ALMA finds possible signs of neutron star in supernova 1987A


The artist’s depiction of the supernova 1987A depicts the dusty interior areas of the exploding star’s remains (red), in which a neutron star can be hidden. This inner region contrasted with the outer shell (blue), where the energy from the supernova collided (green) with the envelope of the gas emitted from the star before its powerful explosion. Sincerely: NRAO / AUI / NSF, B. Saxton

In the 33-year-old mystery around Supernova 1987A, two teams of astronomers made a compelling case. Based on observations from the Atacama Large Millimeter / Submillimeter Array (ALMA) and a theoretical follow-up study, scientists provide new insights to the argument that the neutron star is hidden deep inside the remnants of the exploding star. It will be the youngest neutron star ever known.


Ever since astronomers saw one of the brightest explosions of a star in the night sky, building a supernova 1987A, they have been searching for a compact object that should have formed into fragments left by the explosion.

Because particles known as neutrinos were detected on Earth on the day of the explosion (23 February 1987), astronomers expected a neutron star to have formed at the collapsing center of the star. But when scientists found no evidence for that star, they wondered if it later fell into a black hole instead. For decades, the scientific community has been eagerly waiting for a signal from this object that has been hidden behind a thick cloud of dust.

the blob’

Recently, observations from the ALMA radio telescope provided the first indication of a missing neutron star after the explosion. Extremely high-resolution images revealed a hot “blob” in the dusty core of SN 1987A, which is brighter than its surroundings and matches the suspicious location of the neutron star.

ALMA finds possible signs of neutron star in supernova 1987A

Extremely high-resolution ALMA images revealed a hot “blob” in the dusty core of Supernova 1987A (inset), which may be the location of the missing neutron star. The red color shows dust and cold gas at the center of the supernova remnant taken at radio wavelengths with ALMA. The green and blue color shows that the shock wave propagating from the exploded star is hitting a ring material around the supernova. The green represents a flare of visible light, captured by NASA’s Hubble Space Telescope. The blue color reveals the hottest gas and is based on data from NASA’s Lunar X-ray Observatory. The ring was initially made to shine by a flash of light from the original explosion. In later years the ring material has become quite luminous as it contains an explosion shock slam. Credit: ALMA (ESO / NAOJ / NRAO), p. Saigan and R. Indebetouw; NRAO / AUI / NSF, B. Saxton; NASA / ESA

Mikako Matsura from Cardiff University and a member of the team said that we were very surprised to see this hot drop made of thick cloud of dust in the supernova remnant mixing this drop with Alma. “There must be something in the cloud that has warmed up the dust and that makes it shine. That’s why we suggested that there is a neutron star hidden inside the dust cloud.”

Even though Matsuura and his team were excited by the result, they thought about the brightness of the blob. “We thought the neutron star might be too bright to exist, but then Dani Page and his team published a study that indicated that the neutron star might actually be bright because it is so small,” Matsuura he said.

Denny Page is an astrophysicist at the National Autonomous University of Mexico, studying SN 1987A from the beginning. “I was halfway through my PhD when a supernova happened,” he said, “It was one of the biggest events of my life that changed the course of my career to try to solve this mystery.” It was like this. Modern Holy Grave. “

Theoretical study by Page and his team, published today The Astrophysical JournalALMA strongly supports the suggestion made by the team that a neutron star is powering the dust drop. “Despite the supreme complexity of a supernova explosion and the extreme conditions governing the interior of a neutron star, the detection of a hot drop of dust is a confirmation of many predictions,” Page explained.

These predictions were the location and temperature of the neutron star. According to the supernova computer model, the explosion “kicked” the neutron star from its birthplace at a speed of hundreds of kilometers per second (ten times faster than the fastest rocket). The drop is exactly where astronomers think the neutron star would be today. And the temperature of the neutron star, which was predicted to be around 5 million degrees Celsius, provides enough energy to explain the brightness of the blob.

ALMA finds possible signs of neutron star in supernova 1987A

This colorful, multidimensional image of the complex remains of Supernova 1987A is produced with data from three different observatories. The red color shows dust and cold gas at the center of the supernova remnant taken at radio wavelengths with ALMA. The green and blue color shows that the shock wave propagating from the exploded star is hitting a ring material around the supernova. The green represents a flare of visible light, captured by NASA’s Hubble Space Telescope. The blue color reveals the hottest gas and is based on data from NASA’s Lunar X-ray Observatory. The ring was initially made to shine by a flash of light from the original explosion. In later years the ring material became quite shiny, as it had an explosion shock slam. Credit: ALMA (ESO / NAOJ / NRAO), p. Saigan and R. Indebetouw; NRAO / AUI / NSF, B. Saxton; NASA / ESA

No pulsar or black hole

Contrary to common expectations, the neutron star is likely not a pulsar. “The power of a pulsar depends on how fast it rotates and on the strength of its magnetic field, both will require very finely tuned values ​​to match the observations,” Page said. ” While the thermal energy emitted by the hot surface of the young neutron star naturally fits the data. “

“The neutron star behaves exactly as we expect,” James Latimer of Stony Brook University in New York and a member of Page’s research team. Lattimer also closely followed SN 1987A, which was published before SN 1987A, an approximation of the neutrino signal of supernovae that matched later observations. “Those neutrinos suggested that a black hole is never formed, and furthermore it seems difficult for a black hole to explain the apparent brightness of a blob. We compared all the possibilities and concluded that a hot neutron star is the most likely. Chances are. “

This neutron star is a 25 km-wide, extremely hot ball of ultra-dense matter. A spoonful of its contents will weigh more than all buildings within United New York City. Because it can only be 33 years old, it will be the youngest neutron star ever. The second-smallest neutron star that we know of is located in the supernova remnant Cassiopeia A and is 330 years old.

Only a direct picture of the neutron star will provide definitive evidence that it exists, but astronomers may have to wait a few more decades until the dust and gas in the supernova remnant become more transparent.

Credit: National Radio Astronomy Observatory

Detailed alma image

Although many telescopes have produced SN 1987A images, none of them have been able to observe its origin with high precision like ALMA. Observations with the first (3-D) ALMA showed the types of molecules already found in the supernova residue and confirmed that it produced a large amount of dust.

Remy Indebetouw of the National Radio Astronomy Observatory and the University of Virginia said, “This discovery builds on years of ALMA observations that show the core of the supernova in greater detail for continued improvements in telescopes and data processing.” ALMA has been a part of the imaging team.


Scientists have found evidence of a missing neutron star


more information:
Dany Page et al, NS 1987A in SN 1987A, The Astrophysical Journal (2020). DOI: 10.3847 / 1538-4357 / ab93c2

Provided by the National Radio Astronomy Observatory

Quotes: ALMA finds possible indications of a neutron star in Supernova 1987A (2020, 30 July). Retrieved 30 July 2020 from https://phys.org/news/2020-07-alma-neutron-star-supernova-1987a.html.

This document is subject to copyright. No part may be reproduced without written permission, except for any impartial behavior intended for personal study or research. The content is provided for information purposes only.

Leave a Reply

Your email address will not be published.