2023-11-09 05:00:13
In the far reaches of the Universe, astronomers are tracking down glows testifying to the existence of distant galaxies. Among these celestial entities, some almost hide from our sight, like the newcomer in our cosmic catalog: Nube. Resulting from a chance discovery by an international team, this galaxy (Galaxies is a quarterly French magazine devoted to science fiction. With…) is distinguished by its low luminosity (Brightness designates the characteristic of what emits or reflects …), rivaling that of the Small Magellanic Cloud (Small Magellanic Cloud or SMC in English) is a galaxy…). The details of this discovery were published on October 18 on the pre-print server arXiv, arousing the curiosity of the scientific community (A scientist is a person who devotes himself to the study of a science or sciences and who.. .).
A 100′′×100′′ region around Nube. The image is an RGB color composition using the HiPERCAM bands g, r and i and a black and white image (Black and white are considered colors or not depending on the discipline which…) g + r for the background.
Galaxies with a central surface brightness less than 26 mag/arcsec2 are commonly called “near-dark galaxies”. They are often omitted in optical catalogs due to their low optical emission (Optics is the branch of physics that deals with light, radiation, etc.). Yet they can reveal extremely weak optical emission when imaged deeper.
Led by Mireia Montes of the University of La Laguna, Spain, the team detected Nube during visual inspection of a Project field. ) IAC Stripe 82 Legacy. This project aims to explore Stripe 82, a 2.5 degree wide strip along the celestial equator in the Southern Galactic Cape.
Located regarding 350 million light years away, Nube has an effective surface luminosity of regarding 26.75 mag/arcsec2. The galaxy is estimated to be 10 billion years old.
Regarding its other characteristics, Nube is very extensive, with a mass radius of 22,500 light years. Its stellar mass is approximately 390 million solar masses, while the total mass of its halo is estimated at 26 billion solar masses. These results suggest an effective surface density of approximately 0.9 solar masses/parsec2.
The study authors conclude that Nube is the most massive and largest galaxy of its type detected to date. It is also distinguished by its low luminosity, ten times lower, and its radius three times larger than that of typical ultra-diffuse galaxies (UDG) of similar stellar masses. UDGs are very low density galaxies, comparable in size to the Milky Way (also called “our galaxy”, or sometimes…), but comprising only 1% of the stars in our galaxy.
Researchers are analyzing the origin and nature of Nube, wondering whether its extreme properties result from its initial formation or from a later evolutionary process linked to its environment. They suggest that a soliton profile, typical of dark matter, is typical of dark matter. ‘English…) fuzzy, reproduces very well the observed distribution of Nube stars.
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