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.
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.
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.
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.
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
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.
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