Tag: Sun

Waves on Sun Give NASA New Insight into Space Weather Forecasting

Our sun is a chaotic place, simmering with magnetic energy and constantly spewing out particles. Sometimes the sun releases solar flares and coronal mass ejections — huge eruptions of charged particles — which contribute to space weather and can interfere with satellites and telecommunications on Earth. While it has long been hard to predict such events, new research has uncovered a mechanism that may help forecasting these explosions.

The research finds a phenomenon similar to a common weather system seen on our own planet. Weather on Earth reacts to the influence of jet streams, which blow air in narrow currents around the globe. These atmospheric currents are a type of Rossby wave, movements driven by the planet’s rotation. Using comprehensive imaging of the entire sun with data from the NASA heliophysics Solar Terrestrial Relations Observatory — STEREO — and Solar Dynamics Observatory — SDO — scientists have now found proof of Rossby waves on the sun.

The results, published in a new article in Nature Astronomy may allow for long-term space weather forecasting, thus helping better protect satellites and manned missions vulnerable to high-energy particles released from solar activity.

Rossby waves, large movement patterns in the atmosphere, have been found on the sun, and their discovery could help make better long-term space weather predictions.
Credits: NASA’s Goddard Space Flight Center/Genna Duberstein, Producer

“It’s not a huge surprise that these things exist on the sun. The cool part is what they do,” said lead author Scott McIntosh, director of the High Altitude Observatory at the National Center for Atmospheric Research in Boulder, Colorado. “Just like the jet stream and the gulf stream on Earth, these guys on the sun drive weather — space weather.”

Currently, we can forecast short-term effects after a solar flare erupts, but not the appearance of the flare itself. Understanding the solar Rossby waves and the interior process that drive them, may allow for predictions of when the solar flares might occur — an invaluable tool for future interplanetary manned missions which will fly through regions unprotected from the damaging energetic particles flares can release.

The scientists tracked coronal brightpoints — small, luminous features that can be observed on the sun, directly tied to magnetic activity beneath the surface — using data from 2010 to 2013 with NASA’s heliophysics fleet of space observatories.

In this north pole view of the sun, the brightpoints can be seen circling counter-clockwise, revealing the magnetized Rossby waves flowing beneath the surface.
Credits: NCAR High Altitude Observatory

“The main thing is we were able to observe Rossby waves because of STEREO A and STEREO B, in conjunction with SDO, which allowed us to get a full picture of the entire sun,” said co-author William Cramer, a graduate student at Yale University in New Haven, Connecticut.

The STEREO mission used two near-identical observatories in orbit ahead and behind Earth, STEREO A and STEREO B, to get a complete 360-degree view of the sun.

“These missions allowed the researchers to see the entire sun for over three years, something that would not be possible without the STEREO mission,” said Terry Kuchera, STEREO project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. In October 2014, after eight years in orbit, STEREO B lost contact with ground operations, but the multi-point view STEREO offers remains invaluable. “Having more than one vantage point to look at the sun has a lot of uses, and even with just STEREO A and SDO we can understand how events, like coronal mass ejections, move through the solar system better than we can with just one eye on the sun.”

The results clearly show trains of brightpoints slowly circling the sun traveling westwards, revealing the magnetized Rossby waves flowing beneath the surface. The researchers also found the brightpoints shed light on the solar cycle — the sun’s 22-year activity cycle, driven by the constant movement of magnetic material inside the sun. The brightpoints may serve as a clue, linking how the solar cycle leads to increased numbers of solar flares every 11 years.

“These waves couple activity happening on instantaneous timescales with things that are happening on decadal and longer timescales,” McIntosh said. “What this points to, is that something that might at first glance appear random, like flares and coronal mass ejections, are probably governed at some level by the process that are driving the wave.”

When terrestrial satellites were first used to observe the jet stream on Earth, it allowed huge advances in predictive weather forecasting. These results show such forecasting advances may also be possible with observations of the entire sun simultaneously.

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Editor: Rob Garner

 

Photo Credit: NASA

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NASA Scientists Demonstrate Technique to Improve Particle Warnings that Protect Astronauts

Our constantly-changing sun sometimes erupts with bursts of light, solar material, or ultra-fast energized particles — collectively, these events contribute to space weather. In a study published Jan. 30, 2017, in Space Weather, scientists from NASA and the National Center for Atmospheric Research, or NCAR, in Boulder, Colorado, have shown that the warning signs of one type of space weather event can be detected tens of minutes earlier than with current forecasting techniques – critical extra time that could help protect astronauts in space.

