Superposition of B, V and Rc images of UGC 6456 taken with BTA/SCORPIO. The inset shows the HST WFPC2/F555W image of the region around UGC 6456 ULX marked by the square; the circle indicating the 0.8′′ error box of the ULX position derived from the Chandra data. Credit: Vinokurov et al., 2019.
Russian astronomers have performed a detailed study of one of the ultraluminous X-ray sources (ULXs) in the galaxy UGC 6456. Results of the research, presented in a paper published November 20 on arXiv.org, suggest that this source, designated UGC 6456 ULX, is one of the brightest known ULXs in the optical range.
ULXs are point sources in the sky that are so bright in X-rays that each emits more radiation than 1 million suns emit at all wavelengths. They are less luminous than active galactic nuclei, but more consistently luminous than any known stellar process. Although numerous studies of ULXs have been conducted, the basic nature of these sources still remains unsolved.
At a distance of about 14.8 million light years away, UGC 6456 is one of the closest blue compact dwarf galaxies. It hosts the UGC 6456 ULX—a transient source not well studied, whose properties remain undisclosed.
Now, a team of astronomers led by Alexander Vinokurov of Special Astrophysical Observatory in Nizhnij Arkhyz, Russia, reports a new study of UGC 6456 ULX, which identified an optical counterpart of this ULX and shed more light on the parameters of this source. The research was based mainly on the analysis of archival images of UGC 6456 ULX obtained with Chandra X-Ray Observatory and the Hubble Space Telescope (HST).
"We present preliminary results of a study of the ultraluminous X-ray source UGC 6456 ULX. (...) To identify an optical counterpart of UGC 6456 ULX, we used archival images from Chandra X-Ray Observatory and HST," the astronomers wrote in the paper.
According to the study, UGC 6456 ULX showcases luminosity changes by more than two orders of magnitude with a peak value of 17 duodecillion erg/s in the 0.3–8 keV energy range. The absolute magnitude of this source in the bright state exceeds −7.6, which makes it one of the brightest ULXs in the optical range so far identified.
The research found that UGC 6456 ULX exhibits high optical and X-ray variability, however the nature of such behavior is uncertain and requires further studies. The astronomers noted that the variability of this source has an amplitude similar to that observed in NGC 7793 P13—a well studied ULX with a neutron star.
Moreover, the study reports a correlation between the optical and X-ray fluxes in UGC 6456 ULX. This may indicate that the optical emission from this source is produced by re-processing of the X-rays in outer parts of the optically-thick wind. According to the researchers, the detection of broad and variable hydrogen as well as helium emission lines supports the scenario of a strong wind coming from the supercritical accretion disk.
"The existence of such a wind is confirmed by the presence of the wide hydrogen and helium emission lines in the optical spectra, that are typical for the all spectroscopically studied ULXs," the authors of the paper concluded.
Citation: Ultraluminous X-ray source UGC 6456 ULX investigated in detail (2019, November 29) retrieved 29 November 2019 from https://phys.org/news/2019-11-ultraluminous-x-ray-source-ugc-ulx.html
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Supporters of the climate movement Ende Gelaende protest at the coal-fired power station Lippendorf near Leipzig, Germany, Sunday, Nov. 24, 2019. Ende Gelaende is an action alliance for an immediate coal exit, climate justice and a fundamental system change. The alliance announces a mass action of civil disobedience in the Saxony and Lusatian coal mining area in Germany. (AP Photo/Jens Meyer)
Mass protests, a last-minute venue change and talk of climate tipping points are adding some unplanned drama to this year's international talks on tackling global warming.
Delegates from almost 200 countries had hoped to put the finishing touches to the rules governing the 2015 Paris accord, ironing out a few wrinkles left over from last year's conference in Katowice, Poland, and setting the scene for a major review of their efforts in 2020.
But then Brazil pulled its offer of hosting the talks and stand-in Chile, rattled by anti-government protests, canceled five weeks before the meeting. Next, President Donald Trump served formal notice that the United States was quitting the Paris accord, delivering a symbolic blow to one of his predecessor's signature achievements.
And scientists? Well, they didn't have any good news either. Study after study published in recent months has underscored the rapid pace of global warming and the need to urgently cut emissions of greenhouse gases.
Against that backdrop, the Dec. 2-13 meeting in Madrid has gained fresh impetus.
"We have to do more in less time," said Spanish environment minister Teresa Ribera, whose country stepped in at short notice to host the talks, saying it wanted to support "constructive multilateralism" in the wake of Chile's announcement and the U.S. withdrawal.
Supporters of the climate movement Ende Gelaende protest in front of a coal-fired power station Lippendorf near Leipzig, Germany, Sunday, Nov. 24, 2019. Ende Gelaende is an action alliance for an immediate coal exit, climate justice and a fundamental system change. The alliance announces a mass action of civil disobedience in the Saxony and Lusatian coal mining area in Germany. (AP Photo/Jens Meyer)
U.N. climate chief Patricia Espinosa said Saturday that "science tells us we are still in time" to tackle the climate crisis.
"That doesn't mean changing the world by tomorrow, but we must make decisions today," she said during a visit to the meeting venue.
Organizers expect around 25,000 visitors, including heads of state, scientists, seasoned negotiators and activists to attend the two-week meeting.
The main items on the agenda include finalizing rules on global carbon markets and agreeing how poor countries should be compensated for destruction largely caused by emissions from rich nations.
Proposals to create a worldwide market for emissions permits have been around for decades. The idea is that putting a price on carbon dioxide—the main greenhouse gas—and gradually reducing the available permits will encourage countries and companies to cut their emissions, notably by shifting away from fossil fuels toward renewable energy sources.
A participant takes a selfie ahead of the Climate Summit COP25 in Madrid, Spain, Friday, Nov. 29, 2019. The Climate Summit COP25 runs between 2 Dec. until 13 Dec in Madrid. (AP Photo/Manu Fernandez)
The European Union and some other jurisdictions already operate limited emissions trading systems, but efforts to roll these out worldwide have been hampered by fears that the lack of robust and transparent rules could corrupt the market.
"It would be great news to finalize this issue," said Ribera. But she warned that the "solvency and integrity of the system" was a concern.
"If we cannot complete it correctly, it's better to lay the ground for later completion," said Ribera.
That view was echoed by Yamide Dagnet, a former EU climate negotiator now with the Washington-based environmental think tank World Resources Institute.
