How we imagine the Milky Way galaxy might not be entirely true. Most of us think about the galaxy as a massive central mass circled by a flat disc of stars that twirls around it. That might be the case, but some pieces are missing.
Astronomers know that Milky Way’s disc is warped, and its edges are flying around the outer rim of the galaxy. The question now is, what caused that warp to occur?Â
Here is what you need to know.
Milky Way Under Investigation: a Warp to Remember
For decades, researchers debated what could cause a warp in Milky Way’s disc. Of course, there were some intriguing theories followed by more uncertainty and almost possible reasons.
Researchers have previously suggested that it is actually the remnant of a collision with another galaxy in the past. Well, this belief might actually stick this time around.
Now, a team of researchers may finally put that debate to rest.
The team’s work
The team utilized data from the Gaia space observatory, launched back in 2013 by the ESA, and information from APOGEE, an infrared spectrograph.
Borja Anguiano is a post-doctoral research associate at UVA and part of the team. He released a statement discussing the new batch of data:
“By combining information […], we’re starting to understand how different components of the galaxy are moving.”
The results
Researchers have been developing a model that defines the galactic warp parameters, how fast the warp is moving, where it begins in the outer disc and its shape. The model offered essential new data.
Apparently, the warp is not a result of our galaxy’s own internal mass at all. It is just a remnant of gravitational tugging on the Milky Way’s disc by a past collision of a satellite galaxy.
The team believes the satellite in question is the Sagittarius Dwarf Spheroidal Galaxy, approximately 3 billion years ago. More research is needed to figure out other stuff.
However, researchers are now closer than ever to finally reveal what happened.