Earth’s magnetic field and atmosphere protect us on the ground from most of the harmful effects of space weather, but astronauts in low-Earth orbit — or even, one day, in interplanetary space — are more exposed to space weather, including bursts of fast-moving particles called solar energetic particles, or SEPs.

“Robotic spacecraft are usually radiation-hardened to protect against these kinds of events,” said Chris St. Cyr, a space scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and lead author on the study. “But humans are still susceptible.”

composite image of coronal mass ejection

Scientists from NASA and the National Center for Atmospheric Research have shown that data from a ground-based instrument called K-Cor can give scientists early warning of a certain type of incoming space weather that can impact astronauts. This composite image shows a coronal mass ejection, a type of space weather linked to solar energetic particles, as seen from two space-based solar observatories and one ground-based instrument. The image in gold is from NASA’s Solar Dynamics Observatory, the image in blue is from the Manua Loa Solar Observatory’s K-Cor coronagraph, and the image in red is from ESA and NASA’s Solar and Heliospheric Observatory.

Credits: NASA/ESA/SOHO/SDO/Joy Ng and MLSO/K-Cor

Scientists observe coronal mass ejections using a type of instrument called a coronagraph, in which a solid disk blocks the sun’s bright face, revealing the sun’s tenuous atmosphere, called the corona. Space-based coronagraphs are more widely used in space weather research because of their wide-field solar views that are not interrupted by cloud cover or Earth’s rotation. But ground-based coronagraphs have their own advantages — while they can only observe the sun in the day during clear weather, they can return data almost instantly, and at a much higher time resolution than satellite instruments. This speed of data return could make a significant difference, given that SEPs can move at nearly the speed of light — so their total travel time can be less than an hour from the time they’re accelerated near the sun to when they reach Earth.

“With space-based coronagraphs, we get images back every 20-30 minutes,” said St. Cyr. “You’ll see the CME in one frame, and by the time you get the next frame — which contains the information we need to tell how fast it’s moving — the energetic particles have already arrived.”

For this study, scientists worked backwards to see whether they could use a ground-based coronagraph to get that key information on the CME’s speed fast enough to lengthen the warning time. They selected a SEP event and then went back to check if the data was available from a coronagraph called K-Cor, which is part of NCAR’s High Altitude Observatory and sits on top of the Mauna Loa volcano in Hawaii. Their search confirmed that the necessary information to predict the arrival of the energetic particles was available about 45 minutes before the particles arrived at Earth — tens of minutes before they left the sun’s inner atmosphere.

The next step is to repeat this study over and over — using both archived data and future observations — in order to see if the early signatures of these energetic particles can be reliably detected in K-Cor’s images. This confirmation, along with planned improvements that would put K-Cor’s images online even faster, could make it possible for this technique to become a  tool in space weather forecasting, such as is provided for the nation by the U.S. National Oceanic and Atmospheric Association.

“Currently, processed images from K-Cor are available on the internet in less than 15 minutes after they’re taken,” said Joan Burkepile, an author on the study based at NCAR and principal investigator for the K-Cor instrument. “We’re installing a more powerful computer at the observatory in Hawaii to process the images seconds after they are acquired and provide the data on the internet within a minute or two of acquisition.”

By Sarah Frazier

NASA’s Goddard Space Flight Center, Greenbelt, Md.

Editor: Rob Garner

Photo Credit: NASA

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First Solar Images from NOAA’s GOES-16 Satellite

The first images from the Solar Ultraviolet Imager or SUVI instrument aboard NOAA’s GOES-16 satellite have been successful, capturing a large coronal hole on Jan. 29, 2017.

The sun’s 11-year activity cycle is currently approaching solar minimum, and during this time powerful solar flares become scarce and coronal holes become the primary space weather phenomena – this one in particular initiated aurora throughout the polar regions. Coronal holes are areas where the sun’s corona appears darker because the plasma has high-speed streams open to interplanetary space, resulting in a cooler and lower-density area as compared to its surroundings.