"Without proper oversight and robustness these mechanisms could severely undercut climate action by creating loopholes, letting countries off the hook for making meaningful emission cuts, resulting in double counting and jeopardizing environmental integrity," she said.
Following the call of Fridays For Future Hungary and Extinction Rebellion Hungary young environmentalists demonstrate to demand measures against climate change in Budapest, Hungary, Friday, Nov. 29, 2019. (Zoltan Balogh/MTI via AP)
The question of compensating poor countries for environmental destruction—technically referred to as loss and damage—is also likely to be sensitive, said Dagnet. Attributing specific weather disasters such as hurricanes and floods, or slow but irreversible changes like sea level rise and desertification, to climate change remains a delicate issue given the potential sums involved.
Concerns about the cost of climate change are growing on all fronts. Trump cited financial demands on the United States as one of the reasons for quitting the Paris accord; European countries have hesitated to raise fuel prices for fear of sparking yellow vest-style protests like those seen in France; meanwhile, businesses are beginning to consider the price not just of reducing emissions but also of failing to do so.
Scientists say the time to act is now, if the world wants to meet the goal set in Paris of keeping global warming well below 2 degrees Celsius (3.6 degrees Fahrenheit), ideally 1.5 C by the end of the century. By some measures average temperatures have already increased by one degree Celsius since pre-industrial times, with the sharpest rise occurring in the last few decades.
Protesters march to demand action on climate change, on the streets in Lagos, Nigeria Friday, Nov. 29, 2019. Protesters around the world joined rallies on Friday as a day of worldwide demonstrations calling for action against climate change. (AP Photo/Sunday Alamba)
A demonstrator holds a poster during a protest climate strike ralley of the 'Friday For Future Movement' in Leipzig, Germany, Friday, Nov. 29, 2019. Cities all over the world have strikes and demonstrations for the climate during this ClimateActionDay. (AP Photo/Jens Meyer)
A woman shouts slogans as she marches with others during a worldwide protest demanding action on climate change in Brussels, Friday, Nov. 29, 2019. (AP Photo/Francisco Seco)
Thousands of demonstrators attend a protest climate strike ralley of the 'Friday For Future Movement' in front of the Federal Administrative Court building in Leipzig, Germany, Friday, Nov. 29, 2019. Cities all over the world have strikes and demonstrations for the climate during this ClimateActionDay. (AP Photo/Jens Meyer)
Chilean Environment Minister and chair of COP25 Carolina Schmidt attends a press conference ahead of the Climate Summit COP25 in Madrid, Spain, Friday, Nov. 29, 2019. The Climate Summit COP25 runs between 2 Dec. until 13 Dec in Madrid. (AP Photo/Manu Fernandez)
Participants walk ahead of the Climate Summit COP25 in Madrid, Spain, Friday, Nov. 29, 2019. The Climate Summit COP25 runs between 2 Dec. until 13 Dec in Madrid. (AP Photo/Manu Fernandez)
"Global warming is going faster," said Johan Rockström, co-director of Germany's Potsdam Institute for Climate Impact Research. "Climate impacts are occurring earlier and we are approaching potentially irreversible thresholds earlier than we previously thought."
Rockström and several colleagues recently warned that the world is heading for several " tipping points " that could sharply accelerate the pace of climate change. They include deforestation in the Amazon and the decline of ice sheets in Greenland and Antarctica.
Such messages resonate with environmental activists like Laura Laguna, a member of the Madrid chapter of Fridays for Future, one of the groups planning to protest during the climate talks, known as the 25th Conference of the Parties, or COP25.
"We are close to the point of no return on global warming," Laguna said. "Our generation's future depends on what we do now."
Ribera, whose formal title is interim minister for ecological transition, indicated that European Union leaders may try to send a strong signal during the meeting that the bloc is prepared to make sharper cuts to its emissions than previously pledged. A recent proposal to aim for "climate neutrality" by 2050 failed to win support from all of the EU's 28 member states—including the host of last year's talks, Poland.
Citation: Science warnings, US retreat add urgency to UN climate talks (2019, November 30) retrieved 30 November 2019 from https://phys.org/news/2019-11-science-retreat-urgency-climate.html
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Smog is seen blanketing the Iranian capital in this November 13, 2019 picture
Air pollution forced the closure of schools and universities in parts of Iran on Saturday, including Tehran, which was cloaked by a cloud of toxic smog, state media reported.
The young and elderly and people with respiratory illnesses were warned to stay indoors and sporting activities were suspended for the start of the working week in the Islamic republic.
The decision to shut schools and universities in the capital was announced late Friday by deputy governor Mohammad Taghizadeh, after a meeting of an emergency committee for air pollution.
"Due to increased air pollution, kindergartens, preschools and schools, universities and higher education institutes of Tehran province will be closed," he said, quoted by state news agency IRNA.
Schools in the capital would also be closed for a second day on Sunday, Taghizadeh said later.
"Having examined the index of pollutants in Tehran... it was decided for all schools to be closed tomorrow in Tehran province, except for the counties of Firuzkuh, Damavand and Pardis," he was quoted as saying.
An odd-even traffic scheme was imposed on Saturday to restrict the number of private vehicles on roads in the capital and trucks were banned outright in Tehran province, IRNA reported.
The scheme would be lifted on Sunday, but heavy vehicles would still be barred from the city, said Taghizadeh.
Industry to be halted
But activities would be halted on Sunday for all sand mines and industries in Tehran that contribute to air pollution, he added, without specifying which ones.
Schools were also closed on Saturday in the northern province of Alborz and in the central province of Esfahan, IRNA reported, citing officials.
Other areas where schools were shut included the northeastern city of Mashhad, Orumiyeh city in northwestern Iran and Qom city, south of Tehran.
In Tehran, average concentrations of hazardous airborne particles reached 146 micrograms per cubic metre on Saturday morning, according to air.tehran.ir, a government-linked website.
By mid-afternoon, the index had dropped to 107 after winds blew away some of the pollution hanging over the capital.
The World Health Organization's advised maximum level is 50.
The pall of pollution has shrouded the sprawling city of eight million for days and is only expected to clear on Monday when rain is forecast.
Air pollution was the cause of nearly 30,000 deaths per year in Iranian cities, state media reported earlier this year, citing a health ministry official.
