With the help of the ALMA and NOEMA telescopes, scientists have first directly documented radioactive molecules in the interstellar space.
The radioactive part of the molecules was an isotope of aluminum, reported on the official site of the ESO Observatory.
Observations showed that the isotope was scattered in space as a result of the collision two stars, the remainder of which is known as the CK Chanterelle. This is the first direct observation of radioactive aluminum with an established source: earlier this isotope was identified by gamma radiation, the source of which was not reliably established.
A group of researchers led by Tomas Kaminsky of the Harvard Smithsonian Astrophysical Center in Cambridge registered the ALMA (Atacama Large) antenna arrays Millimeter / submillimeter Array) and NOEMA (Northern Extended Millimeter Array) source of radiation from the radioactive isotope of aluminum-26. This source, originally designated as CK Chanterelles, was discovered in 1670: it was then described by observers as a bright red "new star". Visibly first with the naked eye, she quickly weakened. Now, this remnant of the merger of two stars is only visible in a powerful telescope.
348 years after the observation of the initial event, the study of the remnant of this merger of two stars, which took place in the form of an explosion, led to a clear and convincing registration of the radiation of the radioactive isotope of aluminum-26. This is the first case of convincing recording of an unstable radioactive molecule outside the solar system. The first observation of this isotope in a star-shaped object is also important in the wider context of the chemical evolution of the galaxy, for the first time, an active source of radioactive nuclide aluminium- 26, "Kaminsky notes.
Kaminskii and his team recorded the unique spectral features of the molecules consisting of aluminum-26 and fluorine (26AlF) in the remnants of the explosion surrounding the CK Chanterelle. During the rotational motion in space, these molecules radiate at certain wavelengths in millimeter range – this process is called a rotational transition.
Radioactive alumina-26 decays with the formation of a more stable isotope, in the process of which one of the protons in its nucleus turns into a neutron. At the same time, the perturbed core produces a very high energy photon – a gamma photon
Observations of the radioactive isotope of aluminum give an opportunity to take a new look at the event of the merger of stars, which gave rise to the object CK Chanterelles. They also show that the deep and dense inner layers of the star, in which heavy elements and radioactive isotopes are generated, can collide and thrown into space when collisions of stars.
"We are now seeing the stars of the star, broken three hundred years ago under the time collision, "Kaminski says.
Astronomers have determined that the two merged stars were relatively small-massed, with masses between 0.8 and 2.5 solar, with one of the stars being a red giant. The distance to the object is about 2000 light years.