The Hubble Space Telescope caught it in the far reaches of our galaxy. The neighboring Large Magellanic Cloud (LMC) survives a massive event. The galactic collision with the Milky Way is now in the telescope images.
Many researchers theorize that the LMC is not in orbit around our galaxy. It’s just passing through. They believe the LMC has just completed its closest approach to the much more massive Milky Way. This caused most of the spherical halo of gas surrounding the LMC to disappear.
Survivor
Now, for the first time, astronomers have been able to measure the size of the LMC halo. It is extremely small, about 50,000 light years in diameter. That’s about 10 times smaller than the halos of other galaxies that have the mass of the LMC. Its compactness tells the story of its encounter with the Milky Way.
“LMC is a survivor,” Andrew Fox of the European Space Agency in Baltimore said in a statement. «Although it has lost a lot of its gas, it has enough left to continue forming new stars. Therefore, new star-forming regions can still be created. “A smaller galaxy would not have lasted.” Although quite deteriorated, the LMC still retains a halo of compact, squat gas.
Star Lab
Most of the LMC’s halo faded away due to a phenomenon called ram pressure detachment. «I like to think of the Milky Way as a giant hair dryer. It expels gas from the LMC as it approaches us,” Fox said. “The Milky Way is pushing back so hard that the impact pressure has removed most of the original mass from the LMC’s halo. “There’s only a little bit left, and it’s this small, compact remnant that we’re seeing now.”
Due to its mass and proximity to the Milky Way, the LMC is a unique astrophysical laboratory. Observing the galactic collision with the Milky Way helps scientists understand what happened in the early universe, when galaxies were closer to each other. It also shows how messy and complicated the process of interaction between galaxies is.
