Hubble sees the aftermath of the Milky Way’s interaction with the Large Magellanic Cloud
In a recent observation, NASA’s Hubble Space Telescope documented a close interaction between the Milky Way and one of its nearest galactic neighbors, the Large Magellanic Cloud (LMC). This recent analysis of the LMC, led by Andrew Fox of the European Space Agency’s Space Telescope Science Institute (STScI) in Baltimore, reveals the effects of its near-collision with the Milky Way’s vast halo, including a significant reduction in own halo of the LMC of gas.
The Halo of the LMC: a surprising measurement
For the first time, Hubble data made this possible researchers to measure the size of the LMC’s halo, which is now estimated to be 50,000 light-years across, significantly smaller than other galaxies of similar mass. This contraction of the halo, Fox explains, points to the effects of the LMC’s encounter with the Milky Way, which has stripped away a significant portion of its outer gas layer. Despite these losses, the LMC still contains enough gas to form new stars, increasing the resilience of the otherwise extinct dwarf galaxy.
Aries-Pressure Stripping: The Force at Play
A process known as ram pressure stripping is responsible for much of the halo loss from the LMC. As the LMC approached the Milky Way, the larger galaxy’s gravitational influence exerted a ‘wind’ effect, pushing the gas from the LMC back into a tail-like stream that now trails the galaxy. Sapna Mishra, lead author of the research paper, compared this force to a powerful ‘hairdryer’, which removes the gas from the LMC. However, this gas is not expected to be completely lost as the galaxy begins to move away from the Milky Way after its closest pass.
Future research and cosmic implications
As the team moves forward, there are plans to study the leading edge of the LMC’s halo, which remains largely unexplored. Scott Lucchini of the Center for Astrophysics | Harvard & Smithsonian noted that this research will focus on the collision points between the two halos, providing insight into the nature of galactic interactions in the early days of the universe.
