Home-made face masks may need at least two layers to stop Covid-19 spread: Study

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.

Mumbai, Jan 27: The country's largest car maker Maruti Suzuki India (MSI) on Monday said it has increased prices of select models by up to Rs 10,000 with immediate effect to offset the impact of rising input costs.

The price change varies across models and ranges up to 4.7 per cent (ex-showroom Delhi) and are effective from January, 27 2020, MSI said in a statement.

The price of entry level model Alto range has gone up in the range of Rs 9,000-6,000, S-Presso between Rs 1,500 to 8,000, WagonR between Rs 1,500 and Rs 4,000.

The company has also increased the price of its multi purpose vehicle Ertiga between Rs 4,000-10,000, Baleno by Rs 3,000 to 8,000 and XL6 by up to Rs 5,000 (all prices ex-showroom Delhi).

Currently, the company sells a range of vehicles starting from entry-level small car Alto to premium multi purpose vehicle XL6 with price ranging from Rs 2.89 lakh to Rs 11.47 lakh (ex-showroom Delhi).

New Zealand's research institute in Antarctica is scaling back the number of projects planned for the upcoming season, in an effort to keep the continent free of coronavirus, it was reported on Tuesday.

The government agency, Antarctica New Zealand, told the BBC on Tuesday that it was dropping 23 of the 36 research projects.

Only long-term science monitoring, essential operational activity and planned maintenance will go ahead.

The upcoming research season runs from October to March.

"As COVID-19 sweeps the planet, only one continent remains untouched and (we) are focused on keeping it that way," Antarctica New Zealand told the BBC.

The organisation's chief executive Sarah Williamson said the travel limits and a strict managed isolation plan were the key factors for keeping Scott Base - New Zealand's research facility - virus free.

"Antarctica New Zealand is committed to maintaining and enhancing the quality of New Zealand's Antarctic scientific research. However, current circumstances dictate that our ability to support science is extremely limited this season" she said.

Earlier in April, Australia announced that it would scale back its activity in the 2020-21 summer season.

This included decreasing operational capacity and delaying work on some major projects.