Milky Way humming in microwave emissions?
A European space observatory has discovered previously unknown islands of star formation and a haze of microwave radiations in our galaxy, the source of which is a complete mystery.india Updated: Feb 14, 2012 19:12 IST
A European space observatory has discovered previously unknown islands of star formation and a haze of microwave radiations in our galaxy, the source of which is a complete mystery.
The Planck space observatory was launched in 2009 to analyse small fluctuations in the omnipresent cosmic microwave background (CMB) - complementing data gathered by NASA’s Wilkinson Microwave Anisotropy Probe.
To understand the structure of the CMB is to open a window on the conditions immediately after the Big Bang. This extremely faint radiation is the ancient “echo” of the creation of the Universe over 14 billion years ago. The Discovery News reported.
However, Planck’s toolkit is not limited to measuring ancient microwaves from the dawn of time, it is also building an all-sky map of Milky Way. To remove the microwave radiation being emitted from our galaxy, a very accurate survey of microwave sources within our cosmic backyard is required to be conducted.
And it is this survey that’s bringing up a number of surprises.
On Monday, at an international conference in Bologna, Italy, Planck scientists presented the intermediate results from the mission ahead of its first cosmological dataset expected to be released in 2013.
“The images reveal two exciting aspects of the galaxy in which we live,” said Planck scientist Krzysztof M. Gorski from NASA’s Jet Propulsion Laboratory in Pasadena, Calif., and Warsaw University Observatory in Poland.
“They show a haze around the center of the galaxy, and cold gas where we never saw it before.”
This microwave “haze” is being emitted from a region surrounding the Milky Way’s heart.
Typically, this kind of emission would be expected from regions that have experienced supernova activity. However, the microwaves detected have a “harder” spectrum, basically implying that the microwave emission is unusually energetic.
When contrasted with the microwave radiation elsewhere in our galaxy, the
galactic core’s emission is a real peculiarity.
There are theories, which ponder over the source that generate this emission.
“Theories include higher numbers of supernovae, galactic winds and even the annihilation of dark-matter particles,” said Greg Dobler, Planck collaborator from the University of California in Santa Barbara, Calif.
The microwave emission apparently has the characteristics of synchrotron radiation, when particles emit energy as they interact with powerful magnetic fields.
However, dark matter - the material that is thought to make up 83 percent of all the mass in our universe - could be the reason.
Although dark matter often seems to be the “go-to” explanation for odd cosmic behaviour, the obliteration of clouds of dark matter accumulating around the galactic core may produce the energy needed to explain this microwave phenomenon.
Besides microwave anomaly, Planck’s capability to survey the whole sky has resulted in a map of cold interstellar clouds of carbon monoxide (CO).
Astronomers seek out the microwave emission associated with CO so that vast clouds of invisible hydrogen molecules may be divulged.
Molecular hydrogen is the fuel behind star formation processes, so the discovery of earlier unknown clouds of carbon monoxide will certainly boost our understanding of star birth in the Milky Way.
First Published: Feb 14, 2012 13:38 IST