Month: August 2019

Astronomers Discover Vast Ancient Galaxies, Which Could Shed Light On Dark Matter

Astronomers used the combined power of multiple astronomical observatories around the world and in space to discover a treasure-trove of previously unknown ancient massive galaxies. This is the first multiple discovery of its kind and such an abundance of this type of galaxy defies current models of the universe. These galaxies are also intimately connected with supermassive black holes and the distribution of dark matter.

The Hubble Space Telescope gave us unprecedented access to the previously unseen universe, but even it is blind to some of the most fundamental pieces of the cosmic puzzle. Astronomers from the Institute of Astronomy at the University of Tokyo wanted to see some things they long suspected may be out there but which Hubble could not show them. Newer generations of astronomical observatories have finally revealed what they sought.

“This is the first time that such a large population of massive galaxies was confirmed during the first 2 billion years of the 13.7-billion-year life of the universe. These were previously invisible to us,” said researcher Tao Wang. “This finding contravenes current models for that period of cosmic evolution and will help to add some details, which have been missing until now.”

But how can something as big as a galaxy be invisible to begin with?

“The light from these galaxies is very faint with long wavelengths invisible to our eyes and undetectable by Hubble,” explained Professor Kotaro Kohno. “So we turned to the Atacama Large Millimeter/submillimeter Array (ALMA), which is ideal for viewing these kinds of things. I have a long history with that facility and so knew it would deliver good results.”

Even though these galaxies were the largest of their time, the light from them is not only weak but also stretched due to their immense distance. As the universe expands, light passing through becomes stretched, so visible light becomes longer, eventually becoming infrared. The amount of stretching allows astronomers to calculate how far away something is, which also tells you how long ago the light you’re seeing was emitted from the thing in question.

“It was tough to convince our peers these galaxies were as old as we suspected them to be. Our initial suspicions about their existence came from the Spitzer Space Telescope’s infrared data,” continued Wang. “But ALMA has sharp eyes and revealed details at submillimeter wavelengths, the best wavelength to peer through dust present in the early universe. Even so, it took further data from the imaginatively named Very Large Telescope in Chile to really prove we were seeing ancient massive galaxies where none had been seen before.”

Another reason these galaxies appear so weak is because larger galaxies, even in the present day, tend to be shrouded in dust, which obscures them more than their smaller galactic siblings.

And what does the discovery of these massive galaxies imply?

“The more massive a galaxy, the more massive the supermassive black hole at its heart. So the study of these galaxies and their evolution will tell us more about the evolution of supermassive black holes, too,” said Kohno. “Massive galaxies are also intimately connected with the distribution of invisible dark matter. This plays a role in shaping the structure and distribution of galaxies. Theoretical researchers will need to update their theories now.”

What’s also interesting is how these 39 galaxies are different from our own. If our solar system were inside one of them and you were to look up at the sky on a clear night, you would see something quite different to the familiar pattern of the Milky Way.

“For one thing, the night sky would appear far more majestic. The greater density of stars means there would be many more stars close by appearing larger and brighter,” explained Wang. “But conversely, the large amount of dust means farther-away stars would be far less visible, so the background to these bright close stars might be a vast dark void.”

As this is the first time such a population of galaxies has been discovered, the implications of their study are only now being realized. There may be many surprises yet to come.

“These gargantuan galaxies are invisible in optical wavelengths so it’s extremely hard to do spectroscopy, a way to investigate stellar populations and chemical composition of galaxies. ALMA is not good at this and we need something more,” concluded Wang. “I’m eager for upcoming observatories like the space-based James Webb Space Telescope to show us what these primordial beasts are really made of.”

6.0 Earthquake Strikes Taiwan’s Yilan, Whole Country Feels Shock Waves

A magnitude 6.0 earthquake struck northeastern Taiwan’s Yilan County at 5:28 a.m. this morning (Aug. 8), according to the Central Weather Bureau (CWB).

The epicenter of the temblor was 36.5 kilometers southeast of Yilan County Hall at a depth of 22.5 kilometers, based on CWB data.

The quake’s intensity, which gauges the actual effect of the tremor, registered a 6 in Yilan County and a 4 in Hualien County, New Taipei City, Taipei City, Hsinchu County, Taoyuan City, and Taichung City. An intensity level of 3 was felt in Nantou County, Keelung City, Miaoli County, Hsinchu City, Changhua County, and Yunlin County.

An intensity level of 2 was recorded in Chiayi County, Chiayi City, and Tainan City. An intensity level of 1 was reported in Taitung County, Kaohsiung City, Pingtung County, and Penghu County.

