Thursday, February 22, 2024

Evidence for Neutron Star Inside SN 1987a Supernova Remnant | NASA Webb

Evidence for Neutron Star Inside SN 1987a Supernova Remnant | NASA Webb

The NASA/European Space Agency/Canadian Space Agency James Webb Space Telescope has found the best evidence yet for emission from a neutron star at the site of a recently observed supernova. The supernova, known as SN 1987A, occurred 160,000 light-years from Earth in the neighboring Large Magellanic Cloud galaxy. SN 1987A was a type II supernova that was observed on Earth in 1987, the first supernova that was visible to the naked eye since 1604—before the advent of telescopes. It provided the astronomical community a rare opportunity to study the evolution of a supernova and what was left behind, from the very beginning. SN 1987A was a core-collapse supernova, meaning the compacted remains at its core are expected to have formed either a neutron star or a black hole. Evidence for such a compact object has long been sought, and whilst indirect evidence for the presence of a neutron star has previously been found, this is the first time that the effects of high energy emission from the young neutron star has been detected.

LEFT: Webb’s 2023 NIRCam (Near-Infrared Camera) image of SN 1987A that highlights the object’s central structure, expanding with several thousands km/s. The blue region is the densest part of the clumpy ejecta, containing heavy elements like carbon, oxygen, magnesium and iron, as well as dust. The bright ‘ring of pearls’ is the result of the collision of the ejecta with a ring of gas ejected about 20,000 years before the explosion. Now spots are found even exterior to the ring, with diffuse emission surrounding it. These are the locations of supernova shocks hitting more exterior material from the progenitor star. The outer ejecta is now illuminated by X-rays from the collision, while the inner ejecta is powered mainly by radioactivity and a putative compact object.

RIGHT: An international team of astronomers has now used two of Webb’s instruments to study the emissions from the core of SN 1987A. The top image features the data from Webb’s MRS (Medium Resolution Spectrograph) mode of the MIRI instrument (Mid-InfraRed Instrument). The bottom image depicts data from Webb’s NIRSpec (Near Infrared Spectrograph) at shorter wavelengths. Spectral analysis of the MIRI results showed a strong signal due to ionized argon from the center of the ejected material that surrounds the original site of SN 1987A. The NIRSpec data found even more heavily ionized chemical species, particularly five times ionized argon (meaning argon atoms that have lost five of their 18 electrons). Weak lines of ionized sulphur were also detected with MIRI. This indicated to the science team that there is a source of high-energy radiation in the center of the SN 1987A remnant, illuminating an almost point-like region in the center. The most likely source is believed to be a newly born neutron star.

Image Description: A graphic with three images, each of a glowing, ring-shaped nebula. The left side shows a large, full-color image of the nebula and its surroundings, labelled “NIRCam”. A rectangle in the center of the nebula is highlighted and two images of this area are pulled out to the right. Both are shown in shades of orange. The top one is labelled “MIRI MRS Argon II” and the bottom one “NIRSpec IFU Argon VI.

Read the research paper: 

Credit: NASA, ESA, CSA, STScI, and C. Fransson (Stockholm University), M. Matsuura (Cardiff University), M. J. Barlow (University College London), P. J. Kavanagh (Maynooth University), J. Larsson (KTH Royal Institute of Technology)
Release Date: February 24, 2024

#NASA #Astronomy #Space #Science #Stars #NeutronStar #Emission #SN1987A #Supernova #SupernovaRemnant #Dorado #Constellation #LargeMagellanicCloud #Galaxy #Cosmos #Universe #JWST #SpaceTelescope #ESA #Europe #CSA #Canada #GSFC #STScI #UnitedStates #STEM #Education

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