The problem worsens in Tehran during winter, when a lack of wind and the cold air traps hazardous smog over the city for days on end—a phenomenon known as thermal inversion.
Most of the city's pollution is caused by heavy vehicles, motorbikes, refineries and power plants, according to a World Bank report released last year.
Citation: Smog in Iran shuts schools, universities (2019, November 30) retrieved 30 November 2019 from https://phys.org/news/2019-11-smog-iran-schools-universities.html
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Illustration shows the mid-sized lander on the lunar surface. Credit: NASA
As NASA presses forward with the agency's mission to the Moon, Mars and beyond, the development of top-tier technology is critical to success. With emphasis on lunar exploration and scientific investigation, the desire to deliver a wide variety of payloads to the Moon has increased.
For NASA's Commercial Lunar Payload Services (CLPS) initiative—which is leading the effort—this is no new concept. NASA has already awarded commercial contracts for payload delivery to the lunar surface, and expects to establish additional partnerships to support upcoming lunar ventures.
Several of these payloads will require vehicles capable of exploring the environment—such as a rover—to achieve their scientific objectives. To prepare for these missions, NASA has conducted a number of studies to identify and examine the technologies needed not only to reach, but to gather valuable data from, the Moon. These studies have led to important developmental efforts in areas such as advanced propulsion, navigation, communication, landing and other critical lander subsystems.
In one recent study, NASA developed a concept for a mid-sized lander that would deliver a rover to the polar regions of the Moon. This design focuses on demonstrating a highly accurate, large payload lunar landing vehicle. The system-level requirements focus on maximizing the mass delivered to the surface while maintaining landing site accuracy.
"This lander was designed with simplicity in mind to deliver a 300 kilogram rover to a lunar pole," said Logan Kennedy, the project's lead systems engineer at NASA's Marshall Space Flight Center in Huntsville, Alabama. "We used single string systems, minimal mechanisms and existing technology to reduce complexity, though advancements in precision landing were planned to avoid hazards and to benefit rover operations. We keep the rover alive through transit and landing so it can go do its job."
Multiple NASA field centers contributed to this complex effort—the results of which are captured in a technical paper available to the public on the NASA Technical Reports Server. As NASA turns to commercial partners to land scientific instruments—and eventually humans—on the Moon's surface, companies can benefit from work NASA has already done.
"As robotic lunar landers grow to accommodate larger payloads, simple but high-performing landers with a contiguous payload volume will be needed," Kennedy said. "This concept was developed by a diverse team of people over many years and meets that need.
"We hope that other lander designers can benefit from our work," he added.
Citation: NASA shares mid-sized robotic lunar lander concept with industry (2019, November 30) retrieved 30 November 2019 from https://phys.org/news/2019-11-nasa-mid-sized-robotic-lunar-lander.html
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TOP STORIES
Globalstar is borrowing $199 million through a loan arranged by its controlling shareholder Thermo and fleet operator EchoStar. Globalstar said it will use the funds to pay off a $66 million loan arranged in June, and to make pre-payments towards a separate $152 million loan. Globalstar has rights to global S-band satellite spectrum, which it is seeking to use for terrestrial connectivity. EchoStar recently acquired Helios Wire and ordered two S-band smallsats from Tyvak to secure S-band spectrum rights with international regulators. Mike Dugan, EchoStar president and chief executive, said the company sees “potential opportunities to collaborate with Globalstar in S-band development.” The new credit facility with EchoStar matures in November 2025. [Globalstar]
Malaysian satellite operator Measat selected Arianespace to launch its next satellite on an Ariane 5 rocket. Measat-3d, a communications satellite Airbus Defence and Space is building, is scheduled to launch on the European heavy lift vehicle in 2021. Measat-3d has a target weight of 5,734 kilograms, and is expected to have an operational life of 19 years. The satellite will carry C-, Ku-, and Ka-band payloads for Measat, plus an L-band payload for South Korean satellite operator KT Sat. Measat-3d will have coverage over Africa, the Middle East and Asia, including Malaysia. [Arianespace]
Roscosmos is using drones and Earth-imaging satellites to monitor construction at Russia’s Vostochny Cosmodrome in an effort to keep the program from falling further behind schedule. Roscosmos CEO Dmitry Rogozin told Russian President Vladimir Putin that Roscosmos is using satellite imagery to check progress on a weekly basis. A first launch of Russia’s Angara 5 rocket from Vostochny, once planned for 2020, is now targeted for 2023, Rogozin said. Cosmodrome preparations are also underway to support the launch of a super-heavy Russian rocket from Vostochny in 2028, he said. [Kremlin]
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Marlink has finished construction of a satellite network in rural French Guiana.The network, comprised of a large ground station antenna and around 50 very small aperture terminal satellite dishes, provides internet access to schools, colleges, government agencies and the public. French Guiana has Europe’s primary spaceport, the Guiana Space Center, along the coast, but the majority of the territory is covered by the Amazon. Marlink said it completed the rural connectivity project with the Collectivité Territoriale de Guyane government, and local public company SPLANG. [Marlink]
Comtech Telecommunications has acquired Canadian ground systems company UHP Networks for $40 million. Comtech said the purchase allows it to leverage UHP routers and very small aperture terminal equipment in its products. UHP also brings connections to U.S. mobile network operators, international government agencies, and Fortune 500 companies. Comtech said it agreed to pay an additional $10 million in earn-out payments if UHP meets agreed upon sales targets over the next 12 months. Comtech expects the acquisition to close late in the second half of its fiscal 2020. [Comtech]
An Indian Polar Satellite Launch Vehicle (PSLV) put 15 satellites into orbit Tuesday night. The PSLV lifted off at 10:58 p.m. Eastern time from the Satish Dhawan Space Center. The primary payload was Cartosat-3, the latest in a series of Indian high-resolution remote sensing satellites. The rocket also carried 12 Dove cubesats for Planet, the American remote sensing company, and Meshbed, a communications testbed cubesat developed by Analytical Space Incorporated and MITRE Corporation. [NASASpaceFlight.com]
Eutelsat says it is willing to support a public auction of C-band spectrum by the FCC provided it is compensated. The satellite operator, which dropped out of the C-Band Alliance coalition of other satellite operators this fall, said it would support the FCC’s plans announced last week for a public auction of 280 megahertz of satellite C-band spectrum for terrestrial 5G services as long as some proceeds from the spectrum sale go toward covering costs satellite operators will incur moving out of the band. The FCC hasn’t disclosed if auction proceeds would be used to cover such costs, although there are provisions to do so in a Senate bill introduced last week. [SpaceNews]
Satellite Internet of Things startup Lacuna Space has teamed up with Swiss wireless company Miromico to develop communications devices to link with Lacuna’s future constellation. Lacuna and Miromico plan to conduct commercial trials next year using Lacuna’s prototype satellite. Lacuna has slightly increased the target size of its first-generation constellation from 32 satellites to 36 satellites. The company hopes to have the constellation in a 500-kilometer low Earth orbit by the end of 2022. Lacuna and Miromico plan to develop a global supply chain for customers to buy modems, antennas and other user equipment. [Lacuna Space]
An Ariane 5 launched two satellites Tuesday after several days of delays.The rocket lifted off from Kourou, French Guiana, at 4:23 p.m. Eastern, deploying the TIBA-1 satellite 27 minutes after liftoff and Inmarsat’s GX5 satellite seven minutes later. TIBA-1, named after the ancient Egyptian capital of Tiba, is the Egyptian government’s first satellite, built by Airbus and Thales Alenia Space. Inmarsat GX5, built by Thales Alenia Space, is the first of eight additional satellites and payloads Inmarsat ordered after completing its first-generation Global Xpress high-throughput satellite system. GX5 has more capacity than its four predecessors combined. The launch, delayed by ground equipment problems and weather, was the was the 250th of an Ariane rocket, and one of the last for the Ariane 5, which has 11 missions remaining. [SpaceNews]
SpaceNews Senior Staff Writer Jeff Foust contributed to this newsletter.