Located along the so-called Pacific Ring of Fire, Taiwan uses an intensity scale of 1 to 7, which gauges the degree to which a quake is felt in a specific location.

Reports are filtering in of products falling off of store shelves and ceiling tiles falling in Yilan County. A woman in Taipei was reported to be in critical condition after her wardrobe fell on her during the initial 6.0 quake.

The MRT in Taipei is already running normally and Taiwan’s High Speed Rail is expected to resume normal operations shortly. Taiwan Railways Administration (TRA) train tracks are currently being inspected in Yilan City and Nan’ao, Taiwan, but the rest of the TRA’s trains are expected to operate normally.

CWB officials are warning the public to beware of aftershocks.

Scientists Have Found a Way to Better Predict Where Volcanoes Will Erupt Next

Not every volcanic eruption is a Mount Vesuvius-like catastrophe, with rivers of fire and flying rock that rains down on unsuspecting Pompeiians.

Sometimes, volcanoes’ summits collapse, forming miles-wide depressions called calderas, which are peppered by eruptive vents. When rivulets of magma force their way out of these vents, those small eruptions can spew dangerous amounts of lava and gas.

But the locations and threat levels of these vents are difficult to predict – eruptions can sometimes occur miles from the caldera’s center. That leaves cities located on or near volcanic fields, like Naples, Italy, facing a constant risk of poisonous volcanic gas, ash, and explosive bursts of lava.

Now, however, a group of scientists have figured out how to accurately pinpoint where on a volcano’s surface or in a caldera’s volcanic fields these damaging vent eruptions are likely to occur.

“Calderas have fed some of the most catastrophic eruptions on Earth and are extremely hazardous,” the scientists wrote in a new study published Wednesday in the journal Science Advances. That hazard is often underestimated by local populations, they added.

Mount Kilauea in Hawaii, which erupted last year, is speckled with such vents. The eruptions forced nearly 1,500 people to flee their homes, CBS News reported.

“These vents have lava coming out of them like fountains, which then leaks across the landscape like a slug,” Eleonora Rivalta, the lead author of the study, told Business Insider.

The scientists hope that insights from their new model could help communities like Hawaii’s better prepare for and anticipate future eruptions.

Magma’s fickle pathways
Magma, the liquid or semi-liquid rock under the Earth’s crust, makes up most of our planet’s mantle (its intermediary layer). When magma pushes its way to the surface, that causes a volcanic eruption.

Magma likes to take the path of least resistance as it surges upward. So figuring out what that path is can enable scientists to predict where it will next breach our planet’s surface. That’s what Rivalta’s team set out to do.

The easiest path, the researchers found, is for magma to move through rocks that are more “stretched out” than their nearby counterparts – less compressed, in other words.

Although many geologists thought the path of least resistance would be through an existing pathway or fault, Rivalta’s team found that vents are often “single-use only”, meaning magma erupts through them once and never again.

Rivalta and her colleagues used these discoveries to make computer models of future magma paths to the surface. They compared the predictions of their model to the known eruptive behaviour of vents across Italy’s Campi Fleigrei, outside of Naples.

This 8-mile-wide active volcanic field – known as the “burning fields” – first erupted almost 50,000 years ago, though the most recent major eruption was in 1538.

Rivalta’s model accurately mapped Campi Flegrei’s 70 eruptions over the past 15,000 years, including the highly damaging Monte Nuovo eruption in 1538.

Predicting the next Yellowstone eruption
Between 1600 and 2017, 278,880 people around the world were killed by volcanic activity and the consequences of those eruptions, like starvation or tsunamis.

Since the 1980s, deaths related to volcanic eruptions have been rather limited, as geographer Matthew Blackett reported in The Conversation. This isn’t because scientists have gotten better at predicting eruptions – it’s a matter of chance, since recent eruptions have been far from heavily populated areas.

So Rivalta hopes to leverage her group’s new research to give cities like Naples more information about impending eruptions. She also wants to apply this new model to Mount Etna in Sicily, and use it to examine the supervolcano under Yellowstone National Park.

That enormous volcano last erupted more than 640,000 years ago. If it were to erupt again, the supervolcano would spew ash across thousands of miles of the US.

Following the Yellowstone volcano’s last eruption, it collapsed on itself, creating a 1,500-square-mile caldera that’s ripe for new appearances of magma.

“Yellowstone is a caldera with tons and tons of vents,” Rivalta said. “The question of where the next one might appear is very relevant to this caldera.”

