Johns Hopkins astronomers will discuss a new satellite galaxy simulation

Newswise – With a new simulation that shows how satellite galaxies orbit larger galaxies like the Milky Way, researchers at Johns Hopkins University have reconciled long-held views of what astronomers actually see using telescopes and what theorists have predicted they should see.

“When people started seeing these streams of satellite galaxies all over their telescopes, the modelers who run these super computer simulations said, ‘Oh! Impossible! These should be very rare at best!'” said Charlotte Welker , a post-doctoral student, who worked on the solution with Janvi Madhani, a second-year doctoral student.

They believe that the problem does not actually lie with our cosmological model of the universe, but stems from the simulations themselves, as past simulations suffered from a lack of resolution at small scales and a lack of volume at large scales. .

“It’s a real ah-ha moment,” said Susan Kassin, an astronomer at the Space Telescope Science Institute, who advised the team.

The team will discuss their findings at 5:15 p.m. EST on June 14 with press availability at the American Astronomical Society conference, to be held broadcast live.

Hopkins’ team used what they call “zoom-in simulation” to survey a larger area at a higher, closer resolution. Called New Horizon, this cosmological simulation was developed by their collaborators in Paris in 2018.

The resulting simulations showed that 30% of Milky Way-like galaxies displayed planes, compared to previous studies that had found planes in less than 2% of candidate systems.

“With this new result, we no longer have to abandon our model of cosmology or adopt a new theory of gravity to explain the appearance of these planes,” Madhani said.

The Johns Hopkins researchers worked on their simulation with scientists from the Institut d’Astrophysique de Paris and Yonsei University in Seoul. This work was supported by National Science Foundation Grant No. 1815251 and an STScI/RSAC grant.


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