If your dog has been alive and kicking its paws about for a decade, the widely held belief is that it has aged as much as a human would have done by the grand old age of 70. This conversion factor—each year of a dog's life accounting for seven human years—comes from dividing human life expectancy of around 77 by the canine life expectancy of around 11.
The underlying assumption is that each calendar year a dog lives though is equivalent to seven human years at any stage of a dog's life. But new research suggests that things aren't so simple. And if we look at some basic developmental milestones, it's clear why.
For example, most dog breeds reach sexual maturity between the ages of six and 12 months—the upper end of that range corresponding, by the traditional conversion, to a human age of seven. And at the other end of the spectrum, although unusual, some dogs have been known to live for over 20 years. Under the "factor-of-seven" conversion rule, this would equate to an unfathomable 140 human-equivalent years.
To make matters more complicated, dogs' life expectancy depends significantly on the breed. Smaller dogs tend to live significantly longer, suggesting that they age more slowly than bigger dogs.
All of this raises the question of what exactly we mean by age. The most obvious way to describe it is simply the length of time that has passed since birth. This is known as the chronological definition of age.
However, there are other descriptions. "Biological age", for example, is a more subjective definition, which relies on assessing physiological indicators to identify an indivdual's development. These include measures like the "frailty index"—surveys which take into account an individual's disease status, cognitive impairments and levels of activity.
For example, if you've spent a lot of time eating junk food and smoking cigarettes instead of taking exercise and eating healthily, the chances are your biological age will exceed your chronological age. Or, you might be a 60-year-old with the body of a 40-year-old if you've looked after yourself well.
A new look at a dog's life
When it comes to comparing animal ages across species, the biological definitions of age are far more useful than their chronological counterparts. Knowing a hamster is six weeks old doesn't give you a good picture of that animal's life stage even if you know the life expectancy of a hamster is only three years. Learning that a hamster has reached an age at which it can reproduce gives a much better picture of its level of maturity.
The authors of the new ageing study suggest that a sensible way to measure biological age is though so-called "epigenetic clocks"—changes to the packaging of our DNA that accumulate over time in all mammals.
In particular, "methylation"—the addition of methyl groups (a carbon atom bonded to three hydrogen atoms) to DNA—seems to be a good indicator of age. Many prominent physiological markers, such as the development of teeth, seem to occur at the same levels of methylation across different species. So by matching the levels of methylation in Labrador retrievers and humans, the researchers derived a formula to map dog age to its human equivalent.
That formula is: human equivalent age = 16 x ln(dog's chronological age) + 31.
Here "ln" represents a mathematical function known as the natural logarithm. The logarithm function is well-known in the non-linear scales for energy released during earthquakes (Richter) or for measuring sound (decibels). It comes in useful for measuring quantities whose sizes vary over many orders of magnitude. It's even possible, as I explore in my new book The Maths of Life and Death, that a logarithmic experience of the passing of time might explain why we perceive time speeding up as we get older.
In the graph below, you can see how the natural logarithm works to convert the years a dog has lived (dog age) into the equivalent human age in the red dashed curve. The curve suggests that dogs mature extremely rapidly at first, but that their ageing then slows down, meaning that most of their lives are experienced as a form of protracted middle age.
A handy short cut is to remember that the first dog year counts for 31 human years. Then, every time the dog's chronological age doubles after that, the number of equivalent human years increases by 11. So eight calendar years represents three "doublings" (from one to two, two to four and then four to eight) giving a dog age equivalent of 64 (that's 31 + 3x11).
This useful approximation is plotted as the black curve on the conversion figure below. The green line represents the discredited factor-of-seven rule that suggests unrealistic ages at the higher end of the dog age spectrum.
Most dog lovers will already have suspected that the human-to-dog age relationship is non-linear, having noticed that, initially, their pets mature much more quickly than the linear factor-of-seven rule suggests.
A more sophisticated refinement to the factor-of-seven rules has suggested that each of the dog's first two years correspond to 12 human years while all subsequent years count for four human equivalents. The blue curve in the above figure, which represents this ad hoc rule, shows better agreement with the new logarithmic law.
In practice the new molecular insights into human-to-dog age conversion encapsulated by the logarithmic law suggest that dogs move into middle age even more rapidly than most dog-owners would have suspected. It's worth bearing in mind, when you find that Rex is reluctant to chase the ball like he once did, that he's probably got more miles on the clock than you've been giving him credit for.
More information: Tina Wang et al. Quantitative translation of dog-to-human aging by conserved remodeling of epigenetic networks, (2019). DOI: 10.1101/829192
Citation: Are 'dog years' for real? An explanation of calculating canine age (2019, November 29) retrieved 30 November 2019 from https://phys.org/news/2019-11-dog-years-real-explanation-canine.html
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Fresh evidence of an unknown particle that could carry a fifth force of nature gives the NA64 collaboration at CERN a new incentive to continue searches.