This animation from January 29, 2017, shows a large coronal hole in the sun’s southern hemisphere from the Solar Ultraviolet Imager (SUVI) on board NOAA’s new GOES-16 satellite. SUVI observations of solar flares and solar eruptions will provide an early warning of possible impacts to Earth’s space environment and enable better forecasting of potentially disruptive events on the ground. This animation captures the sun in the 304 Å wavelength, which observes plasma in the sun’s atmosphere up to a temperature of about 50,000 degrees. When combined with the five other wavelengths from SUVI, observations such as these give solar physicists and space weather forecasters a complete picture of the conditions on the sun that drive space weather.
Credits: NOAA/NASA

SUVI is a telescope that monitors the sun in the extreme ultraviolet wavelength range. SUVI will capture full-disk solar images around-the-clock and will be able to see more of the environment around the sun than earlier NOAA geostationary satellites.

The sun’s upper atmosphere, or solar corona, consists of extremely hot plasma, an ionized gas. This plasma interacts with the sun’s powerful magnetic field, generating bright loops of material that can be heated to millions of degrees. Outside hot coronal loops, there are cool, dark regions called filaments, which can erupt and become a key source of space weather when the sun is active. Other dark regions are called coronal holes, which occur where the sun’s magnetic field allows plasma to stream away from the sun at high speed. The effects linked to coronal holes are generally milder than those of coronal mass ejections, but when the outflow of solar particles is intense – can pose risks to satellites in Earth orbit.

The solar corona is so hot that it is best observed with X-ray and extreme-ultraviolet (EUV) cameras. Various elements emit light at specific EUV and X-ray wavelengths depending on their temperature, so by observing in several different wavelengths, a picture of the complete temperature structure of the corona can be made. The GOES-16 SUVI observes the sun in six EUV channels.

Data from SUVI will provide an estimation of coronal plasma temperatures and emission measurements which are important to space weather forecasting. SUVI is essential to understanding active areas on the sun, solar flares, and eruptions that may lead to coronal mass ejections which may impact Earth. Depending on the magnitude of a particular eruption, a geomagnetic storm can result that is powerful enough to disturb Earth’s magnetic field. Such an event may impact power grids by tripping circuit breakers, disrupt communication and satellite data collection by causing short-wave radio interference and damage orbiting satellites and their electronics. SUVI will allow the NOAA Space Weather Prediction Center to provide early space weather warnings to electric power companies, telecommunication providers, and satellite operators.

panel of six colored images of the sun
These images of the sun were captured at the same time on January 29, 2017 by the six channels on the SUVI instrument on board GOES-16 and show a large coronal hole in the sun’s southern hemisphere. Each channel observes the sun at a different wavelength, allowing scientists to detect a wide range of solar phenomena important for space weather forecasting.
Credits: NOAA

SUVI replaces the GOES Solar X-ray Imager (SXI) instrument in previous GOES satellites and represents a change in both spectral coverage and spatial resolution over SXI.

NASA successfully launched GOES-R at 6:42 p.m. EST on Nov. 19, 2016, from Cape Canaveral Air Force Station in Florida and it was renamed GOES-16 when it achieved orbit. GOES-16 is now observing the planet from an equatorial view approximately 22,300 miles above the surface of Earth.

NOAA’s satellites are the backbone of its life-saving weather forecasts. GOES-16 will build upon and extend the more than 40-year legacy of satellite observations from NOAA that the American public has come to rely upon.

For more information about GOES-16, visit: www.goes-r.gov/ or www.nasa.gov/goes

To learn more about the GOES-16 SUVI instrument, visit:

http://www.goes-r.gov/spacesegment/suvi.html

Michelle Smith
National Oceanic and Atmospheric Administration, Silver Spring, Md.
michelle.smith@nasa.gov

Rob Gutro
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Robert.j.gutro@nasa.gov

Editor: Karl Hille

Photo Credit: NASA

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Eclipse 2017: NASA Supports a Unique Opportunity for Science in the Shadow

The first total solar eclipse in the continental United States in nearly 40 years takes place on Aug. 21, 2017. Beyond providing a brilliant sight in the daytime sky, total solar eclipses provide a rare chance for scientists to collect data only available during eclipses. NASA is funding 11 scientific studies that will take advantage of this opportunity.

“When the moon blocks out the sun during a total eclipse, those regions of Earth that are in the direct path of totality become dark as night for almost three minutes,” said Steve Clarke, director of the Heliophysics Division at NASA Headquarters in Washington, D.C. “This will be one of the best-observed eclipses to date, and we plan to take advantage of this unique opportunity to learn as much as we can about the sun and its effects on Earth.”

The August 2017 total solar eclipse will provide a unique opportunity to study Earth, the sun, and their interaction because of the eclipse’s long path over land. The path of the total eclipse crosses the U.S. from coast to coast, so scientists will be able to take ground-based observations over a period of more than an hour to complement the wealth of data provided by NASA satellites.

