A colossal bubble in the center of the Milky Way of unknown origin is capturing the attention of scientists from the Fermi telescope, gathered in Spain for the first time.
A month before his assassination in October 1963, US President John F. Kennedy approved the launch of satellites to alert of the worst imaginable disaster: atomic bomb explosions. In 1967, this watchdog program named Vela detected mysterious bursts not from Earth, but from outer space. These signals were later identified as the most powerful radiation in the universe, possibly originating from outside our galaxy, ushering in a new way of observing the universe: gamma-ray astronomy. The gamma rays, invisible to the human eye, are omnipresent and allow the study of the most violent phenomena in the cosmos. The Fermi gamma-ray telescope, launched by NASA in 2008, can detect a new source of gamma rays within hours and alert other space and terrestrial telescopes to observe them. Short gamma-ray bursts last fractions of a second and occur when two neutron stars collide. Long bursts, lasting a few minutes at most, occur when a star 30 times larger than the Sun explodes forming a supernova. The Fermi telescope has identified over 7,000 sources of gamma rays from both inside and outside the Milky Way since its launch. Its findings show that Earth is a tiny point in space surrounded by gamma-ray sources. The Fermi telescope’s equipment is constantly bombarded by charged atomic particles. Despite being designed to last only five years, its large solar panels continue to function despite losing efficiency due to constant radioactive bombardment. Astrophysicist Miguel Ángel Sánchez Conde will be the new scientific coordinator of the Fermi-LAT collaboration. One of his main goals is to use the telescope to try to identify dark matter. Dark matter makes up 25% of the entire universe, but no one has been able to observe it or determine what it is made of. One of the «biggest mysteries» the team faces is in the center of our galaxy, where there is a black hole – Sagittarius A* – with a mass four million times greater than the Sun. Since 2010, a constant signal has been captured from the galactic center, but in other galaxies with supermassive black holes at the center, nothing similar is seen. In 2010, Fermi discovered a gigantic bubble-shaped structure just above and below the center of our galaxy. These Fermi bubbles remain one of the biggest mysteries of our cosmic environment. The Irish astrophysicist Deirdre Horan anticipates a major moment in about a month when the three large terrestrial gravitational wave detectors LIGO, Virgo, and Kagra, in the US, Europe, and Japan respectively, begin to operate. Fermi’s wide field of view can greatly assist in capturing electromagnetic signals as counterparts to gravitational waves.
