Artist rendition of a radio telescope discovering ultra-fast radio bursts that were recently discovered and the focus of this recent study. (Credit: Daniëlle Futselaar/www.artsource.nl)
A recent study published in Nature Astronomy examines the discovery of what astronomers are dubbing “ultra-fast radio bursts”, a new type of fast radio bursts (FRBs) that the team determined lasts for a mind-boggling ten millionths of a second or less. Traditionally, FRBs have been found to last only thousandths of a second, but this study builds on a 2021 study that hypothesized FRBs could possibly last for millionths of a second. This also comes after astronomers recently announced the discovery of the oldest and farthest FRB ever observed, approximately 8 billion light-years from Earth.
Three new Fast Radio Bursts discovered by the Westerbork telescope were shown to have pierced the halo of our neighbouring Triangulum Galaxy. Invisible electrons in that galaxy deform the FRBs. From sharp, new, live images, astronomers could estimate the maximum number of invisible atoms in the Triangulum Galaxy for the first time. (Credit: ASTRON/Futselaar/van Leeuwen)
Fast Radio Bursts (FRBs) are cosmic mysteries that are slowly but surely revealing their secrets. These bright flashes of light are visible in the radio wave part of the spectrum and usually last only a few milliseconds before fading away forever. They come from random locations across the Universe and are so powerful that we can see them emanating from billions of light-years away.
Astronomers have used a newly upgraded radio telescope array to find five new FRBs and discovered that multiple bursts pierced right through the Triangulum Galaxy (M33). These brief flashes lit up the gas inside M33, allowing astronomers to calculate the maximum number of otherwise invisible atoms.
Artist view of the neutron star VT 1137-0337. Credit: Melissa Weiss, NRAO/AUI/NSF
Neutron stars are dense remnants of large stars. They are the collapsed cores of stars formed during a supernova explosion. While we know generally how they form, we are still learning how they evolve, particularly when they are young. But that’s starting to change thanks to large sky surveys, which have allowed astronomers to observe a neutron star that could be little more than a decade old.
Artist depiction of an Odd Radio Circle. Credit: CSIRO
In radio astronomy, circle-shaped objects are fairly common. Since diffuse ionized gas often emits radio light, objects such as supernova remnants, planetary nebulae, and even star-forming regions can create circular arcs of diffuse gas. But in 2019 astronomers began to discover radio circles they couldn’t explain, in part because they are so large.
In a new survey, astronomers using the Hubble Space Telescope have managed to pinpoint the location of several Fast Radio Bursts (FRBs). FRBs are powerful jets of energy that, until recently, had mysterious, unknown origins. The research team, which includes University of California Santa Cruz’ Alexandra Manning and Sunil Simha, as well as Northwestern University’s Wen-fai Fong, performed a survey of eight FRBs, from which they were able to determine that five of them originated from a spiral arm in their host galaxies.
Where is all the missing matter? That question has plagued astronomers for decades, because the Universe looks emptier than it should, given current theories about its makeup. Most of the Universe (70%) appears to be composed of Dark Energy, the mysterious force which is causing the Universe’s rate of expansion to increase. Another 25% of the Universe is Dark Matter, an unknown substance which cannot be seen, but has been theorized to explain the otherwise inexplicable gravitational forces which govern the formation of galaxies. That leaves Baryonic Matter – all the normal ‘stuff’ like you, me, the trees, the planets, and the stars – to make up just 5% of the Universe. But when astronomers look out into the sky, there doesn’t even seem to be enough normal matter to make up 5%. Some of the normal matter is missing!
Fast radio bursts are some of the most mysterious events known in astronomy, but they are slowly becoming better understood. Case in point: recent observations of a fast radio burst in the Milky Way reveals the powerhouse behind the blasts: a flaring magnetar.
Taken with the HAWK-I instrument on ESO’s Very Large Telescope in the Chilean Atacama Desert, this stunning image shows the Milky Way’s central region with an angular resolution of 0.2 arcseconds. This means the level of detail picked up by HAWK-I is roughly equivalent to seeing a football (soccer ball) in Zurich from Munich, where ESO’s headquarters are located. The image combines observations in three different wavelength bands. The team used the broadband filters J (centred at 1250 nanometres, in blue), H (centred at 1635 nanometres, in green), and Ks (centred at 2150 nanometres, in red), to cover the near infrared region of the electromagnetic spectrum. By observing in this range of wavelengths, HAWK-I can peer through the dust, allowing it to see certain stars in the central region of our galaxy that would otherwise be hidden.
