The Times Australia
The Times World News

.
The Times Real Estate

.

For the first time, astronomers have linked a mysterious fast radio burst with gravitational waves

  • Written by Clancy William James, Senior Lecturer (astronomy and astroparticle physics), Curtin University
For the first time, astronomers have linked a mysterious fast radio burst with gravitational waves

We have just published evidence[1] in Nature Astronomy for what might be producing mysterious bursts of radio waves coming from distant galaxies, known as fast radio bursts[2] or FRBs.

Two colliding neutron stars[3] – each the super-dense core of an exploded star – produced a burst of gravitational waves when they merged into a “supramassive” neutron star[4]. We found that two and a half hours later they produced an FRB when the neutron star collapsed into a black hole.

Or so we think. The key piece of evidence that would confirm or refute our theory – an optical or gamma-ray flash coming from the direction of the fast radio burst – vanished almost four years ago. In a few months, we might get another chance to find out if we are correct.

Brief and powerful

FRBs are incredibly powerful pulses of radio waves from space lasting about a thousandth of a second. Using data from a radio telescope in Australia, the Australian Square Kilometre Array Pathfinder (ASKAP[5]), astronomers have found[6] that most FRBs come from galaxies so distant, light takes billions of years to reach us[7]. But what produces these radio wave bursts has been puzzling astronomers since an initial detection[8] in 2007.

The best clue comes from an object in our galaxy known as SGR 1935+2154. It’s a magnetar[9], which is a neutron star with magnetic fields about a trillion times stronger than a fridge magnet. On April 28 2020, it produced a violent burst of radio waves[10] – similar to an FRB, although less powerful.

Read more: A brief history: what we know so far about fast radio bursts across the universe[11]

Astronomers have long predicted that two neutron stars – a binary – merging to produce a black hole[12] should also produce a burst of radio waves. The two neutron stars will be highly magnetic, and black holes cannot have magnetic fields. The idea[13] is the sudden vanishing of magnetic fields when the neutron stars merge and collapse to a black hole produces a fast radio burst. Changing magnetic fields produce electric fields – it’s how most power stations produce electricity. And the huge change in magnetic fields at the time of collapse could produce the intense electromagnetic fields of an FRB.

A black field with two illustrations of galaxies in the foreground, and a yellow beam connecting them
Artist’s impression of a fast radio burst traveling through space and reaching Earth. ESO/M. Kornmesser, CC BY[14][15]

The search for the smoking gun

To test this idea, Alexandra Moroianu, a masters student at the University of Western Australia, looked for merging neutron stars detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO[16]) in the US. The gravitational waves LIGO searches for are ripples in spacetime, produced by the collisions of two massive objects, such as neutron stars.

LIGO has found two binary neutron star mergers. Crucially, the second, known as GW190425[17], occurred when a new FRB-hunting telescope called CHIME[18] was also operational. However, being new, it took CHIME two years to release its first batch of data[19]. When it did so, Moroianu quickly identified a fast radio burst called FRB 20190425A[20] which occurred only two and a half hours after GW190425.

Exciting as this was, there was a problem – only one of LIGO’s two detectors was working at the time, making it very uncertain[21] where exactly GW190425 had come from. In fact, there was a 5% chance this could just be a coincidence.

Worse, the Fermi[22] satellite, which could have detected gamma rays from the merger – the “smoking gun” confirming the origin of GW190425 – was blocked by Earth[23] at the time.

A nighttime view of white curved pipes arranged in a grid pattern CHIME, the Canadian Hydrogen Intensity Mapping Experiment, has turned out to be uniquely suited to detecting FRBs. Andre Renard/Dunlap Institute/CHIME Collaboration

Unlikely to be a coincidence

However, the critical clue was that FRBs trace the total amount of gas they have passed through. We know this because high-frequency radio waves travel faster through the gas than low-frequency waves, so the time difference between them tells us the amount of gas.

Because we know the average gas density of the universe[24], we can relate this gas content to distance, which is known as the Macquart relation[25]. And the distance travelled by FRB 20190425A was a near-perfect match for the distance to GW190425. Bingo!

So have we discovered the source of all FRBs? No. There are not enough merging neutron stars in the Universe to explain the number of FRBs – some must still come from magnetars, like SGR 1935+2154 did.

And even with all the evidence, there’s still a one in 200 chance this could all be a giant coincidence. However, LIGO and two other gravitational wave detectors, Virgo[26] and KAGRA[27], will turn back on[28] in May this year, and be more sensitive than ever, while CHIME and other radio telescopes[29] are ready to immediately detect any FRBs from neutron star mergers.

In a few months, we may find out if we’ve made a key breakthrough – or if it was just a flash in the pan.

Clancy W. James would like to acknowledge Alexandra Moroianu, the lead author of the study; his co-authors, Linqing Wen, Fiona Panther, Manoj Kovalem (University of Western Australia), Bing Zhang and Shunke Ai (University of Nevada); and his late mentor, Jean-Pierre Macquart, who experimentally verified the gas-distance relation, which is now named after him.

