OzGrav

  • Home
  • About
    • Vision & Mission
    • Join OzGrav
    • Mental Health and Wellbeing
    • Getting started in OzGrav
    • Funding Opportunities
    • Diversity and Inclusion
    • Code of Conduct
    • OzGrav Mentoring Program
    • Nodes & Partners
    • Facilities & Capabilities
    • Reports >
      • Annual Reports
      • Industry Success Stories
      • Strategic Plan
    • Member resources
  • Our People
    • Chief Investigators
    • Partner Investigators
    • Associate Investigators
    • Postdocs and Students >
      • Faces of OzGrav
    • Professional & Outreach staff
    • Governance Advisory Committee
    • Scientific Advisory Committee
    • Executive Committee
    • Equity & Diversity Committee
    • Early Career Researcher Committee
    • Professional Development Committee
    • Research Translation Committee
    • OzGrav Alumni
  • Research Themes
    • Instrumentation
    • Data/Astro
  • Education and Outreach
  • Events
    • OzFink workshop 2023
    • 2022 OzGrav ECR Workshop and Annual Retreat
    • Upcoming and Past Events
  • News/Media
    • News
    • Newsletter
    • How to write a research brief
  • Contact Us
  • Home
  • About
    • Vision & Mission
    • Join OzGrav
    • Mental Health and Wellbeing
    • Getting started in OzGrav
    • Funding Opportunities
    • Diversity and Inclusion
    • Code of Conduct
    • OzGrav Mentoring Program
    • Nodes & Partners
    • Facilities & Capabilities
    • Reports >
      • Annual Reports
      • Industry Success Stories
      • Strategic Plan
    • Member resources
  • Our People
    • Chief Investigators
    • Partner Investigators
    • Associate Investigators
    • Postdocs and Students >
      • Faces of OzGrav
    • Professional & Outreach staff
    • Governance Advisory Committee
    • Scientific Advisory Committee
    • Executive Committee
    • Equity & Diversity Committee
    • Early Career Researcher Committee
    • Professional Development Committee
    • Research Translation Committee
    • OzGrav Alumni
  • Research Themes
    • Instrumentation
    • Data/Astro
  • Education and Outreach
  • Events
    • OzFink workshop 2023
    • 2022 OzGrav ECR Workshop and Annual Retreat
    • Upcoming and Past Events
  • News/Media
    • News
    • Newsletter
    • How to write a research brief
  • Contact Us

​RESEARCH HIGHLIGHT: LIMITS ON WEAK SUPERNOVA EXPLOSIONS FROM ISOLATED STARS

15/11/2021

0 Comments

 
Picture
Artist's illustration of a supernova - Carl Knox, OzGrav-Swinburne University

​Many of the heaviest stars in the Universe will end their lives in a bright explosion, known as a supernova, which briefly outshines the rest of its host galaxy, allowing us to view these rare events out to great distances. At the lower end of this mass range, the supernova explosion will squeeze the core of the star into a dense ball of neutrons that is much denser than what can be reproduced in laboratories. So, scientists must rely on theoretical models and astronomical observations to study these objects, known as neutron stars.

At the very low end of this range, the supernova explosions are thought to be weaker and dimmer, but even for state-of-the-art supernova simulations, it’s challenging to test this hypothesis. In our recently published study, we found a new way to test these weaker supernovae: by associating weaker supernova explosions with slowly moving neutron star remnants, neutron star speeds could accurately estimate the weaker supernovae, without the need for expensive simulations.

Neutron stars don’t shine bright like other stars, but instead produce a very narrow beam of radio waves which may (if we’re lucky) point toward the Earth. As the neutron star rotates, the beam of light appears to flash on and off, creating a lighthouse effect. When this effect is observed, , we refer to it as a pulsating star, or pulsar. Recent advances in radio telescopes allow for precise measurements of pulsar velocities. We combined our measurements with simulations of millions of stars and found that the typically high pulsar speeds did not allow for many weak supernovae.

However, there is a caveat: many of the massive stars that produce neutron stars are born in stellar binaries. If a normal supernova occurs in a stellar binary, the neutron star remnant will experience a large recoil kick—like a cannonball rushing away from the exploding gunpowder—and it will likely eject away from its companion star where it may later be observed as a single pulsar. But if the supernova is weak, the neutron star may not have enough energy to escape the gravitational tug of its companion star, and the stellar binary system will remain intact. This is a necessary step in the formation of neutron star binaries, so the existence of these binaries proves that some supernova explosions must be weak.
​
We found that to explain both the existence of neutron star binaries and the absence of slow-moving pulsars, weak supernovae can only occur in very close stellar binaries, not in single, isolated stars. This is useful for modelling supernova simulations and adds to a growing body of research suggesting that weak supernovae may only happen in stellar binaries which have previously interacted with each other. Studies like this, which simulate many stars in relatively low detail, are key to understanding the effects of uncertain physics on stellar populations, which is unfeasible with highly-detailed simulations. 
 
Written by PhD student Reinhold Wilcox, Monash University
0 Comments



Leave a Reply.

         


    OzGrav News


    Archives

    March 2023
    December 2022
    November 2022
    September 2022
    July 2022
    June 2022
    May 2022
    April 2022
    March 2022
    February 2022
    January 2022
    December 2021
    November 2021
    October 2021
    September 2021
    August 2021
    July 2021
    June 2021
    May 2021
    April 2021
    March 2021
    February 2021
    January 2021
    December 2020
    November 2020
    October 2020
    September 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    January 2020
    December 2019
    August 2019
    July 2019
    June 2019
    April 2019
    March 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    July 2018
    April 2018
    March 2018
    February 2018
    December 2017
    November 2017
    October 2017
    September 2017
    August 2017
    June 2017
    May 2017
    April 2017
    March 2017
    February 2017
    December 2016
    September 2016
    June 2016
    February 2016

    Categories

    All
    Event
    Media

      Keep up to date with ozgrav news and events

    Subscribe to Newsletter

    RSS Feed

Picture
Picture
Picture
Picture
Picture
Picture
Picture
Picture
We acknowledge and pay respects to the Elders and Traditional Owners of the land on which our six Australian nodes stand

​© 2022   The ARC Centre of Excellence for Gravitational  Wave Discovery (OzGrav)
Banner images: An artist's impression of gravitational waves generated by binary neutron stars.  Credits: R. Hurt/Caltech-JPL
Picture