A team of scientists in Canada have found a Fast Radio Burst (FRB) that repeats every 16 days. This is in stark contrast to other FRBs, which are more sporadic. Some of those sporadic FRBs occur in clusters, and repeat irregularly, but FRBs with a regular, repeatable occurrence are rare.
CHIME consists of four metal "half-pipes", each one 100 meters long. Image Credit: CHIME/Andre Renard, Dunlap Institute.
Canadian scientists using the CHIME (Canadian Hydrogen Intensity Mapping Experiment) have detected 13 FRBs (Fast Radio Bursts), including the second-ever repeating one. And they think they’ll find even more.
CHIME is an innovative radio telescope in the Okanagan Valley region in British Columbia, Canada. It was completed in 2017, and its mission is to act as a kind of time machine. CHIME will help astronomers understand the shape, structure, and fate of the universe by measuring the composition of dark energy.
CHIME’s unique design also makes it well-suited for detecting fast radio bursts.
The CHIME Telescope, located at the Dominion Radio Astrophysical Observatory (DRAO), in British Columbia. Credit: chime-experiment.ca
Since they were first detected in 2007, Fast Radio Bursts (FRBs) have been a source of mystery to astronomers. In radio astronomy, this phenomenon refers to transient radio pulses coming from distant sources that typically last a few milliseconds on average. Despite the detection of dozens of events since 2007, scientists are still not sure what causes them – though theories range from exploding stars, black holes, and magnetars to alien civilizations!
To shed light on this mysterious phenomena, astronomers are looking to new instruments to help search for and study FRBs. One of these is the Canadian Hydrogen Intensity Mapping Experiment (CHIME), a revolutionary new radio telescope located at the Dominion Radio Astrophysical Observatory (DRAO) in British Columbia. On July 25th, still in its first year, this telescope made its first-ever detection, an event known as FRB 180725A.
The detection of FRB 180725A was announced online in a “Astronomer’s Telegram” post, which is intended to alert the astronomical community about possible new finds and encourage follow-up observations. The detection of FRB 180725A is very preliminary at this point, and more research is needed before its existence as an FRB can be confirmed.
As they stated in the Astronomers Telegram announcement, the radio was signal was detected on July 25th, at precisely 17:59:43.115 UTC (09:59.43.115 PST), and at a radio frequency of 400 MHz:
“The automated pipeline triggered the recording to disk of ~20 seconds of buffered raw intensity data around the time of the FRB. The event had an approximate width of 2 ms and was found at dispersion measure 716.6 pc/cm^3 with a signal-to-noise ratio S/N ~20.6 in one beam and 19.4 in a neighboring beam. The centers of these, approximately 0.5 deg wide and circular beams, were at RA, Dec = (06:13:54.7, +67:04:00.1; J2000) and RA, Dec = (06:12:53.1, +67:03:59.1; J2000).”
Research into Fast Radio Bursts is still in its infancy, being a little more than a decade old. The first ever to be detected was the famous Lorimer Burst, which was named after it discoverer – Duncan Lorimer, from West Virginia University. This burst lasted a mere five milliseconds and appeared to be coming from a location near the Large Magellanic Cloud, billions of light years away.
So far, the only FRB that has been found to be repeating was the mysterious signal known as FRB 121102, which was detected by the Arecibo radio telescope in Puerto Rico in 2012. The nature of this FRB was first noticed by a team of students from McGill University (led by then-PhD Student Paul Scholz), who sifted through the Arecibo data and determined that the initial burst was followed by 10 additional burst consistent with the original signal.
The NSF’s Arecibo Observatory, which is located in Puerto Rico, is the world largest radio telescope. Arecibo detected 11 FRBs over the course of 2 months. Credit: NAIC
In addition to being the first time that this Canadian facility detected a possible FRB coming from space, this is the first time that an FRB has been detected below the 700 MHz range. However, as the CHIME team indicate in their announcement, other signals of equal intensity may have occurred in the past, which were simply not recognized as FRBs at the time.
“Additional FRBs have been found since FRB 180725A and some have flux at frequencies as low as 400 MHz,” they wrote. “These events have occurred during both the day and night and their arrival times are not correlated with known on-site activities or other known sources of terrestrial RFI (Radio Frequency Identification).”
As a result, this most-recent detection (if confirmed) could help astronomers shed some additional light on what causes FRBs, not to mention place some constraints on what frequencies they can occur at. Much like the study of gravitational waves, the field of study is new but rapidly growing, and made possible by the addition of cutting-edge instruments and facilities around the world.
