The smooth edge of the disk of the Sombrero galaxy spoke about its turbulent past. Observations using the Hubble telescope allowed scientists to suggest that in the past the object survived a merger with another large galaxy. An article describing the study is published on NASA’s website.
Sombrero Galaxy (M104) is a spiral galaxy located in the constellation Virgo at a distance of about 29.3 million light-years from Earth. For a long time, the object attracted increased attention of astronomers due to a strange structure resembling sombrero.
Observations of the galaxy with the Hubble telescope showed that the galaxy is surrounded by an expanded halo rich in various metals. At the same time, the metal signatures of the star in the Sombrero halo were much paler than in the halo of other galaxies. In particular, the researchers found that there are almost no stars with a low content of metals in it – while stars with a high content of heavy metals were in excess.
Trying to answer the question of why this happens, the researchers created a model that showed that in the past the galaxy probably collided with a larger object. At the same time, no other consequences of the collision were discovered by the scientists either before or after the study.
“The absence of low metal stars was a big surprise. And the abundance of stars with a high content of metals only added additional questions. Hubble’s metallicity measurements (that is, the abundance of heavy elements in stars) are further evidence that Sombrero can tell us a lot about the assembly and evolution of galaxies”.
Paul Goodfroix, lead author of the study