In 2015, a team of scientists spotted an unexpected glitch, or "anomaly", in a nuclear transition that could be explained by the production of an unknown particle. About a year later, theorists suggested that the new particle could be evidence of a new fundamental force of nature, in addition to electromagnetism, gravity and the strong and weak forces. The findings caught worldwide attention and prompted, among other studies, a direct search for the particle by the NA64 collaboration at CERN.
A new paper from the same team, led by Attila Krasznahorkay at the Atomki institute in Hungary, now reports another anomaly, in a similar nuclear transition, that could also be explained by the same hypothetical particle.
The first anomaly spotted by Krasznahorkay's team was seen in a transition of beryllium-8 nuclei. This transition emits a high-energy virtual photon that transforms into an electron and its antimatter counterpart, a positron. Examining the number of electron–positron pairs at different angles of separation, the researchers found an unexpected surplus of pairs at a separation angle of about 140º. In contrast, theory predicts that the number of pairs decreases with increasing separation angle, with no excess at a particular angle. Krasznahorkay and colleagues reasoned that the excess could be interpreted by the production of a new particle with a mass of about 17 million electronvolts (MeV), the "X17" particle, which would transform into an electron–positron pair.
The latest anomaly reported by Krasznahorkay's team, in a paper that has yet to be peer-reviewed, is also in the form of an excess of electron–positron pairs, but this time the excess is from a transition of helium-4 nuclei. "In this case, the excess occurs at an angle 115º but it can also be interpreted by the production of a particle with a mass of about 17 MeV," explained Krasznahorkay. "The result lends support to our previous result and the possible existence of a new elementary particle," he adds.
Sergei Gninenko, spokesperson for the NA64 collaboration at CERN, which has not found signs of X17 in its direct search, says: "The Atomki anomalies could be due to an experimental effect, a nuclear physics effect or something completely new such as a new particle. To test the hypothesis that they are caused by a new particle, both a detailed theoretical analysis of the compatibility between the beryllium-8 and the helium-4 results as well as independent experimental confirmation is crucial."
The NA64 collaboration searches for X17 by firing a beam of tens of billions of electrons from the Super Proton Synchrotron accelerator onto a fixed target. If X17 did exist, the interactions between the electrons and nuclei in the target would sometimes produce this particle, which would then transform into an electron–positron pair. The collaboration has so far found no indication that such events took place, but its datasets allowed them to exclude part of the possible values for the strength of the interaction between X17 and an electron. The team is now upgrading their detector for the next round of searches, which are expected to be more challenging but at the same time more exciting, says Gninenko.
Among other experiments that could also hunt for X17 in direct searches is the LHCb experiment. Jesse Thaler, a theoretical physicist from the Massachusetts Institute of Technology, says: "By 2023, the LHCb experiment should be able to make a definitive measurement to confirm or refute the interpretation of the Atomki anomalies as arising from a new fundamental force. In the meantime, experiments such as NA64 can continue to chip away at the possible values for the hypothetical particle's properties, and every new analysis brings with it the possibility (however remote) of discovery."
More information: Jonathan L. Feng et al. Protophobic Fifth-Force Interpretation of the Observed Anomaly in Be8 Nuclear Transitions, Physical Review Letters (2016). DOI: 10.1103/PhysRevLett.117.071803
D. Banerjee et al. Search for a Hypothetical 16.7 MeV Gauge Boson and Dark Photons in the NA64 Experiment at CERN, Physical Review Letters (2018). DOI: 10.1103/PhysRevLett.120.231802
A.J. Krasznahorkay, et al. New evidence supporting the existence of the hypothetic X17 particle arXiv:1910.10459v1 [nucl-ex]: arxiv.org/abs/1910.10459v1
Citation: The plot thickens for a hypothetical X17 particle (2019, November 29) retrieved 29 November 2019 from https://phys.org/news/2019-11-plot-thickens-hypothetical-x17-particle.html
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RBC Signals sees ground infrastructure business following path forged by cellular network expansion
Ron Faith is well acquainted with high-tech startups. Before becoming president and chief operating officer of RBC Signals in 2018, Faith co-founded and served as chief operating officer of Clonefone, a mobile web services company. He was also the CEO of enterprise software vendor Datacastle Corp. when it was acquired in 2017 by the data protection company Carbonite.
Now, Faith and Christopher Richins, RBC Signals, CEO and co-founder, are leading the Seattle company that provides satellite communications infrastructure as a service. RBC Signals is expanding its global network of ground stations by combining excess capacity in existing antenna networks with its own antennas.
Ron Faith, President and COO of RBC Signals
In August, the company unveiled RBC Signals Xpress, a product aimed primarily at Earth observation satellite operators hungry for data downlink capacity. Customers pay $19.95 per pass for the X-band downlink service with a monthly minimum of $595.
RBC Signals also is beginning to work with U.S. government customers. The firm announced its first Small Business Innovation Research (SBIR) contract in June for the Air Force Research Laboratory Space Vehicles Directorate. RBC Signals announced a second Space Vehicles Directorate SBIR in September to prepare ground stations to handle both commercial and government demand.
Faith spoke with SpaceNews about RBC Signals and the lessons he sees in the growth of cellular networks at the World Satellite Business Week conference in September.
Why are startups turning to companies like RBC to supply ground infrastructure for their satellites?
The business is maturing. It wasn’t dissimilar in the cellular industry in the early days where wireless carriers felt they had to do everything, including building their own towers. Over time as they looked at scale and what they wanted to invest their capital in, they ultimately decided to go with companies like American Tower or Crown Castle to host and operate the cellphone tower infrastructure. They now do that for all the carriers. We believe you’re going to see something similar happen in the ground segment for all the satellite operators, whether they’re in communications, Internet of Things, Earth observation constellations. Increasingly, what will differentiate them is something other than building out a bunch of ground infrastructure.
What’s unique about RBC Signals?
We are dedicated to creating multi-tenant, multi-mission, flexible ground infrastructure that can be provided on a service basis. That allows the satellite operator to push out a capital expenditures associated with that. It’s more efficient for them overall. When somebody builds their own ground station, they may only be utilizing that ground station a few tens of minutes a day. The vast majority of the time it is sitting there idle. We’ve partnered with folks that own ground station infrastructure to sell their unused capacity. We pass that savings on to end customers. One of the things we announced recently was RBC Signals Xpress, which is an X-band downlink service targeted toward existing Earth observation satellite operators who want to augment what they’re already doing for command and control with the ability to bring more data down to the ground.
