Mysterious 'Fast Radio Burst' Pinpointed for First Time
Powerful transient radio flashes in the universe pop off randomly and appear to defy explanation, but astronomers have made a breakthrough in pinpointing the exact source of one of these fast radio bursts.
Powerful transient radio flashes in the universe pop off randomly and appear to defy explanation, but astronomers have made a breakthrough in pinpointing the exact source of one of these fast radio bursts, known simply as "FRBs."
Only a handful of FRBs have ever been positively identified by looking back through the data archives of radio telescopes. They may be extremely short lived, but they are so powerful that, for the briefest of moments, come from a phenomenon that can generate more energy than our sun can pump out for 10,000 years.
As dazzling as these events are, their apparently random nature (they seem to be generated well beyond our galaxy and appear anywhere in the sky) and extremely short (millisecond) burst makes follow-up observations nigh-on impossible. However, on Wednesday, astronomers using the Commonwealth Scientific and Industrial Research Organisation (CSIRO) radio telescopes in eastern Australia and the National Astronomical Observatory of Japan's Subaru telescope in Hawaii, announced a breakthrough.
Usually, FRBs are found months or even years after they've been detected by radio telescopes. By analyzing radio archives, the FRB signals can be teased out. Unfortunately, this method leaves no room for follow-up observations of the region of sky the signal was detected, leaving their origin a mystery. To rectify this, the international team set up an early warning system so that as soon as a signal is received, other observatories are alerted and are able to quickly zoom in on the region of sky where the FRB was detected.
(This system is akin to the alert system between NASA's Swift space telescope that detects gamma-ray bursts, or GRBs, and ground-based observatories so rapid follow-up observations can zoom in on the energetic explosion.)
So, on April 18, 2015, the Australian 64-meter Parkes Radio Telescope detected an FRB flash and immediately notified the collaboration. Within 2 hours, the CSIRO Compact Array telescope, located 400 kilometers (250 miles) north of Parkes, slewed in the direction of where the pulse was spotted and was able to detect a radio emission from the blast site which lasted for 6 days before fading. Already astronomers had done something unprecedented; they had identified the location of a FRB and measured its radio afterglow.
Meanwhile, atop Mauna Kea in Hawaii, the Subaru telescope was able to begin its observing run, identifying the precise source of the FRB and radio afterglow. As the location of the April 18 FRB was known to a precision of 1,000 times better than previously discovered FRBs, Subaru made the groundbreaking discovery that this FRB originated inside a galaxy 6 billion light-years away.
What is particularly interesting is that, after further observations of this random galaxy, the researcher found it to be an old elliptical galaxy - the kind of galaxy where you wouldn't expect to see much in the way of star formation. This is the first indication that FRBs probably aren't generated by star formation processes.
"This is not what we expected," said Simon Johnston, Head of Astrophysics at CSIRO and a member of the research team. "It might mean that the FRB resulted from, say, two neutron stars colliding rather than anything to do with recent star birth."
What's more, this observation was used as a tool to identify how much material the radio emission from the FRB traveled through, eventually reaching Earth 6 billion years later. And for this one event, it seems to exactly match our theoretical models as to the distribution of matter, including dark matter, in the universe.
"The good news is our observations and the model match - we have found the missing matter," said Evan Keane from the SKA Organisation, and lead author of the study published in the journal Nature. "It's the first time a fast radio burst has been used to conduct a cosmological measurement."
It is hoped that, now a system is in place to make rapid and precise observations of FRBs, more FRBs can be used out to further refine cosmological models.
As for what generated this particular FRB, some production mechanisms have been ruled out and others have become more likely, but at least we know where it came from and what kind of galaxy produced it. But even better, astronomers estimate the universe sparkles with 10,000 FRBs throughout the entire sky every day - we just need more radio telescopes looking for them.
An artist's impression of a fast radio bursts and the CSIRO Parkes radio telescope in Australia.
