Giant penguin fossil found in New Zealand

Leiden, Jul 2: Astronomers have discovered a luminous galaxy caught in the act of reionizing its surrounding gas only 800 million years after the Big Bang.

The research, led by Romain Meyer, PhD student at UCL in London, UK, has been presented at the virtual annual meeting of the European Astronomical Society (EAS).

Studying the first galaxies that formed 13 billion years ago is essential to understanding our cosmic origins. One of the current hot topics in extragalactic astronomy is 'cosmic reionization,' the process in which the intergalactic gas was ionized (atoms stripped of their electrons).

Cosmic reionization is similar to an unsolved murder: We have clear evidence for it, but who did it, how and when? We now have strong evidence that hydrogen reionization was completed about 13 billion years ago, in the first billion years of the universe, with bubbles of ionized gas slowly growing and overlapping.

The objects capable of creating such ionized hydrogen bubbles have however remained mysterious until now: the discovery of a luminous galaxy in which 60-100 percent of ionizing photons escape, is likely responsible for ionizing its local bubble. This suggests the case is closer to being solved.

The two main suspects for cosmic reionization are usually 1) a population of numerous faint galaxies leaking ~10 percent of their energetic photons, and 2) an 'oligarchy' of luminous galaxies with a much larger percentage (>50 percent) of photons escaping each galaxy.

In either case, these first galaxies were very different from those today: galaxies in the local universe are very inefficient leakers, with only <2-3 percent of ionizing photons escaping their host. To understand which galaxies governed cosmic reionization, astronomers must measure the so-called escape fractions of galaxies in the reionization era.

The detection of light from excited hydrogen atoms (the so-called Lyman-alpha line) can be used to infer the fraction of escaping photons. On the one hand, such detections are rare because reionization-era galaxies are surrounded by neutral gas which absorbs that signature hydrogen emission.

On the other hand, if this hydrogen signal is detected it represents a 'smoking gun' for a large ionized bubble, meaning we have caught a galaxy reionizing its surroundings. The size of the bubble and the galaxy's luminosity determines whether it is solely responsible for creating this ionized bubble or if unseen accomplices are necessary.

The discovery of a luminous galaxy 800 million years after the Big Bang supports the scenario where an 'oligarchy' of bright leakers emits most of the ionizing photons.

"It is the first time we can point to an object responsible for creating an ionized bubble, without the need for a contribution from unseen galaxies.

Additional observations with the upcoming James Webb Space Telescope will enable us to study further what is likely one of the best suspects for the unsolved case of cosmic reionization," said Meyer.

In the wake of the gas leak at a factory in Visakhapatnam, the National Disaster Management Authority (NDMA) has issued detailed guidelines for restarting industries after the lockdown and the precautions to be taken for the safety of the plants as well as the workers.

In a communication to all states and union territories, the NDMA said due to several weeks of lockdown and the closure of industrial units, it is possible that some of the operators might not have followed the established standard operating procedures.

As a result, some of the manufacturing facilities, pipelines, valves may have residual chemicals, which may pose risk. The same is true for the storage facilities with hazardous chemicals and flammable materials, it said.

The NDMA guidelines said while restarting a unit, the first week should be considered as the trial or test run period after ensuring all safety protocols.

Companies should not try to achieve high production targets. There should be 24-hour sanitisation of the factory premises, it said.

The factories need to maintain a sanitisation routine every two-three hours especially in the common areas that include lunch rooms and common tables which will have to be wiped clean with disinfectants after every single use, it added.

For accommodation, the NDMA said, sanitisation needs to be performed regularly to ensure worker safety and reduce the spread of contamination.

To minimise the risk, it is important that employees who work on specific equipment are sensitised and made aware of the need to identify abnormalities like strange sounds or smell, exposed wires, vibrations, leaks, smoke, abnormal wobbling, irregular grinding or other potentially hazardous signs which indicate the need for immediate maintenance or if required shutdown, it said.

At least 11 people lost their lives and about 1,000 others were exposed to a gas leak at a factory in Andhra Pradesh''s Visakhapatnam on May 7.

The incident took place after it restarted operations when the government allowed industrial activities in certain sectors following several weeks of lockdown.

The lockdown was first announced by Prime Minister Narendra Modi on March 24 for 21 days in a bid to combat the coronavirus threat. The lockdown was then extended till May 3 and again till May 17.

Hyderabad, May 6: Away from city lights, two hours before Sunrise, people in India and across the world can witness Annual Meteor Shower called Eta Aquarids till May 28.

Observed since time immemorial, Meteor shower are commonly known as shooting stars which are nothing but dust flakes of comet/asteroid entering earth atmosphere.

This Annual Eta Aquarids Meteor Shower peaked on Wednesday at 02.30 am on Wednesday whereas presence of Full Moon was an obstacle outshining bright streaks of lights of this meteor shower zipping across the South Eastern sky.

As this meteor shower is active till May 28, people can still watch this celestial spectacle in early morning every day, Planetary Society of India (PSI) Director N Sri Raghunandan Kumar interacting with UNI said.

As per International Meteor Organization (IMO), 50 meteors per hour are expected to be seen on day of peak today. And this number would vary as days pass on till May 28 while earth passes through dust cloud of comet debris in its orbit.