Is lack of downlink capacity an issue?
Satellite operators are trying to find more commercial customers. While the cost of launch has come down significantly and the cost of manufacturing satellites has come down significantly, we believe that the same price disruption needs to happen in the ground segment. Because we’re able to have such a cost-efficient ground infrastructure with our partners, we’re able to pass some of that savings along. This new X-band downlink service is $20 per pass, which we think is groundbreaking, pun intended.
How has the reception been far?
It’s brand-new and we’ve been flooded with inquiries about it. There is this thirst for ways to bring more data down to the ground and to do it more cost effectively so the satellite operators can bring new data products and services and solutions to market that hit the right economic price points for their customers.
You’ve been flooded with inquiries. Do you have enough capacity to take on a flood of customers?
For this we do, because we have over 70 antennas in over 50 locations around the world. There is a large amount of excess capacity from our partners and most of the X-band downlink services travel through our partner network.
Who are your customers?
We’ve done a good job over the past year diversifying our customer base. It’s not just commercial customers looking for a ground stations as a service. It’s also government customers looking to augment their existing capabilities with commercial partners such as ourselves.
You recently announced an Air Force Small Business Innovative Research award.
Yes. That’s our second phase one SBIR award. Our first phase one SBIR was for adding cloud compute infrastructure into the ground station so that you could do compute as a service at the ground station very quickly. We believe in a distributed computing architecture going forward where there’s some processing onboard on the satellite. Obviously, a lot of processing is going on in the cloud, but there’s also some processing that makes sense to do at the ground station. By putting an Amazon Web Services outposts or a Microsoft Azure stack or even virtual server capabilities on the ground station that allows you to process some things there effectively.
Now you won a second SBIR.
This one is for dual use, where ground stations being used commercially can also be used by the Air Force. There’s the scheduling aspect. You have to integrate with their existing ways of doing command and control, scheduling and things of that nature. They want to leverage what we already do, but they still have to do it in a way that works for them and works for them at scale.
With these SBIR programs, they want to bring in innovation because traditionally that has been challenging for them. By working with smaller companies such as ourselves, they can bring in that innovation.
RBC Signals’ networks consists of more than 70 antennas in 50 locations around the world. Credit: RBC Signals
Many government agencies are talking about the need for innovation.
That’s because they recognize space as a contested domain. There are large nation states that they’re competing with in that domain. For them to continue to have superiority, they need to bring in innovation. My guess as to how this plays out is that the innovative companies that are bringing the innovation are going to ultimately must work with the primes, who know how to work with that customer at scale.
Why will they work with primes?
Primes know how to run the programs at scale and deal with all the paperwork, red tape and everything else, while still bringing in innovation. The government customer doesn’t want that innovation stifled.
Is hiring an issue for RBC?
We made a couple hires recently. A lot of the hires we’re doing right now are on the execution side of things. We’re deploying a lot of ground stations around the world. You want certain expertise in being able to place ground stations in very remote locations that sometimes are weather challenged. We’ve got ground stations we’ve deployed in northern Alaska on the North Slope.
Could the U.S. government be an important customer for RBC Signals?
It’s one of the areas that’s growing very rapidly because they have great needs in this area. We’ve only entered the U.S. government business in the last year. We are already seeing a lot of traction. All sides of the business are growing. Whether its Kongsberg Satellite Services, Swedish Space Corp. or ourselves, all of us are seeing dramatic growth. When you go from 1,500 satellites in orbit to what’s going to be 15,000 plus and all those satellites have to talk to the ground, there just isn’t enough ground infrastructure for all that. You need to more efficiently manage the ground infrastructure that’s there and you need to add capacity. We’re doing both.
I understand you also build dedicated antennas for customers.
Yes. If they need the full capacity of the antenna, we will build a dedicated antenna. It’s also for scheduling. By having a guaranteed or dedicated antenna, they can schedule activity any time they want to. Whereas in the network, access is on more of a first-come first-serve basis. Increasingly, we see hybrid deals. A customer may want one dedicated or guaranteed antenna for telemetry, tracking and control. They can schedule it anytime they need it. But they are also taking advantage of the network of shared antennas for data download. They get the price advantages associated with that and the flexibility to expand and contract. This is like what we saw in cloud computing, where if you needed committed compute capacity, you could get that from Amazon Web Services (AWS) or Microsoft. If you want on-demand capacity, you can get that as well. There are different price points and different service level agreements associated with that.
You’re drawing a lot of comparisons to cloud computing.
Many of the lessons learned from the cloud computing world are applicable here. Especially for Earth observation or internet of things, most the value is in the data that’s coming down and what you are going to do with the data. Then, you can utilize similar methodologies that have been used in cloud computing and make them applicable in this model. It’s a natural extension. We’ve seen Amazon come into the market as well. We announced our collaboration with Amazon Ground.
One of RBC Signals’ ground-station installation teams in Deadhorse, Alaska. Credit: RBC Signals
What is your relationship with Amazon Ground?
We can add their antennas to our network. Just as we work with the Indian Space Agency and AWS as a network partner, we work with Amazon Ground. It is also the case that our network locations are complimentary to theirs. They’re going to build out primarily on their data centers, which are in mid-latitude locations. We have lots of locations that are conducive to customers in sun synchronous orbits. Customers shouldn’t have to choose between them. Customers should be able to come to us and say, “I want to use these stations,” because they may be an AWS customer and want to do low-latency compute for some jobs. But then they also want to use our ground stations in northern Alaska, for example. We can provide them both.
Anything else you want to say?
We think it’s an exciting time. If traditional players continue down the old path, building specialized one-off systems for one satellite or one mission, the industry is not going to grow and scale. Quite frankly, one of the other reasons for doing ground infrastructure as a service is you get higher resiliency and lower latency. You can quickly and easily reschedule on a different antenna within the network.
Are people concerned that not operating their ground network could slow the flow of data?
