Far out cosmology: our galaxy has ancient clusters (Introduction)

by David Turell , Saturday, December 19, 2020, 21:48 (1433 days ago) @ David Turell

Just recently discovered:

https://phys.org/news/2020-12-milky-primordial-history-fossil.html

"Just as archaeologists dig hoping to find traces of the past, an international group of astrophysicists managed to get into the thick cloud of dust around the center of the Milky Way (also known as the bulge) discovering primordial clumps of gas and stars never before seen. They named this new class of stellar system 'Bulge Fossil Fragments.'

***

"Researchers found out about this new class while analyzing Liller 1. The latter is a stellar system in the Milky Way bulge that for more than 40 years has been classified as a "globular cluster," i.e. a system composed of millions of same-aged stars (the Milky Way has at least 150 globular clusters). However, researchers observed Liller 1 closely and found out that its real identity is actually more fascinating than so far believed. Indeed, Liller 1 is a fossil fragment of one of the giant stellar clumps that, approximately 12 billion years ago, merged to form the central region (bulge) of the Milky Way.

"'Our results clearly show that Liller 1 is not a globular cluster, but a much more complex object," says Professor Francesco Ferraro, first author and coordinator of the study. "It is a stellar relic, a fossil finding that contains the history of the Milky Way formation."

"The existence of "cosmic findings" had already been suggested when researchers discovered a similar object, Terzan 5, some years ago. Terzan 5 looked like a globular cluster within our galaxy bulge, but, at a closer analysis, its features were not consistent with those of other globular clusters.

"However, an isolated case is just an intriguing anomaly. This is why Liller 1 is so important. Terzan 5 and Liller 1 shared features confirm the existence of a new class of stellar systems unidentified until today.

"What are the features of the Bulge Fossil Fragments? These objects are disguised as globular clusters, but are fundamentally different, if one looks at the age of the stars composing them. Two stellar populations are in these systems: one is as old as the Milky Way—it formed 12 billion years ago—and the other one is much younger. On the one hand, this shows that these stellar systems appeared during the Milky Way early stages of formation; on the other hand, it demonstrates that they are able to engender multiple events of stellar generation.

***

"'The history of the Milky Way is written in these fossil remains. The latter are tokens of an age during which the Universe was very young, just 1 billion years old," concludes professor Ferraro. "Now we need to go deeper. Thanks to the discovery of these fossil remains we can start reading the history of the Milky Way and maybe re-define our knowledge about the formation of the bulge.'"

Comment: Note the age of the Milky Way at 12 billion years, which is just 1.78 billion years from the estimated Big Bang. As I see God in charge of evolving the universe, I see Him here starting early to set up the proper galaxy to contain a special planet for life.