RSS chief pays tribute to Gauri Lankesh, Dharam Singh

Bengaluru, Mar 10: Karnataka Health Minister B Sriramulu on Tuesday paid a surprise visit to the Kempegowda International Airport and checked all measures taken by authorities and doctors to prevent the spread of coronavirus.

Till date, 45 people have tested positive for the deadly coronavirus infection across India.

A resident of Bengaluru was tested positive for coronavirus on Monday.

Bengaluru, Jun 8: Facing a shortage of labour, some top builders in the city have initiated efforts to bring back the migrant workers, who have returned to their native places following the COVID-19 lockdown, and are holding parleys with Railway authorities for operation of special trains to ferry them.

After the lockdown was announced, many construction projects came to a halt and accordingly the labourers were rendered jobless. These migrant workers preferred to go back to their home state as they were not paid when the projects were stopped and were caught in the big financial mess. Many of these migrants even chose to cover thousands of kilometres by foot when even trains, buses or any motor vehicles were not operating.

Keeping their woes in view, the Centre decided to run the Shramik Special trains to ferry them to their native places. But, after they were gone, the builders found themselves in a lurch. An executive of a builder told PTI "Yes, our builder and a few others are in talks with the Railways to run the special train to bring back the labourers." She said nothing has been materialised as of now.

According to her, the builders took the contact numbers of the workers when they left the city to their home states and are now contacting them one by one. The South Western Railway has so far sent 3.11 lakh migrant workers in 216 Shramik Special trains starting from May 3 to June 6.

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.