Hubble’s New Portrait Of Jupiter

A new Hubble Space Telescope view of Jupiter, taken on June 27, 2019, reveals the giant planet’s trademark Great Red Spot, and a more intense color palette in the clouds swirling in Jupiter’s turbulent atmosphere than seen in previous years. The colors, and their changes, provide important clues to ongoing processes in Jupiter’s atmosphere.

The bands are created by differences in the thickness and height of the ammonia ice clouds. The colorful bands, which flow in opposite directions at various latitudes, result from different atmospheric pressures. Lighter bands rise higher and have thicker clouds than the darker bands.

Among the most striking features in the image are the rich colors of the clouds moving toward the Great Red Spot, a storm rolling counterclockwise between two bands of clouds. These two cloud bands, above and below the Great Red Spot, are moving in opposite directions. The red band above and to the right (northeast) of the Great Red Spot contains clouds moving westward and around the north of the giant tempest. The white clouds to the left (southwest) of the storm are moving eastward to the south of the spot.

All of Jupiter’s colorful cloud bands in this image are confined to the north and south by jet streams that remain constant, even when the bands change color. The bands are all separated by winds that can reach speeds of up to 400 miles (644 kilometers) per hour.

On the opposite side of the planet, the band of deep red color northeast of the Great Red Spot and the bright white band to the southeast of it become much fainter. The swirling filaments seen around the outer edge of the red super storm are high-altitude clouds that are being pulled in and around it.

The Great Red Spot is a towering structure shaped like a wedding cake, whose upper haze layer extends more than 3 miles (5 kilometers) higher than clouds in other areas. The gigantic structure, with a diameter slightly larger than Earth’s, is a high-pressure wind system called an anticyclone that has been slowly downsizing since the 1800s. The reason for this change in size is still unknown.

A worm-shaped feature located below the Great Red Spot is a cyclone, a vortex around a low-pressure area with winds spinning in the opposite direction from the Red Spot. Researchers have observed cyclones with a wide variety of different appearances across the planet. The two white oval-shaped features are anticyclones, like small versions of the Great Red Spot.

Another interesting detail is the color of the wide band at the equator. The bright orange color may be a sign that deeper clouds are starting to clear out, emphasizing red particles in the overlying haze.

The new image was taken in visible light as part of the Outer Planets Atmospheres Legacy program, or OPAL. The program provides yearly Hubble global views of the outer planets to look for changes in their storms, winds and clouds.

Hubble’s Wide Field Camera 3 observed Jupiter when the planet was 400 million miles from Earth, when Jupiter was near “opposition” or almost directly opposite the Sun in the sky.

Dead Planets Can ‘Broadcast’ For Up To A Billion Years

Astronomers are planning to hunt for cores of exoplanets around white dwarf stars by ‘tuning in’ to the radio waves that they emit.

In new research led by the University of Warwick, scientists have determined the best candidate white dwarfs to start their search, based upon their likelihood of hosting surviving planetary cores and the strength of the radio signal that we can ‘tune in’ to.

Published in the Monthly Notices of the Royal Astronomical Society, the research led by Dr Dimitri Veras from the Department of Physics assesses the survivability of planets that orbit stars which have burnt all of their fuel and shed their outer layers, destroying nearby objects and removing the outer layers of planets. They have determined that the cores which result from this destruction may be detectable and could survive for long enough to be found from Earth.

The first exoplanet confirmed to exist was discovered orbiting a pulsar by co-author Professor Alexander Wolszczan from Pennsylvania State University in the 1990s, using a method that detects radio waves emitted from the star. The researchers plan to observe white dwarfs in a similar part of the electromagnetic spectrum in the hope of achieving another breakthrough.

The magnetic field between a white dwarf and an orbiting planetary core can form a unipolar inductor circuit, with the core acting as a conductor due to its metallic constituents. Radiation from that circuit is emitted as radio waves which can then be detected by radio telescopes on Earth. The effect can also be detected from Jupiter and its moon Io, which form a circuit of their own.

However, the scientists needed to determine how long those cores can survive after being stripped of their outer layers. Their modelling revealed that in a number of cases, planetary cores can survive for over 100 million years and as long as a billion years.

The astronomers plan to use the results in proposals for observation time on telescopes such as Arecibo in Puerto Rico and the Green Bank Telescope in West Virginia to try to find planetary cores around white dwarfs.

Lead author Dr Dimitri Veras from the University of Warwick said: “There is a sweet spot for detecting these planetary cores: a core too close to the white dwarf would be destroyed by tidal forces, and a core too far away would not be detectable. Also, if the magnetic field is too strong, it would push the core into the white dwarf, destroying it. Hence, we should only look for planets around those white dwarfs with weaker magnetic fields at a separation between about 3 solar radii and the Mercury-Sun distance.