The 11 NASA-funded studies cross a range of disciplines, using the total solar eclipse to observe our sun and Earth, test new instruments, and even leverage the skills of citizen scientists to expand our understanding of the sun-Earth system. The studies are listed below, followed by the name of the principal investigator and their home institution.

Studying the sun

During a total solar eclipse, the moon blocks out the sun’s overwhelmingly bright face, revealing the relatively faint solar atmosphere, called the corona. Scientists can also use an instrument called a coronagraph – which uses a disk to block out the light of the sun – to create an artificial eclipse. However, a phenomenon called diffraction blurs the light near the disk in a coronagraph, making it difficult to get clear pictures of the inner parts of the corona, so total solar eclipses remain the only opportunity to study these regions in clear detail in visible light. In many ways, these inner regions of the corona are the missing link in understanding the sources of space weather – so total solar eclipses are truly invaluable in our quest to understand the sun-Earth connection.

The sun-focused studies are:

  • Exploring the Physics of the Coronal Plasma through Imaging Spectroscopy during the 21 August 2017 Total Solar Eclipse (Shadia Habbal, University of Hawaii)
  • Testing a Polarization Sensor for Measuring Temperature and Flow Speed in the Solar Corona during the Total Solar Eclipse of 2017 August 21 (Nat Gopalswamy, NASA’s Goddard Space Flight Center)
  • Chasing the 2017 Eclipse: Interdisciplinary Airborne Science from NASA’s WB-57 (Amir Caspi, Southwest Research Institute)
  • Measuring the Infrared Solar Corona During the 2017 Eclipse (Paul Bryans, University Corporation for Atmospheric Research)
  • Citizen Science Approach to Measuring the Polarization of Solar Corona During Eclipse 2017 (Padma Yanamandra-Fisher, Space Science Institute)
  • Rosetta-stone experiments at infrared and visible wavelengths during the August 21 2017 Eclipse (Philip Judge, University Corporation for Atmospheric Research)

Studying Earth

Total solar eclipses are also an opportunity to study Earth under uncommon conditions. The sudden blocking of the sun during an eclipse reduces the light and temperature on the ground, and these quick-changing conditions can affect weather, vegetation and animal behavior.

The Earth-focused studies are:

  • Solar eclipse-induced changes in the ionosphere over the continental US (Philip Erickson, Massachusetts Institute of Technology)
  • Quantifying the contributions of ionization sources on the formation of the D-region ionosphere during the 2017 solar eclipse (Robert Marshall, University of Colorado Boulder)
  • Empirically-Guided Solar Eclipse Modeling Study (Gregory Earle, Virginia Tech)
  • Using the 2017 Eclipse viewed by DSCOVR/EPIC & NISTAR from above and spectral radiance and broadband irradiance instruments from below to perform a 3-D radiative transfer closure experiment (Yiting Wen, NASA’s Goddard Space Flight Center)
  • Land and Atmospheric Responses to the 2017 Total Solar Eclipse (Bohumil Svoma, University of Missouri)

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Photo Credit: NASA

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NOAA’s GOES-16 EXIS Instrument Observes Solar Flares

On January 21, 2017, the GOES-16 Extreme Ultraviolet and X-Ray Irradiance Sensors (EXIS) observed solar flares.

Solar flares are huge eruptions of energy on the sun and often produce clouds of plasma traveling more than a million miles an hour.  When these clouds reach Earth they can cause radio communications blackouts, disruptions to electric power grids, errors in GPS navigation, and hazards to satellites and astronauts. The EXIS instrument on NOAA’s GOES-16, built by the University of Colorado’s Laboratory for Atmospheric and Space Physics in Boulder, Colorado, measures solar flares at several wavelengths and improves upon current capabilities by capturing larger flares, measuring the location of the flares on the sun, and measuring flares in more wavelengths. The GOES-16 EXIS will provide forecasters at the NOAA’s Space Weather Prediction Center with early indications of impending space weather storms so they can issue alerts, watches, and warnings.

exis1

Current geostationary satellites measure solar X-ray and extreme ultraviolet fluxes. The higher resolution EXIS instrument will provide new capabilities, including the ability to capture larger solar flares.

The figure shows an example of EXIS observations at two different wavelengths of a flare that peaked at 11:05 UTC [6:05 a.m. EST] on January 21, 2017. This is a relatively small flare, yet the brightness of the sun in soft (lower energy) X-rays increased by a factor of 16. EXIS will give NOAA and space weather forecasters the first indication that a flare is occurring on the sun, as well as the strength of the flare, how long it lasts, the location of the flare on the sun, and the potential for impacts here at Earth.

