'Obama received gifts worth USD3K during Jan 2015 India visit'

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.

U.S. electric vehicle maker Tesla Inc is "very close" to achieving level 5 autonomous driving technology, Chief Executive Elon Musk said on Thursday, referring to the capability to navigate roads without any driver input.

"I'm extremely confident that level 5 or essentially complete autonomy will happen and I think will happen very quickly," Musk said in remarks made via a video message at the opening of Shanghai's annual World Artificial Intelligence Conference (WAIC).

"I remain confident that we will have the basic functionality for level 5 autonomy complete this year."

Automakers and tech companies including Alphabet Inc Waymo and Uber Technologies are investing billions in the autonomous driving industry.

However industry insiders have said it would take time for the technology to get ready and public to trust autonomous vehicles fully.

The California-based automaker currently builds cars with an Autopilot driver-assistance system.

Tesla is also developing new heat-projection or cooling systems to enable more advanced computers in cars, Musk said.

Industry data showed Tesla sold nearly 15,000 China-made Model 3 sedans last month.

Tesla has become the highest-valued automaker as its shares surged to record highs and its market capitalisation overtook that of former front-runner Toyota Motors Corp.

Google on Monday announced it is gradually winding down its free public Wi-Fi Station programme currently available at over 400 railway stations in India, and will work with the Indian Railways and Railtel Corporation to help them with existing sites so they can remain useful resources for people.

Google launched its Station initiative in India in 2015 to bring fast, free public Wi-Fi to over 400 of the busiest railway stations in the country by mid-2020.

"We crossed that number by June 2018 and implemented Station in thousands of other locations around the country in partnership with telecommunications companies, ISPs and local authorities," Caesar Sengupta, Vice President, Payments and Next Billion Users, Google, said in a statement.

"Over time, partners in other countries asked for Station too and we responded accordingly. We're grateful for these partnerships, especially with the Indian Railways and the Government of India, that helped us serve millions of users over the last few years," he added.

According to Google, the decision to shut Station has been taken keeping the affordable mobile data plans and mobile connectivity in mind that is improving globally including in India.

"India, specifically now has among the cheapest mobile data per GB in the world, with mobile data prices having reduced by 95 per cent in the last 5 years, as per TRAI in 2019," said Sengupta.

The Indian users consume close to 10GB of data, each month, on average, according to reports.

"Our commitment to supporting the next billion users remains stronger than ever, from continuing our efforts to make the internet work for more people and building more relevant and helpful apps and services," Sengupta noted.

Global networking giant Cisco last year teamed up with Google to roll out free, high-speed public Wi-Fi access globally, starting with India.

The first pilot under the partnership was rolled out at 35 locations in Bengaluru.

Sengupta said that in addition to the changed context, the challenge of varying technical requirements and infrastructure among our partners across countries has also made it difficult for Station to scale and be sustainable, especially for our partners.

"And when we evaluate where we can truly make an impact in the future, we see greater need and bigger opportunities in building products and features tailored to work better for the next billion user markets," he said.