References

  1. ^ just published evidence (www.nature.com)
  2. ^ fast radio bursts (theconversation.com)
  3. ^ neutron stars (theconversation.com)
  4. ^ supramassive” neutron star (www.ozgrav.org)
  5. ^ ASKAP (www.atnf.csiro.au)
  6. ^ astronomers have found (www.science.org)
  7. ^ billions of years to reach us (theconversation.com)
  8. ^ an initial detection (www.science.org)
  9. ^ magnetar (earthsky.org)
  10. ^ violent burst of radio waves (www.nature.com)
  11. ^ A brief history: what we know so far about fast radio bursts across the universe (theconversation.com)
  12. ^ black hole (theconversation.com)
  13. ^ The idea (www.aanda.org)
  14. ^ ESO/M. Kornmesser (www.eso.org)
  15. ^ CC BY (creativecommons.org)
  16. ^ LIGO (www.ligo.org)
  17. ^ GW190425 (www.ligo.org)
  18. ^ CHIME (chime-experiment.ca)
  19. ^ to release its first batch of data (theconversation.com)
  20. ^ FRB 20190425A (www.chime-frb.ca)
  21. ^ very uncertain (theconversation.com)
  22. ^ Fermi (fermi.gsfc.nasa.gov)
  23. ^ blocked by Earth (link.springer.com)
  24. ^ average gas density of the universe (theconversation.com)
  25. ^ Macquart relation (www.nature.com)
  26. ^ Virgo (www.virgo-gw.eu)
  27. ^ KAGRA (gwcenter.icrr.u-tokyo.ac.jp)
  28. ^ turn back on (www.ligo.caltech.edu)
  29. ^ other radio telescopes (www.mwatelescope.org)

Read more https://theconversation.com/for-the-first-time-astronomers-have-linked-a-mysterious-fast-radio-burst-with-gravitational-waves-202341

The Times Features

Best Deals on Home Furniture Online

Key Highlights Discover the best deals on high-quality outdoor furniture online. Transform your outdoor space into a stylish and comfortable oasis. Explore a wide range of d...

Discover the Best Women's Jumpers for Every Season

Key Highlights Explore lightweight jumpers for spring and summer, ensuring breathability and ease. Wrap up warm with cozy wool jumpers for the chilly autumn and winter season...

Uncover the Elegance of Gorgeous Diamond Tennis Necklaces

Key Highlights Diamond tennis necklaces are a timeless piece of jewelry that exudes elegance and sophistication. They feature a continuous line of brilliant-cut diamonds, cre...

Dental Implants vs. Dentures: Which Is Better for You?

When it comes to replacing missing teeth, two of the most common options are dental implants and dentures. Both have their advantages and disadvantages, so choosing between them ...

What Neck Pain Really Means (And Why It’s More Than Just Poor Posture)

Neck pain is often brushed off as something temporary — a tight spot after a long day at the desk or a poor night’s sleep. But when the discomfort keeps returning, it could be a ...

The Work of Gosha Rubchinskiy: Fashion, Culture, and Youth

From Designer to Cultural Architect Gosha Rubchinskiy is not just a fashion designer—he's a cultural force. Born in Moscow in 1984, Rubchinskiy began his career in fashion in t...

Times Magazine

The Essential Guide to Transforming Office Spaces for Maximum Efficiency

Why Office Fitouts MatterA well-designed office can make all the difference in productivity, employee satisfaction, and client impressions. Businesses of all sizes are investing in updated office spaces to create environments that foster collaborat...

The A/B Testing Revolution: How AI Optimized Landing Pages Without Human Input

A/B testing was always integral to the web-based marketing world. Was there a button that converted better? Marketing could pit one against the other and see which option worked better. This was always through human observation, and over time, as d...

Using Countdown Timers in Email: Do They Really Increase Conversions?

In a world that's always on, where marketers are attempting to entice a subscriber and get them to convert on the same screen with one email, the power of urgency is sometimes the essential element needed. One of the most popular ways to create urg...

Types of Software Consultants

In today's technology-driven world, businesses often seek the expertise of software consultants to navigate complex software needs. There are several types of software consultants, including solution architects, project managers, and user experienc...

CWU Assistive Tech Hub is Changing Lives: Win a Free Rollator Walker This Easter!

🌟 Mobility. Independence. Community. All in One. This Easter, the CWU Assistive Tech Hub is pleased to support the Banyule community by giving away a rollator walker. The giveaway will take place during the Macleod Village Easter Egg Hunt & Ma...

"Eternal Nurture" by Cara Barilla: A Timeless Collection of Wisdom and Healing

Renowned Sydney-born author and educator Cara Barilla has released her latest book, Eternal Nurture, a profound collection of inspirational quotes designed to support mindfulness, emotional healing, and personal growth. With a deep commitment to ...

LayBy Shopping