I don’t think that’s a perception. For some of the more established players, it’s like what has been happening to enterprise data centers. Big banks were concerned about owning their data centers. They had security concerns and access concerns. But they have learned over time that going to AWS or to Microsoft Azure is a much better decision for them. You’ve seen all the banks and all the folks who used to have big data centers move large amounts of their workloads into the cloud. We’re going to see something similar happen here. Some players might want to own one ground station. But as they are putting up constellations and needing more access to more ground stations around the world, it’s just going to be too capital intensive for them to do it all themselves. They are going to turn to the equivalent of an American Tower or Crown Castle from the cellular industry, to somebody who’s providing ground stations as a service in the new market.
This article originally appeared in the Oct. 7, 2019 issue of SpaceNews magazine.
Figure: Caged compounds regulate the circadian clock with light (image by Issei Takahashi, Nagoya University)
Researchers at Japan's Institute of Transformative Bio-Molecules (ITbM) of Nagoya University, the Netherlands' University of Groningen, and colleagues have found a new way to regulate the biological clocks of cells. Further studies on their approach, published in the Journal of the American Chemical Society, could lead to treatments for a variety of conditions, including sleep disorder.
"We provide a new approach to precisely control the function of the circadian clock using light," explains ITbM biochemist Tsuyoshi Hirota, who led the research with University of Groningen chemist Ben Feringa. "The circadian clock controls the daily rhythms of our physiology. Its dysfunction is related to many diseases, such as sleep disorder, metabolic diseases and cancer. A new way to control the circadian clock could reveal molecular clock mechanisms and form the basis of therapeutics for circadian-clock-related diseases."
The researchers' approach involved controlling a molecule called longdaysin, which they found regulates cellular circadian clocks. Longdaysin binds to an enzyme called CKI, inhibiting its activity and lengthening the time for the biological clock to go through one sleep-wake cycle.
To control this process, the team incorporated a chemical "cage" into longdaysin that responds to light, called a photo-removable protecting group (PPG). Under dark conditions, PPG prevented longdaysin from binding with CKI. When the compound was exposed to UV or purple light, the PPG released longdaysin, enabling it to bind to and inhibit CKI. The process was successful in human cells, mouse tissue, and in zebrafish larvae.
This level of control of longdaysin activity with light could lead to the development of therapeutics to adjust the clock period of people with a condition called familial advanced sleep phase. Genetic mutations related to CKI lead to the condition, causing a person to get abnormally sleepy very early in the evening, and so goes to sleep early, and awakes and is energetic very early in the morning.
The researchers say their study could also help further investigations into circadian organization in mammals, identifying the relationship between circadian clock disruption and disease development, and the search for therapeutics that use light-dependent regulation to treat circadian-clock-related diseases.
The team next plans to manipulate cellular circadian clocks within cell populations and investigate how circadian clocks in individual cells communicate with each other.
The article, "Controlling the Circadian Clock with High Temporal Resolution through Photodosing," was published in the Journal of the American Chemical Society.
More information: Dušan Kolarski et al. Controlling the Circadian Clock with High Temporal Resolution through Photodosing, Journal of the American Chemical Society (2019). DOI: 10.1021/jacs.9b05445
Citation: Compound controls biological clock with light (2019, November 29) retrieved 29 November 2019 from https://phys.org/news/2019-11-compound-biological-clock.html
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The Indian government claims that the national tiger population has more than doubled since 2006, but independent scientists have found this highly unlikely. It is almost impossible for the tiger population to grow with such speed in such an inexplicable manner, according to the scientists.
The tiger is a national symbol of India and a unique animal that draws worldwide attention. In the early 19th century, tens of thousands of tigers roamed in the forests in India and 29 other nations. Today, some 200 years later, hunting, poaching of tigers and their prey and a loss of habitat have led to a sharp decrease in the total number of tigers. Three of the nine subspecies—the Bali tiger, the Caspian tiger and the Javan tiger—are extinct. One of the six remaining subspecies—the South China tiger—is now believed to be extinct in the wild.
Worth more alive than dead
Faced with the prospect of a world without tigers, scientists, celebrities and officials from 13 nations met in St. Petersburg in Russia in 2010. The world's first Global Tiger Summit was a highly profiled arrangement with celebrities like actor Leonardo DiCaprio and supermodel Naomi Campbell rubbing shoulders with Chinese premier Wen Jiabao and Russian strongman Vladimir Putin, who at the time was prime minister between two terms as president.
With only about 3200 number of tigers "guesstimated" to be left in the wild, the sole aim of this meeting was to develop a plan to double the numbers by the next Tiger lunar year, 2022. At the end of the meeting, all the participating nations declared that they would double their number of wild tigers by 2022. Donors had promised to give no less than 208 million British pounds to the conservation of one of the most charismatic and popular animals in the world.
In India, still the home of the world's largest tiger population, official figures stated that there were only 1,411 tigers in 2006. Based on this, India's government had every reason to be proud when they chose the International Tiger Day, 29 July 2019, to announce that the population of tigers in India had reached 2,967 animals. This was one third more than the number in 2014—2,226 tigers—and more than a doubling of the 1,411 animals reported in 2006.
"Conclusions based on flawed methods"
There is only one problem with the official Indian statistics: They are based on unreliable methods, according to a new scientific paper that has attracted a lot of attention. The scientists claim that the official tiger census reports are based on fundamental mathematical flaws and design deficiencies that have resulted in inexplicable ecological patterns. Independent journalists have also expressed serious concern about the lack of transparency in data-sharing with independent scientists, and they have also found serious errors in the reported photographic data.
"It is extremely unlikely that the number of tigers in India has increased in the way the government claims, because the implied mechanisms describing the tiger population change make little sense from an ecological point of view," says Arjun Gopalaswamy. He is the Science Advisor (Global programs) of the Wildlife Conservation Society, and the first author of the newly released paper.
Professor Nils Chr. Stenseth from the University of Oslo, one of the co-authors of the new paper, agrees.
"Whenever empirical observations go against known ecological patterns, it calls for immediate scrutiny of the methodological validity of the analysis," says Stenseth.
Tigers are territorial
One of the big problems with the official numbers is that the surveys report an initial contraction of the areas where tigers are found, but at the same time indicates that the population is rising.
"And then, there is an abrupt reversal of this pattern. This suggests a complete inversion of the famous occupancy-abundance relationship in ecology. Furthermore, the territorial nature of top predators, such as tigers, precludes the possibility of such an inverted relationship at such time scales," says Gopalaswamy.