NASA successfully launched GOES-R at 6:42 p.m. EST on November 19, 2016 from Cape Canaveral Air Force Station in Florida and it was renamed GOES-16 when it achieved orbit. GOES-16 is now observing the planet from an equatorial view approximately 22,300 miles above the surface of the Earth.

NOAA’s satellites are the backbone of its life-saving weather forecasts. GOES-16 will build upon and extend the more than 40-year legacy of satellite observations from NOAA that the American public has come to rely upon.

For more information about GOES-16, visit: www.goes-r.gov/ or www.nasa.gov/goes

Lauren Gaches
National Oceanic and Atmospheric Administration

Photo Credit: NASA

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NASA Scientist Studies Whether Solar Storms Cause Animal Beachings

A long-standing mystery among marine biologists is why otherwise healthy whales, dolphins, and porpoises — collectively known as cetaceans — end up getting stranded along coastal areas worldwide. Could severe solar storms, which affect Earth’s magnetic fields, be confusing their internal compasses and causing them to lose their way?

Although some have postulated this and other theories, no one has ever initiated a thorough study to determine whether a relationship exists — until now. NASA heliophysicist Antti Pulkkinen, who works at the agency’s Goddard Space Flight Center in Greenbelt, Maryland, has teamed with the federal Bureau of Ocean Energy Management, or BOEM, and the International Fund for Animal Welfare, or IFAW, to determine whether a link exists.

Strandings occur around the world, involving as few as three to as many as several hundred animals per event. Although a global phenomenon, such strandings tend to happen more often in New Zealand, Australia, and Cape Cod, Massachusetts, said project collaborator Katie Moore, the director of IFAW’s global Animal Rescue Program. Headquartered in Yarmouth Port, Massachusetts, IFAW operates in 40 countries, rescuing animals and promoting conservation to secure a safe habitat for wildlife.

“These locations share some key characteristics, such as the geography, gently sloping beaches, and fine-grained sediment, which we think all play some role in these events,” she said.

Skewed Compasses

Another possibility is that these animals’ internal compasses are somehow skewed by humans’ use of multi-beam echo sounders and other sonar-type equipment used to map the seafloor or locate potential fishing sites, to name just a few applications.

“However, these human-made influences do not explain most of the strandings,” said Pulkkinen, an expert in space weather and its effect on Earth. “Theories as to the cause include magnetic anomalies and meteorological events, such as extreme tides during a new moon and coastal storms, which are thought to disorient the animals. It has been speculated that due to the possible magnetic-field sensing used by these animals to navigate, magnetic anomalies could be at least partially responsible.”

Indeed, magnetic anomalies caused when the sun’s corona ejects gigantic bubbles of charged particles out into the solar system can cause problems for Earth-orbiting satellites and power grids when they slam into Earth’s protective magnetosphere. It’s possible they could affect animals, as well, Pulkkinen said.

“The type of data that Antti has accumulated, together with the extensive stranding data at our disposal, will allow us to undertake the first rigorous analysis to test possible links between cetacean mass strandings and space-weather phenomena,” said Desray Reeb, a marine biologist at BOEM’s headquarters in Sterling, Virginia. Reeb approached Pulkkinen about launching a research effort after hearing his presentation about space weather in June 2015.

Massive Data-Mining Effort

With funding from BOEM and NASA’s Science Innovation Fund, Pulkkinen and his collaborators are carrying out a massive data-mining operation. The team will analyze NASA’s large space-weather databases, including field recordings and space observations, and stranding data gathered by BOEM and IFAW.

“We estimate that records on the order of hundreds of cetacean mass strandings will be available for study, thus making our analyses statistically significant,” Pulkkinen said. “We therefore expect that we will be able to reliably test the hypothesis. So far, there has been very little quantitative research, just a lot of speculation,” Pulkkinen continued. “What we’re going to do is throw cold, hard data at this. It’s a long-standing mystery and it’s important that we figure out what’s going on.”

The team expects to complete the study by the end of September and publish its findings in a scientific, peer-reviewed journal. Should the study reveal a statistical correlation, team members said the results won’t necessarily imply a causal link. However, it would provide the first thorough research into this hypothesis and offer the first step toward determining if it’s correct.

