New challenge to the hypothesis of galaxy formation

A team led by an astronomer at Indiana University has recently discovered that some large galaxies have traits that show they have just been formed. This is contrary to the widely accepted belief that giant glowing galaxies (like the Milky Way galaxy) began to form and develop after the Big Bang explosion, about 13 billion years ago. .

Future studies of the nature of giant galaxies may open new doors for research into the origin and early development of galaxies.

John Salzer - the principal researcher - says the brightness of the 15 related galaxies indicates that they are giant systems like the Milky Way. However, these galaxies are very unusual because they have a lot of chemical substances, which suggests that star formation occurs very little inside. The amount of heavy elements is quite small (heavier elements than helium are called metal by astronomers), implying that they may be very young and have only recently formed.

The amount of chemicals in the galaxies along with the statements about star development and the increase in chemical chemistry in general show that perhaps these galaxies are only 3 to 4 billion years old; therefore they form 9 to 10 billion years after the Big Bang. Most hypotheses about galaxy formation predict that these giant light-emitting systems must form much earlier.

If this event is proven to be true, the aforementioned galaxies could allow astronomers to understand the phases in the process of galaxy formation and the development process that is difficult to study because they are thought to be formed from the early stages of the universe and located far away from us.

Salzer said: 'These objects are a new door unique in the process of galaxy formation, allowing us to study systems that are fairly close to undergoing similar development in almost all galaxies formed very early in the history of the universe '.

Images of the Milky Way. The new finding contradicts the widely accepted belief that giant glowing galaxies (like the Milky Way galaxy) began to form and develop after the Big Bang explosion, shortly after, about 13 billion years. before. (Photo: NASA / JPL-Caltech)

The discovery is that the KISS survey results are much more than for the 2,400 star-forming galaxies. The survey was created with the objective of collecting basic observation data about emission sources. Spectroscopic measurements carried out later on sources yielded a discovery of 15 low-chemical light-emitting systems.

Salzer said: 'The reason we look for galaxies like this is related to the characteristics of the KISS survey method. Galaxies are selected through their strong emission lines, which is the only way to detect these specific galaxies. ' Previous surveys were carried out by other scientists who could not find the aforementioned unusual galaxies. '

While the theory holds that the galaxies in the survey are quite young and quite new and attractive, but it may not be the only explanation for them. There is another explanation that they are the result of a combination of two smaller galaxies that have just happened recently. This combined model may explain the size of the object, because the result of a large combination may be the reduction in the amount of metal due to the dilution effect of the untreated gas as well as the Increase the strong but short brightness caused by dense star formation . Looking for ways to distinguish the two possibilities, Salzer and his team plan to propose observations with the Hubble Space Telescope (NASA), using high-resolution formations to determine whether Large galactic systems are the result of a combination or not.

Salzer received a reward with support from the National Science Foundation totaling $ 1.2 million for the survey. Participating in the Astrophysical Journal Letters study also included astronomer Anna Williams of Wesleyan University in Middletown, Conn., And Caryl Gronwall of the University of Pennsylvania.

Salzer is collaborating with the University of India after pausing his work as professor of astronomy at Wesleyan, hoping to officially join the University of India next year. The authors also appreciate the participation of members of the KISS survey team including Gary Wegner, Drew Phillips, Jessica Werk, Laura Chomiuk, Kerrie McKinstry, Robin Ciardullo, Jeffrey Van Duyne and Vicki Sarajedini in spectroscopic observations. that they carried out in recent years.