ISRO to inject Chandrayaan 2 into lunar orbit

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.

With the scrapping of Mitron and Remove China Apps from its Play Store gaining a lot of attention in India, Google on Thursday said that it removed a video app "for a number of technical policy violations", while adding that it also does not allow an app that "encourages or incentivizes users into removing or disabling third-party apps".

Both the apps became immensely popular in India within a short span of time due to the prevailing anti-China sentiment amid border tensions between India and China in Ladakh and calls by Indian activists to boycott Chinese products.

Reports suggested that the Mitron app is a repackaged version of TicTic, which is a TikTok clone.

The Remove China Apps was designed to help users identify applications of Chinese origin.

Without naming the apps, Google hinted that the Mitron app may make a comeback on the Play Store once it fixes some technical issues, but the chances of the Remove China Apps are thin.

"We have an established process of working with developers to help them fix issues and resubmit their apps. We've given this developer (of the video app) some guidance and once they've addressed the issue the app can go back up on Play," Sameer Samat, Vice President, Android and Google Play, said in a statement.

Google said that its Android app store was designed to provide a safe and secure experience for the consumers while also giving developers the platform and tools they need to build sustainable businesses.

Samat said that Google Play recently suspended a number of apps for violating the policy that it does not allow an app that "encourages or incentivizes users into removing or disabling third-party apps or modifying device settings or features unless it is part of a verifiable security service".

"This is a longstanding rule designed to ensure a healthy, competitive environment where developers can succeed based upon design and innovation. When apps are allowed to specifically target other apps, it can lead to behaviour that we believe is not in the best interest of our community of developers and consumers," Samat said.

"We've enforced this policy against other apps in many countries consistently in the past - just as we did here," he added.

New Delhi, Jul 19: Three of the 10 most valued companies added a total of Rs 98,622.89 crore to their market valuation last week, led by stellar gains in IT major Infosys.

Seven companies from the coveted list witnessed a decline in their market valuation last week, but their cumulative loss of Rs 37,701.1 crore was less than the total gain made by three firms -- Reliance Industries Limited, Hindustan Unilever Limited and Infosys.

The market capitalisation of Infosys zoomed Rs 52,046.87 crore to Rs 3,85,027.58 crore. Shares of Infosys had rallied over 9 per cent on Thursday after the company posted a stronger-than-expected 12.4 per cent rise in the first quarter consolidated net profit.

Hindustan Unilever Limited added Rs 25,751.07 crore in its market valuation which stood at Rs 5,48,232.26 crore at close on Friday. Reliance Industries' m-cap jumped Rs 20,824.95 crore to Rs 12,11,682.08 crore.

In contrast, HDFC's valuation plunged Rs 13,920.21 crore to Rs 3,13,269.70 crore and that of Tata Consultancy Services (TCS) declined Rs 7,617.34 crore to Rs 8,26,031.21 crore.

The valuation of ICICI Bank tumbled Rs 4,205.71 crore to Rs 2,29,156.24 crore and that of Kotak Mahindra Bank by Rs 4,175.28 crore to Rs 2,62,864.37 crore.

Bharti Airtel's m-cap dipped Rs 4,009.83 crore to Rs 3,09,521.05 crore and HDFC Bank's by Rs 3,403.97 crore to Rs 6,03,463.97 crore.

The valuation of ITC declined by Rs 368.76 crore to Rs 2,38,469.29 crore.

In the ranking of top-10 firms, RIL was at the number one rank followed by TCS, HDFC Bank, HUL, Infosys, HDFC, Bharti Airtel, Kotak Mahindra Bank, ITC and ICICI Bank.

During the last week, the 30-share BSE index advanced 425.81 points or 1.16 per cent.