Universe reached peak heat 11 billion years ago
Melbourne: Astronomers have identified the point where the Universe moved from heating to cooling - 11 billion years ago, when the temperature was an astonishing 13,000 degrees Celsius, hotter than the surface of the Sun.
An international team, led by researchers from Swinburne University of Technology, found evidence that the Universe broke its rising `fever` about 11 billion years ago.
They measured the temperature of the Universe when it was 3 to 4 billion years old by studying the gas in between galaxies - the intergalactic medium.
During these early years of the Universe`s development, many extremely active galaxies were `switching on` for the first time and heating their surroundings.
"However, 11 billion years ago, this fever seems to have broken and the Universe began cooling down again," lead researcher Elisa Boera, a PhD student from Swinburne`s Centre for Astrophysics and Supercomputing, said.
"The intergalactic medium is an excellent recorder of the Universe`s history. It retains memory of the big events that affected its properties, such as temperature and composition, during its different phases of evolution," said Boera.
In the study, Boera collected the bluest light that Earth`s atmosphere transmits harsh ultraviolet (UV) light from 60 quasars.
This UV light comes from slightly later in the Universe`s development, allowing the new temperature measurement.
"The quasar light suggests that the Universe had cooled by about 1000 degrees C within 1 billion years after reaching its maximum of 13,000 degrees," Boera said.
"This cooling trend has probably continued to the present day," said Boera.
"We think the answer is helium," co-author of the study, Swinburne Associate Professor Michael Murphy said.
"Fourteen per cent of the intergalactic gas is helium and, 12 billion years ago, it was absorbing the intense radiation from active galaxies, losing electrons in the process," Murphy said.
"The electrons whizz around, heating up the gas. It`s similar to the greenhouse effect on Earth: Carbon dioxide gas absorbs infrared radiation and heats our atmosphere.
"Once all the helium was ionised, the radiation would simply pass through the gas without heating it. Then, as the Universe expands the gas cools down, just like the cold gas sprayed from an aerosol can - it quickly cools as it expands out of the can," said Murphy.
The study has been published in the Monthly Notices of the Royal Astronomical Society.
More from India
More from World
More from Sports
More from Entertaiment
- When Subramanian Swamy shocked people at a wedding!
- Mumbaikars join hands to save Pakistani teen with rare illness
- PM Modi speaks at Golden Jubilee celebrations of poet Dinkar’s works
- Mumbai: Diamond export company denies job to Muslim youth
- Vadodara: Policemen seen dancing with bar girls
- Coal scam: Naveen Jindal, Madhu Koda and others get bail
- Mirage 2000 fighter jet landing was part of capability demonstration: IAF
- One year of Modi govt: Arun Jaitley addresses press conference
- DNA: IAF Mirage 2000 fighter plane lands successfully on Yamuna expressway
- DNA: Osama documents show 'Indian brother in Madinah' financed al Qaeda
- ISIS executes Syrian fighter using anti-tank rocket launcher
- Zee Media Exclusive: Kangana, Madhavan talk about their film 'Tanu Weds Manu Returns'
- Zee Media Exclusive interview with Congress leader Kamal Nath
- Woman robbed at gunpoint inside Hyderabad ATM
- DNA: Harmful chemicals found in Maggi, Nestle India still in denial mode
- Is MSG in 'Maggi' noodles harmful for you?
- Mumbai firm booked for denying Muslim MBA graduate job on religious grounds, probe ordered
- Jayalalithaa makes public appearance, meets Governor: As it happened
- New IPL rules could see Chennai Super Kings lose MS Dhoni
- `Piku` hits jackpot, does Rs 100 crore business worldwide
- Geelani's passport application incomplete, cannot be processed: MEA
- CBSE Class X Results 2015 to be announced today?
- Lalu Yadav invites Jitan Ram Manjhi for joint fight against BJP, JD(U) upset
- Littering, defacement to be made punishable offence
- CBSE Class 10 Results 2015 may not be announced today
- IPL 2015, Qualifier 2: CSK vs RCB - As it happened...
- Kejriwal slams notification on LG's powers, says Modi running Delhi govt through back door
- India to soon have its own space shuttle!
- Check rajresults.nic.in: Rajasthan Board Class 12th results 2015 to be declared today
- Check JAC 12th Inter Arts Result 2015: JAC 12th Inter Arts Result 2015 declared on jac.nic.in