“Nobody has ever found just the bare core of a major planet before, nor a major planet only through monitoring magnetic signatures, nor a major planet around a white dwarf. Therefore, a discovery here would represent ‘firsts’ in three different senses for planetary systems.”

Professor Alexander Wolszczan from Pennsylvania State University, said: “We will use the results of this work as guidelines for designs of radio searches for planetary cores around white dwarfs. Given the existing evidence for a presence of planetary debris around many of them, we think that our chances for exciting discoveries are quite good.”

Dr Veras added: “A discovery would also help reveal the history of these star systems, because for a core to have reached that stage it would have been violently stripped of its atmosphere and mantle at some point and then thrown towards the white dwarf. Such a core might also provide a glimpse into our own distant future, and how the solar system will eventually evolve.”

UPDATE :Typhoon Lekima Hammering Japan’s Ryukyu Islands and Soaking Taiwan Before Heading to Eastern China

Typhoon Lekima is hammering Japan’s southern Ryukyu Islands while also soaking Taiwan before heading for eastern China by this weekend.

Lekima is currently centered about 180 miles west of Kadena Air Base in Okinawa and is heading northwestward.

After rapidly intensifying Tuesday into Wednesday, Lekima became a super typhoon (winds 150 mph or greater) for a short time late Thursday into early Friday. Lekima has since weakened slightly to a Category 4 hurricane.

Damaging winds and heavy rain continue battering Japan’s southernmost Ryukyu Islands, including Ishigaki and Miyako, and the super typhoon’s outer eyewall tracks across the islands. Winds had gusted as high as 46.6 m/s or 104 mph at Miyako Shimojishima Airport as of early Friday morning local time (JST). Sustained typhoon force winds (33.5 m/s or 75 mph) has been reported in Miyako. Ishigaki has received 198 mm or around 7.8 inches of rainfall so far.

Typical of intense tropical cyclones, the eye of Lekima wobbled as it tracked through the Ryukyu Islands, passing near the islands of Tarama and Minna, about 200 miles east-southeast of Taipei, Taiwan.

Lekima will pull away from southern Japan during the early morning hours of Friday, and winds will begin to come down.

Japan’s Meteorological Agency has issued storm warnings, equivalent to typhoon warnings, for the southern Ryukyu Islands. Storm surge warnings have also been issued.

Lekima is forecast to move north of Taiwan on Friday afternoon into the evening, local time in Taiwan (CST). Heavy rain and strong wind gusts from Lekima will still impact parts of Taiwan even though the center of the typhoon won’t make landfall there.

The Central Weather Bureau in Taiwan has issued typhoon warnings for northern parts of Taiwan.

More than a foot of rain is currently forecast through Saturday in the higher elevations of Taiwan. The excessive rainfall could trigger flooding, as well as landslides.

Rainfall totals of more than 8 inches had already been reported on Thursday in parts of Taiwan as of early Friday morning, local time.

This weekend, Lekima will be on a weakening trend as it curls northward near the eastern coast of China, potentially including near Shanghai.

Heavy rain could trigger flooding in eastern China. Strong winds and storm surge flooding are also possible depending on the exact track and intensity of Lekima as it moves near, inland or offshore from the coastline.

Typhoon Krosa
Several hundred miles to the east of Lekima is Typhoon Krosa which now has winds equivalent in strength to a Category 2 hurricane.

Krosa may be getting weakened by its relatively slow motion, which cools water down in a process called upwelling.

Krosa is forecast to drift near Iwo Jima and the Ogasawara Islands later this week but will otherwise remain over the open waters of the Western Pacific the next five days. Extended periods of gusty winds and heavy rainfall are expected in the Ogasawara Islands.

When Krosa begins to gain more latitude, it’s possible Krosa could approach mainland Japan early next week as a typhoon, but the forecast this far out in time is highly uncertain.

Francisco made landfall in southern Japan as typhoon Tuesday morning local time, with maximum sustained winds of 85 mph, according to the U.S. Joint Typhoon Warning Center.

More than 15 inches of rain soaked the Tokushima Prefecture, according to the Japan Meteorological Agency. Parts of the Miyazaki Prefecture saw more than 10 inches of rain.

A Quiet Typhoon Season Before This Week
This year had been uncommonly calm for typhoon activity through Aug. 4 in the Northwest Pacific, which is normally the most active region on Earth for tropical cyclones. The only typhoon recorded in 2019 through Aug. 4 was Wutip, the first Category 5 super typhoon on record in February. Wutip passed south of Guam and Micronesia as a Category 4 storm, producing more than $3 million in damage.

