Did rapid spin delay 2017 collapse of neutron stars into black hole?

Does it immediately become a black hole when two stars spiral into one another? Is it possible to spin down before collapsing into a black hole?

The Chandra X-ray Observatory, which is an observatory, has been observing the merger for a while.

If the merged stars collapsed immediately to a black hole, there would be no evidence of an X-ray afterglow from the merger. The material from the merged neutron stars can be seen in the afterglow as a rebound of material. After the merger, this hot material kept the remnant glowing for more than four years. Chandra detected X-ray emissions from a jet of material shortly after the merger.

The delayed collapse hypothesis, which is predicted theoretically, favors the idea that debris in an accretion disk will fall into a black hole.

If the merged stars were to collapse directly to a black hole with no intermediate stage, it would be hard to explain the X-ray excess that we see right now. Done. There is a chance that we are seeing something more than the jet. We might get some information about the new object.

Margutti and her colleagues, including first author Aprajita Hajela, who was Margutti's graduate student when she was at Northwestern University, report their analysis of the X-ray afterglow in a paper recently accepted for publication in The Astrophysical Journal.

A kilonova has a radioactive glow.

The Advanced Laser Interferometer Gravitational-wave Observatory detected waves from the merger. The theory that many heavy elements are produced in the aftermath of mergers inside hot ejections was confirmed by a burst of visible and IR emissions from satellites and ground-based telescopes. Light that is emitted during the decay of radioactive elements is what causes the kilonova to glow.

Chandra saw no X-rays until nine days later, suggesting that the merger produced a narrow jet of material that missed Earth. The head of the jet expanded and began emitting X-rays in a larger jet visible from Earth.

After the merger, the X-ray emissions from the jet grew fainter as the jet slowed down and expanded. The decline in X-ray emissions stopped about 900 days after the merger and remained constant until the end of 2020.

Margutti said that the fact that the X-rays stopped fading quickly was the best evidence yet that something is being detected in X-rays in this source.

The researchers think that the excess X-rays are produced by a shock wave. The shock was caused by the delayed collapse of the merged neutron stars, which caused its rapid spin to counteract the collapse. The material around the stars got 888-269-5556 888-269-5556 888-269-5556 888-269-5556 888-269-5556 888-269-5556 888-269-5556.

Margutti said that the emission of the kilonova is produced by shocked material in the circumbinary medium.

She said that the radiation is reaching us now because it took time for the heavy kilonova ejecta to be decelerated in the low density environment. The process of producing radio and X-rays for the jet is the same as it is for the radio and X-rays for the jet, but the jet is much, much lighter, so it is decelerated by the environment and shines in the X-ray and radio from the very

The X-rays come from material falling towards the black hole that formed after the neutron stars merged, according to the researchers.

This would be the first time we have seen a kilonova afterglow or the first time we have seen material falling onto a black hole.

Chandra is the only observatory that can see light from this collision. Chandra and radio telescopes could distinguish between the different explanations. Radio emission is expected to be detected again in the next few months or years if it is a kilonova afterglow. If the X-rays are being produced by matter falling onto a black hole, then the X-ray output should stay steady or decline rapidly, and no radio emission will be detected over time.

Margutti hopes that LIGO and other telescopes will be able to capture the waves from more neutron star mergers so that the series of events preceding and following the merger can be pinned down more precisely and help reveal the physics of black hole formation. There is only one example available for study.

The detection of a kilonova afterglow would imply that the merger did not produce a black hole. Astronomers may be able to study how matter falls onto a black hole a few years after its birth.

Margutti and her team recently announced that the Chandra telescope had detected X-rays. The data is being analyzed. There was no radio detection associated with the X-rays.

More information: The emergence of a new source of X-rays from the binary neutron star merger GW170817, arXiv:2104.02070 [astro-ph.HE] arxiv.org/abs/2104.02070 Journal information: Astrophysical Journal Letters Citation: Did rapid spin delay 2017 collapse of neutron stars into black hole? (2022, March 5) retrieved 6 March 2022 from https://phys.org/news/2022-03-rapid-collapse-neutron-stars-black.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.