Astronomers refer to the period when our universe was only about 3 to 6 billion years old „cosmic noon“. It was a stage following the Big Bang and “Cosmic Dawn”, when most stars and black holes formed in the universe according to current models. Experts also assume that many supermassive black holes in the centers of galaxies were going through an active period at this time.
American astronomer Allison Kirkpatrick from the University of Kansas and her collaborators wanted to test this assumption using the amazing performance of the Webb Telescope. They therefore focused the attention of the space telescope on a small section of the sky that bears the designation Extended Groth Strip (ESG).
Observing Cosmic Noon Galaxies
The ESG is a barren and empty part of the northern sky between the constellations of Ursa Major and the Shepherd. There is nothing interesting to see with the naked eye. In 2004 and 2005, however, he examined it in detail Hubble telescope, who discovered more than 50,000 galaxies there. In 2011 ESG observed The Spitzer Infrared Telescope, who discovered galaxies with an active core here, but there were significantly fewer of them than experts expected. The researchers explained the smaller number of galaxies discovered by the insufficient sensitivity of the infrared telescope, which, according to them, was unable to detect fainter galaxies or galaxies hidden behind dust.
From The James Webb Space Telescope astronomers expected it to include discoveries of many other active galaxies in the ESG region. But that didn’t happen. Project Cosmic Evolution Early Release Science program (CEERS)who searched for active galaxies in the ESG, found a very similar number of them as Spitzer’s infrared telescope had previously.
TIP: Astronomers have tracked down the oldest quasar: It is more than 13 billion light-years away
Kirkpatrick and her colleagues in their as yet unpublished by research apparently confirm that during the period “Cosmic Noon” active galaxies were relatively rare. Many of the galaxies observed by the Webb Telescope resembled our own Milky Way. These are spiral galaxies with a limited amount of cosmic gas and a relatively calm supermassive black hole at their center. The researchers also conclude from this that our Milky Way probably never went through an active galaxy period.
2023-09-05 09:55:10
#young #universe #supposed #full #active #galaxies #Webb #telescope #find
