. 24/7 Space News .
PHYSICS NEWS
Resolving the jet or cocoon riddle of a gravitational wave event
by Staff Writers
Bonn, Germany (SPX) Feb 22, 2019

Artist's impression of the jet of material launched after the merger of the two neutron stars.

An international research team including astronomers from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has combined radio telescopes from five continents to prove the existence of a narrow stream of material, a so-called jet, emerging from the only gravitational wave event involving two neutron stars observed so far. With its high sensitivity and excellent performance, the 100-m radio telescope in Effelsberg played an important role in the observations.

In August 2017, two neutron stars were observed colliding, producing gravitational waves that were detected by the American LIGO and European Virgo detectors. Neutron stars are ultra-dense stars, roughly the same mass as the Sun, but similar in size to a city like Cologne. This event is the first and only one of this type that has been observed so far, and it happened in a galaxy 130 million light-years away from Earth, in the constellation of Hydra.

Astronomers observed the event and the subsequent evolution across the entire electromagnetic spectrum, from gamma-rays, X-rays to visible light and radio waves. Two hundred days after the merger, observations combining radio telescopes in Europe, Africa, Asia, Oceania, and North America proved the existence of a jet emerging from this violent collision.

These findings are now published in the scientific journal Science by an international team of astronomers, led by Giancarlo Ghirlanda from the Italian National Institute for Astrophysics (INAF).

This neutron star merger represented the first case where it was possible to associate a detection of gravitational waves to an object emitting light. The event has confirmed scientific theories that have been under discussion for tens of years, and the association of neutron star mergers with one of the most powerful explosions in the universe: gamma-ray bursts.

After the merger, a huge amount of material was expelled into space, forming a shell around the object. Astronomers have been tracing its evolution at different wavelengths. However, there were still some remaining questions concerning this event that could not be clarified by any previous observations.

"We expected part of the material to be ejected through a collimated jet, but it was unclear whether this material could successfully pierce through the surrounding shell." explains Ghirlanda. "There were two competing scenarios: In one case, the jet cannot break through the shell, instead generating an expanding bubble around the object.

In the other, the jet is successful in penetrating the shell and then propagates further into space," expands Tiziana Venturi (INAF). Only the acquisition of very sensitive radio images with very high resolution would discard one scenario or the other. This required the use of a technique known as very long baseline interferometry (VLBI) that allows astronomers to combine radio telescopes all around the Earth.

The authors of this publication conducted global observations in the direction of the merger on 12 March 2018 using thirty-three radio telescopes from the European VLBI Network (that connects telescopes from Spain, the United Kingdom, The Netherlands, Germany, Italy, Sweden, Poland, Latvia, South Africa, Russia, and China), e-MERLIN in the UK, the Australian Long Baseline Array in Australia and New Zealand, and the Very Long Baseline Array in the USA.

"Our 100-m radio telescope in Effelsberg participated in the observations and was a key element, due to its high sensitivity and excellent performance," says Carolina Casadio, a member of the research team from the Max Planck Institute for Radio Astronomy (MPIfR).

The data from all telescopes were sent to JIVE, The Netherlands, where the most advanced processing techniques were used to produce an image with a resolution comparable to resolving a person on the surface of the Moon. In the same analogy, the expanding bubble would appear with an apparent size equivalent to a truck on the Moon, whereas a successful jet would be detected as a much more compact object.

"Comparing the theoretical images with the real ones, we find that only a jet could appear sufficiently compact to be compatible with the observed size," explains Om Sharan Salafia from INAF in Italy. The team determined that this jet contained as much energy as produced by all the stars in our galaxy during one year.

"And all that energy was contained in a size smaller than one light-year," says Zsolt Paragi, also from JIVE.

"Within Europe we utilize the RadioNet consortium for an efficient use of our members' radio telescopes. The observations described here combine radio observatories all over Europe and world wide. They require a well-coordinated effort of the collaborating observatories and institutions to achieve such exciting results," explains Anton Zensus, Director at MPIfR and coordinator of the RadioNet consortium.

In the coming years, many more of these neutron star binary mergers will be discovered. "The obtained results also suggest that more than 10% of all these mergers should exhibit a successful jet," explains Benito Marcote from JIVE.

"These types of observations will allow us to unveil the processes that take place during and after some of the most powerful events in the universe," concludes Sandor Frey from the Konkoly Observatory in Hungary.

Research Report: "(Re)solving the Jet/Cocoon Riddle of the First Gravitational Wave Electromagnetic Counterpart," G. Ghirlanda et al., 2019 Feb. 21, Science


Related Links
Max Planck Institute For Radio Astronomy
The Physics of Time and Space


Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Monthly Supporter
$5+ Billed Monthly


paypal only
SpaceDaily Contributor
$5 Billed Once


credit card or paypal


PHYSICS NEWS
US-UK-Australia funding to improve global gravitational wave network
Washington DC (SPX) Feb 18, 2019
The National Science Foundation (NSF) is awarding Caltech and MIT $20.4 million to upgrade the Laser Interferometer Gravitational-wave Observatory (LIGO), an NSF-funded project that made history in 2015 after making the first direct detection of ripples in space and time, called gravitational waves. The investment is part of a joint international effort in collaboration with UK Research and Innovation and the Australian Research Council, which are contributing additional funds. While LIGO is sched ... read more

Comment using your Disqus, Facebook, Google or Twitter login.



Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

PHYSICS NEWS
Space behaviour focus of Expedition 58

Technology developed in Brazil will be part of ISS

Virgin Galactic takes crew of three to altitude of 55 miles

Astronauts optimistic for ISS launch after botched flight

PHYSICS NEWS
SpaceX releases Israeli moon lander, pair of satellites into orbit

Russia Completes Engine Tests of Soyuz Rocket's 2nd Stage Using New Fuel

NASA greenlights SpaceX crew capsule test to ISS

Raptor engine beats Russian RD-180 record in combustion chamber pressure says Musk

PHYSICS NEWS
Weather on Mars: Chilly with a chance of 'dust devils'

InSight is the Newest Mars weather service

After a Reset, Curiosity Is Operating Normally

Creating a Space Colony Cryptocurrency

PHYSICS NEWS
China improves Long March-6 rocket for growing commercial launches

Seed of moon's first sprout: Chinese scientists' endeavor

China to send over 50 spacecraft into space via over 30 launches in 2019

China to deepen lunar exploration: space expert

PHYSICS NEWS
Arianespace to orbit the first six satellites of the OneWeb constellation

United Launch Services, SpaceX awarded satellite contracts

RIT faculty part of NASA's $242 million SPHEREx mission

18m pounds for OneWeb satellite constellation to deliver global communications

PHYSICS NEWS
NASA set to demonstrate x-ray communications in space

Malaysia to end bauxite mining ban despite environment fears

New technology captures movement of quantum particles with unprecedented resolution

Scientists use tire fibers to increase fire resistance of concrete

PHYSICS NEWS
NIST 'Astrocomb' Opens New Horizons for Planet-Hunting Telescope

Discovery of Planets Around Cool Stars Enabled with Hobby-Eberly Telescope

NASA Selects New Mission to Explore Origins of Universe

New NASA research consortium to tackle life's origins

PHYSICS NEWS
New Horizons Spacecraft Returns Its Sharpest Views of Ultima Thule

Tiny Neptune Moon Spotted by Hubble May Have Broken from Larger Moon

Ultima Thule is more pancake than snowman, NASA scientists discover

New Horizons' evocative farewell glance at Ultima Thule









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.