Tomasz Nowakowski is a writer for Phys.org.
The University of Arizona is one of the places that reported the discovery of a new dwarf galaxy. Tucana B is the first quenched and isolated object of this type found in the extreme outskirts of the Local Group. The paper was published on the arXiv pre-print server.
The most dark-matter-dominated, and least chemically evolved dwarf galaxies are the so-called ultra-FAint dwarf galaxies. They are thought to be the best candidate fossils from the universe's early stages.
A team of researchers led by David J. Sand have found a new UFD during a visual search for faint dwarf galaxy companions to the distant dwarf spheroidal galaxy Tucana. They used the data from theDESI to create their interactive color image viewer.
We uploaded a custom file to mark off a region with a projected radius of 100 kpc and searched for visual over-densities of resolved stars with underlying diffuse light, indicative of a dwarf galaxy. The field was inspected at different scales. The astronomer explained that Tucana B stood out during the search, and is partially resolved into stars in the Legacy survey viewer.
Tucana B is 6 degrees from the Tucana dwarf spheroidal, and is 1.6 million light years away from the line of sight. The distance from the Earth to Tucana B was 4.5 million light years.
Tucana B has a half-light radius of 260 light years, and an absolute magnitude of 6.9 mag, which makes it comparable to the satellite galaxies of the Milky Way. The UFD only has an old metal-poor stellar population.
Tucana B is unique among recent discoveries at this approximate distance due to the lack of star formation and neutral gas. Tucana B's isolation may indicate that its star formation was quenched by reionization or some other internal mechanism.
Sand's team sees Tucana B as a great target for future space-based follow-up observations aiming to pin down its structure and star formation history.
In particular, Tucana B may provide a definitive opportunity to understand the role that reionization plays in the quenching of the faintest galaxies.
Finding more objects like Tucana B is necessary in order to better understand the demographic of the field UFD population.
More information: D.J. Sand et al, Tucana B: An Isolated and Quenched Ultra-faint Dwarf Galaxy at D=1.4 Mpc. arXiv:2205.09129v1 [astro-ph.GA], arxiv.org/abs/2205.09129The Science X Network will be launched in 2022.
Citation: New ultra-faint dwarf galaxy discovered (2022, May 26) retrieved 26 May 2022 from https://phys.org/news/2022-05-ultra-faint-dwarf-galaxy.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
All Rights Reserved © 2024