March 13, 2013, marks 20 years since the W. M. Keck Observatory began taking observations of the cosmos. Located in arguably one of the most extreme and beautiful places on the planet -- atop Mauna Kea, Hawai'i, 13,803 ft (4,207 m) above sea level -- the twin Keck domes have observed everything from asteroids, planets, exoplanets to dying stars, distant galaxies and nebulae. Seen in this photograph, the Keck I and Keck II telescopes dazzle the skies with their adaptive optics lasers -- a system that helps cancel out the turbulence of the Earth's atmosphere, bringing science some of the clearest views attainable by a ground-based observatory.
To celebrate the last two decades of incredible science, Discovery News has assembled some of the most impressive imagery to come from Keck.
Starting very close to home, the Keck II captured this infrared image of asteroid 2005 YU55 as it flew past Earth on Nov. 8, 2011.
Deeper into the solar system, the Keck NIRC2 near-infrared camera captured this beautiful observation of the oddball Uranus on July 11-12, 2004. The planet's north pole is at 4 o'clock.
This is a mosaic false-color image of thermal heat emission from Saturn and its rings on Feb. 4, 2004, captured by the Keck I telescope at 17.65 micron wavelengths.
A nice image of Saturn with Keck I telescope with the near infrared camera (NIRC) on Nov. 6, 1998. This is a composite of images taken in Z and J bands (1.05 and 1.3 microns), with the color scaling adjusted so it looks like Saturn is supposed to look to the naked eye.
This is Saturn's giant moon Titan -- a composite of three infrared bands captured by the Near Infrared Camera-2 on the 10-meter Keck II telescope. It was taken by astronomer Antonin Bouchez on June 7, 2011.
Another multicolored look at Titan -- a near-infrared color composite image taken with the Keck II adaptive optics system. Titan's surface appears red, while haze layers at progressively higher altitudes in the atmosphere appear green and blue.
This image of Neptune and its largest Tritan was captured by Caltech astronomer Mike Brown in September 2011. It shows the wind-whipped clouds, thought to exceed 1,200 miles per hour along the equator.
A color composite image of Jupiter in the near infrared and its moon Io. The callout at right shows a closeup of the two red spots through a filter which looks deep in the cloud layer to see thermal radiation.
HR 8799: Three exoplanets orbiting a young star 140 light years away are captured using Keck Observatory's near-infrared adaptive optics. This was the first direct observation by a ground-based observatory of worlds orbiting another star (2008).
Now to the extremes -- an image of Stephan's Quintet, a small compact group of galaxies.
The Egg Nebula: This Protoplanetary nebula is reflecting light from a dying star that is shedding its outer layers in the final stages of its life.
This is WR 104, a dying star. Known as a Wolf Rayet star, this massive stellar object will end its life in the most dramatic way -- possibly as a gamma-ray burst. The spiral is caused by gases blasting from the star as it orbits with another massive star.
Narrow-field image of the center of the Milky Way. The arrow marks the location of radio source Sge A*, a supermassive black hole at the center of our galaxy.
A high resolution mid-infrared picture taken of the center of our Milky Way reveals details about dust swirling into the black hole that dominates the region.
A false-color image of a spiral galaxy in the constellation Camelopardalis.
A scintillating square-shaped nebula nestled in the vast sea of stars. Combining infrared data from the Hale Telescope at Palomar Observatory and the Keck II telescope, researchers characterized the remarkably symmetrical “Red Square” nebula.
Galaxy cluster Abell 2218 is acting as a powerful lens, magnifying all galaxies lying behind the cluster's core. The lensed galaxies are all stretched along the shear direction, and some of them are multiply imaged.
The central starburst region of the dwarf galaxy IC 10. In this composite color image, near infrared images obtained with the Keck II telescope have been combined with visible-light images taken with NASA’s Hubble Space Telescope.
Keck I (right) and Keck II (left) domes at Mauna Kea.
Keck I and Keck II aim their adaptive optics lasers at the galactic center.