Japan is accustomed to typhoons. In a typical year, three typhoons strike Japan, according to data from the Japan Meteorological Agency analyzed by nippon.com. Landfalls are most common in August, but the most destructive typhoons tend to be in September.

Since 1950, no other year had gone from Feb. 28 to Aug. 4 without any typhoons, as noted by Dr. Phil Klotzbach of Colorado State University. Francisco put an end to that streak when it became a typhoon on Aug. 5.

In a typical season (1981-2010), the Northwest Pacific sees about eight named storms and five typhoons by Aug. 2. This year had brought just five named storms and one typhoon by that date.

The amount of accumulated cyclone energy in the Northwest Pacific – which is calculated based on how strong tropical cyclones get and how long they last – was only a little over half of average for the year as of Aug. 2, according to data compiled by Colorado State University.

So, what’s the difference between this quiet period and now?

At least one factor that may be having its hand on the “on” switch for the west Pacific is the Madden-Julian Oscillation.

The MJO is essentially a wave of increased storminess, clouds and pressure that moves eastward around the globe once every 40 days or so.

In the tropics, the MJO is known to kick up or assist in tropical cyclone development.

A robust MJO wave is now moving through eastern Asia and the western Pacific, and likely helped the recent tropical cyclone outbreak fester.

Magnetic Plasma Pulses Excited By UK-Size Swirls In The Solar Atmosphere

An international team of scientists led by the University of Sheffield have discovered previously undetected observational evidence of frequent energetic wave pulses the size of the UK, transporting energy from the solar surface to the higher solar atmosphere.

Magnetic plasma waves and pulses have been widely suggested as one of the key mechanisms which could answer the long-standing question of why the temperature of the solar atmosphere rises dramatically, from thousands to millions of degrees, as you move away from the solar surface.

There have been many theories put forward, including some developed at the University of Sheffield — for example, heating the plasma by magnetic waves or magnetic plasma — but observational validation of the ubiquity of a suitable energy transport mechanism has proved challenging until now.

By developing innovative approaches, applied mathematicians at the Solar Physics and Space Plasma Research Centre (SP2RC) in the School of Mathematics and Statistics at the University of Sheffield, and the University of Science and Technology of China, have discovered unique observational evidence of plentiful energetic wave pulses, named after the Nobel laureate Hannes Alfvén, in the solar atmosphere.

These short-lived Alfvén pulses have been found to be generated by prevalent photospheric plasma swirls about the size of the British Isles, which are suggested to have a population of at least 150,000 in the solar photosphere at any moment of time.

Professor Robertus Erdélyi (a.k.a. von Fáy-Siebenbürgen), Head of SP2RC, said: “Swirling motions are everywhere in the universe, from sinking water in domestic taps with a size of centimeters, to tornadoes on Earth and on the Sun, solar jets and spiral galaxies with a size of up to 520,000 light years. This work has shown, for the first time, the observational evidence that ubiquitous swirls in the solar atmosphere could generate short-lived Alfvén pulses.

“The generated Alfvén pulses easily penetrate the solar atmosphere along cylinder-like magnetic flux tubes, a form of magnetism a bit like trees in a forest. The pulses could travel all the way upward and reach the top of the solar chromospheric layers, or, even beyond.”

Alfvén modes are currently very hard to observe directly, because they do not cause any local intensity concentrations or rarefactions as they make their journey through a magnetised plasma. They are hard to be observationally distinguished from some other types of magnetic plasma modes, like the well-known transversal magnetic plasma waves, often called kink modes.

“The energy flux carried by the Alfvén pulses we detected now are estimated to be more than 10 times higher than that needed for heating the local upper solar chromosphere,” said Dr Jiajia Liu, postdoctoral research associate.

“The chromosphere is a relatively thin layer between the solar surface and the extremely hot corona. The solar chromosphere appears as a red ring around the Sun during total solar eclipses.”

Professor Erdélyi added: “It has been a fascinating question for the scientific community for a long while — how the Sun and many other stars supply energy and mass to their upper atmospheres. Our results, as part of an exciting UK-China collaboration, involving our very best early-career scientists like Drs Jiajia Liu, Chris Nelson and Ben Snow, are an important step forward in addressing the supply of the needed non-thermal energy for solar and astrophysical plasma heating.

“We believe, these UK-sized photospheric magnetic plasma swirls are also very promising candidates not just for energy but also for mass transportation between the lower and upper layers of the solar atmosphere. Our future research with my colleagues at SP2RC will now focus on this new puzzle. “