Astronomers have long predicted that as many as 20,000 black holes could be hiding in our galaxy’s center, but so far no one has been able to spot them. For the first time, scientists have detected a gravitational wave produced by the collision of two neutron stars. There is actually one in progress right now with the neighbouring Andromeda Galaxy. Neutron stars form when massive stars explode in supernovas and collapse upon themselves. They gravitationally interact with stars, cosmic collisions so to speak, and lose energy.
The destruction of the LMC, as it is devoured by the Milky Way, will wreak havoc with our galaxy, waking up the black hole that lives at its center and turning our galaxy into an ‘active galactic nucleus’ or quasar. Although these fireworks are unlikely to affect life on Earth, there is no definite way to predict how quasars will affect our planet.
This phenomenon will generate powerful jets of high energy radiation emanating from just outside the black hole. However, recent measurements indicate that the Large Magellanic Cloud has nearly twice as much dark matter than previously thought.
Astrophysicists at Durham University have predicted that the collision between the LMC and our own galaxy could occur much sooner than the expected crash between us and neighbouring galaxy Andromeda. The catastrophic coming together with the Large Magellanic Cloud could wake up our galaxy’s dormant black hole, which would begin devouring surrounding gas and increase in size by up to ten times.
“While two billion years is an extremely long time compared to a human lifetime, it is a very short time on cosmic timescales”, said lead author Dr Marius Cautun, a postdoctoral fellow in Durham University’s Institute for Computational Cosmology.
Most larger galaxies are surrounded by a group of smaller satellite galaxies that orbit them, in a similar way to how bees move around a hive. Typically, these satellite galaxies have a quiet life and orbit around their hosts for many billions of years. Previous studies mostly captured colliding galaxies when their black holes were about 10 times further apart than those captured in this study. The paper’s co-author, Professor Carlos Frenk, said: Beautiful as it is, our universe is constantly evolving, often through violent events like the forthcoming collision with the LMC. Barring any disasters, like a major disturbance to the solar system, our descendants, if any, are in for a treat – a spectacular display of cosmic fireworks as the newly awakened supermassive black hole at the centre of our galaxy reacts by emitting jets of extremely bright energetic radiation.
The Milky Way is on a collision course with a nearby galaxy. These U-turns cause the density in the Milky Way’s stellar halo to decrease dramatically where the stars flip directions.
The collision ripped the dwarf to shreds, leaving its stars moving in very radial orbits that are long and narrow like needles, said Vasily Belokurov of the University of Cambridge and the Center for Computational Astrophysics at the Flatiron Institute in New York City.
This is a telltale sign that the dwarf galaxy came in on a really eccentric orbit and its fate was sealed. Wyn Evans of Cambridge said “the sausage shape just jumped out at us. As the smaller galaxy broke up, its stars were thrown onto very radial orbits. These Sausage stars are what’s left of the last major merger of the Milky Way”.
Astronomers using data from ESA’s Gaia satellite have discovered a new dwarf satellite galaxy of the Milky Way. Artistic rendering of the Milky Way galaxy and the Sausage galaxy 8 billion to 10 billion years ago. The new research also identified at least eight large, spherical clumps of stars called globular clusters that were brought into the Milky Way by the Sausage galaxy. Their existence suggests there are likely about 10,000 black holes within just three light years of the Galactic Center. Researchers said data from the NASA’s orbiting Chandra X-ray Observatory allowed them to detect a dozen black holes surrounding Sagittarius, Columbia University astrophysicist Chuck Hailey, lead author of the study published in the journal Nature, said on Thursday.