“Save More Animals”

“The results of this study will be informative for researchers, stranding network organizers, resource agencies, and regulatory agencies,” Reeb said. “If we understand the relationship between the two, we may be able to use observations of solar storms as an early warning for potential strandings to occur,” added Moore, who said she “was immediately keen” to get involved in the study. “This would allow stranding responders in global hotspots, and really around the world, to be better prepared to respond, thus having the opportunity to save more animals.”

For more technology-related news, go to: http://gsfctechnology.gsfc.nasa.gov/newsletter/Current.pdf

Lori Keesey
NASA’s Goddard Space Flight Center

Photo Credit: NASA

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NASA’s Fermi Discovers the Most Extreme Blazars Yet

NASA’s Fermi Gamma-ray Space Telescope has identified the farthest gamma-ray blazars, a type of galaxy whose intense emissions are powered by supersized black holes. Light from the most distant object began its journey to us when the universe was 1.4 billion years old, or nearly 10 percent of its present age.

NASA’s Fermi Gamma-ray Space Telescope has discovered the five most distant gamma-ray blazars yet known. The light detected by Fermi left these galaxies by the time the universe was two billion years old. Two of these galaxies harbor billion-solar-mass black holes that challenge current ideas about how quickly such monsters could grow.

Credits: NASA’s Goddard Space Flight Center/Scott Wiessinger, producer

“Despite their youth, these far-flung blazars host some of the most massive black holes known,” said Roopesh Ojha, an astronomer at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “That they developed so early in cosmic history challenges current ideas of how supermassive black holes form and grow, and we want to find more of these objects to help us better understand the process.”

Ojha presented the findings Monday, Jan. 30, at the American Physical Society meeting in Washington, and a paper describing the results has been submitted to The Astrophysical Journal Letters.

Blazars constitute roughly half of the gamma-ray sources detected by Fermi’s Large Area Telescope (LAT). Astronomers think their high-energy emissions are powered by matter heated and torn apart as it falls from a storage, or accretion, disk toward a supermassive black hole with a million or more times the sun’s mass. A small part of this infalling material becomes redirected into a pair of particle jets, which blast outward in opposite directions at nearly the speed of light. Blazars appear bright in all forms of light, including gamma rays, the highest-energy light, when one of the jets happens to point almost directly toward us.

Previously, the most distant blazars detected by Fermi emitted their light when the universe was about 2.1 billion years old. Earlier observations showed that the most distant blazars produce most of their light at energies right in between the range detected by the LAT and current X-ray satellites, which made finding them extremely difficult.

Then, in 2015, the Fermi team released a full reprocessing of all LAT data, called Pass 8, that ushered in so many improvements astronomers said it was like having a brand new instrument. The LAT’s boosted sensitivity at lower energies increased the chances of discovering more far-off blazars.

The research team was led by Vaidehi Paliya and Marco Ajello at Clemson University in South Carolina and included Dario Gasparrini at the Italian Space Agency’s Science Data Center in Rome as well as Ojha. They began by searching for the most distant sources in a catalog of 1.4 million quasars, a galaxy class closely related to blazars. Because only the brightest sources can be detected at great cosmic distances, they then eliminated all but the brightest objects at radio wavelengths from the list. With a final sample of about 1,100 objects, the scientists then examined LAT data for all of them, resulting in the detection of five new gamma-ray blazars.

Expressed in terms of redshift, astronomers’ preferred measure of the deep cosmos, the new blazars range from redshift 3.3 to 4.31, which means the light we now detect from them started on its way when the universe was between 1.9 and 1.4 billion years old, respectively.

“Once we found these sources, we collected all the available multiwavelength data on them and derived properties like the black hole mass, the accretion disk luminosity, and the jet power,” said Paliya.

Two of the blazars boast black holes of a billion solar masses or more. All of the objects possess extremely luminous accretion disks that emit more than two trillion times the energy output of our sun. This means matter is continuously falling inward, corralled into a disk and heated before making the final plunge to the black hole.

“The main question now is how these huge black holes could have formed in such a young universe,” said Gasparrini. “We don’t know what mechanisms triggered their rapid development.”

In the meantime, the team plans to continue a deep search for additional examples.

“We think Fermi has detected just the tip of the iceberg, the first examples of a galaxy population that previously has not been detected in gamma rays,” said Ajello.

NASA’s Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy and with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden and the United States.

For more information on Fermi, visit:

https://www.nasa.gov/fermi

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By Francis Reddy

NASA’s Goddard Space Flight Center, Greenbelt, Md.

Photo Credit: NASA 

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