithaca, New York. (ANI)

Super-sensors to measure ‘signature’ of inflationary universe

Washington, May 4 (ANI): Scientists have built super-sensitive microwave sensors that would help provide evidence in support of the “inflation theory” of the cosmos, which says the universe expanded rapidly from a subatomic volume.

The new detectors, built at the National Institute of Standards and Technology (NIST), were made for a potentially ground-breaking experiment by a collaboration involving NIST, Princeton University, the University of Colorado at Boulder, and the University of Chicago.

This is part of a long-standing project at NIST’s Boulder campus plays a critical role in the study of the cosmic microwave background (CMB)-the faint afterglow of the Big Bang that still fills the universe.

This project previously built superconducting amplifiers and cameras for CMB experiments at the South Pole, in balloon-borne observatories, and on the Atacama Plateau in Chile.

The new experiment will begin approximately a year from now on the Chilean desert and will consist of placing a large array of powerful NIST sensors on a telescope mounted in a converted shipping container.

The detectors will look for subtle fingerprints in the CMB from primordial gravitational waves-ripples in the fabric of space-time from the violent birth of the universe more than 13 billion years ago.

Such waves are believed to have left a faint but unique imprint on the direction of the CMB’s electric field, called the “B-mode polarization.”

These waves-never before confirmed through measurements-are potentially detectable today, if sensitive enough equipment is used.

If found, these waves would be the clearest evidence yet in support of the “inflation theory,” which suggests that all of the currently observable universe expanded rapidly from a subatomic volume, leaving in its wake the telltale cosmic background of gravitational waves.

“The B-mode polarization is the most significant piece of evidence related to inflation that has yet to be observed,” said Ki Won Yoon, a NIST postdoctoral scholar.

“A detection of primordial gravitational waves through CMB polarization would go a long way toward putting the inflation theory on firm ground,” Yoon added.

The data also could provide scientists with insights into different string theory models of the universe and other “unified” theories of physics.

The new NIST detectors may also have applications closer to home, such as in reducing glare in advanced terahertz imaging systems for detecting weapons and contraband. (ANI)