A central assertion in the new scientific paper is that India's claims of doubling the tiger population size over the 12-year period from 2006 to 2018 are not backed by reliable scientific evidence. However, that does not necessarily mean that the number of tigers in India is lower than the official 2,967.
"Our emphasis is on questioning the mechanism driving the change in tiger population numbers, which seems very improbable. The root of the problem lies in the fact that tigers are counted in a way that creates a lot of uncertainty. If this uncertainty is not accounted for, we may get misleading impressions of population change," says Gopalaswamy.
When science mixes with politics
The authors of this new study refer to a study from 2018, which describes how agencies in the US, Sweden, Romania and Canada exaggerated population changes in wolves and brown bears. The scientists who wrote the 2018 paper coined the term "political populations" to suggest that the claimed changes of such populations are unreliable.
Doubling the number of wild tigers by 2022 was proclaimed as India's official goal in 2012, with financial commitments of about 330 million US dollars pledged at the 2010 Global Tiger Summit.
"We worry that when large financial investments are made to meet ecologically unrealistic goals, it can induce social pressure or motivation bias on conservation agencies," Stenseth comments.
"It appears that in all these cases, the authorities had the ambition of meeting targets with respect to animal numbers and it seems like they wanted to fulfil the ambition because they wanted to look good," he adds.
In 2015, Arjun Gopalaswamy wrote a co-authored paper demonstrating mathematically the unreliability of the approach in practical situations for counting tigers. You would have to be a mathematician or statistician to understand the objections, but the paper was accepted for publication by a renowned scientific journal.
Urged to withdraw the paper
This inspired officials and scientists affiliated to the Indian government to urge the editors of the journal to withdraw the paper, without any scientific rationale. The journal decided this was unnecessary but instead invited the critics to write a formal scientific rebuttal. They waited for four years to do this, until the announcement of the 2018 census results (in August 2019). The tiger numbers back in 2015 also showed an impressive increase over the preceding four years, but Gopalaswamy was not convinced.
"Our earlier work also showed that the uncertainty about the estimates turned out to be much larger than what was reported, prompting the need for a re-analysis," recounts Gopalaswamy.
"Claims based on unreliable scientific evidence may assist in short term fundraising, but they will be seriously detrimental in the longer term because they promote the most advertised conservation strategies instead of the most effective ones," he comments.
"It is my opinion that wildlife management should be based on the best possible science instead of being mixed up with politics in order to make the authorities look good. This also emerges as the bottom line of Gopalaswamy's excellent work," professor Stenseth comments.
"This is not the first time we are subjected to reports claiming inexplicable changes in India's tiger population size. Three decades ago, when the—now abandoned—pugmark census methodology was used, Indian officials reported a steady rise in tiger numbers until 2004. The alleged number of tigers that year was 3642, before immediately crashing to 1411. This change was then attributed to changes in counting methodology. It now seems like history is repeating itself," says Dr. K. Ullas Karanth. He is another co-author of the new scientific paper, the Director of Centre for Wildlife Studies, Bangalore and one of the world's foremost tiger biologists.
It is worth noting that India lost its tigers from two key reserves when the unreliable pugmark census methodology was previously used. India's latest tiger census report now reveals, like a déjà vu, that tigers were not detected in three reserves.
Response in popular media
In response to the new scientific article by Gopalaswamy and colleagues, the National Tiger Conservation Authority (NTCA) and the Wildlife Institute of India (WII), the agencies responsible for India's national tiger surveys, claim to have rebutted the scientific findings of this new article. However, like in 2015, they have responded directly in popular media with no scientific backing in a peer-reviewed journal.
"The responses in the popular media appear to invite a fresh set of doubts about the reliability of India's tiger surveys as they, conceptually, reveal more scientific contradictions. Since all data are available, at this time it would be best to thoroughly re-analyse them," opines Gopalaswamy.
Everybody loves the tiger
The authors of the new scientific paper feel that the tigers of India fit the description of a "political population," but not perhaps in the same way as for instance the wolf in Norway. The wolf in Norway is highly controversial, you either love or hate the wolf, but more or less everybody appear to love the tiger in India. The tiger is also an international icon; one of the most popular endangered animals in the world.
"The national investments made for tiger conservation is indicative of a great political will to save tigers in India. This makes it all the more necessary for a robust tiger monitoring program to be put in place," says Gopalaswamy.
The editorial in the scientific journal Nature 30 October 2019 concludes that the Indian government could be doing more if they want to save the tiger. To begin with, the government "…must trust independent scientists with the raw data, so that one of the Earth's most iconic species can survive into the future," wrote the editors of Nature.
Arjun Gopalaswamy and the other authors of the scientific paper feel that there is a growing trend among conservationists to generate a single, nation-wide or continent-wide, number of a target species. And even though large (often record-breaking) amounts of effort are invested, in practice, these numbers are usually accompanied by such high uncertainties that they are simply not useful for science or conservation.
"This is a global problem and not limited to India's tigers. We call for a shift in the monitoring approach itself, to a science-based approach where the emphasis shifts to generating sound knowledge that can direct conservation resources appropriate and in real time," Gopalaswamy concludes.
More information: Chris T. Darimont et al. Political populations of large carnivores, Conservation Biology (2018). DOI: 10.1111/cobi.13065
Arjun M. Gopalaswamy et al. An examination of index-calibration experiments: counting tigers at macroecological scales, Methods in Ecology and Evolution (2015). DOI: 10.1111/2041-210X.12351
Arjun M. Gopalaswamy, K. Ullas Karanth, Mohan Delampady, Nils Chr. Stenseth: How sampling‐based overdispersion reveals India's tiger monitoring orthodoxy. Conservation Science and Practice. 2019; e128
Qamar Qureshi, Rajesh Gopal, and Yadvendradev Jhala: Twisted tale of the tiger: the case of inappropriate data and deficient science. PeerJ. 2019; 7:e7482. Published 2019 Aug 20.
National Tiger Conservation Authority: Status of Tigers in India - 2018: summary report. Published 29/07/2019.
Liu et al. (2018). Genome-Wide Evolutionary Analysis of Natural History and Adaptation in the World's Tigers. Current Biology, October 25, 2018.
Citation: Indian authorities may have exaggerated claims of rising tiger numbers (2019, November 29) retrieved 29 November 2019 from https://phys.org/news/2019-11-indian-authorities-exaggerated-tiger.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
