A team of astronomers has confirmed that, over the past four years, there has been an increase in X-ray explosions in the supermassive black hole Sagittarius A (Sgr A *), located in the center of the Milky Way.
Sagittarius A * is a supermassive black hole, located 26,000 light-years from the Solar System in the center of the Milky Way. The research results support previous studies that have detected that the black hole is becoming more active.
In 2017, Belgian astrophysicist Emmanuelle Mossoux, from the University of Liège, and French astronomer Nicolas Grosso, from the Strasbourg Astronomical Observatory, published a report on their observations of the Sagittarius A* black hole over 16 years with telescopes XMM-Newton, Chandra and Swift.
During this period, researchers recorded a total of 107 flashes, which have been increasing in intensity since 2014. The article reports that since August 31, 2014, the number of bright X-ray flashes has tripled, while the number of weak flashes, in contrast, have declined since August 2013.
Scientists have prepared a report for the period of 2016 to 2018, which shows that our galactic center is becoming increasingly agitated. During this period, astronomers observed 14 new outbreaks, which together with previous data give a total of 121 outbreaks for the period from 1999 to 2018.
The authors also present results of the preliminary analysis of data for the year 2019, during which the Swift telescope recorded up to four bright flashes, an unprecedented number in such a short period of time.
The 2019 data obtained by the XMM-Newton and Chandra telescopes are still in preparation for publication, but scientists believe it will be possible to draw preliminary conclusions about the causes of the increased X-ray activity.
When studying and reviewing the methods to determine their rate and distribution, astronomers found that one of the previous conclusions was incorrect: in fact, there was no decrease in the rate of weak explosions, which showed stability throughout the analyzed period.
The results are described in an article accepted for publication in the scientific journal Astronomy & Astrophysics, with a pre-publication of the article available in the arXiv archive of scientific articles.