Scientists at the European Space Agency’s (ESA) Herschel space observatory announced Tuesday their observations of the black hole located at the center of the Milky Way as it appears to be devouring a feast of molecular gas.
Known as Sagittarius A*, or Sgr A* for short, the neighborhood black hole boasts a mass roughly 4,000,000 times that of the Sun.
Located 26,000 light years away from the Solar System, it is several hundred times closer to Earth than any other galaxy with an active black hole at its center and thus an ideal natural laboratory for scientists to observe the behavior and environment surrounding the “enigmatic objects,” according to the ESA.
Because vast amounts of dust lie in the plane of the Milky Way between Earth and the Galaxy’s center, much is obscured at visible wavelengths. However, by harnessing far-infrared wavelengths, scientists have been able to peer through the debris in order to detect a variety of simple molecules whose signatures offer a window of understanding into some of the most basic properties of the interstellar gas surrounding the black hole.
In analyzing such debris, astronomers have been surprised to discover just how hot the molecular gas located in the heart of the Milky Way is: while most interstellar clouds register just a few tens of degrees above the -273 degrees Celsius of absolute zero, according to the ESA these gas are measuring at 1000 degrees Celsius.
And while part of the reason for such heating is explained by the fierce ultraviolet radiation coming from a cluster of massive stars located near the center of the Galaxy, astronomers are not convinced that this alone is able account for the unique phenomenon.
One possibility, according to Javier Goioechea whose team from the Centro de Astrobiolgia in Spain oversaw the observation and accompanying study, is the emission from strong shocks in highly-magnetized gas in the region as as result of collisions between gas clouds, or in material flowing at high speed from stars and protostars.