Cosmic radio burst traced back to distant dwarf galaxy

A burst of cosmic radio waves has finally been traced back to its source: an old dwarf galaxy located more than 3 billion light years from Earth.

Such bursts are rare and last only briefly, but have been of interest since their first detection almost ten years ago due to their appearance from outside our galaxy.

Fast radio bursts flash for just a few milliseconds and need to be very powerful in order to be observed from Earth. Combined with their origin being outside our galaxy, the fact that none of those originally observed were detected again has led to such bursts causing great interest in the astronomical community.

The Fornax dwarf galaxy, which, like the galaxy responsible for the cosmic radio burst, is significantly smaller than our own Milky Way. Image courtesy of ESO/Digitized Sky Survey 2

A repeating burst discovered in 2012 allowed researchers to monitor its area of the sky with the Karl Jansky Very Large Array (VLA) in New Mexico and the Arecibo radio dish in Puerto Rico.

The development of high-speed data recording and real-time data analysis software by an astronomer at the University of California, Berkeley, allowed the VLA to detect a total of nine bursts over the period of a month last year.

The VLA’s detection pinpointed the burst to within a tenth of an arcsecond, subsequent efforts by larger European and American radio interferometer arrays further narrowed it to within one-hundredth of an arcsecond, within a region about 100 light years in diameter. Deep imaging by the Gemini North Telescope followed and revealed an optically faint dwarf galaxy that the VLA found to continuously emit low-level radio waves.

Image courtesy of Danielle Futselaar (www.artsource.nl)

This emission is typical of a galaxy with an active nucleus perhaps indicative of a central supermassive black hole. It is also noted that extremely bright exploding stars – called superluminous supernovae – and long gamma ray bursts also occur in this type of galaxy. Both such events are believed to be associated with the massive, highly magnetic and rapidly rotating neutron stars called magnetars.

“All these threads point to the idea that in this environment, something generates these magnetars,” said co-author and UC Berkeley astronomer Casey Law.

“It could be created by a superluminous supernova or a long gamma ray burst, and then later on, as it evolves and its rotation slows down a bit, it produces these fast radio bursts as well as continuous radio emission powered by that spindown. Later on in life, it looks like the magnetars we see in our galaxy, which have extremely strong magnetic fields but rotate more like ordinary pulsars.”

Law’s theory is but one, though the new data has ruled out several explanations for the origin of the radio bursts that had previously been offered. Law’s team are the first to observe the bursts as a cosmological phenomenon and where said phenomenon is occurring; the objective now is to figure out the reason for the phenomenon’s occurrence.

Only 6% of space enthusiasts would like to live in the first low-Earth orbit settlements

A new survey has found that only 6% of respondents would be happy to live in a proposed Equatorial Low Earth Orbit (ELEO) settlement, where humans live in a small cruise ship-like space station at a similar orbit to the ISS.

Four conditions were set for respondents to assess and while at least 30% said they agree with at least one of them, the number shrank significantly when it came to those who could accept all the conditions.

These were that the settlement itself would require permanent residence, would be no bigger than a large cruise ship, would contain no more than 500 people and would require residents to be willing to devote at least 75% of their wealth to move in.

The example settlement used in the survey is Kalpana Two, pictured, a conceptual cylindrical space habitat visualised by Brian Versteeg. Measuring 110 m x 110m it would rotate to provide simulated gravity on the “ground” and zero-gravity near the cylinder’s core where occupants can ‘fly’, and would be capable of housing 500 – 1,000 people

The study, conducted by researchers from San Jose State University (SJSU) and the FAA Office of Commercial Space Transportation (AST) sought to assess the desirability of such a settlement. Previous similar studies had suggested early space settlements would need to be significantly smaller than believed, and located far closer to Earth.

The research was conducted via an Internet survey made available to the public between 8 January 2016 and 17 June 2016. The survey, using Qualtrics software, received 1,075 responses and was distributed via an email list, social media and spac- related organisations. It should therefore be noted that the respondents are not representative of the general population: 95% actually identified as space enthusiasts.

“95% of respondents were self-described space enthusiasts and 81% were male. 70% were from North America and 20% from Europe,” the study authors Al Globus, from SJSU, and Tom Marotta, from AST, wrote in the research paper.

“This is not surprising as the authors made no attempt to select a random sample of any particular group, but rather to simply distribute the survey as widely as we could.”

Kalpana Two, the conceptual space station the survey was based on. Images courtesy of Brian Versteeg

The paper itself is rather enthusiastic about the 6% figure, pointing out that while it is a low percentage of those who responded, if considering it 6% of those who globally identify as “space enthusiasts” there are likely more than enough to fill these early settlements.  The authors also acknowledge that such a number is not all that surprising given the demands of the move.

However, while the enthusiasm and optimism is laudable, it’s worth noting that those principally willing to give up the most were small in number and tended to fall on the wealthier spectrum. So while the possibility of the project exists, it seems that, as with all commercial space projects so far, it would principally have to cater to the rich.

Moreover, when responding to the main attraction of life in space, “the most common remark was simply that it was ‘in space’ not any particular characteristic of living in space”. There seems in the responses to be a certain enthusiasm that may not hold up in the actual moment of decision.

The fact that people like the idea of living in space is no surprise; the survey however does little to assuage the realities of the situation. Enthusiasm is promising, however the main result of this survey seems to be that blind optimism is only truly backed up by vast amounts of money.

Life expectancy to break the 90-year barrier by 2030

New research has revealed that the average life expectancy is set to increase in many countries by 2030 and, in South Korea specifically, will improve so much as to exceed an average of 90 years. The study analysed long-term data on mortality and longevity trends to predict how life expectancy will change from now until 2030.

The study was led by scientists from Imperial College London in collaboration with the World Health Organization. Looking at 35 industrialised nations, the team highlighted South Korea as a peak for life expectancy; predicting expectancy from birth, they estimate that a baby girl born in South Korea in 2030 will expect to live 90.8 years, while men are expected to live to be 84.1 years.

Scientists once thought an average life expectancy of over 90 was impossible, according to Professor Majid Ezzati, lead researcher from the School of Public Health at Imperial College London:

“We repeatedly hear that improvements in human longevity are about to come to an end. Many people used to believe that 90 years is the upper limit for life expectancy, but this research suggests we will break the 90-year barrier,” he said.

“I don’t believe we’re anywhere near the upper limit of life expectancy -if there even is one.”

South Korea leads in life expectancy. Image courtesy of jedydjah. Featured image courtesy of Carey and Kacey Jordan

Ezzati explained that the high expectancy for South Korean lives was likely due to a number of factors including good nutrition in childhood, low blood pressure, low levels of smoking, good access to healthcare, and uptake of new medical knowledge and technologies. It is likely that, by 2030, South Korea will have the highest life expectancy in the world.

Elsewhere, French women and Swiss men are predicted to lead expectancies in Europe, with 88.6 years and nearly 84 years respectively. The UK is expected to average 85.3 years for women (21st in the table of countries studied) and 82.5 years for men (14th in the table).

The study included both high-income countries and emerging economies. Among the high-income countries, the US was found to have the lowest predicted life expectancy at birth. Averaging similar to Croatia and Mexico, the researchers suggested this was due to a number of factors including a lack of universal healthcare, as well as the highest child and maternal mortality rate, homicide rate and obesity among high-income countries.

A lack of universal healthcare is one of the reasons the US trails behind in life expectancy. Image courtesy of HSeverson

Notably, the research also suggests that the life expectancy gap between men and women is closing and that a large factor in increasing expectancy is due in no small part to older sections of the population living longer than before.

Such increased longevity is not without issue, however, as countries may not be prepared to support an ageing population.

“The fact that we will continue to live longer means we need to think about strengthening the health and social care systems to support an ageing population with multiple health needs,” added Ezzati.

“This is the opposite of what is being done in the era of austerity. We also need to think about whether current pension systems will support us, or if we need to consider working into later life.”